Awesome find!!

[LBMiller5]

Hello Everyone!

As you all know, I have been playing around with several PC case fans. Most of the PC case fans have the bearing shaft molded into the plastic part of the fan, and then have a seperate metal flux ring pressed into the inside of the fan. They look like this:

http://innov8tivedesigns.com/rcgroups/Fan1small.jpg


If you pop out the flux ring, it looks like the photo below:

http://innov8tivedesigns.com/rcgroups/FluxRing2.jpg


This one is about 0.5mm thick, and is about 10mm deep. I was thinking about turning an endbell completely out of aluminum, including the flux ring part of the rotor as one piece. Then you could take one of these steel flux rings from a PC fan, and press it into the inside of the rotor housing to contain the magnets. With this method you don't have to press a flux ring onto the endbell, and the alignment is perfect since the entire rotor is turned as one piece. When you were done, you would have a nice double stack motor for 25mm stators.

Anyhow, I was taking apart a PC Case fan a couple days ago to get the flux ring, and instead of the usual flux ring as seen above, I made an amazing find. Instead of having the shaft molded into the plastic, there was an entire metal can inside the fan. I got so excited when I saw this that I ripped the fan apart to get to the rotor. In my haste I forgot to take a picture of the fan before I ripped it up, but this is what I found inside:

http://innov8tivedesigns.com/rcgroups/panaflo2.jpg

http://innov8tivedesigns.com/rcgroups/panaflo3.jpg

Is this thing beautiful or what! The shaft is 3mm in diameter, so I will be able to press it out and install a longer one. The rotor measures 32.3mm inside diameter and 34.3mm outside diameter making the wall thickness 1.0mm. The flux ring part is 14.5mm deep, with about 12.5mm useable above the curved corner. I looked at the engconcepts.net webpage, and they have some 12 x 5 x 2 mm magnets that would work perfect in this rotor. As you can see in the photos, it already has 8 cooling holes punched into it as well! I wanted to check the balance on it, so I chucked the end of the shaft up in my Dremel tool and ran it up to full speed. At 30,000 RPM there was no vibration whatsoever! This thing is just begging to be turned into a triple stack brushless motor!

The thing I need to find now is a set of stators for it. I ran some numbers in the Rotor Calculator, and if I use 5mm wide by 2mm thick magnets, I need to have a stator that is 27.5mm in diameter to give me an air gap of 0.20mm.

So here is the $64,000.00 Question.....

Does anybody out there have a 27.5mm stator about 12mm thick, or several that could be stacked up to be 12mm thick, or know of somewhere that I can get one? This thing is just too nice to leave lying on a shelf.

Oh, for those interested, the fan I took this out of was an older one made by Matsu****a, and had the name "PANAFLO" on the sticker. It was a standard 80mm size fan. There was a small hole, about 1/4" in diameter, on the front side of the fan that you could see the end of the bearing shaft through. So be on the lookout for these, I am sure it will make a great motor.

I am going to be checking all the junk bins at the local computer stores trying to find more of these!

Well, If anybody has any leads, please post them here in this thread.

Thanks!

Lucien

[swatson144]

To narrow down your search I'd look for shops that do a lot of servers. Panaflo is a cadilac of a fan and are not found in the computers where price was the driving issue. So it is probably a waste of time looking at mom n pop shops. Compaq Intel and IBM servers generally came with panaflo fans.

You can get them new from places that specialize in custom/quiet cases like http://www.casecooler.com/vanstealquie.html . fortunatly the price has followed all other electronics and now they can be had for 5-11$ new retail. Can't say as they have the same build though, as I have none instock. Odds would be good as they are still touted as "Hydro Wave" bearings.

[DadHav]

Hi Lucien, There is an animal like you are looking for. You posted a reply to my question about winding with braided wick. The picture of the green stator there, is a 27.5 LRK about 17 mm thick. It was given to me, but the person said it came from a full hight hard drive. If I can find anything else about it I'll let you know. Jay or someone also might be able to guide you in the right direction. I'd love to help get that stator on the endangered species list. I'd send you this one, but I'm just finishing the design to use it. I'll say one thing in addition though: This motor or a motor like you want to build will be very powerful and swing a big stick. A three mm shaft pressed into the thin housing might be a little light duty. Can you make a reinforcement bushing on the lathe?
Good Luck.
John

[LBMiller5]

John,

Thanks for the tip! I was at work today, and I was cleaning up some shelves in the warehouse. I came accross this old SCSI Drive cabinet I had completely forgotton about. It had 2 full size, full height drives in it. I asked my supervisor about it and he said "Throw it out", which translated into motor-speak means "Go ahead and tear them apart and see what kind of cool motors might be inside." :wink: Since it was about 1:00 in the afternoon, and I had not taken lunch yet, I figured now would be a good time to take a lunch break.

For those of you out there who are not computer geeks, here is a little side information. When the first "Miniature" hard drives came out, the standard size was 5-3/4" wide by 7 inches deep, and were about 3 inches tall. This is the size of 2 standard computer CD-ROM drives stacked on top of one another. Here is a photo of a full sized hard drive sitting next to a modern sized 3-1/2" hard drive. :shock:

http://innov8tivedesigns.com/rcgroups/BigDisk1.jpg

This thing weighs about 10 pounds! Almost 10 times what a modern hard drive weighs. Here is an end view shot showing the height difference, almost 5 times as high:

http://innov8tivedesigns.com/rcgroups/BigDisk2.jpg

Here is a shot of the drive with the cover removed. This drive has 14 platters in it, and buried inside the central hub is the treasured 3-phase brushless motor! :)

http://innov8tivedesigns.com/rcgroups/BigDisk3.jpg

Another neat item found inside hard drives are rather large NeFeB magnets used to drive the head actuating mechanism. The magnets in this drive are the largest I have ever seen! :shock: These puppies are almost 1/2 inch thick. There are 4 total inside this one, and they are so strong, that if you had these back when you were a kid, you could use the 4 of them to stick your little brother to a refrigerator so tight that he would be there until someone with a crow bar came to pry him off! :twisted: Here is the other side of the drive showing the magnets:

http://innov8tivedesigns.com/rcgroups/BigDisk4.jpg

Here is a close-up of the magnets after they were removed. That is a "D" size battery next to it for a size comparison:

http://innov8tivedesigns.com/rcgroups/BigDisk7.jpg

The magnets are the 4 pieces in the center. The other four huge pieces of chrome plated steel form the back iron core to contain the flux field of the magnets. That is one huge amount of flux to contain!!

Now we get to the good part! After stripping off the magnet, head assembly, electronics, and the disc platters, we are left with the motor. Here is a shot of the motor, again with a "D" sized battery for comparison:

http://innov8tivedesigns.com/rcgroups/BigDisk5.jpg

After reading John's (DadHav) last post, I was hoping to find a 27.5mm stator inside this motor. The outer part of the motor that you see above is a precision turned aluminum housing that forms the outer part of the motor. This is an exact precision fit to the hole in the center of the disc platters. Within this is the steel flux ring, then the magnet ring, and then the stator assembly. These motors are sealed units that are pressed together in large hydraulic arbor presses, so the only way to get them apart is through very delicate surgery, AKA a big vise and a hack saw! :wink:

Well after a few minutes cutting it in half from both sides, I split the case apart and this was the result:



http://innov8tivedesigns.com/rcgroups/BigDisk6.jpg

At the bottom you can see the split case halves after hack sawing them apart. At the top is the iron flux ring with a black ceramic magnet inside it. And finally, there in the middle is the stator assembly. Here is a close-up of the stator:

http://innov8tivedesigns.com/rcgroups/BigDisk8.jpg

It looked close to the size I wanted, but was it actually 27.5mm :?:

A quick run back to my office to get my dial calipers. The ones I had in my office are inch unit calipers. A quick check with the calipers showed 1.122 inches. OOh, that sounded close. Where is my calculator? OK here it is. Lets see 1.122 x 25.4 = 28.5mm. Close but no cigar. But wait, I am exactly 1mm larger, if I use 1.5mm thick magnets instead of 2mm magnets, I get the exact same air gap! Maybe I can use this after all!

The stator is a 12 pole type, and the measurements ended up being 28.5mm OD by 16.5mm long. It looks like the center shaft hole is 11mm or so, I will have to wait until I get the stator off the shaft to see. The stator could probably be used as is if I wanted to. It appears to be wound with a triple-strand wind of 27ga wire in a WYE configuration. It is tough to see exactly how many turns there are, but it looks like triple strand 10-turn wind. I am not sure if it is the typical LRK style or not. It would be tough getting this thing apart without damaging the windings, but I am going to give it a shot. Chances are I am going to have to re-wind it, since it is a little too long for what I need.

I think that the proper thing to do with this is to leave it as-is and design a motor around it. Either that or find someone that has a 27.5mm stator that would be willing to trade. I will have a second one of these after I tear apart the other hard drive.

Has anybody else found anything like this before? If not this is a great place to look.

Here is another stator from a drive I took apart a couple days ago sitting next to the one from above. This one is from a 3-1/2" Half Height drive, and looks like the other one's little brother!. It is a 9-pole stator that measures 18mm in diameter by 10.5mm tall. A bit small, but still useable for a smaller airplane. This is about the same size as the stator used in the "Little Screamer" motors if memory serves me correctly.

http://innov8tivedesigns.com/rcgroups/BigDisk9.jpg

Well that is enough for now. Too much stuff to play with, and too little time to play!

See you all later.

Lucien

[latrans]

LB,

I just saw this thread and I found it very interesting as the part from the fan you described is exactly what I've been looking for! I've taken apart several hard drives and have collected some of the 27.5 mm 12 arm stators that you mentioned but have been at a loss for a can to put them in (no lathe). Now it seems that you've found what I've been looking for. Would it be possible for you to post a picture of one of these panaflo fans? Do you know what the fan was originally installed in? Any help would be appreciated.

Latrans

[LBMiller5]

The fan is a Panaflo unit. I actually found another one of these fans last week. It was in an HP Tape drive. Here is a photo of the back of the fan.

http://innov8tivedesigns.com/rcgroups/FanBack.jpg


And here is a photo of the front of the fan. If you find one with the 1/4" hole on the front like this one, you will know it is the right one:

http://innov8tivedesigns.com/rcgroups/FanFront.jpg


Here is what the fan looked like on the back side once I removed it from the housing:

http://innov8tivedesigns.com/rcgroups/FanHub.jpg


You can clearly see the can inside the fan hub. The magnet ring is of the rubber variety, so it was easy to pry out with a small screwdriver. After I pulled the magnet out, I cut through the plastic fan in two places, opposite each other, and then broke the fan in half to release the metal can.

Here is a photo of the matched set I now have.

http://innov8tivedesigns.com/rcgroups/RotorCans.jpg


The rotor cans have an inside diameter of 32.3mm, and are a perfect fit for a 27.5mm stator when using 5mm wide by 2mm thick magnets. Here is the GB rotor calculator with these values used:


I hope that helps you out!

Lucien

[latrans]

Lucien,

I was wondering if you have made any progress with this motor? Did you ever find a stator and if so how'd it perform? I still haven't been able to find one of those panaflo fans that you described. If you are still looking I'd be willing to trade a stator for an endbell.

Adam

[LBMiller5]

DadHav had a 27.5mm Stator that was exactly what I needed, so I traded him the 28.5mm one in the photos above for it. The one I got from him was 19mm thick, so I split it in half to make two 9.5mm stators. The rotor cans are about 12.5mm deep inside, so I may chuck them up in the lathe and trim a couple mm off the back side and use 10mm magnets with the 9.5mm stators. They should be pretty powerful!

I have had a lot of work & family stuff going on the past few weeks, so the motor building has taken a back seat. I hope to get back at things this weekend.

Lucien

[saitrix]

What sort of power area do you think we are talking here? GBx2 area?

I got a fan sitting here that i can see the can, has no holes it in but its dimentions are roughly 35mm diameter, 18mm deep. Worth taking apart for the motor?

[LBMiller5]

Probably more like GBx3. With a 27.5mm Stator compared to a 22.7 in the GBx motors, there will be about a 21% increase in available torque due to just the diameter increase. The 9.5mm thickness of the stator is a little thicker than 2 of the GBx 22.7mm stators that are 4.5mm thick each, so there is another 5% available here. Also being a 12-tooth stator will give about a 33% increase in torque over the 9 tooth stator, so if you take all the increases and multiply them together you get 3.37 times the power of a single stator GBx1 motor, and if you consider that there are some inefficiencies, it would be safe to say that the motor would be equivilent to a GBx3 motor, cabably of absorbing 150-180 watts of power. I figure that it will probably be able to turn an 11x7 or 12x6 prop with ease, but I will have to build it first to see. It will probably take a 2100ma 3-cell Li-Po pack delivering around 15-18 amps to power this bad boy!

Lucien

[saitrix]

So what do you think to the bad boy i may have?

[LBMiller5]

Sorry about that, somehow I missed the last line of your previous post. I guess it is because most people have their "Signature" line at the end of the post, and I did not notice your question.

Would it be possible for you to post a photo or two of your fan? The one I found was 32.3mm ID and 34.3 OD, so it looks to be in the same ball park as mine. If so it would make a good rotor can. You will have to either drill out or press out the motor shaft and install a longer one to use it however. You will have to find a suitable stator and magnet combo to make it work properly, and that can be a real treasure hunt!

Good luck!

Lucien

[saitrix]

Ill make pictures for you tomorrow, its a delta fan which are classed as the most powerful pc fans about.

[saitrix]

Here is the fan.

http://img232.exs.cx/img232/6333/deltafan207custom4it.jpg (http://www.imageshack.us)

[LBMiller5]

That one looks like a keeper! :D

If you take a hacksaw blade and carefully cut between 2 of the fan blades about 90% of the way through the plastic, you can stick a straight screwdriver in the slot and twist it to break the fan free. Just be careful not to cut too deep and nick the metal can. As thick as the plastic is on that one, you may want to put a second cut directly opposite the first one to allow it to pry open easier.

From the photo, it looks like the shaft is pressed in, so you will be able to press the shaft out and put in a longer one.

Keep up up to date on your progress.

Lucien

[Jay C]

Lucien,

The stator Dadhav was referring to came for the same sized drive. I have a set of the same mags you show ... be careful, they bite!

I'm looking forward tot he resultant motor from Dadhav ... it was too big for anything I fly.

Jay

[latrans]

SO I finally found one of these panaflo fans with the correct size endbell and I have several of the 27.5mm 12 arm stators. Has anyone built one of these yet? I'm a little uncertain about the approprite # of turns of wire and magnet poles to use for a motor this size as this will be my first dip into the lrk pool. Any suggestions? Also, ball park, what kinda amps will I be looking at here? I was thinking about putting this motor into a slow stick to start out with so a big low pitch prop is what I'm going to be using. I just like the idea of the ridiculous over kill this motor will be for a slow stick :twisted:.

Latrans

[ScubaSteve]

Saitrix,

Can you resize your image so we don't have to scroll horizontally? Thanks. :wink:

[saitrix]

Yes i will :) Sorry about that but on my screen it only takes up half the width! What resolution you using? 800x600?

[Q]

Steve, it's the bloody long URL in Lucien's post that pushes the page out.

[LBMiller5]

Q,

I removed the "Bloody Long" URL from my post, and the page has re-sized.

It was a link to one of the rotor calculator pages that showed the magnet spacing.

Lucien

[Q]

Lucien, I hope you don't take it the wrong way. It's all meant with the tongue in cheek. Reading my post again it could ba taken a little harsh.
Sorry

[LBMiller5]

Of course not!

No offense taken! :D

Lucien

[latrans]

I was hoping for a little advice from you guys on an issue I have with building a motor that will be using a can from a panaflo fan, this is primarily directed at you Lucien since you have pratical experience with them. I need to remove the original shaft and replace it with a longer one. I know that this is not an overly complex task but it took me quite a while to find an appropriate fan so I really really want to get it right the first time. So do you have any advice as to what the best way would be? I have some ideas but wanted to know what your thoughts were on the matter and I suppose I should mention that I'm unfortunately limited in the area of tools i.e. no drill press. I'm open to any and all suggestions.

Thanks

Adam

[LBMiller5]

latrans,

I have been very busy lately tending to other pursuits. I plan on getting back to the motor building very soon. I will try using a "No Advanced Tools" method of popping out the shaft and replacing it with a longer one on one of my motor cans to see if it can be done successfully. I will post step by step directions when I do.

The stator I have has fairly narrow slots between the poles, so I will most likely do a multiple strand wind with 30ga wire to get the best fit. I am not really concerned with getting the absolute best possible performance from the motor, I just want good reliable power for a large size foamy airplane.

Lucien

[latrans]

Just a little FYI (and to keep this thread alive and at least somewhat relavent to gobrushless :) ) I've found that the GB bearing tubes are a perfect fit for the 27.5mm hard drive stators that can be used in conjunction with the panaflo endbells.

Adam

[LBMiller5]

Yes they are!!

I purchased 2 for this purpose myself. They should work great.

Last weekend I put in adjustable metal shelving in my entire garage to organize my "Stuff" aka "Junk". I also built in a section to have a workbench to build motors and models and computers (I have too many hobbies!) Very shortly I will have a perfect set-up to build anything I want, so I will not have any more excuses to keep me from building some motors!

I will post results as I get them.

Lucien

[latrans]

Lucien,

Are you having the same worries that I am about being able to get enough copper on these stators to make a decent motor? Just doesn't seem like there's a whole lot of room there.

Adam

[DadHav]

Hi Latrans, Lucien, I have some of these also. Are they the ones I got from you Lucien? I was wondering about the same thing, with regard to the thin openings and wire space. I also wonder what effect the wide legs will have on performance. Is this a good feature. Would the wide legs of the stator work better with doubled up poles? I.E. NNSSNNSS

[LBMiller5]

Yes John, I think the one you are referring to came from me.

SinceI have 2 of these rotors, I was thinking about winding one on every tooth of the sttor, and winding the other on every other tooth, but with as much wire as I could fit in, then compare the 2 to see which one works better.

It should prove interesting.

Lucien

[DadHav]

Lucien, I'm anxious to see how that will turn out.
Good Luck.
John

[latrans]

Hi DadHav, Lucien. About the size of the stator arms: DadHav do you mean the width of the end of the arm (hammer/head)? I've noted that the arm itself is thick and I think that is a good thing - more iron means it won't become saturated as quickly.........right? About the size of the head with doubled up poles - don't know. In a related issue, and in response to your thoughts on winding every arm and every other arm Lucien I noticed that one of these stators I have was wound so that the wire encircled two arms at a time (effectively making it a six arm?). I think this would make the motor more efficient than skipping every other arm. In this case I think that two magnets per pole would be in order. I'll need to look at that stator again to be sure of how it was wound, it may have been a little more complex than I described.

Adam

[LBMiller5]

By winding every other tooth you can completely fill the slots on either side of the pole piece without worrying if it will interfere with the next wind. If you wind 2 teeth at a time, you still have to leave the slot half empty to leave room for the next wind.

Lucien

[latrans]

I see (DUH, I feel a little stupid). I picked up one of these stators over the weekend and put some wire to it just to see how much of what would fit on there. In two layers you can get 16-17 turns of 24 gauge wire on but you can forget about putting that many turns on adjacent arms so probably 13 turns (of 24 gauge at least) is probably going to be the maximum. All in all that's really not too bad. One thing that I was wondering about is how are the # of turns required for a specific application affected by the stators diameter? I know that if you double the stator height then the # of turns should roughly be halved but does a similar rule apply to width.

Distributed LRK??

Latrans

[latrans]

Well I've been out of action as of late as I had one of my planes stolen which had all of my electronics on and I haven't had the $$ to replace everything yet. Its hard to motivate yourself to build motors when you know that you can't run them when you're done (that's the best part :D ).

Back to topic. I'd been thinking about an easy way to replace the original shaft with a longer one that would not require any special tools. I'd been a little hesitant on this step as I had only one of the panaflo rotors and really did not want to ruin it. Fortunately I have come across 3 more of them so I decided to just give it a go since I really don't see a use for 4 250-300 watt motors in the near future.

So this is what I did. As mentioned previously the GoBrushless bearing tubes are a perfect fit for these 27.5mm stators. Once you have reduced the stator height to the appropriate size for the rotor simply press it on to the bearing tube. Now slide the rotor over the stator bearing tube assembly. You will notice that the shaft will not reach the second bearing. Now flip the whole thing over (so that the bearing tube is point up) and place on a flat surface with a hole. I used my vice with the jaws almost completely closed (just enough room for the old shaft to slide between them. Make sure your surface is FLAT. Finally insert your new, longer, shaft into the back of the bearing so that its front end is against the back of the original shaft and while holding the whole motor steady use a small hammer (I used the side of a wrench) simply tap the back of the new shaft. The result will be that you will push the old shaft out while simulataneously pushing the new shaft in. Continue tapping until only 3mm or so of the new shaft sticking out the back of the bearing tube, use a c-clip to secure. Viola! A simple and effective method for shaft replacement for the Panaflo rotor.

Next I will be winding and testing. My first attempt will be a 14 pole distributed LRK. I'd more than welcome any input anyone may have on winding and magnet specifications.

Adam

[swatson144]

Sorry to hear about your gear! I hate a thief. One of my firm beliefs is a thief should be tied to a bumper hitch and tested for maximum speed plus 20 mph, while anyone caught "in possession of stolen property" should have the chance to see if they can outrun the thief by 20 mph, or get atop him.

[latrans]

Well at long last I've finally completed this motor! It took me a little while to replace my gear but I've finally done it.

I built my first effort with the ABCX4 winding scheme 14t of 24g and 16 magnet poles using 10x4x2 N50 magnets terminated wye. All in all I would say that I'm pleased with finally completing this motor but I have to admitt that I'm a little disapointed with the performance. It would seem that the Kv is a tad on the low side (understatement of the year) but I only ran it on a 2s kokam 1500 lipo pack so it remains to be seen what the performance wil be like on 3s. I have more stators so I plan on winding another one or two for comparison.

A few building notes:

14t of 24g makes for a pretty full stator, you could get a few more turns on but it would be a buggar (of course some can get 26t of 26g on a gb 22.7 stator so I guess anything is possible) but given my eyeball test of what the Kv is like at 14t I don't see much point in going with a higher # of turns with this winding scheme.

16 of 10x4x2 magnets is a good fit for this motor. The space between each mag is aprox. 1.5 mm. I couldn't find any random junk around my house that was the correct thickness to use as a spacer so I took some sand paper to 8 regular square tooth picks and reduced them to the right size and then broke them in half. This worked fineand was actually not as much of a PITA as I thought it would be, I'm sure someone else will come up with a better solution.

Does anyone have any thoughts on a better wind for this motor? I thought that my next attempt would be the same scheme but maybe 12 or 11 turns. I know that the microdan 2505 motors use the same winding scheme and magnet poles with 10 turns for a 9x5HD prop. My intent was to build this motor for a 12x6 prop which is why I choose 14t ............hmmm maybe I should be closer to 10t myself.

Thoughts?

Adam

[swatson144]

I'd suspect your low KV was mostly from 16p. I built a 12 arm 25mm 16 (also a 14p) and found it would be good for swingin a lwan mower blade but under propped with anything less. I've been finding <10p good. You may want to have a look at NNSSNNSS etc arrangement of your 16 mags, for 8p. I think you'll find it to swing a 12x6 with authority. I didn't notice anything about stack height, but unless you are more than 15mm you should be good with a 12x slowfly as they are meant to be on gearboxes anyway and will give good thrust at lower rpm. If you get a higher KV than the SF like go to a TE or HD.

#71 is a 10p 16t delta with 12mm stack height.

I keep looking for 40mm stator laminates. I got shafting and bearings all together. I've found a funky 15 arm but I have reservations about it. Got all excited today when I found a 40mm drive motor in a olds miniscribe esdi drive but it turned out to be 4 arm. :cry:

[latrans]

Swatson,

You maybe right about the # of magnet poles, I'll try it with 8. However if that is the problem then I'm a little confused because I have seen good results posted at RCGroups with 12 arm stators and 16 poles, both for the microdan motors and in the thread 'Olmods motor build'. In fact it was Olmod who suggested the ABC wind with 16 poles to me. But I guess there is no arguing with the fact that the motor turns to slowly to be of any use as it is.

BTW the stator is 27.5x10mm (that is all that will fit in one of these panaflo bells)

Another thing that may be worth noting is that the heads of the stator arms are a good bit wider than the magnets are. I really don't know what effect that would have but I doubt that it would be deleterious.

Correct me if I'm wrong but If I wanted to try 10 poles I would need to wind AaAaBbBbCcCc right? I can't remember the web site that has the winding tables. That might make for an interesting motor.

Ironically I had intended to put this motor in a slow stick to start with but the day before I finished the motor I was flying my SS and tried something stupid which resulted in snapping the wing in half in a full throttle dive. The damage was amazing. The motor shaft was bent at about a 90 degree angle and the aluminum tube for the fuse was crumpled in the opposite direction so the whole front end now looks like a Z. My own fault.

As always any input is looked for and welcome,.......... Lucien. Just kidding.

Adam

[swatson144]

I usually use this one.
http://www.bavaria-direct.co.za/models/files/Winding_Scheme_Calculator.htm

and double check here
http://www.powerditto.de/Kombinationstabelle2.html

Ok 10mm stack, you should be OK with your 14t wye, with a 10p. I got 34 oz @ 15A with #71 you should see about the same or a bit more. You have about 10% more diameter and I have about 20% more stack. My wind would be about 13-14t wye on a 10mm stack. seems very simular indeed. 34oz on a SS? ok with out cussing I just have to say Golly! #71 will jerk my Formosa to 2G vertical.

Sorry about your SS I've bashed a few myself. www.allerc.com sells the slope glider version for 29$ (says no motor or landing gear but they have always come with the L gear) who needs another motor and gearbox paper weight? . They also have parts. I keep a few on hand :shock: If you replace it Glue the wing rods full length and the center fold. tape them with real packing tape and you'll have a wing that won't break. It may rip down the length but thats an easy fix with gorilla glue. I was pyloning one of mine yesterday AM and hit the light pole (actually 3 times before I managed to get away from it) I just flew off and made a slow pass to look it over. It's not really a crash if it don't hit the ground right? :lol: Then had to land and recenter the wing. :D

I think the last fuse I bought came with the wing reinforcement rods and joiners and was about 8$ I still need to put it and the steelhead wing panels together to make an high lift 4 CH, but that'll be to finish the thread on kit configs or general, where ever I started it.

[latrans]

Swatson,

I looked over the winding tables in the link you gave me and they say that ABCx4 with 8 poles is a bad combo. Have you actually built a motor like that?

Your # 71 with 10p is that wound AabBCcaABbcC?

Adam

[saitrix]

Just opened up the delta. It has an outside diameter for 39mm :shock: Wall thickness of 1mm so the inside diameter is 37mm. It is 25mm long for the can. It has 2 ball bearings aswell for the shaft :D Also its a rubber magnet inside it. The stator is a 4 tooth, so its 2 pole motor. The stator is only 29mm though! The magnet is 3.5mm thick so roughtly a 0.5mm gap there, i bet its smaller as im only using a metal ruler. Seems very big. Now the golden question, can i get a magnet/stator setup to fit?

[swatson144]

You can see some of my 8p as #85-88. They seem to work well for a "bad" combination :) They are really 2 motors I switched rotors on and tested as 4 different motors, so you should be able to see the difference between 16 mag NNSSNN and 8 mag NSNSNS along with what difference the 2 turns make. These are all 5mm stack no cheese.

Yes the 10p is AabBCcaABbcC

Note that all of these motors will provide enough thrust to pull the rotor from the bearings. The little 5mm stack allmost got loose in the garage. If I had just dunked the throttle to full it would have really been exciting. details are here.
http://www.gobrushless.com/forum/viewtopic.php?t=440&highlight=hidey

and instructions for a cheap easy retainer ring, are in the same thread.

[saitrix]

I have no got pics of the can :D Thats a Himax HC2812-0850 with it.

http://www.saitrix.rchomepage.com/deltamotor.jpg

http://www.saitrix.rchomepage.com/deltamotor2.jpg

[latrans]

I had stated previously that the ABCx4 16 mag configuration had a Kv that was too low to be of much use, I'm afraid that I may have to retract that statement now. My initial tests were down with a 2s 1500 kokam pack (these results are what led me to think that this would not be a good combo) but I recently acquired a a TP 3s 1340 pack which I used to retest the motor. Whoa! What a difference that made! I went through several props and I think that either the GWS 11x4.7SF or 11x7 HD prop would be best. No hard numbers yet (I really need to get around to building that thrust stand) but I still think that one of the best indicators of how well my motor is performing is the look of horror on my wife's face and terrified the cats are (she says that my motors "make the cats do disturbing things".

@ Swatson
I just caught th bit about in your last post where you said that you really need a retention clip on these motors to keep the bell on the rotor. I can verify that this is true!

Latrans

[latrans]

Update on the hard drive panaflo motor.

I put the 14T 16P Wye version on the thrust stand last night. On a 3s TP 1340 pack it generated 16oz of thrust with a GWS 11x4.7 SF prop. Pack was not fully charged and I haven't adapted the shaft for a retention clip yet so the rotor pulls 1/4 to 1/3 of the way off the stator at full throttle. Never the less I feel that this is way below what this motor is capable of. the ABCx4 and 16 mag config. has a 8:1 reduction so it should be able to handle a much larger prop but when mated to a 12x6 the motor warms up rather quickly. I'm confused by this as I would not expect this motor to be maxed out by a 12 inch prop. Thoughts?

I suspected that the low thrust numbers may be due to a partially or mostly drained pack so I tested my best GBX2.5 motor afterwards. With this motor I got 25oz of thrust with a 10x4.7 APC prop. So its not a proplem with the power supply. I will say that I was very pleasantly surprised by the performance of my GB motor as it was producing several more ounces of thrust than I thought it was and that wasn't even with a fresh pack! I think that 28oz out of a similar GBX 2.5 with curved magnets is a realistic possibility ........... hint hint Steve :wink:.

I'm going to take swatson's advice and try 16mags in an 8 pole configuration with 9, 10, and 11 inch props. Stay tuned.

Latrans

P.S. Does anyone have any thoughts on this matter? Is anyone even paying attention to this thread anymore? If not I'll stop posting my info here, perhaps this would be better suited to RCGroups. I know that neither the stator nor the endbell are products sold by GB but everything else that I have used to build this motor is.

[swatson144]

I'm a watchin you :D

[latrans]

Did a little work on the motor last night. Started to build a new can with 8 poles NN SS. I learned something about inserting a new shaft into one of these cans (see my previous post made on may 23rd for details) : It is important to use something like a socket to support the front side of the can and make sure it is one of high quality! I have noticed that sockets out of cheap sets are not of uniform length on all sides and thus will not sit straight. Once you have the the old shaft tapped part of the way out use something to support and guide it on the front side. I have a few guides from the guide rail assembly salvaged from cdroms that I use for this. In my haste last night I just set the front of the bell on the open jaws of my vise, slipped a bearing holder over the old shaft and then started in with the hammer, this was a bad idea as the shaft came out crooked. Tried again with another can and a lot more care and it came out fine.

With that done I started glueing in magnets for the 8 pole can. Now here's another thing not to do: I thought I'd glue in 8 then position the other 8 along side them .............opps. I put them in N N N only to realise that they need to be arranged N S N S. And may I say that putting two of these 10x4x2 N50 magnets next to each other is a HUGE PITA.

On a lighter note I found no problems with inserting a threaded shaft into one of these cans.

Now if I could only find more of these hard drive stators I'd try an LRK.

Latrans

[latrans]

The 8 pole version of this motor is only marginally better than the 16 pole one. Thrust goes from 16oz on a 11x4.7 with the 16 pole bell to 20 oz on a 10x4.7 in the 8 pole configuration. This sucks, I'm getting tired of messing around with this thing. I think that the number of turns should be decreased to at least 10.

While this project languishes I have made improvements with my GBX2.5 motor. I'm currently up to 28oz of thrust and I'm still well under 10 amps. Can anybody beat that?

Latrans

[SkyCobra]

Saitrix

That can looks very familiar. I use GBL's 25mm 9pole stators, single(5mm) and double (10)mm, with 1.5mm mags in 12 pole or 6pole, wire according to GBL kits. Be carefull with 6 pole mag configs, watch for can movement. It will come off if you don't pay attention.

Single = 21T, 24 awg, wye, 9-5 HD prop, 21 oz thrust 11.2 amps, 3s lipo
Double = 14T 26 awg,wye, 9-5 HD prop, 16.5 oz thrust, 5.5 amps, 3s lipo

If you don't cut down the can, you can fit a triple in there. Keep the bearings, and I pressed in a new 3mm shaft from a cdrom.

[latrans]

I hooked up my 8pole twelve arm 14t wye motor to the thrust stand and power meter last night. Result was 639 grams of thrust when turning a 12x6 SF prop, which is less than I hoped for from this motor buuuut it was only drawing 8 amps. I find this encouraging as I suspect that this motor is capable of at least double that.

Latrans

[latrans]

Update on the hard drive/panaflo motor. I decided to take another shot at this one so I salvaged some more stator plates to build another 10mm stack. I wound this one for 10poles based on Swatson's suggestion. I took a semi WAG and decided to try 13t delta. I haven't put it on the thrust stand yet but preliminary results are encouraging. With a 10x4.7 gws SF prop it pulls just a little over 15 amps on 3s which is just about what I was looking for, except that I was hoping to turn a 12x6 at that amount of current. I will put her on the thrust stand tonight an see what she does. Keep your fingers crossed.

I was thinking about giving this motor a name. How about Hardflo or Panadrive? Any thoughts?

Adam

[latrans]

Well I put the 10pole 13T Delta motor on the thrust stand last night and the results were less than astounding. On 3s a 10x4.7 GWS SF prop pulled about 15 amps and produced an intial thrust reading of 28 3/4 oz which rapidly dropped off to about 26oz. While this is an improvement over previous incarnations of this motor there was one problem. The motor got VERY hot VERY fast. I have to admitt that I'm a tad confused by this. I would not think that this motor would be overloaded at 15 amps and since there are no shorts ................ why all the heat? Thick laminations? Over-magged? I plan on taking one more shot at this sucker. New plan is going to be 14 pole distributed LRK wind 10t of 22g, I will test both wye and delta. If this doesn't work there will be some free end bells and stators up for grabs. Sigh.

Adam

[swatson144]

sorry to hear that. did you try a smaller prop just to see what is going on? ie you get about the same thrust and a lot less current would indicate over propped and would just need to up the winding or change to wye.

[latrans]

Uh-Oh........... I picked up a few more big hard drives hoping that I might find a stator with better/thinner laminations than the ones that I'm currently using and guess what I found. How about a 27.5x20mm stator with 15 arms.

Here we go again.

Adam

[Tugboat]

I went to Computer Exchange today, picked up a couple Sony CDs for $10, and there was an old, heavy desktop unit sitting outside. Server! It was stripped but had the hard drive and power supply. The hard drive is a Seagate ST-1102A.

I may have something, don't know yet.

Thanks for the tips!

GL

[latrans]

Tugboat,

I'll wager that you do have something good in that hard drive and I know that you have something good in that cooling fan! KEEP THE COOLING FAN! That's one of the hard to find panaflo cooling fans that the endbells for this conversion come from. If you need any guidance on extract the sucker Lucien wrote some good instructions earlier in this thread. If you have any other ??'s I'd be more than glade to help.

Latrans

[Tugboat]

Well, the hard drive's a bust - 18.4mm 6 tooth. :(

Thanks!

[latrans]

Tug,

Why a bust? Sounds like a great candidate for some high speed application such as a small fast prop or a gearbox. Six pole stators will still work with our brushless ESCs.

http://www.powerditto.de/Kombinationstabelle2.html

On this site you will sind all the info you need about stator/maget pole configurations.

Latrans

[Tugboat]

OK, I may set it aside for future reference. It might make a good stator to go in a can from the drawer mechanism motor. I've seen them used as outrunner cans.

Right now I'm trying to get my GBx heli motor ready for a gearbox. I think the 10 magnet thing isn't working well. At 2/3 throttle the motor quiets down, smooths out, and the amps drop from 1.2 to .8 at full throttle (no load). Some weird harmonic from the asymmetrical windings, I think. I may play around with 10 magnets later (I got some 6x6x1s for GBv cans) but I'm switching to 12 in this one for now. Rewinding again...

Thanks!

[latrans]

Weird vibrations/ harmonics generated by the asymetrical magnetic forces inherent to the 9 arm 10pole scheme has been a common problem. I would stay away from it personally but some report good success with it. Frankly I don't see what the advantage or appeal is.

Latrans

[Tugboat]

I wanted a high KV motor for a gearbox, wanted to try something different (like I've got the regular stuff down :roll: ), and liked having a phase all in one place (which causes the problems :( ).

Oh well, redo the magnets and rewind again...

(Edit: AFTER rewinding, I found that a magnet had come loose and slid over next to another one. THAT explains a lot...)

Good Luck!

[latrans]

Well its been awhile but I have news! As I mentioned in a previous post I was hoping to find a similarly sized HDD stator that had thinner laminations than the previous ones and in fact I found just that. New stators are 28.5mm in diameter vs the original 27.5mm ones and the laminations are close to half the thickness. One of the main problems that I encountered previously was that I was getting saturation of the stator core causing big heat losses. Well I think that the thinner laminations have solved that problem. For comparison I built 2 motors one with the 27.5mm stator and 14 10x4x2 magnets 10t delta d-LRK, this is motor #1, motor #2 used the 28.5mm stator with 14 10x6x1.5 magnets but otherwise is the same as #1. On 3s #1 would produce 28oz of thrust with a GWS SF 10x4.7 at 15 amps but would get HOT FAST. Motor #2 with the same battery produces 34oz of thrust with a 11x7 GWS HD prop and (approximately) 37oz with a 11x4.7 GWS SF. With the latter prop amps jumped up to 20 which was WAY too much for the TP1320 which I was using to drive it but neither ESC or motor got excessively hot.

I think motor #2 is capable of much more for the following reasons. A) amp draw was way to high for the battery which really caused significant voltage sag (don't have exact #s but I know that it was running bellow 10 volts). B) motor #2 was built in a very half @$$ed manor. Since the larger stator was an odd sized hole for the bearing tube (11mm) I was forced dig through my parts boxes, I came up with a 3 part bearing that was kinda filed and then glued together. It has BB 3 bearings (one of which isn't straight and has CA in its race) and a long bronze sleeve bearing in the rear portion of the bearing tube. I imagine that all of this adds up to alot of friction. The other problem is that there is no groove for a c-clip at the end of the shaft (cd-rom guide rail was used for a shaft) so I used a trick that I learned from Ron, I put a piece of heat shrink tubing on the end the shaft, shrunk it, and then applied CA to secure it. For the record this is NOT a good idea for a motor that produces 30+oz of thrust. As I was getting around 3/4 throttle the can kept pulling off the stator which caused diminished power in the upper throttle range (not to mention the heat shrink that was being jammed into the rear bearing sleeve).

So I think that with the right battery and a motor that's built properly 40oz of thrust is very doable and possibly much more. I have ordered a custom made bearing tube and a few other parts for version 2 of motor 2 so there will be more to follw.

Do not let the object lesson of my work in this thread be lost on you. Bad stators make bad motors.

Latrans

[latrans]

HA! You thought this thread was dead didn't you? I have to admitt that I am a bit of a slow builder but I have some new and interesting results. In my last post I think that I said that I thought this motor was still capable of more and could do 40+ oz of thrust with an 11" prop........... well I was right. The newest incarnation of this motor now turns that same 11x7 GWS HD prop to produce 42 oz thrust at 17.7amps on 3s (also with a very approximate pitch speed of about 50mph). See my previous post for results from the 10t delta motor. The new motor is still 12s14p but is would with 6t of double stranded 23g terminated wye. I also splurged and had Don at StrongRCMotors.com make me a bearing tube to fit the 11mm bearing tube hole this 28.5mm stator has.

I have to say that I'm more than a little amazed by the differences between the 6t wye motor and the 10t delta motor, 8oz more thrust drawing 2 amps less. With a P-in of 180-190 watts 42oz of thrust with a high pitch prop like this is pretty darn good and probably the most impressive part is that the motor hardly even got warm after 30sec WOT (and I don't mean warm in a relative sense - I mean it barely got warm). I'd love to see what this thing would do with better magnets but unfortunately you can't fit thicker magnets in, maybe if I could find some N52s to replace the N45s and drop a turn .......................

If anyone is interested I have a whole photographic build sequence that I could post.

Latrans

[sheiis]

...uh...duh! Post pics :)

I am very motivated by your results.

[latrans]

okay here are a few pics.

[latrans]

And a few more.

[latrans]

Last one for today.

[latrans]

Here are some pics of the finished motor.

Latrans

[ScubaSteve]

Hey guys w/o getting these thread O/T can we limit the size of attachments to fit within the normal 800x600 viewing window?

[latrans]

LOL I'd been waiting for you to say that Steve. If you could tell me how to correct/fix this I'll do it today. I don't understand why these pics are so big, I posted several of the same pics on rcgroups and they came up normal size.

Adam

[ScubaSteve]

RCGroups installed a mod to their forum s/w that autoresizes all attachments to be no larger than X x Y. We haven't installed that mod yet, and hopefully won't have to. :wink:

To fit it you'd have to open up those images in Paint or something and just resize it down. Then on the forum just edit your post. In the attachments area you should see buttons that say "Add an Attachment" and "Posted Attachments". Click BOTH of them.

Click "Browse" and locate the resized image on your computer. Next to the appropriate supersized attachment below, click "Upload New Version".

:D