13 replies to this topic

[Rob Fredrick]

Several questions regarding Mabuchi 36D motors: stock, several used from the 60's still running good, several NOS purchased over the last year.
Classic (orange), Monogram (red), Revell (grey), Rannali(green), Royale Bobcat(yellow). Evenly mixed between can drive and endbell drive, the Revelle is dual shaft.

1. Timing, polarity, best direction of rotation? I have been told conflicting information on this question. The 2 gentlemen to whom I asked this question would be known by most, if not all, of the moderators of this blog. Hence, I shall not include the names simply the responses.

A. These motors have zero timing thus not necessarily faster clockwise or counterclockwise. Simply attach to a power supply alternating terminals and the direction with the highest pitch scream is the faster direction. (This, infact, is how I've tested my motors for fastest rotation direction since I was 12 years old in 1966. I call it "the scream test")

B. The arms are wound counterclockwise thus the best direction of rotation is clockwise.
Should I break all Mabuchi motors in clockwise?
I have mounted my motors in various configurations (Classic, Garvic, Monogram, Revelle, BZ...clockwise in some, counterclocwise in others).
I found no consistant pattern. Some motors run faster clocwise others counterclockwise.

2. Are these motors essentialy the same? That is, is the only REAL difference the paint on the can?

3. The Cox 36D "NASCAR" motor I occasionaly see for sale: Does the bulbis can hold a bearing? Is it faster than a "standard" 36D? Will it fit as a "standard" 36D in those chassis previously listed?

4. I've heard of "beefed" or "jazzed" 36D motors, I assume non stock magnets and or arms, do they last? Will they melt a standard endbell?
How can I get some? (my fingers are too bent for me to build one)

Thank you in advance for any discussion offered.

(my computer does not like the spell checker option offered...I'm still working on this. PLEASE EXCUSE SPELLING ERRORS)
Rob

[havlicek]

My strictly shadetree thoughts on your questions:

1. Timing, polarity, best direction of rotation? I have been told conflicting information on this question. The 2 gentlemen to whom I asked this question would be known by most, if not all, of the moderators of this blog. Hence, I shall not include the names simply the responses.

...best direction for a zero-advance motor is (as you said) whichever way it spins best.

B. The arms are wound counterclockwise thus the best direction of rotation is clockwise.
Should I break all Mabuchi motors in clockwise?

The direction the arms are wound doesn't necessarily correspond to the way the arm will "like" to spin. Break in the motor spinning the way it spins better, which will also be the way you should mount and run the motor. Unless it is a sidewinder, you only need flip the gear.

2. Are these motors essentialy the same? That is, is the only REAL difference the paint on the can?

There are different winds and in the case of the Champions (should you be so fortunate to have some), there are also the Arco magnets which I think are the only magnet upgrades for 36D other than adapting some other non-slot car motor magnets or magnets from later motors that may fit.

3. The Cox 36D "NASCAR" motor I occasionaly see for sale: Does the bulbis can hold a bearing? Is it faster than a "standard" 36D? Will it fit as a "standard" 36D in those chassis previously listed?

As far as I know, these have the caged bushing. Maybe there is a variant with a bearing???

4. I've heard of "beefed" or "jazzed" 36D motors, I assume non stock magnets and or arms, do they last? Will they melt a standard endbell?
How can I get some? (my fingers are too bent for me to build one)

Like all motors, the stock 36D can be massaged to get better performance to a degree, even with the stock magnets and hardware. Doing it so they can last is a little tricky...but lasting also may depend on how hard you'll be running them.

-john

[TSR]

Whooo!
There are 2 distinct types of Mabuchi FT36 motors.

1/ The 1964 FT36. All are endbell-side drive, all have a large brass can bearing housing, all have an endbell on which the brushes are directly in contact with the plastic material. They are blue (Revell SP500), gold (Russkit "33"), red or metallic red (Monogram X200) or chrome plated (Cox TTX200). If you want a high performance motor, these are NOT the motor to use.

2/ The 1965 FT36D. These can be endbell-side drive, can-side drive or dual shaft. All have an upgraded endbell with hexagonal sintered-steel brush heat sinks with the brushes and springs not compatible with the earlier versions. The can bearing housing has a groove for a retaining ring. In 1965, most were wound pretty much the same (brown wire), but in 1966, upgraded versions were available (red wire).

As far as the Champion motors, ONLY the ones with metal-foil stickers with their number in BIG type on them, are true factory-assembled motors, and they go like this:

1/ "701" is a "selected" Mabuchi stock motor, nothing different from any other Mabuchi FT36D.
2/ "702", "703", "704", "707" are various levels of in house rewinds, some of them using the ARCO magnets developed by Champion (these have a one-piece shim blanking one of the two vent holes), some with ball bearing at one end, some with a Cycolac endbell, pent-roof brush-holder retainers and ball bearings at both ends.

The Cox NASCAR motors were built in Hong Kong and are not Mabuchi motors. While they are slightly faster than the stock 1965 Mabuchi FT36D, they are not any faster than the 1966 model and are not as reliable. They have the same type of self-aligning Gimball bearing as the Mabuchi motors.

To build a SERIOUS FT36D motor, first you need to bullet-proof the endbell using modern 16D hardware (from a Parma or Champion 16D motor). Then you need a set of ARCO magnets, there is no substitute. For the armature, if you own a Champion "707" arm, they are fabulous and indestructible and have the best commutator of any slot car motor ever produced, even counting the Globe-Versitec comms. If you do not, the next best is to have Monty Ohren or someone who REALLY knows his stuff wind you one just like an open-class G7 "pro" arm, with proper epoxy and dynamic balancing.
Then, you can race.

[proptop]

Seeing as we're talking about 36's here...may I ask ya'll a question or two?

I want to wind a couple of arms for a 36 set-up with Arco magnets. The old arms I have are equipped with larger than stock comms...maybe Champion and/or Tradeship? One has slung windings, and the other is shorted somewhere...but the comms are in good shape.


Question: What would be a good kick-butt wind that will survive occasional use? (occasional meaning just run a couple-three dozen laps once-in-a while on a King track)
I have some 29 gauge wire...and was thinking maybe 50 or so turns?

How about a double of 30 gauge? How many turns of that?
Will Silver solder survive the heat at the comm tabs?

Niether of the stacks have any balancing holes drilled in them, and I was planning on using my Tradeship static balancer.

I plan on doing the end bell bulletproofing w/ modern brush hardware, and reinforcing the bushing area...better ventilation.

Chassis will be a scratch built brass and music wire...have yet to decide if an in-line or sidewinder/anglewinder (suggestions?)
Body will be Lexan '69 Torino Talladega, or maybe '70 Plymouth Superbird.


Thanks

[proptop]

Wow...I just looked at a post made by Monty...he said he was winding some 30T. of 25G. and some 32T. of double 28G.
Also some "layered" doubles with different gauge wire. How do ya do a layered wind?



My main concern is if the wires will stay on the comm tabs?

I have some 26G. and maybe will try that...

[havlicek]

Hi Tom,

I have some 29 gauge wire...and was thinking maybe 50 or so turns?

First things first, you gotta try and source some Arco magnets. If not, there are other magnets made for later non-Mabuchi motors (Jeff Easterly may be able to fill you in on this) that are about as strong as the Arcos. Doing a relatively hot wind and using the stock magnets isn't going to produce the best results. Using #29 gauge you're starting with a resistance of around .08 ohms per foot so as an example, a 10 foot piece of #29 wire would have a resistance of .8 ohms. To get you in the ballpark with a .4 ohm wind, you would be using 5 feet of #29 wire per pole...a .5 ohm wind would be around 6 feet of wire-ish etc. You can then translate that to # of turns by winding an unmodified 36D arm with whatever length of wire you want to use. Pay attention to the winding patterns you use and duplicate those on each pole so that the total length of wire on each pole is both neat AND close to the same on each pole. In the end, the patterns you use will be more important than the length in feet of wire since each pole's wind will have to end at the top of the stack where it will meet the commutator. Duplicating the patterns will make the wire on each pole about the same length and of course your "target" of ending at the top of the stack is already taken care of. If you go only by length of wire and your patterns change only a very little...you could still wind up ending at the bottom of the stack and have to add a half turn to get back to the top. The reality is also that being off a bit on length doesn't matter anyway. We're talking about a resistance of eight hundredths of an ohm per foot here and a full turn may only be 2 inches or 1/6 of .08ohm. If you were to take apart several of the same type arms including some that run great, you kmight be very surprised to find out how much the actual wire length varies from pole-to-pole.

Another consideration is that the strength of the field that each pole of the arm produces is proportional to the number of coils or turns...that translates partly at least into the torque potential. Very few turns of wire may produce a lot of RPMs (and a motor that will go "poof"), but little torque. Also, when powered off (braking) and the motor is acting like a generator, it will produce less current with fewer turns...same concept.

I'd try for around 55-60 turns of #29 as a starting point, as 50 turns or so is a good FT16D wind. Even with bulletproofing the endbell, the plastic the endbell is made from will still melt when it reaches a certain temperature. I haven't wound enough 36d motors to be confident about a good #29 wind, but I would think that .4 ohm is a good target. Just be careful about stretching the wire and/or shorting it from over-tensioning it.

Will Silver solder survive the heat at the comm tabs?

"Silver solder" is only a general term describing any solder alloy containing silver ("Ag" is the symbol from the periodic table). Some silver solders have only 2% Ag some have 4 or 5% and those with more silver will have a higher melting temp. Look for an alloy with a melting point into the 400's of degrees Fahrenheidt. Even with an auto-melt Mabuchi endbell, the com may be seeing temps above those which would melt the endbell material and which would melt regular 60/40 electronics solder. There is a high-temp com solder out there from one of the manufacturers, but I forget who makes it. Pure lead may be an option for soldering the com as it has a high melting point temp...but I haven't been able to get good results with lead.

I have some 26G. and maybe will try that...

Considering you're thinking of

(occasional meaning just run a couple-three dozen laps once-in-a while on a King track)

...where the motor will easily reach it's highest temps under that kind of use, I don't think a #26 is necessarily the most prudent way to go...but it might be a lot of fun!

Also some "layered" doubles with different gauge wire. How do ya do a layered wind?

I'm not sure what Mr. Ohren is referring to, but this might be what we called a "series" double wind. Instead of grabbing two pieces of wire and winding, you can do half the number of turns on each pole with a single wire and go completely around twice...OR...on the second time around switch wire gauges. Truthfully, I don't know if there are any advantages or not to doing a double this way and I would ask him as he surely knows the answer. From a practical standpoint, it can save you some wire by not having to roll-out the length you need and putting it on a second spool.

My main concern is if the wires will stay on the comm tabs?

I would also be VERY concerned with shorts and test for them before soldering-off the com. You should also tie the com and you can use either pure cotton thread or unwaxed dental floss, finishing the arm with epoxy (regular Devcon...not the quick-cure should be OK for mild to moderate winds). Either thread or floss will have a failure temp above the point where other things would probably have failed first...like the magnet wire's insulation, the epoxy if it's regular hardware store epoxy, the com if it's the stock com or that lovely white Mabuchi endbell!

-john

[Prof. Fate]

Hi

In the day, 63 to 65, when 36ds were competitive, the standard winds started at 34single. Some aftermarket winds in 65 were 32 and 30 single winds. These "rewinds" will run pretty much forever. In the day, with arcos, a 28 was about as hot as was practical...practical meaning it would survive a race.

The timing on these was set with a little tab on the end of the commutator that slotted into the fiber spacer on the stack. Nominally, it was at "zero"...randomly the timing moved during the construction process and was usually plus 3 to 5 degrees with the occasional -1 or 2 backwards.

Fate

[Rob Fredrick]

Gentlemen,

Thanks for all the usefull information. As they say, I now know enough to be dangerous.

I've checked out all my 36D motors. Only one is the non heat sink type. (brushes contacting the endbell)
Also, this is my only motor with an issue and I'm wondering if a "newer" style endbell (with heat sinks) will fit the can and armature with little or no fabricating.

I purchased the motor NOS several months ago. It ran fine initially. Later it began to be sluggish with power applied.
After about 20 feet of running very slow, the motor would take off and run normally for the rest of my race session.
Now , when power applied the car will not even move but will start up given a slight nudge.

NOS 36Ds are available for less than $20. Is it worth rebuilding this motor? (having completed 36D 101, I'd be willing to now do the corresponding "LAB" and rip this baby apart)

I await further suggestions from the faculty.
Rob

[Pablo]

If this 36D is a special motor, you could rewind a junk motor beforehand as a "warmup" test run to build confidence......then.......just Do It !

[TSR]

You can go straight ahead and use 40 turns of 25AWG wire.

[Hworth08]

There's a pretty good chance the "sick" motor has either thrown the solder off where the wire is soldered to the commutator tab or has been over oiled has a layer of oil on the comm.

If it's over oiling a nice shot or two of lighter fluid directed at the comm and then running the motor will correct that. If the solder has slung off the comm tab the joint can be resoldered.

If I chose to rewind the arm I'd use 90 turns of 30 gage wire that makes a mild 6 volt arm. Far from the fastest but a smooth motor that shouldn't melt the stock end bell and will be a decent match with the stock magnets. A beginner's motor.

If you want a real hotrod find some Arco magnets and a Cox NASCAR motor. Send these parts to Monty along with about a $150 (maybe more) and he'll build the the best 36 motor possible. And it might last a fairly good while or might not. A $50,000 leased motor from Hendricks doesn't always last a race.

[havlicek]

NOS 36Ds are available for less than $20. Is it worth rebuilding this motor? (having completed 36D 101, I'd be willing to now do the corresponding "LAB" and rip this baby apart)

You already pretty much answered your own question. With super clean NOS 36Ds available for $16 or $17 bucks, go straight to the "Lab" and have fun. If you don't epoxy the arm and just give it a quick spin, you can either take it apart just as easily as you did the first time and redo it or if you like it, you can epoxy and even balance it to make the arm "permanent". Most importantly, you seem interested in doing it yourself which is great. Avoid sending the motor out to be done by anyone if you really want to have fun. You'll save a bucket of money and even if the motor doesn't work out exactly the way you wanted, it will be much more satisfying. It isn't rocket science and anyone can do it.

-john

[Rob Fredrick]

There's a pretty good chance the "sick" motor has either thrown the solder off where the wire is soldered to the commutator tab or has been over oiled has a layer of oil on the comm.

If it's over oiling a nice shot or two of lighter fluid directed at the comm and then running the motor will correct that. If the solder has slung off the comm tab the joint can be resoldered.

If I chose to rewind the arm I'd use 90 turns of 30 gage wire that makes a mild 6 volt arm. Far from the fastest but a smooth motor that shouldn't melt the stock end bell and will be a decent match with the stock magnets. A beginner's motor.

If you want a real hotrod find some Arco magnets and a Cox NASCAR motor. Send these parts to Monty along with about a $150 (maybe more) and he'll build the the best 36 motor possible. And it might last a fairly good while or might not. A $50,000 leased motor from Hendricks doesn't always last a race.

[Rob Fredrick]

Don,
Thanks for your suggestions on my "sick" 36D. It is always best to try the simplest and least expensive fix first.
Before I jump into a rewind project, I'll check for oil and defective solder on the com.
Rob