Cutting a motor commutator & motor tweaks

[JohnRobHolmes]

I like a little lively conversation, keeps things interesting.


Just got confirmation that the stock Fantom lathe motor is indeed a 27t. The Kv discrepancies over what I list on my site are likely due to the thinner arm webbing, degrees of timing advance, and weaker magnets as compared to my standard TorqueMaster Pro build.

 

[marvinbeaverdip]

You guys dont know squawt Ive got a 70t handwound in my lathe i bought and i run it on 6-7v and its awesome!.... lol

not really, thread was getting a little tense i thought id throw in a funny.

no $hit.. I'm almost regretting asking my question, I didn't know a catfight would ensue.
I'm not sure how that started, but I got the same message from both Eddie and John; slow is good, but there can be too slow. Since I'd really like to use the power supply, (or a motor break in charger, although I don't have one), I think I'm stuck finding the right motor and doing the calculations to make sure my face speed is adequate.. Who knows, maybe this mystery lathe I'm getting will be be a complete package with all the correct setup.

as for the epoxy balancing, i wonder how well (for crawler motors only) JB weld would work? It's cheap, and not permanant, whereas drilling is cheap but in the wrong hands (probably mine) could do a lot of damage to an arm.

 

[EddieO]

Normal JB weld won't really work.....this stuff is like silly putty. You gotta be able to put some on, spin it....and then either remove or add it to get balance....

You could always just send your arms to me to get balanced.....

And as for your powering issue.....there are other options, you are just not thinking outside the box....

http://www.skycraftsurplus.com/pulsewidthmodulatorkit.aspx

You can find them cheaper, that was just a quick google search. My 12 year old soldered one together after a couple soldering lessons from dad.

Hook it inline with your power supply......and yer good to go. Just a scaled down basic version of a motor checker.

You gotta have boobs to be in a catfight....I don't have boobs, I don't think John does either.....

Later EddieO

 

[JohnRobHolmes]

I weigh 150 wet, no boobs here yet. :lol: I think we both enjoy a good discussion.

I use a TorqueMaster ESC hooked to a 12v power supply or charger with motor break in function to control my lathe speed at the shop. There are certainly plenty of options though, as Eddie pointed out. Anything that can be used to dial in the speed is a good thing. I always double check the rotating speed of a new setup before I make the first cut.

 

[marvinbeaverdip]

Normal JB weld won't really work.....this stuff is like silly putty. You gotta be able to put some on, spin it....and then either remove or add it to get balance....

You could always just send your arms to me to get balanced.....

Later EddieO

Good to know that neither one of you have boobs. There's a plethora of manboobs at our track, and that's not a good look.

I found a two part epoxy a few years ago that comes as two sticks of putty. This seems like a good option, since I could just slice off pieces to get the weight right, mix, adhere, then balance. Adding more if necessary.

Sending my handwould arm to you or john to balance would be kinda like putting a cam in a briggs & stratton and then sending it to Ferrari for tuning. And as for thinking outside the box on a power source, I've got the flux capacitor finished, but simply cant get mr. fusion to fire up.
Actually, my mechanical speed control that came with it is sounding better and better. I think I have an old prop rpm gauge, I can do the basic math and figure out what the drive motor should spin at and take a reading with that I think.

btw, there's a "Kose micro lathe" up on rctech right now.. looks pretty cheesy, but who knows.. maybe it's not that bad. He doesn't list a price, but considering he wants 1/8 wheels as trade it can't be much.
There's also an "Eagle Mod Fashion" for $50 w/ diamond and carbide bits.
Also a Hudy for $40

 

[EddieO]

Uh, buy the hudy.....

That kose looks like a older cobra with a sticker on it. The newer kose lathes were the same as the much more units, as they actually made them for much more....that thing looks pretty worn.

The putty may work that you have, but most epoxy has some form of shrinkage....so that will effect your balance...I could probably just sell you some of mine.....



Later EddieO

 

[Thurzday]

Well I found what I thought was my old Cobra lathe the other day, come to find out it was just a box full of broken Traxxas parts. guess I need to find a new to me lathe. On a good note, Last night I completed winding two arms one 40turn the other 45turn, both in 4 mag cans with p94 brushes. I ran the 45t in my scaler with the clutch tightened down and ran it up against my foot. The clutch slips, the 55t integy never did that:shock:. Why don't more people use the p94 brushes? Cause I'm having a helluva time finding those brushes now, none at any of my LHS.

 

[marvinbeaverdip]

Well I found what I thought was my old Cobra lathe the other day, come to find out it was just a box full of broken Traxxas parts. guess I need to find a new to me lathe. On a good note, Last night I completed winding two arms one 40turn the other 45turn, both in 4 mag cans with p94 brushes. I ran the 45t in my scaler with the clutch tightened down and ran it up against my foot. The clutch slips, the 55t integy never did that:shock:. Why don't more people use the p94 brushes? Cause I'm having a helluva time finding those brushes now, none at any of my LHS.

http://www.teamepiconline.com/shop/item_new.asp?item=4383EPNTXB
$18 for 10 pairs of P-94 brushes. I may buy some too, although my future motors will most likely be Checkpoint cans.. wish I could find a deal like this on checkpoint brushes.

 

[EddieO]

That's a great price for p94 brushes, I wonder what compound they are...some of the p94 compounds were not so good....

P94 brushes were never very popular but they do have some benefits...

Pm me, I can cut you a deal on cp brushes... Won't be that good but still pretty good

Later EddieO

 

[killswitch]

I've always loved the P94s in crawlers. Just rebuilt a motor with a new set of p-94 hoods for a comp tomorrow. "thumbsup"

 

[marvinbeaverdip]

Thanks Eddie, I may put an order in with you if my LHS comes up dry.

Speaking of lathes, I just picked up that hudy. After reading more about it, it sounded like a good deal, and much nicer than my cobra. So now with that in the mail along with my free lathe I have 3. ??!!??!
If anyone reading this thread needs a lathe, I'll probably be selling one of the three very soon.

 

[Thurzday]

I did a little searching this morning and came up with this:shock:
http://www.stormerhobbies.com/cgi-b...3=&pn=&mterm=&oterm=&uterm=&sthumb=on&smode=0 "thumbsup"

 

[JohnRobHolmes]

I almost forgot, I have some p94 brushes too

http://holmeshobbies.com/product.php?productid=327&cat=23&page=1

 

[EGRESSor]

That's a great price for p94 brushes,

http://www.greathobbies.com/productinfo/?prod_id=TRI13507
:ror:

 

[EddieO]

That's the octagon brush, not the p94.....was only ever used on one motor, the Shock....they actually made a p94 and standup version of the shock, which is what most of us ended up ordering in the end. The Octagon brush was not very popular, neither was the XXX compound.

Later EddieO

 

[marvinbeaverdip]

I did a little searching this morning and came up with this:shock:
http://www.stormerhobbies.com/cgi-b...3=&pn=&mterm=&oterm=&uterm=&sthumb=on&smode=0 "thumbsup"

Good link! thanks!

http://www.greathobbies.com/productinfo/?prod_id=TRI13507
:ror:

That's the octagon brush, not the p94.....was only ever used on one motor, the Shock....they actually made a p94 and standup version of the shock, which is what most of us ended up ordering in the end. The Octagon brush was not very popular, neither was the XXX compound.

Later EddieO

Our LHS has a couple of those in stock too, although I know he'll never sell them.. still has the $15.99 price tag on them too. He's got more of a traxxas crowd that frequents his store.

Not that I want those particular brushes, but for other things brushed related I've found that the LHS's will usually "deal" on those items, since no one is buying it anymore. My LHS owner admitted that he has boxes and boxes of old stock and orders that were never picked up. He'll wheel and deal on most any of it. I got him to go half on the checkpoint brushes I dug up, so $6 a set I think. I could only find one set though.

 

[Norris]

I picked up a low end lathe from Integy, I know it's not the best, but all I could get for the time.

I have cut 3 coms so far and I set it up as directed and not happy with the smoothness or should I say the roughness of the coms when finished.

Am I doing something wrong or is the results expected?

 

[JohnRobHolmes]

What speed/ voltage are you running it, and what bit? Are you getting clean cuts and rippled surfaces, or rough cuts that smear the copper around and push it into the segment gaps?

 

[Norris]

7.2 stick pack, bit that came with it a carbide hook. One cut was rippled and another rough.

 

[marvinbeaverdip]

well, I got my "mystery" lathe in the mail the other day. It came with an esc and a bag of old motors. Most of the motors are stock fantoms, so not worth much, but they'll do for comm cutting practice. The lathe itself is an Eagle "mod-fashion" lathe.. quite filthy, but after cleaning it up it's actually not bad. a quick comparison to the cobra lathe and I'd say it's better designed. It came with a carbide insert bit, although the insert looks like it's chipped.. Then the following day the Hudy arrived.. wow. That is a nice piece of kit. I'll take some pictures of all three for those that might be interested in seeing what's different about them. I haven't decided which one I'm going to part with, maybe none of them.