|
|
Post by dave632 on Jul 20, 2014 15:38:02 GMT -7
Just wondering what most use to true up the commutator on pancake motor? Also is there a good comm truing machine available for the inline motors? |
|
|
|
Post by pceng on Jul 20, 2014 18:28:43 GMT -7
Just wondering what most use to true up the commutator on pancake motor? Also is there a good comm truing machine available for the inline motors? Hey Dave , Gotten accustomed to using dremel........ for both pancake & inline...... 1200 or 1400 grit paper........ for taking the waffling off pancakes I start with 800 or 1000.......... usually this will bring you to the copper......... they look real pretty when they look like glass ! ...... Peter |
|
|
|
Post by dave632 on Jul 20, 2014 18:52:13 GMT -7
Me and my sons raced 1/10 scale RC cars long ago and we had a diamond tipped commutator lathe back then. I saw one on E bay but it was for the bigger size motors.
|
|
|
|
Post by Eagle Racing on Jul 20, 2014 20:05:08 GMT -7
I use this for truing my in line motors, Wizzard use to carry them try them.
|
|
|
|
Post by dave632 on Jul 21, 2014 7:58:15 GMT -7
That looks like the one I used to have long ago. It is no longer on the Wizard or JK industries site.
|
|
|
|
Post by Eagle Racing on Jul 22, 2014 4:04:21 GMT -7
Dave try Lucky Bob I believe he carries a com truer on his site. The link is on the Nitro Slot main page at bottom.
|
|
|
|
Post by dave632 on Jul 22, 2014 7:36:32 GMT -7
Thanks, I will check that out.
|
|
|
|
Post by mike11422 on Jul 22, 2014 8:49:04 GMT -7
You can also check out scale engineering, they sell a truer called cobra or something like that. Hudy makes one for slot cars I believe but they are big bucks.
|
|
|
|
Post by dave632 on Jul 22, 2014 14:16:09 GMT -7
Thanks, will do.
|
|
|
|
Post by SlotWerx on Jul 24, 2014 8:54:36 GMT -7
For pancake armatures you want the commutator as flat and as polished as possible (rules permitting). You cannot use a standard arm truer for pancake armatures as there is not enough material to allow this, especially with a JL/AW glass backed armature. For checking the commutator for flatness Scale Engineering offers a great indicating tool that ranges from $50 - $75 depending if you need the indicator or not. VRP has upgraded their commutator polishing tool and it works great. For $20 you get everything you need to do a lot of armatures. When polishing / truing old armatures the tool will hit the outside surface first as this will be the high spot from the brushes wearing on the center. If your car surges and you know without a doubt that the brushes are not spinning then the commutator is more than likely not flat.   |
|
|
|
Post by dave632 on Jul 24, 2014 9:43:54 GMT -7
Thanks, I spotted that dial indicator tool and thought it was a good idea. The other tool looks interesting too.
|
|
|
|
Post by pceng on Jul 24, 2014 15:39:30 GMT -7
Hey all , something to consider besides cost of all the different tools available is the theory one is trying to apply when trueing or polishing comms. Idea is to have as much brush as possible contact comm all the time throughout its rotation. The greater the contact area the better the flow of electric.
New arms with waffle plating I take down to the copper. Old arms will often have a groove worn into them. If this worn spot is round & exposes copper , I leave comm as is. Reason being - the channel the brush has created yields a larger contact surface for the brush........ better flow. Some of these old arms work better than any new ones I have. If it is because of this or not I'm not sure , but it seems to help........ at times.
|
|
|
|
Post by dave632 on Jul 25, 2014 7:41:32 GMT -7
Brush bounce is a big problem with older armatures. My sons and I raced RC and the commutator would wear and no longer have a smooth contact surface. Re-truing the arm would bring back like new performance if the windings were still good. On the pancake motors a special tool would be needed to be sure the comm is perfectly flat. That dial indicator would be a good tool for checking that.
|
|
|
|
Post by Phantom B.S.E. on Jul 25, 2014 7:56:27 GMT -7
Brush bounce is a big problem with older armatures. My sons and I raced RC and the commutator would wear and no longer have a smooth contact surface. Re-truing the arm would bring back like new performance if the windings were still good. On the pancake motors a special tool would be needed to be sure the comm is perfectly flat. That dial indicator would be a good tool for checking that. It's used to check the run out on the com like checking a cam in a real car. |
|
|
|
Post by dave632 on Jul 25, 2014 13:47:31 GMT -7
Yes, that is a good comparison. I remember degreeing cams on my cars although not quite the same thing. I still have the degree wheel and associated tools. I wonder if I can adapt the dial indicator I used to this job?
It would sit atop the rocker arm to measure lift and it had a magnet to mount it to the block. I have to look thru my tools and find it. Thanks for giving me the idea.
|
|
