81 replies to this topic

[dc-65x]

I don't know Martin you'll have to give it a try.  Rubber is not the easiest to machine cleanly.    

 

Personally, I really like the flat bottom grooves the saw blade gives and the blade cut so cleanly. I fed the blade in slowly to a depth of .010", stopped and let it sit there and spin for 30 seconds or so. I think that really helped clean up any fuzziness in the grooves.

[Martin]

Your results look great 

 

I am trying to come up with ways to create the grooves in one pass, to set the spacing. I may try and stack blades with a pre set space between them so they cut together in one go. 

 

The only time I did cut grooves, it was on a O-ring tire, there I used a small hack saw blade so I could follow the curve. A bit hit or miss, but it got it done.

Its fun to come up with ways to create details like this.

 

[dc-65x]

Thanks Martin. You did a really nice job free hand grooving that o-ring tire.

 

I made up the 1/4" wide brass strip main rails and encountered a clearance issue with the rear wheels. The strip is wider than the axle bushing it needs to attach to. A little trimming fixed things:

 

 

The first steps in construction are complete. Along with the main rails I added a drop arm upward stop and an and "anti-spread bar" behind where the drop arm pivot will go:

 

 

The excess piano wire is trimmed and the chassis cleaned up a bit with a Scotch-Brite pad:

 

 

 

There is only one way to describe the chassis so far. Just as Steve Okeefe predicted:

 

 

I've talked to Rodney about the extreme weakness with just those 1/32" thick brass strip main rails. Since I'm building a proof of concept prototype chassis from the MESAC proposal drawing, I'm going refine things  bit.

 

The next step will be adding a piece of 1/16" piano wire to the outside of each main rail.

[dc-65x]

The MESAC proposal drawing shows "optional bracket stiffeners". Here's my jig setup for their installation to attach the motor bracket to the main rails:

 

 

After installation, trimming and Scotch-Brite pad cleanup:

 

 

The drop arm hinge tubes also get attached:

 

 

Trimmed and cleaned up:

 

 

The drawing shows an "optional cross piece" which is U-shaped to connect the main rails to the front axle tube. Since I'll be installing piano wire main rails to the axle tubes, my cross piece is a simple straight job:

 

 

Up next is my first real deviation from the proposal drawing, the addition of a piano wire rail to each 1/4" brass strip main rail. Hopefully that will cure the chassis from going "boing - boing - boing".  

[Steve Okeefe]

No doubt the "optional bracket stiffeners" will go a long way to help strengthen the motor mount.

 

It's the part from there to the drop arm hinge, and to a lesser degree from the drop arm hinge to the front axle.  A piano wire rail on each side should do the trick. much like the late 1967 / early 1968 "rod and strip" chassis:

 

 

 

 

Looking good! 

[dc-65x]

Thanks Steve.  

 

The piano wire outer main rails have simple 90 degree bends at each end. I leaned the rails over until they touched the rear bracket. That let them clear the wheel's set screw bosses:

 

 

A rough cleanup with a Scotch-Brite pad:

 

 

I added 1/4" squares of .032" brass as spacers for the pan mounting cross bars:

 

 

The chassis is now plenty strong. Before adding the wire rails I was afraid of bending the chassis simply handling it:

 

 

The pans go on next:

 

[dc-65x]

Installing the pan cross bars:

 

 

Pans installed and a rough cleanup with a Scotch-Brite pad:

 

 

Starting to look like Veteran class chassis:

 

 

Next I have to come up with a body mount for a 2 1/2" wide chassis that works with a 2 3/4" wide body and attaches above the bodies "bazooka's" (side pipes).

[dc-65x]

I needed to raise up the pin tube body mounts above the bodies molded in side pipes. I decided to use 3/32" X 3/16" rectangular tube.

 

The Rick's jig is amazing. Below is the setup that holds the little rectangular tubes in place at a 2 3/4" width and aligns them fore and aft.

 

Here's jig with the setup........

 

 

.........and with the chassis and the rectangular tubes held and aligned in place:

 

 

The setup worked great. Here's the chassis with body mounts in place after a rough cleanup:

 

 

 

 

Body set on the chassis:

 

 

The rear pin tube has to fit in a  rectangular depression and above the side pipes:

 

 

I think the stance is looking pretty good:

 

 

The last thing to tackle on the chassis is the drop arm.

[dc-65x]

In my effort to beef up my especially flexy chassis it ended up a bit stiffer than I'd hoped. In my perfect 20/20 hindsight I wish I'd used 1/16" brass rod in place of piano wire for everything but the motor mount U-brace.  

 

In an effort gain a bit more flex I cut the front pan cross piece:

 

 

The final piece for this chassis is the drop arm. I cut up a very used Parma style arm. The packaged arm is shown for reference:

 

 

With the drop arm installed and a bit of polishing the chassis is finally finished:

 

 

 

[breese]

Wow!

A true craftsman at work....

[Slot Car Rod]

Here is the Veteran Class chassis I just completed.  It is built like the one in the class proposal drawing.  Rick and I were curious about how a spec. one would run compared to the modified ones.  The brass strip main rails measure .034" thick.

 

 

 

 

 

 

[dc-65x]

Looks great Rodney.   

 

That's a second new Veteran class build.  

[dc-65x]

With the chassis finished, the wheels and tires all trued and ready to go I decided to just throw the thing together and get it on my track for a shake down. I'll shorten the long axles and clean things up later.

 

Since the endbell was already cracked at the bearing I decided to tap the mounting holes so nothing else cracked. With the brushes removed any plastic chips can be blown out of the motor:

 

 

Since this is a 1971 build I used a JET flag and attached it with a nut:

 

 

The crown gear is a 35T Weldun:

 

 

After running this car I was reminded why the 36D Mabuchi's pretty much replaced the Pittman's, Kemtron's, etc. with the average racers at the commercial raceways. It's pretty fast, has good brakes, runs cool and it's cheap.

 

It also set the fastest lap time for my urethane tire equipped cars:

 

 

My other cars and their lap time are in the link below;

 

Track test lap times

 

There is a caveat to my lap times with the Veteran car. I didn't have a set routine for prepping the track surface for  testing the previous cars. I used a method for the Veteran car that worked great for urethane tires and avoids spray gluing the entire track.

 

I clean the track with a Swiffer dry floor duster to pickup most of the dust and wiped my lane down with lighter fluid and a rag.

 

There is still enough dust on the track to really hurt performance. I can run just a single lap, the car gets squirrely and the tires are covered with dust again. I can clean the tires and repeat a thousand times, the tires still pickup dust and traction goes away after one lap.

 

BUT, if I put a little dot of glue on the tires, rub it in and run a lap the tires really pickup that dust. Cleaning the tires with lighter fluid and repeating the process a couple more times and the dust is gone.

 

Then I set the car at the start a turn with the dots of glued rubbed into the tires and drive a few laps. After repeating this for each turn the track is fine to run lap after lap without being squirrely. I really can't even see the glue on the track.   

[Steve Okeefe]

How much does the car weigh?

[dc-65x]

Hi Steve,

 

The car as pictured weighs 161 grams.........or as we used to say in olden times, 5.7 ounces:

 

 

The car has no bad habits. It doesn't tilt or understeer out of the slot. I'm sure it's not the fastest Veteran class car there is but it is very fun to drive.......I like it!   

[Steve Okeefe]

That's a big boy, but not all that surprising given that the 36D motor weighs 51g (1.8 oz.) al by itself.

 

Perhaps in this case the chassis being so stiff in addition to being heavy actually helps the handling.

 

You wrote: "The car has no bad habits."  You may be on to something here.

 

[dc-65x]

I'm happy with the way the car runs Steve so it's time to finish up the way it looks. I fired up the hobby lathe and attacked the wire wheels from the reissue Monogram Ferrari 275P model kit:

 

 

The chrome on my particular example was very thin with lots of red plastic still exposed:

 

 

I used a black wash to cover the red plastic and fill in-between the spokes:

 

 

 

Time to paint that Maserati body.

[Slot Car Rod]

I did a Veteran Class comparison test with the Veteran Class MESAC (car number 20) Ferrari and my spec Veteran Class chassis car (car number 23).

 

According to Victor, he believes the chassis in car number 20 is from the 1972 MESAC Veteran Class championship-winning Don Sloan car.

Car number 23 is built to the original Veteran Class spec sheet design.

 

Tests were done on a small, routed track where 4 second lap times are typical for the Veteran Class cars.  The MESAC car number 20 is about two and a half tenths of a second faster than the spec car number 23 (grey tires).  The MESAC car number 20 is also easier to drive, has better brakes, and you can really push it.  The MESAC car has a real pro car feel to it.  The spec car was fast and fun, and easy to drive.  No tilting with either car.  When pushed, the tails would drift out a little.

 

In my opinion, the Veteran Class would have made a fun race class.

 

 

Tires on car number 23 later changed to grey sponge.  Grey sponge tires were two tenths of a second faster than urethane tires.

 

MESAC grey tires.

[Mark Onofri]

This is what I had in mind but, your's looks like a better idea. Although,a Bonner powered version would rock.

Attached Images

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[dc-65x]

I finally have my Maserati in paint:

 

 

 

Black detail painting is next........

[Pablo]

It's a cute little bugger  

[Martin]

So glad you cut the built in interior out  I never did like bodies that had the intoror as one with the body. 

Looking good Rick.

[dc-65x]

Thanks Martin. 

 

That molded in interior was a pain. The "inner and outer" plastic of the sides of the windscreen were so close together a piece of paper barely fit between them. How did they make a mold that would do that?

 

 

Hi Pablo, here's the that little bugger for real:

 

 

Here's a link to a story on the history of this car from a VeloceToday.ccm article. It is a cool story with great period pictures:

 

Maserati 450S

 

Check out the engine in this thing  

 

[Martin]

Great history Rick.

Things do go better with Coke.

Love the air jack feature and the connection with Jim Hall as a driver of this car.

[Pablo]

From the big driver's smiles I'll be it was a real hoot to drive