Regulating T-Jet Downforce

[NicoRosberg.]

Dash products are not available to all, so they should not be allowed, period.

[Maddman]

Dash products are not available to all, so they should not be allowed, period.

Tell that to the Fray organizers and other groups that allow Dash products and other not widely available items. In turn they will tell you something you may not wish to hear.

Seriously, the Fray started with the John Deere lift pin test years ago. It worked. The pins were inexpensive, widely available and were all alike. If you car picked up the pin it was illegal. A short, easy to administer test. I don't know why it was dropped. It could be that the lift pin test was dropped as AW, Dash and other "modern" ceramic magnets would fail the test. Maybe its time to bring back a similar lift pin test with the pin made by a third party such as the one made by Scale Engineering for the HOPRA Gravity car class.

[NicoRosberg.]

You think it is right that products not all racers can obtain be legal?

The fact the lift pin was dropped shows it's major flaw, it isn't adaptable.

Something that can give measurements, repeatably, is going to be much better. Our hobby still has lots of clever people in it, surely it can be done.

[Maddman]

Thanks for misinterpreting what I said. I am not in favor of prototype parts being allowed. There are classes that do allow such things. Most do not. That being said a lot of "legal" stuff is being shoved out for purchase that is not widely available.

With regard to the pin test being faulty. The old pin test worked. It can work again. Smart people can manufacture such a device much easier than they can design a repeatable gauge out of poor quality kitchen scales.

[NicoRosberg.]

I did not misinterpret anything. I merely asked what your opinion was.

As for the lift test, you are probably right, but so far nobody has made it work again for the Fray. When was it dropped?

I think it much more productive that those smart people design a repeatable digital gauge, but it will probably never happen.

[Wet Coast Racer]

With regard to the pin test being faulty. The old pin test worked. It can work again. Smart people can manufacture such a device much easier than they can design a repeatable gauge out of poor quality kitchen scales.

It sounds like your kind of project, or maybe RichD? There's a lot of smart people in this hobby really, we're lucky about that.

Possibly the folks at Magnet Marshall would be interested?

[NicoRosberg.]

That sounds a great idea.

[Axle]

Dash products are not available to all, so they should not be allowed, period.

Can you please explain this statement? What is the issue with purchasing form Dash? "Not available at all" is simply false. I have maybe 30 Dash chassis, and I've ordered tons of parts (from the public store, open to anyone) for restoring vintage T-jets and building Fray style cars.

The specific parts that are allowed by Fray rules are the killer bee magnets and the 16 ohm armature, both 2 and 3 lam. These parts are available in the pubic section of the dash-motorsports DOT COM web site, and have been listed there for all of the 3 years I've been watching. Anyone can go buy a set of 5 magnets for $ 32.50 right now, and you could put 100 in your cart if you choose to. They are there for anyone who wants them.

Actually, every single part of the full Dash car is available in the public store, and other than when global supply issues were causing shortages, that has been the case for at least a year. And recently there have been plenty of full chassis (some assembly required) available as well as ready to run cars. All publicly available.

Tires are an entirely different story. I had no idea that Fray rules allowed custom tires. ECHORR SS rules don't actually say anything about tires, but the last rule is "No “one of “parts allowed on the cars." So maybe that would rule out home made tires.

I have not been able to find a good source for Fray style silicone foam tires. Wizzard does list them, but they also list 6-8 week lead time, and it seems like they only produce them during certain parts of the year.

Bodies are another issue. Greg's Garage makes really nice bodies, but the volume is very low and the wait time is long. If you're lucky he might start making them again in April of 2022.

So in the world of Fray approved "production" parts, I have found the Dash parts to be super duper easy to purchase, while the fancy tires and low bodies are a months long process at best.

[NicoRosberg.]

I did not say ''at all'', I said ''to all''

I can't buy Dash products from him at all, and I know others in the same boat. If I order, the order will be cancelled, same for them.

He has sales runs that you have to be on a approved list before you can order.

Big events like the Fray should only allow parts that are sold on the open market all year around, in my opinion.

[Maddman]

It sounds like your kind of project, or maybe RichD? There's a lot of smart people in this hobby really, we're lucky about that.

Possibly the folks at Magnet Marshall would be interested?

I wouldn't mind and my Unimat is ready to go. However my current living locations put me in an HO wasteland. It would be better for someone who has a club (or multiple clubs + HOPRA) to work with take up a new lift pin design. I would contact Scale Engineering as they currently make the HOPRA Gravity Car lift pin. Others who could make the pin include RTHO, Quicker Engineering and of course Peter Lentros. Since the top end of the lift pin range would be for the DASH killer bee magnets you might want to contact him to see if DASH would support the design and manufacture of the pin.

[RichD]

A go-no go test using a lift pin should be good enough if you are worried that people are using illegal magnets. I have the standard lift pin that is used to test Gravity type cars, it measures 0.3165 X 1.3185 inches according to my NIST certified calipers and weighs 13.0g on my calibrated scale that only reads to the nearest 0.1 gram. My calibration weight was measured to the nearest 0.0001 gram however. I do not know what grade of steel was used for the standard lift pin, different types of steel have significant differences in their magnetic properties. If I was still working I could get the lift pin analyzed using a non-destructive method like EDS. At the very least you would want to use steel of a known type. I would use a lathe to cut the rod stock to different lengths and use those with a car that had legal magnets as well as one that had stronger magnets.
Since I already have a home made scale that gives me measurements that are at least reproducible I am not eager to mess around with making lift pins, besides I don't have a lathe.
With respect to the availability of Dash parts the main problem would be getting complete rolling chassis, those are made in batches that sell out quickly. Usually the website says when the next batch will be going on sale and I have not had a problem ordering them on that day.
I was aware that Dan Cashmer keeps a list of people that he refuses to sell to. Anyone that falls into that category might ask a friend to place an order for him.

[NicoRosberg.]

That is a work-around, but it would be far more professional if groups only allowed stuff that was available to all, all year around.

As for the 'batches', Viper et al manage to have stock at all times, that should be a minimum for any major series or event.

[NicoRosberg.]

I wouldn't mind and my Unimat is ready to go. However my current living locations put me in an HO wasteland. It would be better for someone who has a club (or multiple clubs + HOPRA) to work with take up a new lift pin design.

I was more thinking of the collective brain power working on a digital solution, something that can adaptable, and accurate.

[Maddman]

The lift pin is a much simpler Go-No Go solution. Once designed and accepted it can be easily mass produced and sold for a reasonable price. The lift pin worked originally, was adapted to serve as the gravity car tech gauge and can be brought back to work again for T-Jets.

If u want a digital solution then get a group together and go for it. Most of us here are MEs at best. I'm an EE but I was raised when relay logic was king. Whatever you develop will be analog to digital at best but who's counting?

Rich - This isn't a one man job. A team is going to be required. The team should include reps of organizations that deal with T-Jets and understand the problem. Also take advantage of racers who double as machinists. My guess is that if you contact Scale Engineering he can tell you what type of steel he is using for the G-Car lift pin. The other person to contact is Joel Pennington as he developed the gauge. Your HOPRA rep can get you in touch with Joel.

With respect with dealing with companies who wont do business with you or a small group of others. I suggest contacting the companies and working out the problem rather than tasking a racing group to take action to solve your issue.

[smalltime]

Big events like the Fray should only allow parts that are sold on the open market all year around, in my opinion.

Maybe, if you start going to the Fray, you'll be able to bend the ear of the organizers.

Just a thought.