49 replies to this topic

[Bill from NH]

Nice start Pablo! If that square tubing doesn't show up, take a piece of round tubing & sand it top & bottom.  I need some flat brass wire for a project, I'm going to make mine from brass rod.

[bluecars]

:good:ANOTHER ONE, ANOTHER ONE

[Pablo]

take a piece of round tubing & sand it top & bottom.

Bill, that sounds like a good project for Bunky - I'll just keep telling him "Bill swears it works great for him"

 

I think I have this build all planned out now.

-single square tube rails from the FSF bracket to a 1" long front .063 chunk with the Turning Man tongue

-.093 thick 1/4 wide brass strip pans connected via "shaker" type center weight .032 platform

 

A little history is in order first.

Square tubing rails - I believe I was the first to try them in retro. But they were more than just tubes - they had .055 wires soldered inside.

A tricky thing to do, I assure you. Any time you solder long lengths of wire to brass, it wants to curl like a Lay's Potato Chip.

The first couple of cars (usually F1's) I built with them were successful enough, so I built more.

 

I studied several worn out square tubers I had retired in my "Boneyard" drawer to get ideas for this new John Clow F1.

One thing stood out - it appears I've been trying to make each and every one slightly stiffer (in the rails) as time went by.

 

Enter the influence of one Marty Stanley, a racer who is as interested in trying weird things as I am

He was a square tube believer from the beginning, and even sent me computer designed drawings of his thoughts on how to improve them even more.

I used some of Marty's theories in making these (slightly stiffer) new generation rails. I hope they retain the magic that made them work in the first place.

 

Now enters the influence of Rob Hanson. I will always remember him, and Bill Fulmer, picking me up at the Chicago airport for a SANO race.

Like Da Cheater sez, "People are the best part of slot car racing". At some point in his son's growth, Rob dropped off the slot radar to give him full attention.

Anyway, years ago, Rob built a F1 D3 (skinny) car for Da Cheater to race in a Checkpoint Cup race in SOCAL.

 

 

Being the ambassador of the hobby he is, Cheater loaned the car to someone and he crashed it hard. Down the road, I was chosen as the guy to fix and restore the car to it's original state as a race car. The only change I made, as I recall, was upgrading the body mount/pan connectors from .063 brass tubes to stainless steel tubes. I think Rob would have approved.

 

I tested that car before I handed it back to Cheater - it handled like a bullet train. I was pretty impressed, and since that day I've wanted to build a similar car with those heavy .093 pans. This is "that car"   Rob's was a skinny D3; imagine what a full width IRRA® 1.625 car will do !

 

Turning Man tongue makes it too easy; tilt is already built in  Tinned it, alligator clipped it, and minitorched it. Perfect, first time.

I beveled the upper edges of the chunk where the tubes connect a-la-dc-65x to allow solder to pool for a super strong connection

[Bill from NH]

Pablo, I won't dispute whether or not you were the first to use square tube main rails in retros, but when did you build your first square railer? Two of the early ones I recall were Can Ams in California. Mike Chavez, who raced at BPR, built one in May, 2007. Steve Walker who raced mostly at Santa Maria, built his June, 2007. IIRC, both used hollow tube rails. Mike's chassis had interchangeable pans of different weights. Photos of both these chassis were posted on Slotblog, but those of Mike Chavez have been removed. Two or three years ago, a square rail Steve Walker roller was being sold by someone else on eBay, I compared the photos of it to Steve's original & it wasn't the same one, so he built some square rail chassis for other racers.

[Pablo]

Rails tacked on to bracket and chunk, in the jig

 

Then out of the jig and checked on a very flat block

 

Looks good to me

[Pablo]

Rail solder joints are finalized, but final length trimming comes later.

I told you it was tricky. Not necessarily better, just tricky

 

[bluecars]

GREAT build so far.

[Pablo]

Thanks Red

Placing a 20 thou steel shim under my .055 front axle uprights when I tack them in raises them exactly midway up the rails.

That way they lay in the tube "valleys" instead of flat on deck, where they would inevitably end up fouling my flatness goals

The steel won't solder to the wires like brass would.

[Pablo]

Mike Steube inspired almost everything here, except for the .032 brass rod awaiting it's destiny as an axle wrap:

[Pablo]

The track will break long before this front end does

[Pablo]

.032 shaker pan needed about .063 height to match the rail/pan levels.

.135 wide .063 brass pieces on both ends of the shaker do the trick.

I used silver solder so when I add the pan connectors and SS pin tubes with 60/40 they won't move (I hope )

Looks a little crooked in the pic, but "it all comes out in the wash"

 

Shaker assembly ready to go with Koford SS pin tubes and .047 wire connectors

[Pablo]

Ready for the final steps

[Pablo]

Tacked

 

Checked for flat and true

 

The completed pan assembly will drop right onto the center section

 

My trick with pieces of tape around the width pins worked well - pans are 1.615

[Pablo]

Ready for tumbling

 

She's a heavy bugger, 68g here, and I'll guess total race weight at 120g.

My intention for the heavy pan/shaker was balance point and centralization of weight about midway between rear axle and flag shaft.

Track test this Saturday.

 

 

[Bill from NH]

When you can, shoot a photo from the front of the front axle uprights. I want to see how you wrapped those joints with the .032 brass rod. I haven't heard of it being used for that purpose.

[Pablo]

Will do, Bill, when it comes out of the tumbler in the AM

I've been using .032 rod to wrap front axles for a while now.

[Bill from NH]

I've been using SS wire, marketed for veterinarian staples, for that purpose. Modelville Hobby sold it during the early & mid-70s. In those days it was customary to wire wrap more joints than just front axle uprights.

[Tim Neja]

HI Paul,  beautiful work as usual. The square tube seems interesting from a flex/handling standpoint.  But won't it be a little subject to "tweaking" in a shunt?  The brass doesn't have memory like piano wire. Curios-- nice looking build!

[Pablo]

Thanks Tim, I think the photos will answer your question

 

 

 

 

 

 

[Eddie Fleming]

Great looking chassis as always from you.

 

Looks like the pans have a lot of movement. No my bad the center pan is the side movement stop. Dummy!

 

It will be interesting to see (hear) how it works.

[James Grandi]

Pablo,

If you don't mind my asking, did you use a micro torch to solder the piano wire in the square tubing? I've always had trouble getting things to stay flat when soldering a long piece of wire to flat brass ( for example, as a brace on a pan ). I've only used a soldering iron for building however - my micro torch is generally used for disassembly only

[Pablo]

Thanks, Eddie, and (you are no dummy) there is a lot of pan movement in this chassis in it's present state.

Easy to tune for less movement. Yes, the shaker platform controls things to a certain extent.

I agree with you, it will be interesting to see how it handles.

If it's too stiff, I can slice the rails off and install new ones with more flex

 

James, thanks for asking, but no heating method will ever solve the problem of steel vs. brass.  Please read my previous posts in this thread.

 

My worries about too much fat are gone - the car weighs in at a svelte 116g

[Pablo]

Track test results:

I think Marty Stanley was right on the money with his theory - it handles like a bullet on rails, possibly better than the Hanson.

No bad habits noted. John loved it and took it home with him.

End of story

[Bill from NH]

Did you beat Red who likes blue?  

[bluecars]

He felt sorry for me and let me win a couple this time. His F1 was awsome!!!