3573 replies to this topic

[havlicek]

Hi Martin,

5 turns short for a 16D though

oh well...I was close I also removed the stack insulators, radiused the stack ends a bit and used a new insulation coating as an experiment, so the stack is a little shorter, so the arm is probably 6 or 7 turns (by wire length) short then. So it will run a bit faster than a stock Parma (I suppose) as a result of the spring substitution and the wind.

-john

[Pablo]

A little more radical than stock will be fine, it is going to be a can drive powerplant for a late 60's Buzco right-hand-drive chassis

Thanks John, you are the Master !!!

[havlicek]

You're very welcome Pablo

-john

[Bill from NH]

16D arms are 60 turns of 30 ga. wire.

[havlicek]

Hi Bill,

OK then...with the slightly shorter stack, I'm pretty much "there"...I guess...until the next guy comes and tells me something different yet again

-john

[Allen00]

Hi John, Here's a chart that I found somewhere a few years ago. I think these are the correct winds and wire size for modern Parma and Pro slot motors.

[havlicek]

Hi Allen...thanks

-john

[Bill from NH]

John, I was wrong on the 16D, it is 70T. But the turns shown in the above chart for Contender & Outlaw S16D are incorrect or not current. Also, the min. length of a S16d arm is not .600" as shown. Zippity's Wellington Slotcar page has this data in updated form for Falcons through open arms.

[Allen00]

I've had that chart for at least 6 years. It's not up to date.

[Marty N]

John, I was wrong on the 16D, it is 70T. But the turns shown in the above chart for Contender & Outlaw S16D are incorrect or not current. Also, the min. length of a S16d arm is not .600" as shown. Zippity's Wellington Slotcar page has this data in updated form for Falcons through open arms.

Bill, you have a link to Zippity's page?

[Bill from NH]

This is the link for Zippity's arm wind spec. chart.

http://www.zippitynz...matureSpecs.htm

If you click on the back arrow at the top of the chart, You'll go to the main page.

[havlicek]

OK then...well, I'm still "in the ballpark" no matter what anyone says!

-john

[Marty N]

Could add to the list JK Hawk, 65/30-25*

[Prof. Fate]

Hi

Curiously, all the contender/wasps that I have seen work out to 65/30, not 60 or 55 as some charts show.

Easy to check with a decent ohm meter without disassembly.

Fate

[havlicek]

Double winds deserve another look. There's more going on here than just an equivalency with a single three sizes larger. I did an experiment with a #28 dbl using a cheap analog for a modern motor ("Walnut") and the result is impressive. They still work well with old motors (especially some 36Ds with Arcos), but I think they may be appropriate for modern open motors where the setups and the magnets are no longer a limiting factor. I did do a triple #30 wind a way back on a long stack for a two hole Mura and that was ridiculous (not to mention a bother to keep neat), but I think doubles may be overlooked today. Maybe they're not worth the trouble to wind...but sometimes I think there's still good stuff to be learned from looking backwards.




-john

[John Secchi]

Many moons ago i used to mess with RC armatures and there was a period when i did multiple winds, managed several with up to 12 or more wires!
Was almost impossible to wind all 12 by hand in one hit but i did manage to wind bunches of 4 at a time starting from a different com tabs, a typical mild wind at that time would have been 17t of 36/35/34 swg [standard wire gauge] in total of 12 wires. Worked quite well but had limited life due to the low temp wire i was using.
[oneofwos]

[havlicek]

Hi John,

12 wires is pretty incredible and resistance must have been way way way down there. I'm going to keep messing around with doubles until I'm sure there's no benefit with them, because right now I suspect there is.

-john

[Victor Poulin]

Double winds deserve another look. There's more going on here than just an equivalency with a single three sizes larger. I did an experiment with a #28 dbl using a cheap analog for a modern motor ("Walnut") and the result is impressive. They still work well with old motors (especially some 36Ds with Arcos), but I think they may be appropriate for modern open motors where the setups and the magnets are no longer a limiting factor. I did do a triple #30 wind a way back on a long stack for a two hole Mura and that was ridiculous (not to mention a bother to keep neat), but I think doubles may be overlooked today. Maybe they're not worth the trouble to wind...but sometimes I think there's still good stuff to be learned from looking backwards.




-john

Wow I'm impressed John !! I also couldn't help but notice that you used the good ol Mura endbell hardware
Hows it sound??

[havlicek]

Hi Vic,

Hows it sound??

It freakin' screams at 6V...I'm afraid to wind it at higher voltage and want to do a better one and ask Bill Bugenis to balance it. It spins way too fast to not give it every chance to live.

-john

[Marty N]

FYI: Not only does it act as a wire three gauges smaller, the effective length of the wire is cut by half. End result, resistance is 1/4 of the base wind. RPM of the is higher as two wires in paralle act like a single wire of twice the diameter. 60/28 done as a doulbe 30/28/2, in example, will turn almost as quick as a 30/25 and with the same net power. Not many blanks will actually take a 30/25 but nearly all will handle the double. Especially if done as a layered wind instead of "two in hand". Packs tighter. The triple has 1/6th the resistance and a quad 1/8th.

[havlicek]

Hi Marty,

Sure thing...I get the resistance, but the thing about doubles is they seem to produce a "softer" torque curve which is desirable in some cases. 30T of #28D would be a tough wind on the thick web blanks...really tough. 30T of #25 single would be REALLY tough. Layered doubles are much easier to do, especially when putting a lot of wire on there, but getting the two conductors the same length is a crap shoot. Winding both conductors at the same time seems a better choice, even if it's more difficult.

-john

[Marty N]

Doesn't seem to make much difference that the two a slightly different lengths.

[NSwanberg]

In my next life I want to try doing a double wind 28 flat wire. Haven't we already hashed over surface conductance long ago in a post far far away?

[havlicek]

In my next life I want to try doing a double wind 28 flat wire. Haven't we already hashed over surface conductance long ago in a post far far away?

I wouldn't mind do any wind with #28 equivalent flat wire. I never was able to find any flat wire except in much larger sizes, but if by "surface conductance" you mean "skin effect"...I'm sure we did go over that somewhere back in the last few thousand posts here Anyway, skin-effect is an "AC" thing (and gets more and more significant as the frequency increases) and the benefit of flat wire would be (I think) a neater coil...maybe more compact. Flat wire could also make com connections more difficult, might even make it more difficult for the epoxy to penetrate the coil fully...I don't know???

-john

[idare2bdul]

When we made our first C can full cobalt motors we were running double 25's at team Checkpoint. Not sure about the turns.

Ungodly top end!

Double winds seemed to be less violent coming off the turns which was one of the reasons I liked them but it seems to indicate they are less efficient, which is what theory also says.