Gobrushless 25mm?

[IloveFLIGHT!]

For the heck of it, in my last order I bought 10 of the 25mm insulated stators. They seem to be of the same quality as the 22.7 stuff. :) Has anyone done anything with these? I can't seem to find any info on these? I think it will make a nice motor. :D

[olmod]

Did you check their data base?

[MorrisM]

Did you get 12 tooth or 9? The last ones I bought had thin insulation. I found it difficult to wind without shorts to the stator. Steve has hinted there will be more insulation someday. Do your stators look well insulated?

Morris

[IloveFLIGHT!]

Did you check their data base?
I guess I did'nt! Now that I look I guess there are people trying them.

[IloveFLIGHT!]

Did you get 12 tooth or 9? The last ones I bought had thin insulation. I found it difficult to wind without shorts to the stator. Steve has hinted there will be more insulation someday. Do your stators look well insulated?

Morris
They are 9 pole and very well insulated! Any suggestions on building?

[BeavrdamElectric]

I'd suggest a Komodo can.

Good Luck!

[MorrisM]

I agree. As far as I know, the Komodo kit for 25mm stators is the only choice you have without doing some lathe work, or perhaps finding a CDRom can.

[mike3976]

Try getting your hands on a MicroDan 25mm bell, the motors are sold thru e-foamies.com, or do a search on Microdan. They make some sweet motors. As far as winding the gb 25mm stators, they are a little more difficult, the trick is not to wind too tight, as the cornors are sharp, even with insulation, but entirely do-able. I,ve got a couple of DIY Microdan kits, and love'em :)

[ScubaSteve]

To be honest the main reason we stock the 25mm stators is because there are several companies worldwide that have designed and marketed motors using them. As a result, I wouldn't expect a GBx 25mm motor anytime soon - it just doesn't make sense to try and jump into an already existing and well supplied market - especially when some of those companies are GB dealers. We avoid directly competing with our dealers as best we can for good reason. It's good business. ;)

What you CAN expect, though, is a GBx 12-pole motor in the near future... although 25mm is a bit too small for us. :)

[IloveFLIGHT!]

I did some measuring, and with a little cutting these stators will fit nicely in the bp-21 I am playing with right now. These laminations are superior to the thick stuff in it.

[Amos]

For the heck of it, in my last order I bought 10 of the 25mm insulated stators. They seem to be of the same quality as the 22.7 stuff. :) Has anyone done anything with these? I can't seem to find any info on these? I think it will make a nice motor. :D


Answers attached
A.

[Amos]

For the heck of it, in my last order I bought 10 of the 25mm insulated stators. They seem to be of the same quality as the 22.7 stuff. :) Has anyone done anything with these? I can't seem to find any info on these? I think it will make a nice motor. :D


Answers attached - back view

[Amos]

Did you get 12 tooth or 9? The last ones I bought had thin insulation. I found it difficult to wind without shorts to the stator. Steve has hinted there will be more insulation someday. Do your stators look well insulated?

Morris

Morris,
You are right. Compared to the komodo smaller stators the insulation is thin.
No problem on first windings. However before rewinding the insulation has to
be checked and nicks repaired. Found out the hard way :eek: Otherwise
the stator plates are easy to stack and align.
A.

[Eagleburger]

To be honest the main reason we stock the 25mm stators is because there are several companies worldwide that have designed and marketed motors using them. As a result, I wouldn't expect a GBx 25mm motor anytime soon - it just doesn't make sense to try and jump into an already existing and well supplied market - especially when some of those companies are GB dealers. We avoid directly competing with our dealers as best we can for good reason. It's good business. ;)

Websites?


What you CAN expect, though, is a GBx 12-pole motor in the near future... although 25mm is a bit too small for us. :)

How soon?:D :D

[olmod]

On the subject of stator insulating you may wish to check this tip out.
http://www.rcgroups.com/forums/showpost.php?p=4849810&postcount=9
cheers.

[olmod]

Did you ever post your 12 s/poles test run specs' ?

[mike3976]

To be honest the main reason we stock the 25mm stators is because there are several companies worldwide that have designed and marketed motors using them. As a result, I wouldn't expect a GBx 25mm motor anytime soon - it just doesn't make sense to try and jump into an already existing and well supplied market - especially when some of those companies are GB dealers. We avoid directly competing with our dealers as best we can for good reason. It's good business. ;)

What you CAN expect, though, is a GBx 12-pole motor in the near future... although 25mm is a bit too small for us. :)

Steve, who else beside Microdan is making 25mm bells? available in the U.S.

Olmod, its pretty easy to get 20+ oz. of thrust at 10 amps or less with ABC x 4 winding, with a two or three stator stack. I'm looking for bells to try some LRK winds.

Steve, again: How soon are you going to release the 30 mili's :D :D

[rhashime]

Komodo 278v1 bells will work with the 25mm stators. But you can only use 1mm thick mags. I used the gobrushless 25mm 12 tooth stators. Komodo 278v1 bell and 16 10x5x1 mags and a strongrc bearing tube. I wound 10 turns of double 26g newbie wire. With a 8x3.8 apc sf it pull 9 amps. I don't have a tach or thrust stand so I don't have any figures on that, but it pulls my 9oz 3d foamie around well.

[IloveFLIGHT!]

:confused: Pardon my lack of knowledge on this subject! But what is a "LRK" wind?

[ScubaSteve]

Eagleburger,

For starters, Microdan (see efoamies.com) and Yellowbrushless.de.

As for the larger motors, it's a big secret. ;)

[ScubaSteve]

Steve, again: How soon are you going to release the 30 mili's :D :D

30mm? Are you nuts? That's still not big enough. :eek: ;)

[PlaneCrazee]

What you CAN expect, though, is a GBx 12-pole motor in the near future... although 25mm is a bit too small for us. :)
Don't tease me like that!!
details, DETAILS!

[PlaneCrazee]

:confused: Pardon my lack of knowledge on this subject! But what is a "LRK" wind?
http://www.powerditto.de/Schemaengl.html

[Amos]

Did you ever post your 12 s/poles test run specs' ?

Olmod,
If you mean 12 poles stator - I don't have any.
I have 25 mm 9 slots stators only.
Following are stats from June 6, 2005 on 25mm stator & Komodo rotor:

Rotor: Komodo 27.8 mm ID, 10.25 mm deep. 12 5 x 10 x 1 mm magnets.
Stator: Gbl 5 plates 25 mm (8.65 mm) 19t 0.45 mm (9 slots)
Shaft: World A/C 3 mm threaded hard Al.
Bearing tube: Home made,+ 2 3x7mm BB.

GWS EP-0947 10.68V 4.1A 360 grams 8.2g/w
APC----9x4.7 10.50V 4.0A 352 grams 8.3g/w
GWS EP-0843 11.00V 2.7A 278 grams 9.3g/w

The same stator with home turned bell and 1.5 mm magnets (see photos):
APC --9x4.7 10.50V 4.7A 398 grams 9.4g/w
GWS 10x4.7 10.34V 5.5A 470 grams 6.2g/w

I do not have RPM readings for the above.
Happy landings,
A.

[mike3976]

30mm? Are you nuts? That's still not big enough. :eek: ;)

O.K. .....When are you guys going to break down and give it up, this tite liped approach can be a little frustrating, just a little. Am I nuts?, ahh, I,ve been called worse :)

[ScubaSteve]

sorry mike just teasing a bit:). you wont see me hyping a product until it's on the shelf though.

and yes, you probably are nuts. ;)

[rafgol]

Those 25 mm 12 pole insulated stators fit great in the komodo cans, but I never could wind a 3 stack stator without shorts. I gave up after xxx times trying. I have tried every single solution found here on rcgroups. The only way of making them fly is giving a good toss out of the window :D .

Microdan must be a great combination, I am sure. But even the method of loose windings gave me shorts. :mad:

Too bad. :cool:

[ScubaSteve]

raf, u tried using the newbie wire?

[rhashime]

Hey Steve,

I tried to check out yellowbrushless.de, but that doesn't seem to be the site. I did a search of the forum and a search on google to no avail. Is there any more info you could give me on this company. Thanks!

[rafgol]

raf, u tried using the newbie wire?


Sir, Yes Sir, I've tried all kinds of wire from my drawer. 0.3 mm, 0.4 mm, 0.6 mm and 0.8 mm. No matter wich one, nothing really helps for those pretty stators. They could become nice LRK motors...

(and yes, I have made 20 + other working brushless combinations, even a 15 teeth 10 magnet pole ex-videodrive motor :) )

So, I gave up trying to wind those 25 mm stators some weeks ago. Gonna try the plastic-bag-way when I have some spare time. (time, hmmm... so precious... :rolleyes: )

[rafgol]

Hey Steve,

I tried to check out yellowbrushless.de, but that doesn't seem to be the site. I did a search of the forum and a search on google to no avail. Is there any more info you could give me on this company. Thanks!

If you can handle some German, otherwise, use babelfish.

http://www.yellow-bl.de/fs/brushlessmotoren.html

[mike3976]

Raff, try carefully placing some medium ca on the stator face edges,try to just place it one the edge, and dont be excessive with the ca, you want like a 1/64" bead. Wait a few seconds for it to begin to flow out, then hit it with kicker. The second Microdan that I built, I got it right the first try with this method, no shorts :)

[mike3976]

Shaft: World A/C 3 mm threaded hard Al.

The above is from Amos, post #24.....This is something I've been thinking about, using a harden'ed aluminum shaft, would lighten things up a little.

ScubaSteve, you guys ever give this any thought?

[yakman]

Eagleburger,

For starters, Microdan (see efoamies.com) and Yellowbrushless.de.

efoamies has no kits, YB well...

As for the larger motors, it's a big secret. ;)

I dont mind waiting for you to get your parts right. I had to throw the last lot of shafts, flux rings and endbells in the bin. Great waste of ~$30 that was :(

[Amos]

Just wonder:
Assuming that less copper can go into 12 slot than into 9 slot same diameter stators -
What are the RPM and thrust or efficiency advantage of a 12 slots compared to 9 slots stators using the same bell and having the same stator thickness? :confused:
A.

[ScubaSteve]

I dont mind waiting for you to get your parts right. I had to throw the last lot of shafts, flux rings and endbells in the bin. Great waste of ~$30 that was :(

yakman, what was the problem?

[Micro Dan]

yea thats the way to do it, works every time.
i paint the CA on with a little brush, works great and its faster when you have about 50 motors to build.
Dan

Raff, try carefully placing some medium ca on the stator face edges,try to just place it one the edge, and dont be excessive with the ca, you want like a 1/64" bead. Wait a few seconds for it to begin to flow out, then hit it with kicker. The second Microdan that I built, I got it right the first try with this method, no shorts :)

[ScubaSteve]

Shaft: World A/C 3 mm threaded hard Al.

The above is from Amos, post #24.....This is something I've been thinking about, using a harden'ed aluminum shaft, would lighten things up a little.

ScubaSteve, you guys ever give this any thought?

Mike,

always been kinda hesitant to use anything other than steel for the shaft, although i've seen some ballsy folks here on rcgroups and the GB forum using even carbon fiber for a shaft... :cool:

perhaps for 20mm or smaller stuff you could get away with it, but honestly with the thrust folks are getting from the GBx line of motors, I'd rather incur the ~5g weight penalty of using a steel shaft vs. an alum one just for the safety "warm-fuzzy". :)

[ScubaSteve]

speak of the devil. :) dan, can you throw some contact info in here for those guys who wanna check out the microDans? ;)

[Micro Dan]

no problem Steve
check out the MicroDAN motors at e-foamies.com.
Tim does the distributing.
BTW i have several motors running a CF shaft, saves about 3G but the 3mm CF rods are in no way very accurately manufactured as far as the OD so what i did was coat the shaft with CA and carefully sand it to fit a bearing.
one day i plan to centerless grind some 1/8" rod down to 3mm.
Dan

[IloveFLIGHT!]

http://www.powerditto.de/Schemaengl.html
Thanks for the link. Now I have a hundred or so other questions!!! LOL :) :confused: Are there power advantages to this style of winding? Can you just cut of the unused poles? Interesting stuff!! :)

[yakman]

yakman, what was the problem?

Bent the endbells trying to put the shafts in. On the second one the shaft also broke and I greased that one. The third one, I ground the shaft down some but still could not get it to go in all the way. So now it is loose in the bearings, so I have not tried it.

These were all done in a vice with a 5mm socket on the receiving end, the same way I have done eight cdroms.

Yeh, I missed the offer to have them replaced.

I have since gotten two single GBX setups from strongmotors , the ones with the set screw in the endbell. Both these work exceptionally well. With a 6mm stack they pull 6400rpm on a 9x5HD prop or about 380grams of thrust for 51watts on 3S. Not too shabby. I am winding another stator for a 8x4HD, to see if I can get some quicker acceleration.



I look forward to getting some of your future stuff if it meets my needs. I just dont want to be a beta tester this time. My poultry student wage cant afford it.

[ScubaSteve]

yakman,

i agree the endbell/shaft pressfit is snug to say the least. it's how we like it. ;)

of course, that's also why we offer prepressed assemblies (included in every GBx kit) at no add'l charge.... uhhh that sounded like a commercial. forgive me:)

[flarssen]

For the heck of it, in my last order I bought 10 of the 25mm insulated stators. They seem to be of the same quality as the 22.7 stuff. :) Has anyone done anything with these? I can't seem to find any info on these? I think it will make a nice motor. :D
I put a stack of five in a KH283. It works great. Also shows how to avoid shorts...
25mm KH283 (http://www.rcgroups.com/forums/showpost.php?p=4498470&postcount=450)


Fred

[yakman]

yakman,

i agree the endbell/shaft pressfit is snug to say the least. it's how we like it. ;)

of course, that's also why we offer prepressed assemblies (included in every GBx kit) at no add'l charge.... uhhh that sounded like a commercial. forgive me:)

I forgive you for sounding like a comercial, but I cant forgive you for being smug in your replies. Not after I gave you ~$30 and have yet nothing to show for it.
I will take up your offer for some prepressed assemblies to replace the unusable ones you sold me.

[ScubaSteve]

How was I smug? I actually confirmed your implication that the press fit was indeed tight. Before we offered the assemblies (when you purchased your kit) we were recommending the use of a drill press or arbor press to seat the shafts correctly. Using a vice you cannot really control the angle at which the shaft is being pressed, thus the problems you had.

Also, why did you grind down the entire length of the shaft just to ease the press fit? Or at least I'm assuming that's what you did, since that's the only way I can see it being loose in the bearings now.

Check your PMs...

[fanfoldfan]

don't let them get to you ... your warning about pressing your own shafts has always been right out front. I prefer un-threaded shafts myself, so I do my own pressing. A decent arbor press, alot of patients, and using the shortest 3mm shaft you can (less to bend) and proper support ... did crumple a flux ring once, but that's another story. :rolleyes:

[Eagleburger]

don't let them get to you ... your warning about pressing your own shafts has always been right out front. I prefer un-threaded shafts myself, so I do my own pressing. A decent arbor press, alot of patients, and using the shortest 3mm shaft you can (less to bend) and proper support ... did crumple a flux ring once, but that's another story. :rolleyes:


I also bought some stuff before the warning was placed on the site. I broke a shaft but have got the equipment to fix the problem. The shafts were way to tight, I would have done things differently. ;)

[fly_boy99]

Steve-

I think you had a great idea by selling the endbells and shafts already pressed. I've always done my own and have no problem doing so but I can see where you would have lots of problems with returns.

ymmv,
fb

[Amos]

Flarsssen,
Beautiful wind. I like the film insulation idea since most shorts that I had were between the wire and the "hammer head". Chapeau!

Any reason you preferred 12 stator poles to 9 stator pols for the Komodo rotor?
Where did you get the 1.2 mm magnets? Did they leave enough clearance for the rotor?
Thanks,
A.

[BeavrdamElectric]

The problem I've had with my GB triple has been runout of the endbell. I haven't tried seriously to address it but I measured .003" runout in the face of the endbell. That translates to .006"+ radially at the end of the flux ring. Put the magnets in there and they're whacking the stator.

Luckily it wasn't enough to cause a problem on the single I got, and after working with the set screw version I got from Don a bit I got it true enough for a double.

But I am about ready to buy my own lathe.

Good Luck!

[flarssen]

Flarsssen,
Beautiful wind. I like the film insulation idea since most shorts that I had were between the wire and the "hammer head". Chapeau!

Any reason you preferred 12 stator poles to 9 stator pols for the Komodo rotor?
Where did you get the 1.2 mm magnets? Did they leave enough clearance for the rotor?
Thanks,
A.
Yes, the film protects the wire from all parts of the stator.

I used the 12 arm stator after having little success with the Komodo 9 arm stator. I discovered later that the lack of success could be caused be the way I winded it (10 magnet pole version). Anyway, the 12 arm stator has much thinner laminations, and should give better efficiency.

I got the magnets from Supermagnete (http://www.supermagnete.de/). The airgap was 0,225mm.

Fred

[Amos]

Yes, the film protects the wire from all parts of the stator.

I used the 12 arm stator after having little success with the Komodo 9 arm stator. I discovered later that the lack of success could be caused be the way I winded it (10 magnet pole version). Anyway, the 12 arm stator has much thinner laminations, and should give better efficiency.

I got the magnets from Supermagnete (http://www.supermagnete.de/). The airgap was 0,225mm.

Fred

Thanks Fred,
I had no problem with the 25mm 9 pole stator and 12 mags in the Komodo
stator. I used it since it is lighter (and nicer) than my own turned bells
and flux ring. Pity that the mags were on the thin side. I'll try and replace
them by 1.2 mm mags.
Thanks again,
A.

[mike3976]

Check out this link in the power systems forum http://www.rcgroups.com/forums/showthread.php?t=471782
I call it an easy to acheive 25mm motor