119 replies to this topic

[Ramcatlarry]

Is jewelers' silver solder a higher melting temp that 600deg F?

[Geary Carrier]

Extra easy jewelers silver solder melts around 1145F.

[Geary Carrier]

We need a better comm than the Mabuchi...

 

 

[havlicek]

That'll work. 

[Jaeger Team]

That'll work. 

...better if with 36D brushes as it was in the old days ?

[havlicek]

...better if with 36D brushes as it was in the old days ?

 

It will work either way Maurizio...just differently.  

[Geary Carrier]

...better if with 36D brushes as it was in the old days ?

 

36D brushes will be used Maurizio, with a few minor endbell mods tossed in the mix...

[Geary Carrier]

First blush, 22/27 five layer coil, just a tad extreme...

 

This is the smallest pattern coil with the most turns I could fit. Certainly not enough turns but I may leave it as is and wind another odd layer coil arm with backing turns.

 

[havlicek]

Looks good Geary!  There's nothing "wrong" with 22/27, it just isn't probably going to be all that useful for a slot car motor, in particular for this kind of project.  Getting a neat coil (such as yours) up to at least the "mid-30s" turns of #27awg is probably a good target to shoot for here.  Still, it's your canvas...so paint-away! 

*I forget if you mentioned it, but what magnets are you planning to use here?  The "dance" between the magnets' strength and the arm wind will for sure come into play here...as you no doubt already know.

*Is this motor destined for drag or "road course" use?  Run times and voltage will definitely be critical, even with *just* #27 wire, not that #27 wire is something to sneeze at in the least.

PS:  I see you figured out one of the old "tricks" for using the Kirkwood coms is to bend those gigantic "hooked tabs" down and back towards the shaft before soldering or brazing to ensure end bell clearance won't be a problem afterwards.    I like your style. 

[Geary Carrier]

Thanks John,

 

Going to use a set of long C can magnets shimmed to fit. I was thinking this arm could survive a few trips down the strip, maybe.

 

This is the first odd layer coil that I've tried, I just wound the first layer and then went back to the comm and started the second layer.

 

We will have to see if there is a chance of the HMP solder surviving...

 

I appreciate your excellent comments as always.

[Geary Carrier]

Resistance measures .061 ohms/pole.

 

Had to put an extra short tip on my 210W Weller gun  to pump enough heat into the joint. The HMP solder has a working temp of 250C with excellent creep resistance, is it is as good as silver braze, no way...

 

 

Weller supercharger...

 

[olescratch]

  Armature looks good. Resistance levels balanced pole to pole.  Did you clean the insulation from the wires before soldering?

[havlicek]

Looks great Geary.  .061 ohms is way down there for a #27 wind.  My #25 winds are usually in the .05+ range, and my #26 winds in the .08+ range, so you're right between them here.  I *think* it can survive for a while as a drag arm, but a lot will depend on the voltage.  With torque more related to the number of turns, it should be a high-revver, so it will "want" some numerically high gears.  Nifty!

[Geary Carrier]

  Armature looks good. Resistance levels balanced pole to pole.  Did you clean the insulation from the wires before soldering?

 

Thanks John,

 

No need to remove the insulation from this wire, just solder away.

 

 

 

Looks great Geary.  .061 ohms is way down there for a #27 wind.  My #25 winds are usually in the .05+ range, and my #26 winds in the .08+ range, so you're right between them here.  I *think* it can survive for a while as a drag arm, but a lot will depend on the voltage.  With torque more related to the number of turns, it should be a high-revver, so it will "want" some numerically high gears.  Nifty!

 

Thanks John,

 

I figure if this can survive for a bit...a reasonable version might be an interesting rewinding project.

[Champion 507]

My thought is that if you stripped the insulation and then crimped the lugs over the wires, it should last until something else fails such as the wire insulation or a part of the motor. Adding a little bit of solder, in my opinion, just makes the connection better. If later the comm spins all the solder off, you still have a good mechanical connection with the crimped lugs. Is that good or bad thinking?

[Champion 507]

Sure hope the old comm is up for the test. Rick Thigpen has had trouble with vintage open arms grenading their comms.

[Geary Carrier]

My thought is that if you stripped the insulation and then crimped the lugs over the wires, it should last until something else fails such as the wire insulation or a part of the motor. Adding a little bit of solder, in my opinion, just makes the connection better. If later the comm spins all the solder off, you still have a good mechanical connection with the crimped lugs. Is that good or bad thinking?

 

Hi Doug,

 

A crimped connection could help but if the solder is thrown you are in trouble.

 

This arm will be wrapped with Kevlar to help hold things together and dissipate some heat, if it works at all, we will see.

 

 

 

Sure hope the old comm is up for the test. Rick Thigpen has had trouble with vintage open arms grenading their comms.

 

I could have used a better comm but for this solder job it might fill the bill.

 

The solder should let go way before the comm has problems.

[Geary Carrier]

Tied and epoxied the arm.

 

Not going to fool with the 16D can and endbell as I really just want to see what the arm will do. I will put the arm in a C can for testing with no balance or comm cut and let 'er rip.

 

[havlicek]

Hi Geary,

     For a "blip spin", the no balance thing may be alright, but those Kirkwood coms can sometimes be pretty far from true so the result might be a little misleading in a bad way.  In other words, the armature could be significantly better than it seems by running it without truing the com.  The other way of saying that is, if it does seem OK, then it will surely be WAY better after balance and com cut. 

[Geary Carrier]

Thanks John,

 

I'll check the runout on the comm and if it's close I will give it a go with a light polish.

[Phil Smith]

Well if you were local I'd loan you my comm lathe. It only takes a couple of minutes and is well worth the effort.

[Phil Smith]

I would think that arm would be just fine for a drag motor. I don't imagine it will get very hot in the breif time it will be under power.

[Geary Carrier]

Well if you were local I'd loan you my comm lathe. It only takes a couple of minutes and is well worth the effort.

 

Hi Phil,

 

I actually have 2 comm lathes but they are for RC motors and I've never got around to modifying them for smaller shafts.

 

Thanks for the offer of the loaner...

 

 

I would think that arm would be just fine for a drag motor. I don't imagine it will get very hot in the breif time it will be under power.

 

That's what I'm thinking-hoping too.

[Phil Smith]

Geary, I'm really interested in how it runs on the strip. I doubt anyone has ever wound an arm like that. Who knows, the smaller guage wire, low wind count combo might be a good one for drag cars. 

[Champion 507]

Phil, I have wound similar arms for drags for almost 10 years now and been very successful.