453 replies to this topic

[Rotorranch]

https://www.ebay.com...traset&_sacat=0

[Martin]

I actually used Letraset on this build as the decals did not exist.

 

It was challenging as there are 2 layers, black and white that have to be lined up.

 

But sounds like you have a solution with Ricks decals.

 

Just wanted to show what could be done with Letraset.

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[Dave Crevie]

Check the model railroad department in your local hobby shop. They most likely will still have some Letraset letter and number sets in stock. Also, they

will have a good selection of Thinfilm water slide decals which are great for metal. Use Champ Decal-set to disolve the film so that only the printing will

be left. Makes it look like the letters were actually painted on.

[Phil Smith]

All my body painting experience was with race bodies. No decals. So I've never heard of Letraset. Very cool! 

 

Nice work, Martin. Is the small script also Letraset?

[Alan Draht]

Hi Martin,

 

I'd never have guessed that body has Letraset instead of decals on it.  Nice job!

 

Alan

[Martin]

Thanks Alan,Phil sorry if I detract from your intense build. I try to be respectful audience.

 

The small script is from a decal sheet. The crown I hand painted. Many years later Pola lights came out with this car in 1/25 scale.

Mine is 1/24 to maximize to width for hard body stock car racing.

[Alan Draht]

No worries.  

 

I wanted to get the"details" of the driver and drop arm spring sorted out and built before turning my attention to the rear end of the car in general and the motor in particular.

 

My next task will be to epoxy the Ram 6 volt armature, balance it, true the commutator, and finally, cut off excess shaft length on both ends of the arm.

 

Since I'm teeing up the replica Maldonado dragster project to begin soon after I complete the Husting replica, I will epoxy a couple of additional 6 volt Ram armatures at the same time as I do the Husting armature, saving time overall with a small batch process.

[Alan Draht]

Following Gene Husting's advice, I taped the commutators of two Ram 857 6-volt armatures and mounted them in the Sherline lathe.  The Husting replica's arm was mounted in the 3-jaw chuck.  The other arm for the Maldonado dragster was mounted in a pin vise. The pin vise with the arm was inserted into the lathe's hollow spindle at the opposite end.  Wax paper was placed underneath both arms to catch epoxy drippings.

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[Alan Draht]

This is the Acraglas epoxy Howie Ursaner mentioned was the choice of many NYC area drag racers in the 1960's.

 

The minimum amount you can mix at one time is 1.25 fluid oz.  I did two armatures with one batch, but 1.25 oz. of epoxy could easily do six arms if you had the equipment.

 

Needless to say, much of the 1.25 oz. batch I mixed was wasted.     

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[Alan Draht]

I set the lathe to rotate at a very slow speed, about one rotation every 1.5 - 2 seconds.

 

After the resin and hardener are mixed, epoxy is dribbled onto the arms' windings and laminations as they turn slowly on the lathe.

 

There are about 15 to 20 minutes of working time from mixing to when the epoxy begins to set up and harden.

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[Alan Draht]

The lathe's slow rotation allows epoxy to flow around the armature's windings and laminations evenly and symmetrically.

 

Turning the armature slowly like it's on a barbecue spit is the key to perfectly even distribution and epoxying success.

 

In fact, the Rod & Custom build article shows Husting used a motorized barbecue spit inside an oven to turn his armatures while first applying and later curing the epoxy.

 

Interestingly, Acraglas epoxy goes from clear at mixing to milky white after it's applied to the armature and it begins to set up and harden.

 

I kept the lathe slowly turning both armatures for a few hours until I was sure the epoxy was hard and the arms didn't need to be rotated anymore.

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[Alan Draht]

I'll let the epoxied armatures cure for a day.  Once the epoxy is fully cured I'll mount the armatures in the lathe and file off the excess at the laminations and at the commutator, then remove the tape protecting the commutator's surface.

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[Alan Draht]

After the armatures cured for a day or so, I took the one destined for the Gene Husting dragster and installed it in a 3-jaw chuck on the lathe.

 

I began by removing excess epoxy on the laminations and continued until the seven pole laminations were exposed.  Then I trued the laminations until all were equal in height and concentric with the armature shaft.

 

 

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[Alan Draht]

Next I trimmed excess epoxy off of the commutator until it was fully exposed.  Then I took the protective tape off.

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[Alan Draht]

I carefully re-installed the armature so that the chuck's jaws gripped metal laminations, not epoxy.  I trimmed excess epoxy from the opposite end of the shaft where the pinion gear is installed.

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[Alan Draht]

The finished product...

 

Acraglas comes with one tube each of black and brown dye which you can add two minutes into mixing the resin and hardener.  (Remember this product is designed for bedding, inletting gun stocks, barrels, scopes, and repairs, so black and brown are the appropriate colors).

 

The next pair of Ram armatures I epoxy will have black dye added.  They will be unique-looking armatures.  

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[Alan Draht]

I'll balance the armature next, then I'll true the commutator on a Hudy comm lathe. Finally, I'll trim off excess shaft lengths.

 

I checked to see how the Ram armature will fit on a Hudy comm lathe.

 

Since this a large diameter armature compared with most slot car motor arms, the rubber O-ring linking the Ram arm to the lathe motor's drive pulley gets stretched pretty tight.

 

If this doesn't look like it's going to work optimally, I'll true the comm on the Sherline lathe.

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[Alan Draht]

The armature was re-installed temporarily so that a set of Pittman 85 motor brushes could be installed.  (The arm has not been balanced yet, so the arm's shaft ends have not been trimmed yet either).

 

 

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[MSwiss]

Go to a hardware store, and get a bigger O ring.

It can be a U.S. O ring.

Czech O ring not necessary. Lol

[Alan Draht]

"Go to a hardware store, and get a bigger O ring."

 

I never thought of that!  So used to buying everything online!

 

I'll have to check out the Home Depot nearby, if it hasn't been looted yet.     

[Alan Draht]

The other thing I have to do with the motor is grind the upper and lower sets of laminations to conform with the shapes shown in Gene Husting's Rod & Custom magazine build articles for this car.

 

I decided that the only way to do this step right is to use a bench grinder.

 

Since I don't have or need one that's full size like Husting's, I bought a mini 3" tool grinder with buffing wheel from Harbor Freight last week online that's inexpensive.

 

It's half the cost of the same model sold online by various vendors (under different brand names), but it takes twice as long to get.  

[Alan Draht]

So, while I'm waiting for the bench grinder to arrive, I am starting to work on getting tires mounted and trued for this car and for the next dragster I build as well.

 

One of the first things that I want to try are the vintage K&B Model-Rama "German Formula" drag tires from the 1960's.  Sealed inside their shrink-wrapped packaging, these 50+ year old rubber tires are reportedly still "fresh" today and perform well.

 

I'll mount/ cement a pair of the K&B tires onto vintage Russkit rear drag wheels.

 

I'll true/ grind them to size meeting class rules (1-3/8" diameter max. x 0.500" wide).

 

I want to see if the K&B tire rubber is porous underneath its smooth skin like other German rubber, such as Graupner model airplane tires, for example.

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[Alan Draht]

The K&B tires fit perfectly on the Russkit wheels.  All I need to do is take the tires out of the package and glue them to the wheels.

 

Graupner tires take more work.

 

First I needed to sort the Graupner tires by firmness, separating "medium" from "hard" tires.  There aren't any "soft" tires in my batch.

 

I used an Exacto knife with a saw-toothed blade edge (instead of a standard razor edge) to saw the center holes out of a pair of "medium" firm Graupner donuts.

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[Alan Draht]

With this step completed, Graupner tires fit perfectly onto Russkit wheels.

 

All that's left to do is glue the Graupner donuts to their rims and true/ grind them to size.

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[Howie Ursaner]

I won a lot of races with Graupner tires on all my track cars. They were all we had for quite a while.