71 replies to this topic

[One_Track_Mind]

Hello, fellow Slotblog members,
I'm hoping that someone can help me in identify these motors? Also, what would be the first thing one would need to do in restoring these? Or at least cleaning up in making these presentable?

Thanks in advance...

For the sake of confusion let's refer to these as A, B, C motors, with A starting on the left.



A: motor


B: motor


C: motor


I can try for better photos and angles if need be? Please, just ask.

[Jairus]

They are all the same type... B can Muras.
Any idea what the arms are tagged?

You will have a PM ....

[TSR]

Hi Brian,
A, B and C are 1969 Mura "B" motors, more than likely the ones marketed as "Long John" in a kit. Some were painted a medium-light green color, some were left un-painted, looks like you got some of those.
It's going to be fun to restore.

[Jairus]

As for cleaning up.... getting the twist pins out is going to be the hardest part.
Toothbrush and soap to clean the endbell.
Sand smooth the can.
Lightly clean the arm and then send out for reconditioning if the com is not worn too much.
Steelwool the endbell hardware.
Check and or replace the bearings with new ones.
Paint the cans after priming with etching primer.
Zap the magnets after putting them back into the can.
Put it all together with tiny screws and test.
At least that's my standard list....
(one motor will take me many weeks by the way)

[TSR]

As for cleaning up.... getting the twist pins out is going to be the hardest part.

Indeed. I use a sharp Excel knife to slightly lift them (use a sheet of paper to protect the finish if the paint is good), then a sharpened, grooved pair of pliers to twist them out in a CCW motion.

[One_Track_Mind]

Philippe,
the wife does not let me play with sharp knives! I end up sticking myself with it! :cry:
I keep around a pair of fingernail clippers to wedge up under the heads of the little stubborn buggers.I will remember the CCW rotation though. These don't work so well on the fresh paint as you pointed out.These motors actually appear to me that they once were black in color? It's hard to tell thru the rust color!

the 'Long John' name your refering was a motor kit? or a motor that came in kit named Long John?

Thanks Jairus for cleaning tips,sounds like some elbow grease would help also!

[Hworth08]

A pair of high quality, sharp nippers will lift the stubborn pin out. Try Dokk's method first though, good nippers will cut the pins off very quickly!

[Jairus]

Cutting the pins off will do NO GOOD! I can grind off the head in seconds but you can't get the end bell off that way...
You gotta remove the whole pin!
Otherwise you might as well encase the whole motor in resin as a paperweight for all the good it will do you.

Dokk has the right technique, using the needle nose pliers, but getting that stupid stovebolt head up where you can get a good bite is the hard part.

I'll try the nippers next time.

[TSR]

These motors actually appear to me that they once were black in color? It's hard to tell thru the rust color!

If they were black, they are the "standard production B" from late 1969, sold assembled and ready to blow.

[Slotgeezer]

Dokk....
A question....
Weren't the 1st-model "B"-production motors made w/ the small vent holes in the can? :think:
Then, the cut-out was added, up by the comm, to increase air circulation, in the 2nd-model motors? :?: Like the 3 motors pictured?
Then, in the 3rd-model motor Mura went to the square venting cut-out, in an attempt to decrease the magnetic field & increase air circulation? :think:
& I seem to remember the last 3rd-models I saw were supplied w/ 36D-sized brush hardware... :?:
I only owned one "B" motor, back then... I wisely listened to Frank Pretzman at Monaco Raceway, & opted for the "new" Green can set-up, w/ the shimmed-up "B"-model endbell...
Just wanted to check my memory.... Thanks, Dokk! ... C-ya! :up:

[One_Track_Mind]

Let's have a looksy inside and see what we find! This is Motor C

For some reason I just like the way the clippers fit the contour of the motor?! I did sneak the sharp knife while wife wasnting looking and kinda picked and scraped the rust from around the button head before resorting back to the clippers.



First peek inside after fighting with the always last stubborn stove pipe rivot!



The arm has no identify markings on it,Only this one drilled balance hole.The comm. looks pretty worn to my untrained eyes. :shock:



Notice the rivot with rust on it>yup..the last stubborn one :x ...my guess would be acid from maybe the solder weeped around it? the brushes show the run time on this comm.



Now the next question :?: How or what would be the easiest way to remove the magnet clips? without damage? or minimum damage?

Thanks for the Help.

p.s. Jeff, thanks for the question to Dokk on this? I simply wouldn't know?

[Jairus]

Push a tiny screwdriver into the can end and give the mag clips a push. Then you can grab them with the needle nose pliers and pull.

[One_Track_Mind]

Moving onto the next motor.This is Motor B



This one is showing some markings for identify,yet the comm.shows a little better condition,to still my untrained eye.





Thanks for tip Jairus on magnet clip removal,worked like a gem once I found a small enough screwdriver.

[Jairus]

Dat's a Thorp arm! Nice find dude!!! :spin: :spin: :spin: :clap: :clap: :clap:
(hmmmm could be a CCW arm too)

[Slotgeezer]

Thorp armature!!! :shock: .... 27-28 wind!!! .... Awesome, my favorite flavor !!!
I wonder... the CCW designation ... is that viewed from the endbell end, or the can end?... :think:
Either way, an excellent find! Congratulations! :up: ... Good racing! :up:

[TSR]

Jeff,
Always seen from the comm side...

[Slotgeezer]

I thought so, but I know enough to ask "the Dokktor"...
Thanks!

[One_Track_Mind]

Holy smokes alive! I take it this a good thing for the Thorp arm? But doesn't this mean that it's not an original motor for a RTR car? Thorp was an aftermarket arm to hop up the rtr cars?

Here is the last motor of the three this is Motor A



This arm is again like motor c with no tag or markings 'cept maybe this red and purple color on the end of stacks? It has several balance drill holes placed on different stacks.



The comm shows some run time...IMO



I did find some color of black paint on the end of this one. I was thinking one was partial painted?




Next question.Do I need to be concered before i remove magnets from can by marking them north,south,left or right?when viewing magnets at end of can? Opposite end of above picture? :doh:

Thank you,

[Slotgeezer]

I don't have the Mura color-codes memorized... I'm sure Dokk has a list to simplify identification!
How about it, Dokk? :think:
Plus, none of these three arms seem to have ever been reconditioned... the comms sure look worn, but still full-size...
C-ya!

[TSR]

The mags are not marked. So best is to mark them now with a dremel disk...
+ and -, just like we used to.

[One_Track_Mind]

Wow!..take a look at this again from motor C i wiped the dust off the end and revealed to me what looks like the colors lavander and pink? light purple,light red?





How about it PdL got a Mura color-codes list?

thanks Jeff :up:

[One_Track_Mind]

:
Plus, none of these three arms seem to have ever been reconditioned... the comms sure look worn, but still full-size...
C-ya!

Hi Jeff,
then in your opinion these could still be turned down,to make nice and bright shiny new again?

[Slotgeezer]

Dokk would know how small the dia. of these old-style Kirkwood comms can go, before performance starts to get weird ( excess heating & LOTS of "brush bounce" due to lack of contact do to small dia. )...
Or, one of the armature reconditioners can tell you, if you measure the current dia. at the smallest point, & give them that info... some reconditioners won't re-work antique slot arms... best to e-mail or call, & ask...
It appears to me that these three motors are using 36D size motor brushes... Right? :think:
My buddy Steve Beck used to work up at American Raceways up in Beverly Hills, & while working the counter memorized the Mura/Lenz color codes... it was almost impossible to race w/ this guy, as his constant chatter & bantering would force you to stop driving your car, & keep laughing! ... Great guy! :up:
Let's see what the good Dokktor turns up! :think:

[One_Track_Mind]

It appears to me that these three motors are using 36D size motor brushes... Right? :think:

hhhmm Jeff..I dunno without comparing them to new ones.
I will look later for 16d,26d, & 36d brushes and do a comparison.

Laughter & Slot Cars Isn't that what fuels us to keep going back?

[TSR]

Jeff,
Those are 16D brushes on them end bells.

How about it PdL got a Mura color-codes list?

These marks were painted with 2 or 3 different colors for the operator to work on the dynamic balancing machine. Colors were unimportant really as long as the strobe picked up one to see where to remove weight. Champion used a black marker and marked the poles "A-B-C".

The comms can be recut but that probably will be the last time as the grooves are deep.Best to do the job is Monty Ohren, and he is used to vintage arms as long as you tell him to preserve the looks.
Remember, those stock arms are not hand wound, are rather messy, so don't spend a fortune on them. The Thorp are better quality really.