453 replies to this topic

[don.siegel]

Yep, those were the two main ones sold commercially Alan, and they seem to have been pretty good sellers. 

 

There were only a couple more available, perhaps only as bare chassis, not the complete kit by Russkit and K&B (sans motor and gears of course). 

 

One from Ayogi in Japan, actually a major supplier of brass parts in the US and UK, including all those nice little American Russkit parts. And the other, highly sought after these days, from International. 

 

 

 

Really looking forward to your work on the magwinder. Here are a couple I found many years ago, before a lot of folks knew or remembered what they were, and one with some pretty serious pitting and oxidation! 

 

 

 

Also this one, with a fascinating partly home-built motor... 

 

 

Don 

[Alan Draht]

Don, those are really cool photos of your vintage dragsters.  Thanks for posting them!

[Alan Draht]

Yesterday, I cut out four flat pieces of magnesium, 10" long x 1-3/8" high, from a sheet of 0.063 thick mill-finished magnesium sheet.

 

I also checked through my stockpile of vintage dragster project-related parts and motors.

 

In other words, I've started my project.

[don.siegel]

Thanks Alan - the short one is of course an alu-winder! 

 

If you need any specific parts let me know, I might be able to help out. 

 

Don 

[Alan Draht]

Thanks, Don!  

 

The plan is to build two Top Fuel dragsters.

 

One will be a replica of Gene Husting's record-setting 0.998 sec car as detailed in his how-to-build series of articles spanning four issues of Rod & Custom magazines, December 1965 through March 1966.  I acquired copies of these old magazines on eBay over the years in preparation for today.

 

I actually remember reading these same Gene Husting articles when I was a kid thinking about doing this fifty-five years ago.

 

The second replica I will attempt to build is of Manual Maldonado's "Car of the Meet" Top Fuel dragster, as pictured in Post #199.

 

I cut four pieces of magnesium sheet to create two sets of rails.

 

I think that I have enough parts that it won't be necessary for me to cannibalize the Russkit and K&B cars.

 

Still, having these cars is very helpful in determining spatial relationships, dimensions, etc.

[Alan Draht]

I will start a new topic in this "Pro Racing Cars & Replicas" section of Slotblog since technically I'm done with this topic of "Re-creating Howie's rocketship -- 2018".

 

Before I do, I have some questions.

 

The first has to do with magnets.  I've searched Slotblog and the internet but cannot find anyone who has an old Simco wire-wound magnet zapper like we had in olden days to re-zap the stock Alnico magnets in Pittman and Ram motors.  If there's no way to do this, then I'll have to figure out if I can substitute eo magnets.

 

In 2013 or thereabouts, I did buy a fairly large Neo magnet where I parked both stock Pittman DC-196 and Pittman DC-85/ 84 Alnico magnets, all correctly aligned in terms of magnetic pole orientation, in order to re-magnetize or strengthen them.  I've never checked to see how "strong" they are because I don't have a gauss meter.  For my previous project I used Neo magnets instead of stock Alnico magnets.

 

The next question is also about motors.  I have accumulated enough vintage parts to build a couple or more "pro" motors for my two replica dragsters.  This includes the mandatory 6 volt Pittman and Ram armatures.  Somewhere along the way I also acquired a 3 volt seven pole Ram armature.  The question is, is it even feasible to use a 3 volt armature on 24, 30 or 36 volt drag strips?

[Alan Draht]

I have other project-specific questions which I can save for the new forum topic discussion, but I am asking this...

 

Hey Fred,

 

If possible, can you post photos of your Top Fuel magwinders?

 

I am particularly interested in the rear end of Maldonado's dragster, how exactly the motor, minus its stock end plates, fits in between the mag rails, how the rails are tied together with the motor, including the brush assembly, sandwiched in-between them.

 

In contrast, Gene Husting's car is built like the kits pictured above in the sense that the motor's modifed end plates and brushes fit through the mag rails.  The rails are the width of the stock motor and are parallel from back to front. 

 

Maldonado's magwinder and others from that era are wider than Husting's car at the rear.  Maldonado's rails taper in from back to front.  With others (like Bob Braverman's car) the rails are parallel -- as wide apart at the front as they are in the rear.

 

I've tried to make out the details of the rear end of Maldonado's car in the few photos I have and there will be a lot of guesswork involved in building a replica if that's all I have to go on.

[Dave Crevie]

Don; cool collection. Brings back the days when slot drag racing was just starting to catch on. There were so many beautiful magwinders

built by the west coast guys. But there were a few that were just cobbled together. All part of the scene back then, and deserve to be preserved. 

[Alan Draht]

Here are some photos of Gene Husting's dragster taken from his Rod & Custom articles.  You can see why I want to build one of these.

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[Alan Draht]

...

 

 

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[Alan Draht]

And here's Manual Maldonado's "magwinder" dragster -- the only photos I have, but just enough to go on.

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[Uncle Fred]

Oh I wish I still had the cars, let alone photos.  

 

A true Magwinder did not use end plates making the spacing and rigidity of the rear end of the chassis critical.  Leaving the end plates in place and lightening them eliminates most of that.

 

A 6 or a 3 volt arm will work on any of those voltages. Keep in mind if you are really going to run 30 or 36 volts with serious amps you need lead wire that can handle it and lots of brush tension.  

[Alan Draht]

Thanks, Fred.  I really appreciate it! 

 

I'm psyched about building both cars.

 

I will build the Gene Husting replica first.  As you said, that car will be easier to build than the true Magwinder that Maldonado built, both because of its design incorporating lightened motor endplates, and because I have Gene Husting's instructions to follow! 

 

Yesterday, I bolted together two pairs of .063 thick magnesium plates, 10" L x 1-3/8" H, using 2-56 screws, one in each corner.

 

Today, I plan to clamp one pair to the milling machine table and begin straightening and squaring all sides/ edges of the assembly, then do the same for the other pair.

 

I sawed these pieces out of a large sheet using a hacksaw, so they're not perfect, but need to be in order to begin the project.

 

Per Gene Husting's instructions, the pairs are bolted together when holes and openings common to both rails are machined in tandem for perfect accuracy and alignment.  When holes/ openings/ features are unique to a left or right side rail, the plates are uncoupled and machined separately.

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[Half Fast]

Does anyone remember the drag strip at the the big slot car place under the 7 train EL on Roosevelt Ave in Queens NY?

 

If I recall correctly, it had smooth buss bars rather than braid along its length, very fast.

 

 

Cheers

[Uncle Fred]

Yes.  The best strips were formica with smooth rails for contact.

[Alan Draht]

I have milled straight parallel edges on the top and bottom sides of both magnesium plate assemblies.  Now they can be securely clamped in a mill vise and machined.  The bottom remains flat of course.  The top of the what will become the car's rails will be shaped to the profile of a Top Fuel dragster as pictured above, but not until all holes and openings are drilled, the interior areas carved out and shaped. 

 

Putting that aside for awhile, I got involved in trying to solve the issue of re-magnetizing the Pittman 85/ Ram 850 motor's original Alnico magnet.  I tried in vain to find a suitable magnetizer like the old Simco machine on the internet and I've concluded there's no way that's ever going to pan out.

 

So, my solution is to use Neo magnets, which I have ordered from K & J Magnetics.  (I used K & J as a source for the Neo magnets I installed in the modified Pittman 196 motor used for my re-creation of Howie's car).

 

Neo magnets should be significantly stronger than the Alnico magnets were when they were new 55 years ago.  With this project in mind, five or six years ago I did take a few complete stock Pittman and Ram motors and placed them in surface contact with a large (and dangerously powerful) Neo magnet to see if I could re-magnetize the Alnico magnets and lamination fields over time.

 

I checked the motors and their Alnico magnets do seem stronger.  My test method is unscientific.  The armature "clicks" into position as I turn the shaft with my fingers.  I could not feel any magnetic force when I did this test before.

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[don.siegel]

Alan, 

There's a guy currently listing a new remagnetizer for can motors on SlotBlog. I asked him if his machine could work on open-frame motors and he said that he thought he could adapt it for that use... I think they're about to be rolled out, so you could ask him if he's made any progress. 

 

I tried the neo trick and it didn't work, but not very systematically, and not with an especially powerful magnet. 

 

The one guy we knew here with an old-time remagnetizer was John Secchi in North London, who just passed away from the virus... I think it's a Simco. 

 

I remember reading a hint a number of years ago that you could go into an old model train store and they would have one, but when I tried that, probably 20 years ago, the guy just laughed and explained to me they haven't used permag DC motors for a long time now. Maybe there's still a real old-time dealer who would have one, however. 

 

Don 

[Alan Draht]

Thanks, Don!  

 

I'm not relying on bringing the old Alnico magnets back to life for use in my dragster's Pittman or Ram motor anymore.  Equal size Neo magnets are the way to go.  There's really no other choice for a dragster built for racing, not for show, although these cars will shine in that regard, too.

 

In fact, since the Neo magnets are probably stronger than new Alnico magnets ever were, the effects may ripple through how the modernized replica dragster is geared compared with how Gene Husting geared his.

 

The same is true for today's tires compared with the cut down Graupner model plane tires of yesteryear.

 

Lot's of new variables to make things interesting.

[Alan Draht]

The problem I'm working on now is gearing.

 

Early in the build process of his dragster, one of Gene Husting's articles talks about and shows photos of him taking a Weldun 64-pitch 23 tooth pinion gear on a 1/8 - inch shaft and placing it in a hole he drilled through the mag plate assembly using the motor's brush side endplate as a guide to positioning the armature shaft bearing.

 

Next he takes a 69 tooth Weldun gear and places it against the 23 tooth pinion with centers in line.  He marks the position of the hole in the 69 tooth gear on the magnesium and then drills a 1/8 - inch hole.  The rear axle goes there.

 

This gear combination yields a 3:1 ratio which was Gene's starting point for testing and fine-tuning his 6-volt Ram motor - powered dragster's performance on the drag strip.

[Alan Draht]

The problem is that I don't have a 69 tooth Weldun gear.

 

I do have one 70 tooth, and a couple each of the 66, 64, and 63 tooth Weldun spur gears.

 

In order to exactly replicate Gene Husting's system of gear combinations and ratios for this car, I need to obtain the missing 64-pitch Weldun spur gears: a 69 tooth, as well as the 68, 67 and 65 tooth gears.

 

Luckily, I also do have a couple each of the full range of useful Weldun pinion gears, 18 through 25 teeth, although most of them have 0.093" pinion shaft holes that need to be reamed out to 0.1250".

[Alan Draht]

This is critical because the 69 tooth / 23 tooth combination and 3:1 ratio is what establishes the dimension between the pinion's center and the axle's center.

 

Once the dimension between the two centers is established, the axle's hole is drilled through the magnesium rail plates.

 

No physical adjustment of that dimension between gear centers is possible.

 

Changing from a 3:1 gear ratio to another ratio while maintaining the same gear mesh between the axle and the pinion gears involves going from a 69 tooth / 23 tooth combination to a 68 tooth / 24 tooth combo, or a 70 tooth / 22 tooth combo, as an example.

 

Since Weldun's 64 - pitch 18 tooth pinion gear is as physically small as it can practically get and still function properly, only the upper range of 60+ tooth axle gears produces useful gear ratios for this dragster.

 

Gaps in my inventory and range of axle gear sizes creates a major problem.

 

I have built an impromptu jig to test out useful gear ratios using the gears I have to find out if there is a dimension between the pinion and axle centers that can be used in common for a decent range of ratios above and below 3:1.

 

I am afraid, however, that I'm going to need to fill the "gaps".

[TSR]

Alan,
I have some Weldun 64P gears, I will check if I have a 69T. Give me a few days.

[don.siegel]

Same here... 

Don 

[Pablo]

Here's what I have:

 

-My biggest Weldun 64P is a 66T.

 

-I have three Weldun 64P pinions with .125 bores: a 23, a 25 and a 27

[don.siegel]

I've got a bunch of 66T, a 68 and a 70 - no 69s! 

 

I think it was EJ's Hobbies that had Weldun gears at one point - might be worth checking with them. 

 

And if you want a 66, a 68 or a 70, just say the word. 

 

Don