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Can I bump this thread?

What can size is Johnson? C-Can? Less height than a FC-130 S can Less than a FK- 180 neither of those magnets will fit

What magnets will fit? It all seems very confusing. ABSlot says I can use Hawk neo magnets. As far as I can make out Hawk is Fk-130? But I have an old Fk-130 and the magnets are not the same as the 13U0. 13UO are notched.

There are many motor magnets out there but if I change magnets I suspect i will be to change the arm to achieve "balance" That is OK.

I don't want a screamer, ProSport PS 4000 specs would be fine
just that I have at least one old Johnson that runs hot because of weak magnets. I could simply replace it with FC-130 using two plastic widgets but where is the fun in that? I would like to play.
 

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QUOTE (Mick Kerr @ 16 Jul 2012, 15:09) <{POST_SNAPBACK}>Hi Mike,
The simplest solution is to use SCX magnets.
They don't have the notch but if you flatten the tabs on the can they should slip right in.
Fix them with epoxy resin (araldite precision is best) or one of the special magnet glues from the like of Proslot.
Use the armature, wrapped with a couple of layers of masking tape and assembled into the can, to set the air gap equal either side.
This should solve your heating problem.
100 turns of 36awg was always a common rewind for these motors.
Don't use too 'hot' an armature or the endbell will melt.
Hope that helps.
Cheers.
Mick.

OK I'll line all my magnets up and have a look. Maybe SCX ones are thicker. I was hoping to either keep the stock armature or buy one ready wound. I know I said I'd like to play but baby steps first.

QUOTE (stoner @ 16 Jul 2012, 15:15) <{POST_SNAPBACK}>does anyone know of a retarder

That would be me.
 

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Given the preponderance of cheap crappy epoxies here, I read Loctite 380 Black Max, if Loctite have that here. It appeals to me because it can be removed.
 

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Could not find any rubberized CA glue today. Ie. 380 Black Max.

Anyone got any thoughts on Rear View Mirror glue? It must be shock resistant and can be removed with super glue remover!
 

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Thank you John. I'll check that out
 

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For guys and Ember,

Looking for a replacement for Johnson?

Rather than buying an FC130 motor and some plastic widgets I have discovered that FK-180 motors are exactly the same length as Johnson 111.

The only difference being that their bushing retaining diameter is 6mm against the Johnson 5mm so the mounting holes would need to be enlarged very slightly.

In case anyone has some old tooth brush motors!
 

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QUOTE (Abarth Mike @ 24 Jul 2012, 12:16) <{POST_SNAPBACK}>For guys and Ember,

Looking for a replacement for Johnson?

Rather than buying an FC130 motor and some plastic widgets I have discovered that FK-180 motors are exactly the same length as Johnson 111. WRONG

The only difference being that their bushing retaining diameter is 6mm against the Johnson 5mm so the mounting holes would need to be enlarged very slightly.

In case anyone has some old tooth brush motors!

What a disgrace having to quote my own post. The FK -180 is about 1.5mm shorter, it will fit and the rear "spigot" will fit just but it needs a spacer and the shaft will not reach the slot in the crown gear. SORRY for the misinformation.
 

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Bump again.

Newbie motor tweaker air gap question.

I replaced the magnets in a J111 with some mystery magnets but kept the original Johnson arm.. (The magnets were donated to me along with a Parma Home set arm.)

It all fits together. I used Loctite 480 as that is what they had. The magnets did fit and are a lot stronger.

Now I have lost 3900 RPM. 21,700 vs 17,800. I probably have more torque but... even if I change to 10/27 I get the same speed as original with 8/27.

The arm/mag clearance was tight when I reassembled. Is it simply a question of air gap? If so what magnitude of air gap makes a difference.

I know I can swap to FC-130 byt where is the added knowledge in that.
 

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300,

The magnets are quite strong a Jeweler's screwdriver sticks to the can! The arm did touch slightly so I will have to measure exactly what the air gap is. 0.1mm I'll use as a yard stick. Cheers.
 

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John,

It gets worse. I read a thread once somewhere about SCX motors where one could improve Rpm by running the motor and using a small grindstone touching the arm.
 
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