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Al Schwartz
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3,378 Posts
Discussion Starter · #1 ·
I recently ordered some of these motors:

TMM

guessing that they might be the same as the motor that I used in the Weslake Eagle.

Well, perhaps they are - the motors are identical in appearance, have the same odd snap-in type connections, the same 64 dp gear and the (removeable) rubber pad on the shaft end. The numbers, however are different; MJ413A for my old motor and MJ421A for the recent purchase.

I did a quick and dirty experiment - checked the no-load current at 3, 6, 9 and 12 volts. Based on the average of three samples of each, the results are identical, 0.10, 0.13, 0.16 and 0.21 A at the respective levels. Several of the motors showed a 0.01 A difference depending on direction and one measured 0.21 A in one direction and 0.23 A in the other. (My power supply reads to 0.1 V and 0.01 A) For comparison, a TSRF motor, unloaded, draws 0.33 A @ 12 volts and a beardog motor pulls 0.11 A @12V.

In addition, the motors "sound" the same - I have a small optical tach but no disk for a 1.5 mm shaft (add to the project list!).

My guess is that the motors are functionally equivalent despite the different numbering but - I have not tried one in a car so the above is all the data I have.

I just spoke with the vendor and they have 200 of them currently in stock

EM
 

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EM,

Thanks for the link. I'm thinking about ordering some. So, do these have an HO-sized pinion gear on them? How many teeth does it have? I'm imagining the only type of crown gear these could mesh up with is a 64 pitch gear by Sonic, correct? That is if I don't want to pull the existing pinion off...

Thanks again,
Steve
 

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Al Schwartz
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3,378 Posts
Discussion Starter · #3 ·
Yes, the pinion as supplied is a 64 DP 10 tooth steel pinion on a 1.5 mm shaft (as opposed to the typical 2 mm shaft of the Mabuchi cans)

The Sonic is a good choice.

EM
 

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Just a thought but have you checked out the brush gear on the motor ?
I had a similar motor and discovered it didnt have any carbon brushes , just strips of brass running on the com. . I never used the motor because I didnt feel it would last to long.

Richard
 

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Sounds like a good deal : )
I notice they have a Johnson DC Motor - G4046 for a buck a piece as well , they might be worth looking into ?
Many thanks for the link .

Richard
 

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EM - thanks for the reply! I've been searching vendors here in the U.S. and it sure is hard finding a suitable 64 pitch crown gear. Do you think there's any safe way to pull the pinion from these motors? I just ordered 8 of these motors and would like to use one for a Mac Pinches' preadd project I'm working on. I'm kind of new at all of this, and I'm not sure what to do about the gear situation...

Thanks for any guidance,
Steve
 

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Al Schwartz
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3,378 Posts
Discussion Starter · #8 ·
You have a couple of options on gearing: The pinion is not hard to remove - just use a pair of needle nose pliers around the shaft under the pinion and tap the shaft out with a piece of 1.5 mm (or less) rod. You need to be careful replacing it since the motor shaft does not extend past the molded plastic end bell at the opposite end and it is easy to crush the commutator against the brush housing with pressure on the pinion end. If you want to go to a 2mm bore pinion, a solder-on sleeve of 1.5 mm ID, 2 mm OD tubing and a solder-on pinion is probably the safe option.

I used Sonic 64 DP crown gears - available from several sources - the 10 tooth pinion, used with their smallest (32 t) crown, gave me a 3.2 : 1 gearset which worked well in my Eagle ( a light car) There are also Wizzard 64 DP crown gears made for HO racing. They are bored for a smaller axle than the typical 0.093" 1/32 axle and would need to be bored out..

Hope this is useful

EM
 

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Graham Windle
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4,442 Posts
Ive just discovered a similar motor is fitted to the philips cdm12 lasers we use in our jukeboxes .A quick phone call to our suppliers has resulted with a few samples coming my way foc to test ,the motors in question run at 5 volts in the laser but may well be rated higher as many of the components used in these things are higher rated than required.. price I have been led to believe is under£4
 

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Phil Smith
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4,534 Posts
I've mentioned the Betta gears (Taylormade) before in this forum but have not had much feedback.
So here is a picture with standard Scalextric for comparison.
The Betta gears are 9:34 the Scalextric 9:26
another advantage is their extremley smooth running.



Contact Betta on 01704 229342
 

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Hi

Re: sleeving the shaft:

I have "thick wall K&S metric" tubing 2mm outside, 1.5 inside. This may be a U.S. only product. A couple years ago chatting about the problem with some germans, I found that tubing there only comes in EVEN numbers...e.g. 1.2, 1.4 and so on.

Fate
How are your 60s cars coming?
 

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Phil Smith
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4,534 Posts
I counted 34 teeath on the contrate pictured, but it is a Taylormade, looking in the Betta catalogue I see they only go down to 36 now.
But it still makes for a very compact package for use in F1 cars and you can get a better range of ratios.
 

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Russell Sheldon
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2,855 Posts
In the UK both ABSlotSport and SCD have 64DP and 80DP 1.5mm bore pinions, as well as matching contrate (crown) gears for 3/32" axles.

Scale Auto make a precision pinion puller. It's rather pricey at $18.00, but it does enable you to remove steel or brass pinions so they can be re-used.



Both ABSlotSport and Scale Auto accept major credit cards and provide an excellent mail-order service (I live in the Middle East / Gulf region).

Kind regards

Russell
 

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Gentlemen,

I just received my order from Electronic Goldmine, the vendor who is selling these little motors. I do live in the U.S. and this vendor is in Arizona, but I received my shipment extremely fast. I highly recommend this shop. If these little motors are worth anything at all as far as performance, they're a perfect size for the skinny 50s and 60s F1 cars.

I'm going to try one with the existing 64 pitch pinion. I'll use the first motor (I now have eight) on Mac's Talbot Lago shell and a popsicle stick chassis (that's for you, BWA!).
And, yes, the combination of the motor and the popsicles, with some lengthwise trimming, is perfect for the Lago.

Thanks again for the recommendation EM!
Steve
 

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Alan Tadd
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4,030 Posts
Well I ordered a few of these motors from Electronic Goldmine....I had an email from them today saying that the mimimum order they accept outside of the USA is $50 plus postage. Not very helpful.

If I am paying the postage any way I can't see why they would introduce this limit?...

Well they won't get any future orders from me, so I'll search the UK Electronic Retailers to try and find a UK source for these little beasties.

Regards

Alan
 

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Graham Windle
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4,442 Posts
Alan I have some small motors similar tothe bear dog which Ive just recieved from our suppliers they are for philips laser heads but are outwardly identical ,although they are suposedly 6volt I have tried one on 12v and it seems ok I,ll send you one to test if you want
 
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