flux ring material?

[juki48]

I was wondering what people have been using to make their own flux rings? I wanna make a 20 mm double and need a flux ring. I now have a mini-lathe :D :D :D so I was wondering if there is an easy way to turn one? would any steel tube work if I turn it down to the desired size? and what would the desired thickness be?

[swatson144]

Nice question. I'm looking for some proper size chrome moly tube to minimize the work in turning. I have had fair luck with large nuts but there is a lot of meat to remove 3/4 7/8 etc. For stock mags it's hard to beat the GBX rings and cans. though when you want a little more diameter for clearance on 5x2 or even 6x2 you have to roll your own for now. I'm really just starting with my new lathe and would like to do something where I can get 2-3 rings of a size per turned piece. If you have an idea let me know please. I have kinda back burnered this until I get info on the motors I've built. Heck if the changes don't give me substantial improvements I'll continue to use my time more effectivly and buy the GBX parts.

[Jay C]

For the 22.7mm stator you can use 1" EMT conduit (not the easiest stuff to machine tho). The flux ring needs to be steel, and for 2mm magnets don't go any thinner than .8mm For my 25mm motors, I'm planning on 1mm thick flux rings :)

Like swatsons said ... I quick turning my own rings when GBx stuff came out ... time is getting short around my house with a growing baby ;)

Jay

[DadHav]

Hello 144, I've been picking up pipe at the local hardware store. The piece below was about 1" I.D. and about 1.3" Outside diameter. This has been working good for the motors I've made with 25 mm stators. I also found some smaller diameter for the 22 and 22.7 stators. I don't know if the quality of the steel matters, but this stuff is really soft. I'm guessing the more iron and less alloy the better. Maybe someone else would have an input there. I use .8 thicknes also on the ring. The thing that I did not like about the pipe is that it's threaded on both ends. This means you need to hacksaw that off or machine it. I'll bet if you checked, you could get some without threads.
Good luck with your machine.

John

[juki48]

I just had and idea :idea: as rare as that is :twisted: I dont know the site off hand, but I have seen some good sources of tuging at bicycle frame building sites. If I get a chance I'll try to find them agan but they had a huge size and material range.

[swatson144]

I just went to finalize my order on www.onlinemetals.com and actualy thought to check and they have 4130 pipe! I added some 1.25x.083x1.084 to my order. He has several different wall thicknesses Looks like it will work fine for my usage. Properties for this material can be found at http://www.suppliersonline.com/propertypages/4130.asp

this stuff should leave boring to a minimum and with a 1" hole already there allow use of standard AR5 tool on the compound. Boring only .028" will get you to a start point of the GBX ring.

If you don't know of this guy he is a godsend to us mini lathe folks. sells at nice enough prices in small sizes. Good source for AL too. Highly recommended by my buddy who has ordered several times from him.

[DadHav]

Hey Juki, I'll buy the beer if I ever run into you. The link you gave has materials that I could have used for just about every motor I've made so far. I'm not sure what the Pro's might say abuot the steel specs, but I think low alloy is what we might want. As far as the aluminum: Good, Good, Good. I Think I'll place an order today for some 7075 for bearing tubes and mabe some larger diameter for end bells. The steel tubing has some pretty good tolerance specs. I would say it will probably be high quality. Don't squeeze it to hard in the chuck though.
Thanks.

John

[juki48]

did I post a link? I think you mean swatson. but I'll still let ya buy me a beer! I think it's amazing to talk to people all over the world about the same hobby! buy the way, that motor looks great! any other's you'd like to post?

[USCG_E7]

Don't overlook the local scrap dealer. Sometimes they'll gets loads of scrap that has been sorted by alloy number. Might save you shipping/handling charges since you get it locally.

You'll likely be making motor mounts, prop adaptors, etc as well and you don't need any specific alloy for stuff like that. You might get some AL rod cheap - the current cost at the recyclers here is $2.00/lb.

I do metal casting using a propane-powered furnace I built and have done a bit of experimenting with my own alloys but nothing real scientific. Most of what I melt down is AL car wheels, cylinder heads, etc. Most of my casting involves parts for Stirling Heat Engines and some small steam engines - I make the castings then machine them to the proper tolerances with the mini-lathe and mill.

[swatson144]

Yep I am guilty. I did check with the scrap yards but they had nothing small.
We seem to be getting off topic but there isn't a "frankenstein" forum and I am pretty sure we would confuse people trying to sort out what they need to build a kit in any other group! Maybe scubasteve will surface long enough to give us a topic with the proper disclaimers saying that some of the parts are made from GB parts but others are cobbled from scratch, and these peices don't go together without modification.

Now that my raw material is coming I'll order some more GB stators etc.

Then I'm gonna build an indexer to drill 5 cooling/lightening holes in my over size cans. Any one interested I'll up it when complete.

[Jay C]

Dave, that's a big lathe for hobby use :)

Juki, check Dave's gallery for more of his work .. they are very nice indeed.

SWatson, what lathe are you using, and by my calculation the 4130 1.25" with a .058" is what you want for the 25mm stuff to give you a 1mm flux ring ... what I plan to use for mine. And yes, please post your lathe how to when you do the indexer. My plan is to install and index plade on my Taig and use the dremel wit the flex shaft as a live tool :) Before I get there, I have to install the plate and make a handpiece holder :)

Jay

[DadHav]

Hi Jay, Guys, OK then, It's beer and motor talk for everyone when I see you. Thanks for asking about pictures. I have some that I can add to my gallary tomorrow. I'd like to see a part of the forum for the kind of talk going on here also, and you are right. We may have a lot of people reading this and then finding out that we're customizing a little bit.
Getting back to the the 25 mm GB stators that are for 15 mm GB magnets. I rewound the triple (15 mm stack) today. This time I used four strands of #30 wire with ten turns, Delta. Man I like this motor know. My test today produced 1lb. 14oz. of pull on my digital fish scale (30oz.) With an APC 9-4/5 prop, while drawing 12.5 amps from a three cell lithium. After ten minutes at full throttle, the motor was only 45 C. I'm sure I can get more out of it when I get some other props. Jay, I know I use the term torque wrongly. Maybe I should say thrust, when I'm talking about how much the motor pulls. Jay thanks for the help on undrstanding the winding charts. On this one I wound the phases in the order that is for a delta hook up. I souldered the ends of one phase to the beginning of the other as I was winding. It really worked nice doing it that way. I'm all ready for a rear end bell/mount on this one know. You mentioned bigger stators. I understand what you're saying. I'd like to try a motor with a 28 mm stator or bigger, but I don't want to spend $38.00 US for an assembly from the LRK parts department. Do you know of any other source, that is in English?
Thanks Everyone.

Dad

[LBMiller5]

Hi DadHav,

Your motor looks great! It sounds like you have a real powerhouse there!

I had a couple questions about the motor if you don't mind.

1. I noticed a white filler material in between the magnets, what is it?

2. What is your stator tip to magnet clearance? It looks like you are using the 15x4x2mm magnets in this one. I assume you have a pair of dial calipers, so could you give the Inside spacing across the pairs of magnets.

3. How thick is your flux ring?

I have been gathering parts to start making my own motors, and your work looks to be of very high quality.

Thanks!

Lucien

[Jay C]

I understand what you're saying. I'd like to try a motor with a 28 mm stator or bigger, but I don't want to spend $38.00 US for an assembly from the LRK parts department. Do you know of any other source, that is in English?
Thanks Everyone.

Dad
Dad (sorry been calling you Dave ;)), I have a 27mm stator you are welcomed to. It's about that same height just PM me your address and it's yours. Other sources are to dismantle old blenders, power tools, ect ... Some nice 12-tooth stators can be found in most western digital hard drives ... tough nuts to crack tho ;) Also, you want mega torque, look at floopy drive stators ... 40mm some of them.

Jay

PS: looking forward to more "gems" from your collection.

[DadHav]

Hi Lucien.Thank you for the compliment. The white stuff. You had to ask. First: I think most people mix Micro Bubles and epoxy for this. I'm almost never satisfied unless I do something different. I have used expandable urathane glue. This is sold by Elmeres or Gorilla glue is great stuff. If you just put a coating in-between the magnets, it foams up to be light and tough. You have to run a blade around on the inside to clean things up, and I'm not sure this is any better than epoxy. On the rotor in the picture I used a different method. I used two part foam. I applied a small amout, let it foam up, cut the stuff even and then applyed a coat of thin CA over the material. This is something that I have used on my nitro planes for special reinforcment. Be forwarned if you try it, that the foam expands 12 times, so you can easily fill up the whole inside of the rotor. That's why I said "you had to ask" I found that out.
Right on the magnet size, although I wonder if I might have done better with 5mm wide pieces. This would have taken up closer to 80 or 85% of the inside diameter. I heard this is a good number. I keep my air gap between .005 & .008" (.125 - .2 MM?). Calipers? Yes, but I design everything in AutoCad or SolidWorks before I cut anything. That way I'm measuring somethiing that I know works. I have lots of measuring tools. I started a Tool & Die maker Apprentiship in 1963 and worked in the trades for almost 18 years. I mastered several youngsters all who ended up making more money than me, because they moved into the Automotive Industry.
Flux rings I use a thickness of about .025" on the small siingles and .032" on the three stator motors. (.64 to .8 mm?) something like that.
Hope this helps, but I think your real Pro's are the guys like Jay, Bret, Pip and some of the others. I think some of this came from them though.
Get in touch any time

DAD

[MouseBuilder]

I made a flux ring using a piece of carbon fiber tube. It's a 1.000"I.D. wrapped tube It has a .050" wall thicken. It works great. :lol: Here is a picture of it. I used a 20mm stator with (12) 5x5x2mm mags. I bought the tube from McMaster Carr $23.00 @ foot.

[Jay C]

I made a flux ring using a piece of carbon fiber tube. It's a 1.000"I.D. wrapped tube It has a .050" wall thicken. It works great. :lol: Here is a picture of it. I used a 20mm stator with (12) 5x5x2mm mags. I bought the tube from McMaster Carr $23.00 @ foot.
A flux ring is called that becaue it provides a path for magnetic flux. A material can not do this if it doesn't contain iron. Carbon fiber will not work as a flux ring. What is happening is that your flux is having to go through the air ... not good. If you take a strip of magnetic metal and insert it into your tube then install the magnets, it will be better than nothing. .8mm is about as thin as you want to go with 2mm thick magnets or your flux ring (also called back iron) will saturate with too much flux.

Aluminum, glass, wood, plastic, stainless steel, nor carbon fiber can be used a flux ring since they are not magnetic.

Jay

[Jay C]

Sorry, forgot to tell you that is a very slick looking mount ... very nice work :D

One note, not sure how many tunrs you are using, but loko like there is a lot of room between teeth on the stator. Consider using thicker wire (same number of turns) to lower the winding resistance and increase your efficiency.

Jay

[teehouse]

When chromemoly was mentioned at the beginning of this thread I immediately thought of all the bicycle frames in my garage. I will be getting my calipers out tomarrow to check diameters. Just a thought. The older ones are high iron content to my thinking. Obviously chromemoly is harder but older steel frams would be higher in ferrous metal content.
I'm new. First posting. Great forum. Happy new year. :D

[swatson144]

Dave, that's a big lathe for hobby use :)

ring ... what I plan to use for mine. And yes, please post your lathe how to when you do the indexer. My plan is to install and index plade on my Jay

Mine is a plate with 3 holes. One in the center to hold a shaft for the can to sit on. one at 0 degrees to align it to a center drill chucked in the drill press. and one 72 degrees and same distance out to mount a rod the size of the holes as a guide.

works thusly. center the 2 nd hole under the drill press. insert endbell or can. pilot hole with center drill, change to dia drill you want and drill hole.
lift stator and place guide pin in 3rd hole place stator on both guides, drill hole rotate and repeat. With a burr one can duplicate slots also.

[DadHav]

Hi There, Jay, or anyone, Do you think it would be beneficial to have a flux ring made out of laminations like the stators are? If so, I have another one of those sure to be rejected crazy ideas.

C YA

DAD

[Jay C]

Hi There, Jay, or anyone, Do you think it would be beneficial to have a flux ring made out of laminations like the stators are? If so, I have another one of those sure to be rejected crazy ideas.

C YA

DAD
I've thought about this recently and reasoned this: the stator is segmented to help control eddy currents. Eddy currents happen in a changing magnetic field. The flux in the rotor is unchanging thus no eddiy currents ... thus no I don't think you would gain anything by segmenting the rotor flux ring other than weight :)

Now this seems logical to me, but I have not tested it nor confirmed it (my disclaimer ;))

Jay

[swatson144]

sure would be amusing to see Dadhav make something like that pretty though :lol: Jayc is right since the flux on the can doesn't move there'd be no real advantage.

[Q]

Hmmmmm, interesting thought if it could work

By rolling some thin sheet steel around a pipe and gluing it with epoxy, we can make any bell size we want.

[swatson144]

I don't remember where I saw it but there is a guy doing just that with a surplus of mild steel transformer laminates he has on hand. I didn't pay much heed as it seems it would be very hard to keep it round and thus your airgaps would go too large. If memory serves he was rolling around a mandrel the size he wanted (or a couple thous less) and cutting the ends to butt together and brazing the 2 ends

[swatson144]

Triggered a thought and I remembered we use to get shim stock in all types and sizes. Below is a url for a source of same in steel. They have it in sizes and thicknesses The url is for .003 x 6 x 100"

http://www1.mscdirect.com/CGI/NNSRIT?PARTPG=NNSRAR2&PMPXNO=1647251

that could work!

[juki48]

yuck, that just sounds like something I could really screw up!

[DadHav]

I was just kidding around when I made this wire flux ring, but since then I've seen a few guys actually make the principle work. One of them used three layers.
I think a better way will materialize.

[DadHav]

Wow, OK This took me longer to type than to make the ring. You guys already found the shim stock. The thin stuff that you found can also be cut with scissors. I think your on to something.

DAD

[swatson144]

Some of the in runner LRK guys are making their flux rings out of florist wire. But the stators are on the outside so they don't have th problem with rotating forces. :evil:

I used silk wing covering to fiberglass a 25mm stock can to a GBX1 flux ring before I got my lathe. Tested fine. maybe a combination of the shim and thin glassing could be used. I call this my frankenmotor. you can't really tell but there is at least 4 wraps of silk cloth in there. the total wall thickness is .99 mm

[juki48]

I think someone should mill the inside of a flux ring with 12 flat sides. curved mag's are ideal but they don't have them for all sizes. if the ring was a dodecagon inside there would be no loss of flux, and placement would be a breeze. I did have to look the name of a 12 sided polygon, don't worry. :wink:

[Q]

I might be able to produce that if I can find the shim stock.
Cutting the metal to size is not hard at all. I'd use a few layers on top of each other and then wrap with one layer of 100gr/m² glass cloth. The whole thing, incl. the mold, can be vacuum bagged to make sure there is no air between the layers as the epoxy sets.
The biggest problem now is to make the mold with 12 sides. If my 4 axis CNC mill were ready I'd be able to produce that in half an hour. :?

[juki48]

nice, what do you need to get your cnc mill going?

[DadHav]

Hi guys, 4 axes mill. Man I can't wait to see some of your creations coming up. I was wondering about the slots in the flux ring. At one time I thought about going just deep enough to locate the magnets. If you go all the way to produce a flat mating surface the ring will get thin at the corners, Right? Is it practical to inrease the diameter of the ring so that you don't have weak points. Years before they had equipment for doing things like this, I scraped things like keyways or splines on a Bridgeport by making a tool the thicknes of the piece to be fitted, and then scrape down the side of the work piece with the quill of the machine. I would imagine you could do this with your ring before the outside diameter is finished. Of course you would need to secure the work piece in some sort of dividing head, and you might need to reindicate when you went back to the lathe. Sounds like a lot of work right? I bought some magnets that have a rounded back on them to fit against the flux ring. They are 5 x 6 x 1.5 mm I think. They might be N48. I never tried them yet, but if you're interested I'll dig up the particulars. Good luck with your CNC. What control? Fanuc? Do you need any programers?
C YA
DAD

[Q]

nice, what do you need to get your cnc mill going?

Not a lot any more. Mostly time. :wink:
Electronics, computer and software are done. It's jsut the mechnical part to be done. Design is ready (in my head).

But in case you have a few thousand $$$ to spare, I could be done a LOT sooner. ;) :P

[Q]

Good luck with your CNC. What control? Fanuc? Do you need any programers?

Thanks.

I am using a CAD application that allows me to export g-code (rhino 3D with a plugin). I can then use a simulator to test the code. To control the steppers I will use either TurboCNC or EMC.
I bought two stepper controller PCBs from embeddedTronics.com and added some stuff I already had for the power supplies and wireing.
The 4th axis will be made using the claw from an old Unimat mill.

I was thinking of either wrapping the thin steel around a round mandrel. When building a dodecagon I can wrap it too so the can will be having 12 sides at the outside too. It will have a uniform thickness.

I think the major question hasn't been asked yet. How much steel do we need in the bell?? Isn't a very thin can going to be saturated very quickly (flux sturation) and thus reduce the max performance?

[DadHav]

Good question, The weight of the ring might not matter that much if you could gaine an appropriate amount of power. Have you guys with the mills ever thought of trying to cut balsa parts by using a high speed spindle adapter? I've cut steel with 1/32 ball mills with very little problem. Is it out of the question to try cutting a kit? I'd be glad to provide a cutter path for sampling posted to what ever control you use. I have AutoCAD, Solid Works, and SmartCam to work with.
C YA
DAD

[swatson144]

I just got my raw materials for flux ring and end bell making ...I think I'm about to go through a bunch of 25mm stators!

[Jay C]

Related to this, I was browsing the loacl Lowes for storage solutions. One closet rod caught my attention. I went back last night with my calipers. The ID is 30.32mm and the wall is 1.03mm. I went ahead and picked up a stick of it for quick prototyping. It's a bit too big (a resulting airgap of .43mm with 5mm wide magnets ... or is it ;)). See the results here (http://www.gobrushless.com/testing/motor_rotor_calculator.php?Stator_dia=25.05&Rotor_dia=30.32&Mag_width=5&Mag_thick=2&num_holes=0&FS_airgap=0&dim_holes=0&num_poles=14&submit=Calculate+Now).

Jay

[swatson144]

well that'd be what like .02 and some change from a gbx? Is it welded tube? How clean is the ID I'll probably have to go and look for a stick.

[Jay C]

well that'd be what like .02 and some change from a gbx? Is it welded tube? How clean is the ID I'll probably have to go and look for a stick.
ID looks real clean but you can see evidence of the seem. I can post the UPC if you need it, but it the white powder coated rods in 4' and 6' lengths. I went with the 18" to 30" adjustable kit ($4.58) to see if the smaller diamerter rod could be used for the 22.7mm stuff. Unfortunately not (at least not with 2mm thick magnets) as the ID was like 26.?? (can't recall right now) versus the 27.3 to match the GBx flux rings.

Jay

[swatson144]

Cool I have a surplus of 1.5mmx5mm maybe close?

[juki48]

I've been wanting to make a 20mm double. see anything in the 24.75 mm id range? I think that's about what I want for 12 10x4x2's.

[DadHav]

Hey Mr. 48. I'd really like to know how you make out with your double 20mm. I tried a triple, but didn't get what I hoped out of it. I used 15x4x1 magnets. Maybe they were to thin. They were N50 though, and really seemed strong.
John

[swatson144]

I've been wanting to make a 20mm double. see anything in the 24.75 mm id range? I think that's about what I want for 12 10x4x2's.

try http://www.onlinemetals.com/merchant.cfm?step=2&id=250
I haven't yet machined any of mine but should do fine. I posted the machining properties several messages up. He is a great source of material for us. I am very satisfied with the service. Great source for AL too.

[Jay C]

OK, I finally got some time to knock up a very crude prototype. I didn't bother trying to dress it up for the photo so no apologies for the poor bachining, chipped paint, or other asthetic flaw ;)

That's a 5mm stch of the uncoated 25mm 12-tooth stators wth custom laster cut cardstock insulators (we'll see how well they do when I start windings), 14 5x5x2 N45 magnets, closet rod flux ring, and a nylon end bell with a GBx short shaft. I knocked the bearing tube out of .5" aluminum rod.

Jay

[swatson144]

I see you cleverly disguised the closet rod SKU as "what is that" back ground 8)

[DadHav]

Hi Jay, It looks like you're gonna be getting real carefull at the underside of the outside leg. I finished a single 25 and put some pictures in my gallary. I was wondering what I'm doing wrong that the thumbnails are shaded in dark? Any ideas? OH: The 15mm Single really runs great. I'm sure you'll be very happy.
John

[swatson144]

I just got to spend a few mins with my lathe and tried the 4130 tube. Nice stuff. I was working on my 25x10 LRK proto. I figured I'd turn the ID to 28 mm and line broach .5 mm wide slots the length if the ring, to use 5x1.5x10 N50 14 poles. ridding me of most all airgap in back, and leaving normal .28 in front. Problem is the harbor fright mini lathe I have has 44t on the spindle which leaves me making a clamp and mounting a protractor ring on the chuck to index the thing. If it had 42t I'd just index on the teeth. Any ideas? I guess in the meantime I get to try out my air hole indexer on the drill press as the end bell will still work with a 25mm and 5x1x10 (in case I botch the broaching) so I might as well finish it. As far as the 4130 tube goes I am sold on it. Highly recommend it as a flux ring material. I turned down the over run to .7 mm wall and and parted it off. rechucked to face the parted end to 7mm for a future single and was very pleased with the firmness it chucked, and it machines sweet!

[DadHav]

Hi 144, Was it you who mentioned On Line Metals? Thanks. I received my 7075 and steel tubing yesterday. I was able to find tubing in any size I needed for the motors I'm making. This leaves very little machining.
I would really like to know how you make out with broaching the flux ring. Will you give us some pictures? I was also thinking about trying the same thing with scraping across the frond end bell in stead of the flux ring. This would locate the magnets by the ends. It might not be as good but it might help. Did you guys ever visit your local used machiery dump. I found an indexer with a few 5-C collets for $15.00 Its really beet up but it works in the drill press for cooling holes in the end bells.
John

[swatson144]

Yep I did mention onlinemetals.com. It is one of the few places I'll plug because any one who complains about them would probably gripe "if you hungem with a new rope". :) GB is another like that :oops:

I just finished a few hours of machining in the garage. I completed my simple cheap end bell indexer, but I got confused and put the center shaft in the wrong hole and fairly screwed up an end bell. (well I was able to drill a hole opposite and recovered enough to use it). The post and stop are made so it's just a matter of drilling 3 more accurate holes in plexiglass to retest.

I'm thinking of a way to lock the chuck in any position to line broach (I think that is the correct term for dragging a tool through metal parrelel th oth bed) so I can broach out a key and then release the clamp and rotate 25.7 degrees and lock it backfor the next. for 14 poles. Building the degree wheel won't be a problem. but the lock is! I thinking cutting edge toward operator and depth controlled by the crossfeed. A mandrel and 5mm broach won't do 'cause how do you index that? That'd be a machining night mare as a solution looking for a problem. Your Idea coupled with keys for the mags in the flux ring would throughly lock the endbell and flux ring together, make a slightly shorter flux ring, as the magnets would sit to the very end of the ring, on both ends. the same method of indexing would work for both.

I have a clean weekend ahead of me so I'm gonna go out and make an end bell and flux ring for a 12 arm 25 and stick 14 4x10x2 in it and stick it on a heavy plane and see if I really like it. Then test it on the stand. Probably be best to get a good baseline anyway. Ooh heck that's wishfull thinking the stinkin wind won't die enough to leave a buick sitting still. So I'll probably wind up benching it before I ever fly it and go off half ****ed and post the results :roll: Heck I may have to try one of those boomerang lookin planes with the motor in the back :shock:

I think you'll enjoy the tubes, I am finding it nice to work with.

[DadHav]

I know what your saying with that 25.7. I just remembered that about twenty years ago I made two 1/10th scale field cannons. Guess what? 14 spokes on the wheels on about a 7 degree angle from the hub. But I remember making something to index the hub and wooden rim. If I can find it I'd be glad to see if it's something one of you guys can use. I have all the threading gears for my old South Bend lathe. Some of them divide by 14. maybe something can be made using a gear. I have indexed the threading gears to chase 6 lead threads for lens housings before. There's probably a combination that would work out to 14.
I'll do some experimenting also, when I get caught up a little. I think shaping across the front end bell the way an AXI motor is made might be the thing to try. I think shaping or broaching the inside flux ring might be a little dificult because of the preasure needed. If I were to try it, I would put the stock in the srongest chuck I have and do the shaping before the outside diameter was finished. That way if it moved you could indicate the piece again and still be OK.
Let us know if you have any luck.
John

[Q]

I will do some epoxy/glass/carbon moulding one of the next weeks as I'm building an RC hovercraft for my son. We have been talking about building a 12 sided tube from sheet metal. I think I'll give that a try. Building up to 1mm thickness should give me a pretty nice bell.

I'm just thinking about how to make the endbell.

[swatson144]

I had originaly thought I'd just drop in a change gear and index on that but there is so much gear slop in the harbor fright lathe I have that that is a no starter! Then I had hopes of just indexing off the spindle spurr, but it's not divisable. It has occured to me to use the thread wheel on a real lathe and feed the broach with the compound may show promise. I'll have a look at this and see if it is feasable on my POS. Probably a clamp and degree wheel would be my best bet. I don't think it is worth the effort to make a proper worm gear indexer. You had mentioned sloting the end bell for magnets and I'm seeing a lot of good sense in that! If one had access to a mill and a divider (which I do but not mine :( ) Make an end bell full length and same od as ID of flux ring. Mill magnet slots in it, which would leave radial fingers. press fluxring over top and glue magnets between the fingers thus securing fluxring at the same time. This way the heavy fluxring would only have to be the length of the magnets. Soon as I figure out how to index my chuck I could probably use a dremel with a cylinder burr as tool post grinder to cut the slots. I'm starting to think a degree wheel out of a motorcycle brake rotor may be a good answer. drill 10 12 and 14 stop holes at slightly differnet distances from center in it and mount an angle plate on top the head to engage the holes... Yep your right I ain't quite got it figured out yet, but I want it to be easy to use, repeatable, and not to darn hard to make or set up.

[DadHav]

Wait a minute, I have an idea. Let's throw this in the toilet and see if it floats. Make a CAD generated drawing with the divisions on it. The drawing is the diameter of your biggest face plate. See where I'm going? The drawing can be fixed to the plate with a light spray of contact cement. This drawing or template can either go on the face, or one could be made to go around the circumference like a tape measure. OK, Now put the collet adapter in, naturally without the threaded part to remove the adapter. You can remove the adapter sleeve with a knock out bar from behind when you're finished. Stick a magnetic base on the bed or ways of the lathe with a pointer to pick up the alignment positions on the drawing templet. I will find my index point then tighten the screw that is used to adjust the spindel bushing. Depending on the diameter of the face plate, you certainly would be accurate to a few thousnths by the time you get to the diameter of the part. You might be able to fix a templet to some other part of the lathe. I.e. My lathe is an antique and has flat belt pullys. You could even wrap a templet around a pully and do the same. If anyone would like to try this, I'd be happy to send them a printable file, as they might require. You know, You could fit a templet to your work piece but it wouldn't be as accurate. Oh, I don't know if everyone does this but I leave a diameter on every aluminium part I make so that I can get it in a collet do do something like this or polish it etc.
I know. The Old Man is nuts, Right?
Dad

[swatson144]

That's pretty much what I had in mind. I was thinking I'd go to a real lathe and bore a hole in round disk to fit my chuck. Slit the disk and weld on a couple of ears to clamp it in place with a bolt. Drill a locator hole in my chuck say 1/4" x 1/8" deep near the head (spindle end) and put a draw bolt (door lock like thing with better tolerance) on the disk. After laying out and drilling the holes 10 12 and 14 each in rings say 3/8" farther from the center assuming 1/4" holes in the plate (for 1/4" shoulder bolts). I could locate the disks retractable pin in the hole in the chuck clamp it in place by tightning a bolt spanning the slit. That would allow me to use the chuck and have the indexer in place secured in place parralel to the face of the chuck but behind the chuck key holes. Kind of think of it as a disk brake for the chuck.

Since my lathe has a flat top I could easily mount an angle plate on top the head with 3 holes drilled and tapped 3/8" apart in a verticle row. SO by using 1 shoulder bolt through any hole in the proper ring of holes in the disk I could index by 10 12 0r 14. do the appropriat operation and advance to the next hole reinsert the shoulder bolt and repeat until all is done. I hope that is clear If it looks like I'll have enough time to make it worth while this after noon I'll heat up the garage and get the measurements and layout the disk then it would certainly be clearer.

I'll probably arrange it so that I can clamp it in other positions using an integrated degree wheel and a pointer just in case other needs arise. I'll have it chucked in my buddies real lathe to bore the ID so I might as well face an inlet for a degree wheel. High tech stuff like laminated card stock held on by 5x5x1 magnets so I can move it to 0 for the starting point. :lol:

[DadHav]

Hey Don't forget to post a few picutes. Good luck with the cold garage. That's not for me.
John

[nacho_daddy]

I mentioned this a while back on eZone...

I managed to make a custom can without a lathe - one of the keys was finding the right size tubing for the flux ring. The only hard part is getting a nice square trim on the ends. I had to cut the tubing to length and then spend some quality time grinding the ends until they were perfectly square. Not fun. If you do have a lathe, you won't have to turn this stuff, just use a cutoff tool and cut to length.

With 1.25" OD .035" wall 4130 steel tubing in combination with 5mm wide and 2mm thick magnets, you end up with a calculated airgap of .286mm with the 25mm stator.

Also, the 1.125" OD .035" wall 4130 steel tubing works well (.313mm airgap) in combination with 5mm wide and 1.5mm thick magnets when used with the 22.7mm stators.

You can get this stuff in short lengths - reasonably priced here:

http://www.aircraftspruce.com/menus/me/steel.html

The double 22.7 stator motor I built using the 1.125" OD .035" tubing worked better than I expected.

Hope this helps!