3573 replies to this topic

[havlicek]

I did what should be the last motor for me to choose from for the Balls-Out Choti Proxy. For this one, I did a #28 doublewind (Bugenis stack and com) that went into a Mabuchi can, with a Mura endbell and some nice stout Parma magnets epoxied-in (I call this unholy offspring a Mamurma...or a Parmubuchi...or a Parbumu...or...Parmurma or...). Both the can and the endbell got bearings, a little dicey with the endbell but it seemed to work out fine. Anyway, I had them so i figured "why not?". I also drilled the can for mounting. I did this because I see people talking about raging hot motors for this thing and, well...because I could. Anyway, the motor howls like a dog that's been hit by a car and draws a little over 3 amps with no break-in and surprisingly doesn't seem to get too hot. It even seems to have decent braking for a doublewind. I just don't know about running something like this, but I'm tempted.




-john

[Pablo]

MuraBuchi

[havlicek]

...hey, you forgot the Parma magnets there Pablo! Could be Murmabuchi

-john

[Pablo]

Parabuchi.

That is a nice sick shade of green there, I'll say that

[Coal Train]

I like it thats funny , So John a good bath in Acitone gets all the glue off the powder coating this is right yes ?
Also does anyone have any .445 blanks for sale ?
And John have you ever tryed a double wind like 7 tuns of 23gauge on all 3 stacks then another 7 turns of 23 gauge ?
Or does anyone know of anyone who has tryed. If it wont work please let me know why not so I can dismiss this feeling
of trying and wasting my time .
Thanks.

[havlicek]

Hi Robert,

Acetone won't touch cured epoxy, it might soften some powder coatings enough to use a wire brush to get the rest of it off. The kind of doublewind you're talking about is cometimes called a "layered" or a "serial" doublewind. I've done doubles and triples both ways (using two or three pieces of wire at the same time, or layering the coils) and from what I've seen...doing both conductors at the same time works better. You can mix gauges if you like, but there's not much reason to do that. A double #23 should be roughly equivalent to a #20 single. Besides being difficult to terminate neatly at the com tabs, the arm would be extremely hot...basically a dead-short. To give you an idea of what you might be dealing with, the #28 double pictured above measures exactly .095 ohms per pole.

-john

[Alchemist]

That's a great color to go with a great motor John!!!

Ernie

[havlicek]

Thanks Ernie

-john

[havlicek]

For a Blogger:

-16D Can, drilled for can mounting
-Upgraded magnets (one piece ceramic) epoxied-in
-New can bushing
-Tradeship endbell, spring posts sleeved with chromed brass (antenna tubing)
-Brush tubes ("heat-sinks") soldered to hoods
-Bugenis arm blank and com, drill blank shaft
-38T/#27 wire, approximately 25 degrees advance

I was able to do a white paint job that seems like it will hold up well (white had been a PITA before for me), the motors runs like the dickens, so I figured the "Czech" label was appropriate



-john

[Marty N]

Very nice John.

[The Bugman]

Dayyyyyyyyyyyyyyyuuummmmm,thats purdy,,,,

[havlicek]

Thanks guys...and please note that this particular motor is legal for the "Balls Out" Proxy

-john

[boxerdog]

Another gem, John. Great work as usual!

[The Bugman]

and ya know,,, a motor like that,might just "be the ticket" for the Balls Out race,,,,,
when ALL those HOT WINDS go up in smoke in 2 races(or less ),,,,,

[Mark Johnson]

Is that still a small brush motor John , or was it upgraded to 36d style ?
Mark

[havlicek]

Hi Mark,

I left the small (FT16D) sized brushes and tubes on this one.

-john

[havlicek]

Here's one for you (whoever you are out there). You know those short stack arms in the Falcons and similar type motors...the ones with the really wide crown and small gap between poles? Well, you take that arm out and remove the magnet wire, throw away the com, press on a new shaft and install a decent com. You now have a really nice arm blank for rewinding. It's a little bit more of a bother because of those tight gaps, but nothing major and they run really well and balance right up (assuming a good shaft). They also have a solid coating on them so shorts aren't an issue as long as you don't maul them too much removing the wire.

I've done this several times now and they always seem to run really well, so if you're looking for a short stack, try one out. Oh yeah, you could also make up longer stacks with a bit more effort and a decent press to squish them together on the new shaft.

-john

[Bill from NH]

John, this is a great idea. Most slot racers have access to a handful of these motors & arms. A few questions, if I may ask. Did you use drill blank shafts on these arms or something else? Are you using .078" piano wire shafts on anything these days? What gage(s) of wire did you wind on these short stack arms? Were they relatively mild winds? How do these arms compare to those in the SCX(?) motors you used to build?

[havlicek]

John, this is a great idea. Most slot racers have access to a handful of these motors & arms. A few questions, if I may ask. Did you use drill blank shafts on these arms or something else? Are you using .078" piano wire shafts on anything these days? What gage(s) of wire did you wind on these short stack arms? Were they relatively mild winds? How do these arms compare to those in the SCX(?) motors you used to build?

Hi Bill,

I'm always looking for sources for parts, so the Falcon-type stuff is a natural. Like you say, there's a boatload of these around because of their disposable nature. The late great Frank Elavsky gave me a bag of these things as have others. The cans (when cut up), make for some neat "Walnut" ^TM type motors, the magnets are pretty cool too for some things. The stacks are also good and have a very hard (albeit a little thick) coating on them too. Problem is the shafts are very short and some aren't real straight (although some are).

Are you using .078" piano wire shafts on anything these days?

I only do that for really oddball things as the gauge/thickness of .078" wire is a little off. I did a motor a couple of months ago with a really long shaft for a 4WD car (both axles driven/one motor) using .078" wire. I had some drill-rod I got a long time ago in 3' length and after checking things out, the piano wire was actually straighter than the drill rod even though the drill rod was a better fit by a thousandth or so. A man's gotta do what a man's gotta do

What gage(s) of wire did you wind on these short stack arms?

The most recent was a group of three PS "euro" setups. I cleaned-up and stripped the three stock arms which was a PITA because the stock wire is very thin and has some sort of lacquer coating, so the wire had to be cut off the stacks. Of the three, one stack couldn't be rebalanced because the arm had been drilled with some BIG holes. One stack's coating was damaged and I didn't want to try repairing it and one worked fine. Of the two that needed new stacks, one got a Falcon stack and the stock length was about perfect for the setup. All three got #31 wire, since the person only wanted a nice bump up from stock...no fire-breathers

Were they relatively mild winds?

Yep, I did 80T/#31 wire and on these short stacks that works out to a little above .8 Ω with some variations because of differences of the thickness of the winding leg of each. Re-using the stock coms on these makes for an easy rebuild and the motors run much better than stock, but still mild.

How do these arms compare to those in the SCX(?) motors you used to build?

The lams used for the SCX motors are a much more conventional looking design, but they use nylon end caps as anti-short devices. Also there was at least one SCX that had a really bizarre lam material that was somewhere between .007" and .014" thick that I haven't seen before or since. The Falcon type motors use a heavy anti-short coating on the stacks that appears to be Hysol or something like it, and has been well heated/fused to form a very hard/shiny coating. When these motors burn up, it's almost certainly not because of shorts against the stack! The thing that's different about the Falcon stacks is that the lams have a very wide crown and a narrow gap, so winding them means you have to work a little harder. Because of the wide crown though, these arms naturally have very little "cog" to them when you turn them by hand in the setup. If you put a "regular" arm in the setup and turn it by hand, you'll feel a definite/pronounced "cog" at each pole. Put a Falcon arm in the same setup and it almost feels like the magnets are dead because there's almost no "cog" effect at all. The racers and motor guys can say better how this type lam translates in terms of track performance, but the Falcon type motors seem to run fine in their stock form. It would be interesting to do up some hot winds with these lams to see how they work in a more critical application...more fun for the rewinders

Anyway, these motors can be salvaged for some neat projects. There's LOTS of them getting tossed, so they shouldn't be hard to come up with. A little elbow grease and "et voilà!"

-john

[Bill from NH]

Thanks John! Lots of good information there. I would say you answered all my questions. The only thing I might possibly add would be a turned down Mura or Ploslot endbell on a Falcon 7 can to put the arms in.

[brucefl]

I was actually hoping you had some of that secret good stuff! lol

I'm still hoping to find something that will hold up to 800 degrees or more, but i just havent been able to find anything of the sort.

If you find something, definetlly let me know, I'd love to get my hands on some!

dupont that makes the highest temp epoxy told me that since epoxy is organic there is a temp limitation and that limit seems to be around 600f(jim greenaway used this single component which looks to be the same as the cotronics product,since the highest temp coated magnet wire is mws ml coated 240 C temp wire since the epoxy exceeds this temp its better than you will need since the wire coating will fail before the epoxy.There is a ceramic 1200 F temp coated but costs about $500.per pound not worth it,dont believe koford when he says he uses 800 f epoxy it doesnt exist,the dupont research scientists told me recently and explained that the limitation of epoxy polymers is around that 600 F unless you add other materials to it which renders it unfit to flow into the fine spaces of the windings.

[havlicek]

Any epoxy good to even a little over say 400F should be fine for about anything anyway.  Magnet wire insulation (also being an organic compound) is only good to that range or less and then things like end bells and magnets would have failed anyway.  Heck, if the can on a motor ever got to 400F, the body would probably melt around the motor just from being close to it.  There's also sometimes a problem properly mixing epoxy in the very small quantities necessary for encapsulating the coils on a single armature.  I've had arms "foam" when I hadn't been as careful as I should have been (over-catalyzed), and I've had arms fail to fully cure (under-catalyzed) too.  There are single part (and also two-part) epoxies that are better suited to motor coil encapsulating from a "bomb-proof" standpoint than the stuff I use, but they have cure-schedules that make them difficult in a home environment.  Really, even on the top open type motors, bomb-proofing is just as much about very accurate balancing and stuff like com-capping and the accuracy/precision of the motor setup as it is the epoxy.  Over-the-top claims about epoxy temperature ratings are probably just good ad-copy.

 

-john

[brucefl]

Hey John I just received the arms real sano work and that skewed arm is wild looking i cant even imagine how you could even wind it,and eventhough the double 26 is so difficult to wind because theres not enough room for the amount of wire, you ve made it look like its not overloaded,thanks again,your a cool dude in a loose mood(to quote out dated jargon), Who do you recommend for balancing.Hey i miss the island my sister lives in port jeff and i miss the blue fishing on the sound and stripers at the montauk lighthouse.

[havlicek]

Hi Bruce,

 

     Glad they got there safely.  There are lots of places to get the balancing done, and of course ProSlot does this (among many other motor services).  Bill Bugenis does balancing and he can be contacted by PM here.  Proformance (PRI) also does balancing and other motor services.  Many use Alpha as well for balancing and various motor services.  Fast Ones (Ron Hershman), Koford and others offer various services as well.  Often these kinds of services can be ordered through your local raceway as well...so there's a possible way to go besides direct.

 

-john

[JoB]

The only thing I might possibly add would be a turned down Mura or Ploslot endbell on a Falcon 7 can to put the arms in.

 

I have a shortened Falcon and a new arm from another F7 that thew arm was bad in. The arm is in pristine condition and the insulation looks very nice!

 

I have also a PS -4002 endbell that basically is a press on fit on the F7 can without any cutting in it, but I have seen in some posts here that very often a cut down mura C-can endbell is recommended? Isn't the PS endbell good enough? Is surely is less work with that one!

 

Regards,