267 replies to this topic

[Pablo]

Thanks, but let's wait for the rules to come out...…….

The current "Mid-engine" rules do not allow it.

[Pablo]

Small progress report:

 

-ProTrack 526 hard fronts, Chicagoland 2 degree steel tongue, ARP 64P 10/52 gears have arrived

-ProTrack N5203 rears on backorder

-Additional stickers en-route from Bulgaria

 

 

Been rolling some freaky motor configuration possibilities around in my head. That's all I have for now 

 

 

 

[eshorer]

Don't get TOO freaky on motor configurations. While the "behind-the-axle" motor placement works on a few cars (the weight behind the rear axle helps to offset the heavier hardbodies), it seems the more vanilla sidewinder cars seem to run best. The best running smaller hardbody car I've seen is the short-track Nascar built by Marco Carvalho that we used in the recent Enduro. There are some good pics of it by Keith Tanaka starting on this page:  https://socald3.smug...nduro/i-4KkfLQW  

Eddie

 

 

 

Been rolling some freaky motor configuration possibilities around in my head. That's all I have for now 

 

 

 

[Don Weaver]

Front wheel mounting is pretty clever...

 

Don

[Ecurie Martini]

Don't get TOO freaky on motor configurations. While the "behind-the-axle" motor placement works on a few cars (the weight behind the rear axle helps to offset the heavier hardbodies), it seems the more vanilla sidewinder cars seem to run best. The best running smaller hardbody car I've seen is the short-track Nascar built by Marco Carvalho that we used in the recent Enduro. There are some good pics of it by Keith Tanaka starting on this page:  https://socald3.smug...nduro/i-4KkfLQW  

Eddie

 

 

After messing about with these toys for 60+ years, I am convinced that the sidewinder, as pictured and assuming other things like motor power, all-up weight, basic chassis design etc. is equivalent, offers the best performance.  The "center pivot + pan" approach is one that I have often used*.  Among other things, the lateral disposition of the motor and spur gearing allows positioning the motor as far below the axle center line as ground clearance rules allow without the inevitable gear mesh compromise that occurs if one attempts this with bevel or crown gear fitments.

 

* Of late I have been moving towards simple, slightly flexible spring steel wire frames + rattle pans in a quest for light weight, critical in 1/32 classes with strict, low power motor restrictions

 

Front wheel mounting is pretty clever...

 

Don

 

A very elegant approach assuming that the wire supports are steel, not brass. Already filed away in the "try it' project folder

 

EM

[Pablo]

Don't get TOO freaky on motor configurations. 

Eddie

 

I hear you, Eddie, and don't worry - I will show you my ideas before going freaky 

[Pablo]

I looked at photos of the BP flat track, looks like there are three right turns, two lefts, and a squiggly turn that turns left then right. So basically we have a flat track that likes hi-grip rear wheels with lots of short straights and a somewhat equal combination of lefts and rights. Am I reading it correctly?

 

Appears most guys use traditional sidewinder configs with an additional weight platform aft of the axle, hung with a wire to soften the effect, with lead pieces stacked mostly on the gear side. True?

 

I put a pinion on a motor and found the left/right balance point to be about .430 from the edge of the can end. I don't yet know exactly how I'll use that info, but I'm sure it will influence me at some point in the design of the motor and gears

 

 

Since I don't live right down the street from Buena Park, California, I have to plan from my desk in Mississippi   

[eshorer]

Not quite. There are more left turns (end of the straight, which has a quick "kink" to the right at the end of the turn, big donut, and lead-on to the straight), and only two rights (at the end of the straight going left from the driver's panel), and the dogleg right after the donut (which isn't a hard right). Therefore, we've found that adding weight to the inside of the left of the car is preferred; it really helps to zip around the donut. The weight behind the rear axle definitely helps to take some "tilt" away from those top-heavy hard bodies. 

Eddie

[Pablo]

Understood, thanks Eddie 

[Pablo]

Don, Noose is painting me a Peter Revson interior 

 

[Pablo]

Noose interior is done

 

[James Wendel]

Sweeeet

 

What type of interior is that and where is if available ???

[Don Weaver]

Cutting out the "box" and adding this really makes the car ...

 

Don

[Pablo]

James, you'd have to ask Noose

[Noose]

James, you'd have to ask Noose

Had it in my stash. Believe it was from a True Scale Lola T70.


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[Pablo]

ProSlot 410 ball bearings soaked in lighter fluid, then bathed in oil and set aside in a baggie

 

 

Jig ball bearings are dirty but exactly the same as the new ones. Rear axle tube cut 1.235" and polished. Spur gear was a little wobbly side to side, so I spun it in my poor man's lathe and sanded it with an emory board until fairly true

 

 

ProTrack rear wheels N5203 are still backordered so I am making a set of JK big hubs with Alpha Wonder Rubber donuts. The OD is going to be real close to the .950 minimum, so don't shoot me if they don't pass muster. At this point I just need something close enough to start soldering. If they don't pass as a race set, at least I'll have a pair of jig wheels tomorrow.…..if they do pass, they will become a set of hard options for the race car. Who knows, the car may actually like hard tires...…. 

 

 

I temporarily attached the pinion to my jig motor with a drop of CA glue to set up the motor/gears/axle relationship 

 

 

Centerline of motor balance point meets centerline of axle/gear/tube/spacers setup

 

 

 

[Bill from NH]

Is the spur gear an ARP part, like the pinion? I'm not familiar with it, so is it aluminum, SS, or another metal?

[MSwiss]

https://www.eagledis...452.html?page=2

[Bill from NH]

Thanks Mike.

[Pablo]

I thought I already covered that in post 27    Just messin' with ya.

 

The answer to my question if Alpha WR donuts will expand to .950 is, "no"    They make about .850 no problem, so they become my rear jig wheels. Since they are actual full size wheels, they will do double duty to give me a guide where the chassis architecture can and cannot go.

 

Front jig wheels will be 13/16 Briggs Jig units sleeved with aluminum 3/32 axle spacers glued in place with CA

 

 

Anybody remember this car - the "This ain't your daddy's Banshee" sidewinder? It handled super and I also remember it came though the esses real sweet. At first glance tilting it up like that may appear to raise the CG, but if you think about the way magnets in an FK motor are oriented, and the physical size of the can and arm, I don't think it raises it much, if at all. Take an FK and lay it flat, feel it, then tilt it up. Tell me your opinion. Not saying I'm going to actually do it on this car. But if I do, don't be surprised 

 

[Pablo]

With jig wheels, gears, etc. all in place I have a clear idea of what must be done in relation to the body. The motor can sit in normal flat sidewinder mode no problem, and the 10/52 gears meet perfectly. All I have to do is shave some meat off the tube to allow it to nest closer in case Eddie wants to try 10/50

 

A couple spots of CA temporarily secures the works in place so I can Sharpie mark exactly where to shave the tube 

 

[Pablo]

Now I can get 'er in there nice n tight 

 

[Ecurie Martini]

A note in passing - perhaps obvious, well known, old news etc. but one that I did not recognize until I had filled several pages with calculations:

 

The center to center distance of a gear set will remain the same so long as the total number of teeth, spur + pinion, is the same i.e.  10:52, 12:50, 14:48 etc will be the same.

 

EM

[olescratch]

Even though using the motor in the traditional position will work, placing it in the same position that was used in the Banshee only adds to the Thingie theme! And This ain't your Daddy's Banshee gets to turn a couple laps now and then! It can handle better than I can drive!

[Pablo]

Yep, that upright trick was used very successfully in the Banshee, it worked sweeet. But once I mocked everything up and looked at the Lola, it's obvious laid flat will be better.

 

Drivetrain all jigged up. The 52 T spur is almost exactly same OD as the jig wheels. I secured the jig motor to the jig with some CA