is this the right parts?

[schaubro]

Hello,
I need a motor for a sloflyer 43" wing that I am going to get. The plane will weight 6.5oz when it is finished. I want some speed and yet thrust to take the plane vertical.
I am planning on running on a 2S 1200 lithium pack. After looking at the performance database, It looks like I want the one listed as:
GBL_00052
9X5 prop
7.6v
11oz. thrust
5.8amps
21T 26AWG 22.71 stator (12) 5X4X2 N45 magnets.

I am thinking that I may run an 8X4 or 7X3.5 prop to achieve a little more speed, but will figure out which one works best when I fly the plane.

Are the following all the parts that I need or am I forgetting something:

22.7mm 9-pole stator
GBx 3mm long shaft
GBx Endbell (the one with the cooling holes)
26g Newbie wire - small rolls - All 3 colors
N45 magnets 5X4X2 15pack
3mm ball bearings (2pk)
Long carbon Fiber bearing tube

I am planning on following the build instructions listed on the web site. Are there any secrets that I should know.

thanks,
tim

[swatson144]

Don't want to put you off but the biggest secret I can give is to read ALL the topics in the forum! Things tend to evolve on a topic and or be missplaced originally. Everything posted here will work, or would be disputed/refuted rather quickly. There are ways people like to do things, because of equipment on hand or lack of it etc. You can pick what you think will work for you, and change it if you find out it doesn't work so well.


if you are gonna build a GBX you probably want a flux ring also.

I recommend you buy a GBV 1.1 kit along with the other stuff. You won't need the rolls of wire if you do. The kit comes with enough wire to do several motors. viewed in that light the kit only costs an additional 3$ and change.

I'd make the flux ring a double and order 2 stators, and change the mags to 2x (10x4x2). start with the GBV kit. the completed GBV kit will drag a parkflier around smartly. When you want more power put the GBX2 on it.

21t is pretty hard to do. I started with 21t and have found that dropping to 18-19t makes winding so much easier. 21t that 3rd wire is a doozy even winding neat, flat and running the 1st layer up the hammerhead. I can't see any performance difference all things being equal.

[Jay C]

I am planning on running on a 2S 1200 lithium pack. After looking at the performance database, It looks like I want the one listed as:
GBL_00052
9X5 prop
7.6v
11oz. thrust
5.8amps
21T 26AWG 22.71 stator (12) 5X4X2 N45 magnets.

Are the following all the parts that I need or am I forgetting something:

22.7mm 9-pole stator
GBx 3mm long shaft
GBx Endbell (the one with the cooling holes)
26g Newbie wire - small rolls - All 3 colors
N45 magnets 5X4X2 15pack
3mm ball bearings (2pk)
Long carbon Fiber bearing tube

I am planning on following the build instructions listed on the web site. Are there any secrets that I should know.

thanks,
tim
you need a GBx single flux ring. The biggest secret is to download and read the GBx tutorial just published. Read it first and ask any questions before you start :) Help me make it fool proof ;)

[schaubro]

I have read the GBx tutorial and now I have a couple of questions:
1) If I use 2 stators, I can use fewer turns of wire (go from 21 to 18 turns) and still gain approx. the same power. Will I gain higher rpm due to fewer turns? What else will be differant?

2) It appears that I can epoxy the 2 stators together or just use temporary wire wraps to hold it until I get some wire wound. Correct?

3) I don't see any weights listed on the gobrushless web site. Is there a way that I can calculate(estimate) the finished weight of my motor?

4) I don't have any sort of press or vice. Will I need one to put the parts together? (If so, then this will give me a good reason to convince my wife that I need to make a trip to Harbor Freight).

thanks,
tim

[swatson144]

I have read the GBx tutorial and now I have a couple of questions:
1) If I use 2 stators, I can use fewer turns of wire (go from 21 to 18

chop



1) Ok I'll step out on a limb here while I try to answer this. IMHO for our purposes the theory of these motors does not have as much impact as it does with larger scale fixed freq motors. say 125 hp 1725rpm 50% duty 240v 3 phase etc. this can all be calc'ed to the letter and built to spec. Those are motors that when started pretty much spool up to speed and stay there while doing work. If the load is within the design parameters everything is happy....Ours are motors that may start slow, fast or somewhere in between, mostly at partial rpm during use with the load varying wildly (diving climbing head/tail wind) So since we have a speed controller I'd have to say (my experience as witness) that an electrical engineer (which I ain't) could crunch figures until the pads on his calculator wore off and it would still be a best guess. Unless we could actually supply a few constants (which we disdain). For example using a DC power supply to power an ESC we could easily prop a motor to burn up in 30mins WOT the same motor in use may outlast the airframe it's installed on (ok some of the airframes my I have used could be outlived by solid rocket propellant but I am assuming a longer life :)) So IMHO wrap it 22t or17t somewhere in it's use it will be underloaded and sometimes it will likely be overloaded, you can find a prop that will make you happy. There are times when you are limited to prop size like on a pusher where there is no room for more than a 6" and that is where the much lower number of turns comes in like in 12t 14t, just trying to make what fits go as fast as possible. 18t 21t very little difference. During flight their advantages and disadvantages will swap like the waveforms that control them.

I'd wait a bit and see I may be missing something If I am wrong someone will correct me and we'll all gain knowledge

2) if you stack them on a 5/16' tube they'll pretty much take care of themselves. If you like to hold the stators and wind without a handle either way would be fine.

3) very good question...I don't have an answer, but I admire the question. The closest I have to GBX has a segmented circle magnet in it so it weighs in a little heavy @ 40g, shaft cut off for a collet adapter. Incedently it turns a 9x6 and hauls a slowstick with a 1200 mHA Lipo for long enough to get tired of holding the Tx >30 mins 18t D.

4) You'll Need a drill press! If you have future needs buy one. If you want one buy one. Else you can probably find one you can use from a neighbor, garage, the rental centers all have one in the back and if you ask parts in hand, I'd be surprised if they'd take any of your money. Every body loves to get involved with something legal they have never heard of.

[Jay C]

I have read the GBx tutorial and now I have a couple of questions:
1) If I use 2 stators, I can use fewer turns of wire (go from 21 to 18 turns) and still gain approx. the same power. Will I gain higher rpm due to fewer turns? What else will be differant?

When you increase your stator stack height you reduce your Kv (RPM/V) but increase your Kt (torque/A). Same thing happens when your increase the number of turns in a winding. I can't predict how your motor will react when you change your windings ... better to follow the design of the builder tester if you want to duplicate their results too.

2) It appears that I can epoxy the 2 stators together or just use temporary wire wraps to hold it until I get some wire wound. Correct?

I've never found it necessary to epoxy or glue the stators nor to remove the insulation nor to add in more plates to make it a true 10mm stack ... but the methods presented in the tutorial can accomodate all of those design alternates. Short answer ... correct :D

3) I don't see any weights listed on the gobrushless web site. Is there a way that I can calculate(estimate) the finished weight of my motor?

The double I made during the tutorial (a 16T 26AWG double (with insulation) and 12 4x10x2mm magnets is 39g. The triple (same specs but matching mags) weighs 50g. I weighed my 16T GBx single and it's 24g.

4) I don't have any sort of press or vice. Will I need one to put the parts together? (If so, then this will give me a good reason to convince my wife that I need to make a trip to Harbor Freight).

thanks,
tim
I use the vice to put the stators on the CF tube. It's a tight fit and it's so much easier to do it with a vice. You can use a large C-clamp and some wood shims in a pinch ... but you can use this as a good excuse to get a bench vice ;)

Jay

[Jay C]

I have read the GBx tutorial and now I have a couple of questions:
1) If I use 2 stators, I can use fewer turns of wire (go from 21 to 18

chop



4) You'll Need a drill press! If you have future needs buy one. If you want one buy one. Else you can probably find one you can use from a neighbor, garage, the rental centers all have one in the back and if you ask parts in hand, I'd be surprised if they'd take any of your money. Every body loves to get involved with something legal they have never heard of.
You won't/don't need a drill press with the GBx parts. Don't try to push the shaft in, pull it in like I show in the tutorial. The only need for the vice is to push the stators on the the GBx bearing tube.

[swatson144]

You won't/don't need a drill press with the GBx parts. Don't try to push the shaft in, pull it in like I show in the tutorial. The only need for the vice is to push the stators on the the GBx bearing tube.

Oops I am corrected. I remember seeing it now, and thinking that makes a whole lot more sense than pressing. I've been reaming the hole and using plain shafts. Thanks