16 replies to this topic

[FLY in the wall]

One of my SCX motors had a hiccup so I had to clean the comm and the brushes. While they are out is there any words of caution or downsides to trying Rick's soldering iron trick?

[lenny broke]

don't burn your fingers on the hot iron
I place the brushes on the iron tip with a pair of tweezers.
Let it heat up till the smoke stops. I then let them cool and give them a bit of a cleanup on a bit of scrap paper. Just rub each side of the brush over the paper, it's abrasive enough to clean them up. You can also give the radiused bit a very light run over with a small rat's tail file to clean it up a bit too. When you refit the brushes to the endbell make sure they slide in and out freely. doesn't hurt to run a small square file over the inside of the brush hoods lightly to remove any dags and edges from them too.

Alan

[rick1776]

Its going to end in tears I tell ya.

[FLY in the wall]

Hubble Bubble. Honest your honour I didn't inhaled.
Smokin

Edit:

Quote

Its going to end in tears I tell ya.

Well almost. I put the hot brushes on my metal soldering iron stand to cool then unplugged the soldering iron. When the iron was cool I stuck it back in the holder and put the holder back in its spot when I heard the pitter patter of brushes droping on to the office floor. Luckily I found them.

Edited by FLY in the wall, 07 September 2010 - 10:34 PM.

[Yngwie]

Hey Fly, some photos of what you have done would be great if you could manage it!

Regards

John

[FLY in the wall]

Ah I put it all back together. I guess I could take it apart again. The cleaner has emptied the waste basket so the paper I used to clean them up has gone.
I could do an "air crash investigation" type recreation.
How much detail do you need? Showing points of tweezers removing brush springs or just the heating up bit.
I prefer this type of "fiddling" to painting anyway

Edit: This is supposed to be performance enhancing. Maybe I'll need Rick's permission for a full exposé

Edited by FLY in the wall, 08 September 2010 - 12:05 PM.

[triggy]

FLY in the wall, on Sep 8 2010, 01:01 PM, said:

This is supposed to be performance enhancing.

I prefer to look at it as "preventative maintenance"

[lenny broke]

well, it just means that the brushes contact the commutator properly.
Rick won't mind, he doesn't race them anyway

[rick1776]

What Lenny said. Go for it Fly. I hope you put the brushes in the exact same way you took them out otherwise they will need to bed to the comm again.

[FLY in the wall]

I tried....

Like most things it is just a little bit of confidence needed. That and not losing the small parts in the gaps in the wooden floor. The comm was all full of detritus so I had to do something anyway. Next on my list maybe making a small square brush holder tweaking tool. That sounds a bit more technical than attacking them with pliers. Of course then I'll need a digital tach as my music tuning software is only a demo and it cuts out after about 10 seconds. It isn't very stable as the frequency numbers jump around a bit. Just having fun experimenting.

I don't do SCX as a rule because the motors are dogs at the 10v we run but I've got one spare motor out of an R5 and found an article in "the outhouse". If there is any change I'll apply the same to an RX81, I very kindly got in a swap.

[haystack]

FLY in the wall, on Sep 9 2010, 02:55 AM, said:

I tried....

Like most things it is just a little bit of confidence needed. That and not losing the small parts in the gaps in the wooden floor. The comm was all full of detritus so I had to do something anyway. Next on my list maybe making a small square brush holder tweaking tool. That sounds a bit more technical than attacking them with pliers. Of course then I'll need a digital tach as my music tuning software is only a demo and it cuts out after about 10 seconds. It isn't very stable as the frequency numbers jump around a bit. Just having fun experimenting.

I don't do SCX as a rule because the motors are dogs at the 10v we run but I've got one spare motor out of an R5 and found an article in "the outhouse". If there is any change I'll apply the same to an RX81, I very kindly got in a swap.

These are commonly available, along with dummy armature slugs, can reformers , bearing aligners etc, from the big 1/24 scale manufacturers. Your only limit is how serious you want to be.

[wizardgm]

rick1776, on Sep 8 2010, 09:40 PM, said:

What Lenny said. Go for it Fly. I hope you put the brushes in the exact same way you took them out otherwise they will need to bed to the comm again.

Rick,
you been reading that 1986 motor article you got from that antique shop !

Also, anytime you heat a brush (which has a small copper content) the brush will become harder.

The one thing that Lenny said that MUST be done, is to take a round file to the brush and re-profile the commy end.

If you do not do this, you risk wearing the commy with the hard brush surface

Regards,
Dennis

[rick1776]

"Rick,
you been reading that 1986 motor article you got from that antique shop !"

Was looking for an old Yamaha KT100 Karting book for my brother the other night. Didnt find the book but I did stumble across a "how to" build slot motors article and a nice G15 chassis design. I'll have to bring it in and show you. You need all the help you can get. Ha ha.

Wizard is the real mastermind behind the SCX motor I just look over his shoulder a lot and pinch his ideas.

Edited by rick1776, 09 September 2010 - 12:47 PM.

[FLY in the wall]

rick1776, on Sep 9 2010, 09:43 AM, said:

Was looking for an old Yamaha KT100 Karting book for my brother the other night.

I used to have an IKF Karting Handbook once upon a time, probably long gone by now as is the kart. In the same drawer there used to be three? slot car mini books from the '60's from a slot car magazine How to tune motors was one.

Is your brother going to compete? Horstman clutch? set the spring height at .290 and start from there. That's about all I remember. That and like stock slot cars it takes more time, effort and money to make a stock Yamaha fast than it does say an open Komet K78/88

Did you get your brother a subscription to the pipe-of-the-month club.

Edited by FLY in the wall, 09 September 2010 - 01:32 PM.

[rick1776]

Clutch???? Thats for people that drive automatic 1.3L bubbles. Direct drive, run and drop, and jump in son. But now Im showing my age.

No hes not competing, his mate just bought one and managed to seize it. Leaned the shite out of it and wondered why it seized. Youth is wasted on the young I tells ya.

[FLY in the wall]

rick1776, on Sep 9 2010, 12:45 PM, said:

Clutch???? Thats for people that drive automatic 1.3L bubbles. Direct drive, run and drop, and jump in son. But now Im showing my age.

No hes not competing, his mate just bought one and managed to seize it. Leaned the shite out of it and wondered why it seized. Youth is wasted on the young I tells ya.

In the Canada /USA they all use clutches and electric starters. Their must be a reason but.... when i raced in UK as you say it is push, drop and jump in. Spin out? do the same. In UK I used to go with my fiance. I raced and tinkered, she watched, as they do,

With a clutch it means one needs a mate to help get the thing started. So it is not easy to turn up at the track alone and race? Then the battery needs to be charged, Lah,lah lah,

Bet it seized as he let off for a corner Newer Karts have giant air boxes. How exactly one covers the carb with ones hand to alleviate said problem I have no idea. Never mind, if it is not too bad some 1000 grit paper and a few minutes and she'll be good to go.

I suppose that is one advantage of a clutch. If the engine does "nip up" it stops instantaneously and has no force applied to it by overrun.

Now he'll need to buy a cylinder head temp gauge. Then he can fine tune the leaning.

What you said about youth

[FLY in the wall]

Duplicate fudging ISP

Edited by FLY in the wall, 09 September 2010 - 05:06 PM.