The Blue Mist ISO

Recently I received a package from Richard Picard containing the most interesting Riggen based HO slotcar I’ve seen. To those of you who keep up with developments on RiggenHO, you will have seen Richard’s work, especially in the “How to” section where he outlines building an ISO chassis.

Richard’s most recent build replicates a chassis seen on Slotblog of an HO ISO period chassis. To the best of our knowledge, the car shown on Slotblog has never been completed. All the same, it is a fascinating item of work with great attention to detail.

I asked Richard about the Slotblog car and what the issues were in replicating that car:

“To be honest this chassis was a real beetch to build. While watching the bits play out over on the it seemed magical - and inspiring.... now I know why Dave has not finished the car... I don't think it actually is all that period correct - parts maybe, even the idea, but if anything it must have not been a popular modification.”

“I say this for two reasons. First - if it was, we would have more evidence of surviving examples of this mod. Second - the wiper system is not really all its cracked up to be... now some of this may be due to my interpretation of how this project was to be completed. I imagine Dave was going to fit it with custom wipers. The Phosphor bronze I have I find a tad too thick for my liking, so I opted for the Tyco wipers instead. So I had to drill out the holes - not easy to do on such thin material.
Trying to unscrew the nuts and bolts on the guide is a pain, so what looks like a serviceable guide compared to the stock discardable Riggen unit really does not buy you much as it’s really tedious to get back together. But building it has given me some insight to a better guide that may be something to continue to develop.”

To the readers who are not aware, Richard does a lot of work with resin HO bodies that are supplied to various outlets such as HO Slot Car Racing. He also was the designer for the wheels on the new Tomy Mega-G car that was released in December 2008. RiggenHO will in the near future feature a Limited Edition based on his “Thing 1” body that has recently gone into production.

For this particular car, Richard has replicated a period body. He calls it “my Thing 2 body - based on the Lancer Mongoose.”

“It was a printed prototype that I sanded and filled and did two pulls off of it. Its close but after looking at some original pics I think the nose needs more of a point to it.”

We’ll give him a pass on the nose detail this time. It’s just to cool and painted in a great period correct color and style. Two thumbs up Richard!

As with any new and untested car, I put them on the track with a certain amount of fear and trepidation. And this was certainly the case here multiplied many times. My fears were turned into questions after the first few laps. It ran as if the motor was bound up and with a ton of rail scraping noise. I did have to sort out a few small details. These are in order of done:

1) Checking the motor’s amp draw showed nearly .75 amps unloaded. This is waaaaay too much. I suspected the brush springs. Richard did a nice touch with Wizzard brush barrels with the screws and soldered-on shunt wires. The brush springs were trimmed and had hung up in the barrel threads and was putting too much pressure on the brushes. Because of this there was also no ‘back pressure’ on the barrel screws. I put in standard Tyco brush springs and the amps went down to .27ish which is about right for the hot arm.

2) The guide pin was too long for the Bowman and had to be trimmed back. Richard didn’t have any problems with pin’s length on his Bowman. So I suspect that there may be a few thousandths difference in the slot bottoms of our respective tracks.

3) The motor can lock-down nuts needed some Loc-Tite. The motor was a touch loose and the car hopped under hard acceleration. We’re only talking about maybe a 10th of a turn on the nut. I believe it was tight to start with, but early stress and vibration loosened them a hair.

4) Added some lead in the ‘prescribed’ places to hold the front down some for my taste.

5) Switched to Wizzard rears that seem to do better on my Bowman road course.

After these few teething pains, the car is a Spit Fire! The motor is of particular interest. The armature is a Wizzard SP-05 balanced green wire. It will push any gravity car well beyond its limits and a few magnet cars as well. The can has been repainted to match the body. The endbell is held into the can with pin for a never-fail R&R pin system.

Of great interest is the detail where the original factory brush barrels have been replaced by Wizzards. This solves a few problems. One is that brush servicing is now a snap and as easy as any Wizzard Storm or P3 car. Also the brush tension and amp draw can be fine-tuned for best motor performance. More importantly, the barrel shanks allow the pickup shunt wires to be soldered on for a never-fail connection.

The pickup system is very nice. Something of this sort is what I envision as the standard replacement for the Oscar that has been utilized on past RiggenHO LE cars. This particular example uses a delrin machined plate with lots of brass attachment hardware. The guide pin is custom unit. The original idea for wipers was to use the hand-trimmed copper material for period correctness. But the Tyco wipers are somewhat plentiful and allow quicker adjustments.

The chassis itself is a complicated item for HO scale, much less a larger scale car. The side ISO arms pivot just ahead of the rear wheels. The fronts of the ISO arms incorporate a bumper system to protect the pickup plate. A period detail is the spring mounted body pin tube holders. With some Vibra-Tite on the nuts, one can adjust the ‘shaker plate’ action for the body.

The car runs very well. That may sound like and easy statement, but one has to consider that this a one-of-a-kind build. It’s one thing to take a pile of factory and limited run parts and hang them together for the Limited Editions. Some fine tuning is then involved to optimize each chassis. It is another matter to be able to take a concept and guesstimate all of the parts interactions and what that means on the track. This is no small accomplishment.

I too have been following the ISO car on the net that this one is inspired from. I’ve had a vision for a simpler design based on the Picard CNCed RiggenHO chassis that has been utilized in the past few LEs. Granted it would have nowhere near the ‘sex appeal’ this car has but would be an affordable runner.

Richard has had similar thoughts and this is his response:

“First - I'd loose the motor mount and use the stock Riggen snap from my modified chassis.

Second the guide would be redone - screws would be #0-80 flat blade screws, rather than the hex head #2-56.

Third - I would retain a similar guide pin set up - if anything of JW's adjustable depth units would work great here for fine tuning.

Fourth - the screws would not pass through the wiper, and rather get sandwiched between the lead wire and the brass backer plate – kind of like some of the TCP pans variations I have found where the wipers were "clamped" rather than glued on.

Fifth - the ISO configuration is limiting with use of a rattle plate - or "floppies" as this chassis had. The ISO basically takes the place of the stock Riggen rattle plate, and dampens vibration - and isolates it from the chassis just as well as the plate - having "floppies" on top of the ISO is just redundant, and takes up too much space and can get in the way of the brush tubes....especially the larger adjustable type.

This is one of the reasons I believe Dave stopped working on the car on His last installment showed the completed motor with fork terminals on the wire leads. Dave sent me some, and man they are still to big and the ISO would not move at all with them on - which lead to the direct soldered connection. So I think the best configuration would be an ISO pan with no floppies and having body mounts like the Super II - front ones - possibly as part of the bumper system, and rear ones - with nothing near the brushes. The ISO could be a simple rod style instead of the narrow brass sections.”

So there you have it Race Fans! One man’s quest to complete another’s. Also I have to say on my end that one has to be careful what he prays for, he might just receive it.

Race more Riggens,

Terry Flynn