14 replies to this topic

[havlicek]

Soooo, it's pretty danged cold outside. I figure I need to be active to keep up the body heat and burn some calories, so I'm gonna wind up a batch of "H-20" arms.  

 

More to follow!  

 

-john

[Pablo]

Thanks for the inspiration, John. I'm also exercising daily here at The Wolcott Ranch, reaching for conclusions and flying off the handle. 

 

Seriously, I have to brag the arm I wound for John Clow's Cucaracha (to replace the stock arm he cooked at 14.5v trying to race the Havlicek arm in my modified Cuc) worked great.

 

Since my winder was out of service at the time, I chucked it up to a mini twist drill and wound it by hand. My hands were hurting and the winds were sloppy.

I baked it with over-the-counter Devcon. In my pre-test to see if it was even worthy of attempting a home balance, it ran real smooth. I thought, the stock arm on these things was unbalanced, John's Cuc has been kept close to stock, why not leave it unbalanced? Track test results, 12.5v, ran fine, plenty fast enough for a stock Cuc, and cool as a cucumber.

 

I have not yet used my drill press to balance an arm yet. But the day is coming... My winder is now back in service. No doubt Hershman is quivering in his shoes as we speak. 

[Bill from NH]

It's warmed up here to 17 F.

[Pablo]

Wind faster; John swears it will warm you up.    Or at least, use the mini oven to keep you warm in between armatures. 

[havlicek]

Yeah, I hear that, Pablo!  

 

Well, first I had to press the stacks and then powder-coat and space them, then install and time the comms. At these prices, this is basically charity work!  

 

-john

[havlicek]

Okey dokey then.  All wound up:

 

The one on the far left is a 22t/25 I had done and was holding up finishing until this batch is ready.  

 

Now I just have to weld, tie, epoxy, cut the comms, re-check, and then send out for balancing... GAK!

 

-john

[havlicek]

BTW, the 22t/25 is for a blogger. The others are just eBay arms. A few times I've just put arms on eBay as opposed to whole motors to see how that goes. I figure that for "general" appeal, somewhere around a G20 C-can arm and a 65t/30 FT16D arm would be good.

 

The really hot stuff is more likely a "niche" thing. I do some hot C-can motors and they don't seem to hang around too long on eBay, but the #27 "sort of G20" arm (which is a danged fast arm, too!) is such a great arm for both road and drag racing, it's hard to beat. For the old motors, a 65t/30 can be popped into a Mabuchi with no other real work and do well in most cars. It might not win a race in a stock set-up, but with other "upgrades" it just might with the right driver!  

 

So, for the few people left that actually build motors, doing just the arm seems like a thing.

 

-john

[SlotStox#53]

Some sweet-looking 20 arms there, John. 

Always good to have just the arms done as without 'em you can't finish a motor. Especially if you've got the set-up with all the right parts just missing a hopped up arm. 

The 65t/30 and the 55t/29 you do are perfect for some Rod & Custom recreations needing a period '66 wind.

[havlicek]

Hi Paul,

 

Thanks. Yep, the 65t/30 and 55t/29 are favorites of mine as well, and are plenty fast for a lot of those cars... the 55t/29 maybe a little too fast for some. I'll be doing a bunch of both after these ones to see how those go as well.  

 

Speaking of these ones, they're all ready to go out for balancing. The 20s come in at .145 ohms and the 22t/25 is right about .050 ohms!

 

 

-john

[Pablo]

No arm dye on mine, please.    The powdercoat residue doesn't bother me, though. 

[Bill from NH]

If you use yellow arm dye, it turns tan as the arm gets too hot. The other colors, as a polished stack, don't alert you to potential problems.

 

One of the misthoughts in the '70s was that a polished stack would introduce more eddy currents.

[Pablo]

Hershman told me lacquer thinner takes arm dye right off. It works!

 

I drove all the way to Atlanta to gain that intel!!

[Bill from NH]

I've used lighter fluid or fine sandpaper, but I've never driven to Atlanta.

[havlicek]

No arm dye on mine, please.    The powdercoat residue doesn't bother me, though. 

 

No problem, Pablo, and while lacquer thinner will remove arm dye (as will straight acetone), it won't budge the powdercoat. That stuff is tough as nails.

 

-john

[Isaac S.]

powder coating is a miracle