453 replies to this topic

[Alan Draht]

I attacked the top set of field laminations first because that's where most of the work is concentrated.

 

The bottom set of laminations involves relatively little shaping.

 

The top set of field laminations in stock form...

Attached Images

• 
• 

[Alan Draht]

After filing, the top set of laminations is shaped to conform closely with the profile of Husting's top laminations... 

Attached Images

• 
• 

[Alan Draht]

Finally, the trailing edge of the top set of laminations is angled on both sides, contoured to align with the armature's metal laminations...

Attached Images

• 

[Alan Draht]

The bottom set of laminations was removed.

Attached Images

• 

[Alan Draht]

The bottom set of field laminations was filed and contoured to match the shape of Gene Husting's laminations.

Attached Images

• 
• 
• 

[Alan Draht]

Back in the car...

 

 

Attached Images

• 

[Alan Draht]

The motor viewed from the rear of the car...

 

 

Attached Images

• 

[Alan Draht]

This dragster is in its final stage of construction.  It's a process of executing a series of small but important details.

 

One detail is polishing the magnesium rails and components.  I removed the mill finish and polished exposed surfaces, but not to a mirror finish.

 

Only the outside facing surface of each rail was polished.  Inside surfaces were left mill finish.

 

Also, instead of clear coating these surfaces, I used car wax to coat and protect polished magnesium surfaces.  True, wax will rub off with handling, but it's easier to renew and maintain than an acrylic or urethane finish.

Attached Images

• 
• 
• 

[Alan Draht]

Another detail I left towards the end of the car's assembly is fabricating nose weights.

 

In his Rod & Custom articles, Gene Husting talked about starting off testing with a 1 ounce weight in the car's nose and adjusting up or down depending on the car's starting line responses.

 

I used a low temperature alloy for this step.  This lead-like alloy melts at about 160 F degrees.

Attached Images

• 
• 

[Alan Draht]

This alloy's low melting point of 160 F degrees makes it fairly simple to use.

 

In this case, I first sprayed mold release agent into the nose of the car where I intended to pour the lead alloy.  I melted the lead alloy in a metal can over a small butane-fed burner.  Then I used a small casting ladle to spoon molten lead alloy out of the can and pour it into the nose of the car.  

Attached Images

• 
• 
• 
• 
• 
• 

[Alan Draht]

Of course you don't know how much these nose weights will weigh before you pour them.  After the lead cools and solidifies, you pull it out of the car and weigh it.

 

One of the first pours weighed 1.8 ounces.

 

 

Attached Images

• 

[Alan Draht]

If you don't like a result, you just put the weight back into the melting pot and do over.  In my case, this happened with a 2.8 oz. weight. 

 

Through trial and error I poured a series of four nose weights which I consider sufficient to start testing with:  1.0 oz., 1.3 oz., 1.4 oz. and 1. 8 oz.

Attached Images

• 

[Alan Draht]

Next I turned to work on the dragster's guide and "hairy" braid detail.

 

Rick T. generously provided a few period-correct guides and braid.

 

These are the components I had to choose from...

 

 

Attached Images

• 

[Alan Draht]

On the left are Corben guides.

 

Next is a single yellow Associated guide with so-called "hairy" copper braid pre-installed.

 

In the middle are a bunch of Aristocraft hairy braids with tabs.

 

Next is the modern Parma guide I used to build and set up the car with a pair of the Aristocraft braids installed.

 

On the far right is International braid.

[Alan Draht]

I considered using the Associated guide because it closely resembles the set-up in Gene Husting's Rod & Custom photos, but the looped braids are set into round holes, and there's nothing to prevent them from twisting themselves out of alignment.

 

I suppose that when the braid is soldered to power wiring, the rigid connection helps maintain the braid's position in the guide.

 

I wanted something less primitive, so I chose to use the Corben guide which has rectangular holes and uses set screws to lock the braid into position, independent of the solder connections.

 

(The braid hasn't been untwisted/ unraveled yet).

Attached Images

• 
• 

[Alan Draht]

To complete this project, all that's left to do, really, is to flat-spot the pinion end of the armature, flat-spot the rear axle for the wheels and spur gear, install the brushes and power wiring between the motor and the guide, set the driver/ roll bar into the chassis, tin the ends of the front axle and press-fit the front wheels, and...

 

...paint and decal the body.

Attached Images

• 

[Alan Draht]

One thing I did which breaks with strict replication of Gene Husting's dragster and the 1966 Rod & Custom class drag race rules is I replaced the stock Ram motor magnet with a modern 5/8-inch square Neo magnet.

Attached Images

• 
• 
• 
• 
• 

[Alan Draht]

The 5/8" square Neo magnet is the same size as the Alnico magnet in two dimensions, and it's 1/8" longer in the fore-aft dimension, so it sticks out 1/8" at the front end, which is hardly noticeable, especially when the body is on the chassis.

 

What is definitely noticeable is the Neo magnet's strength compared with the stock, un-remagnetized 55 year old Alnico magnet.

 

The armature and gear assembly "ratchets" when the rear wheels are turned as each of the arm's seven poles rotate one notch in the Neo magnet's magnetic field.

 

It will enable the motor to generate serious horsepower.  

[don.siegel]

Hi Alan, 

 

Must admit I don't quite understand the magnet part: why go to all that trouble of replicating a period dragster, and beautifully, and then use a modern magnet? 

 

If rezapped, the original magnets work fine - and I've had pretty good performance out of most of my 50 year old motors even without a rezap. 

 

Don 

[TSR]

I second what Don is pointing out. Why using something that did not even exist then?

[hiline2]

When we did our last Proxy drag races we did have a separate "experimental" category for modified motors with NEO mags, but for this build, at least in its intent , go with a Zapped original Mag to run then exchange afterwards and run with the NEO !

[MSwiss]

IMO, it would be way cooler if the car went sub 1, with a period motor.

FWIW, whatever motor is in Mark Mattei's car is fast enough, even on just 16V.

It's just a little rough, and he needs some time tuning up the drop arm assembly.

The question with his, is whether it will do it when he has time to glue and true up some period rubber.

[Phil Smith]

IIt's just a little rough, and he needs some time tuning up the drop arm assembly.

 

That's where I would cheat. I'd try to lock the drop arm where it didn't move and have the weight of the chassis on the guide.

[Dave Crevie]

I was withholding comment until this project was finished, but I think it is close enough at this point. Alan, this has been a totally amazing coverage of how you built this car. Far more than I would have ever expected. The work is absolutely top notch, and it shows in the results. Can't wait to see it run. 

 

I would not deviate in any way from the methods Gene used. It pollutes the mean purpose. However, if you are wanting to build a better version, that is another story, and your prerogative. I do know that very few of us had milling machines at our disposal, so much of the work actually was done by hand using a hobby grinder. Mine was a Craftsman "Lil' Crafty" from Sears Roebuck. That being said, Gene had a lot of equipment at his disposal, so who is to say exactly what was done if it wasn't related in detail in his articles. Thank God he had a good relationship with Jim Miller and the other guys at Model Car Science magazine, or we would probably never know how he did things. One good memory I have taken with me of slot racing in the early 60's is how willing the "big guys" were to share information. I was a teen-aged nobody, and generally ignored by the "pros", but if I had a reasonable question, I usually got an honest answer. That changed when the manufacturers started fielding teams, and proprietary information was closely guarded. In any event, it was a great time to be growing up, and set the direction my life would take. Bringing all that back so that those who missed it could experience it, is a great

gift to give to the hobby.     

[Alan Draht]

Happy July 4th!  

 

I can easily reinstall the original Ram Alnico magnet and put the Neo back in its box, but I'm here to tell you that the original magnet is so weak that without the brushes installed I could twirl the wheels and spin the armature freely.

 

No bueno.

 

Very little of the Alnico's magnetic strength is left and if I were to try running it on Mike's drag strip as is, the results would be pitiful, not to mention there's a high probability the motor will fry before the car makes it to the finish line... at any voltage.

 

So, the question is this:  Where exactly does one re-magnetize a motor such as this in the USA, using the monster Simco or Carlysle remagnetizer's of yesteryear?

 

That's the only way this dragster is going to work.   Otherwise, we're talking shelf queen.