30 replies to this topic

[Jimbolina]

Kindly forgive me with this inquiry as I am attempting to get back into this hobby after decades of not participating, so I am kinda a duck outta water on this would-be build. I am quite puzzled as to why my Mura motor appears to not be an ideal selection with this (vintage) 1/32 Parma chassis and the related gearing setup I show.

 

As you can see, once I position a pinion gear on the motor shaft, there’s no way that spur gear will properly engage.

 

Also, I obviously have to select a less wide set of rear wheels to avoid contact of that motor shaft. Rats! I love these old orange sponges.

 

Anyway guys, please help me out with this setup and enlighten me on the bast path forward.

 

One last question – the allen fastener on this particular (all-aluminum) spur has an odd, rather tiny head, and my regular allen drive I use on the other gears and wheels isn’t small enough to use on this application. Can you let me know what size of driver I require?

 

Thanks!

 

[slotcarone]

Pretty sure that motor is way too powerful for that chassis. Also that spur gear is typically not used on this type of chassis. Usually they are plastic 48 pitch gears. Where are you planning to run this car?

[Jimbolina]

Hey Mike, thanks for your reply.

 

That is simply a motor I grabbed to consider would-be fitment. I probably need one of my old Parma 16D motors in its place.

 

The other spur gear (plastic variety) I have is much smaller in diameter and seems like it most certainly won’t interface with a motor pinion on this particular setup.

 

Again, it is apparent I need some guidance here, and further suggestions are appreciated!

[slotcarone]

Sorry not familiar with that chassis. Typically you would use with a 16D an 8 or 9 tooth pinion with a 28 or 29 tooth plastic spur gear. What track are you running this on?

[Pablo]

I'm no womp expert either.

 

But I can tell you, trying to shoehorn a (powerful) 1/24 motor, gears, and wheels into a 1/32 chassis is going to be a real headache. Yeah, I know the manufacturers may have sold cars like that and made 16D motors fit.

 

To make that work you'd have to have the exact same parts they used.

In the end, you'll end up with an over-powered, ill-handling 1/32 car with parts that don't complement each other.

 

If you really want to use those parts, I'd recommend finding an old photo of a Parma RTR car that actually used a 16D motor.

 

Look at what gears and wheels they used. Maybe it would have been a 501 Parma Deathstar with narrowed tires.

Maybe the tires extended beyond the wheel wells.

 

You best option, IMO, is find a smaller modern FK style motor and gears that fit.

JK also sells wheels (called reverse hubs) where the left side hub allows the gear hub to recess up inside it.

That way the left wheel won't stick way too far out.

 

With a smaller, tamer motor the car will be much more pleasurable to drive. And you'll be able to use different gears to fine-tune the ratio.

 

As far as the screw on the gear, I can't tell what it is. If the thread is 4-40, just get the screw out and use a standard grub screw that uses a .050" wheel wrench.

[Jimbolina]

Excellent recommendations, Paul. Thanks.

 

Yes, I will position a Parma Deathstar and look into those wheels you mentioned.

 

Baby steps…

[Pablo]

Again, start by finding a Parma Womp 1/32 RTR photo so you will know for sure what parts came with it.

If Parma did it, so can you LOL

 

Look in the Slotblog Womp subforum. Here is one:

 

NASCAR Flexi-Womp powered by Mura - Womp-Womp World - Slotblog

[Jimbolina]

Excellent! Thanks again, Paul.

 

Funny you located that thread and image! That’s the exact one that inspired me to procure that particular chassis from one of the forum members, a couple of years ago. Ha!

 

Yes, I will indeed carefully peruse this set of images and see what I can come up with.

 

On a side note, that spur gear in that referenced photo appears a good bit larger in diameter than one of my other Parma (plastic) examples I have in my stash. The reason I positioned that (aluminum) spur in my above initial image was it seemed more able to engage the pinion gear. Any idea what that probable tooth count is on that spur featured in those photos you kindly referenced could be?

[Bill Seitz]

I think that's the Parma Super Womp chassis. It was intended for a 16D and 48P gears, and also 13/16" or 7/8" tires. With today's relaxed ground clearances, you might be able to run .790" tires, but more likely need .830"s at least. This enables running a quite larger spur probably to 32 or 34, maybe 36 in 48P and along with it a 10 or 11t pinion. This will help you with the gear mesh problem.

 

With a 16D, gearing would have been in the 3:1 region, so for 64P gears, a 13/40. I'm not familiar with a solid aluminum spur gear, so don't know what you may have in terms of a set screw, but I have encountered supposedly .050" set screws that don't fit my supposedly .050" hex bit. Try another screw or bit.

[Jimbolina]

Wow, thanks so much, Bill! Nicely detailed rundown of what could, or should work on my situation here.

 

I will disassemble the rear axle setup here shortly, and provide a photograph of that odd spur gear. I did in fact attempt another driver on said spur, but both seemed just too large to engage that tiny set screw. Rats.

 

I will also look into those suggested tires and see what I can come up with…

 

Many thanks!

[grooverunner]

I have one of these womps new in the box. Unused that I got off a friend years ago. I'll post pictures as soon I get back, I'm away for a few days. If anyone is interested.

Ken

[Bill Seitz]

At one time I had a couple of these chassis. They handle far better than the classic Womp pan chassis, but they're from the era that Womps ran 7/8" diameter rear tires and 48P gears. It looks like you've tried to use finer pitch gears, 64 or greater, and the inherently smaller gear diameters this presents is what results in the lack of coming together. I probably used a Mura Wasp and 64P gears with one, but to do that requires eliminating the motor mounting tab and soldering the motor to the chassis. I don't think Womps ever did adhere to strict 1/32 scale width, with the rear wheels at least sticking out from a 2.5" wide body. Super Womp GTPs had the 3.13" wide front and rear to allow the 3"+ width of 1/24 scale cars with the 2.5" pinched middle and would've been the expected bodies on these chassis. This lack of reverence to scale permitted running standard 1/24 .800" wide rear tires with standard 48P spur gears.

 

I've encountered an array of different gears over the years, but they've all used the same set screws with the .050" hex socket, or in the '60s a straight blade slot. I'm not sure what you might have that doesn't take a .050" hex bit. A quick search found that Wiha makes .7mm (.027") and .9mm (.035") hex drivers, so you could have a set screw with one of those standard sizes.

[Jimbolina]

I have one of these womps new in the box. Unused that I got off a friend years ago. I'll post pictures as soon I get back, I'm away for a few days.If anyone is interested.
Ken

 

Cool! Excited to see this example for sure! Thanks for digging it up when you get back.

[Pablo]

Gator Bob car's gears are definitely 48 pitch.

The spur looks like a Cox and I could only guess on the number of teeth.

You want a spur that does not extend lower than the chassis.

 

Bill's 3 to 1 ratio for a Deathstar I agree.

If you go nuts and install that Mura you'll need to go at least 4/1, especially with those big 13/16"-ish wheels.

[Bill from NH]

The spur gear shown in the photo might not be 48P. It looks a one-piece hub and gear teeth. It might be a 50P gear from Europe or Japan. That could explain why a standard allen wrench doesn't fit its setscrew.

[Jimbolina]

Thank you both, Paul and Bill, for this continued discussion and appreciated contributions on my evolving setup.

[Paul Menkens]

Back when I raced regularly stock Flexi Womps were my favorite class, I have five now that I run on my home track, if you get the frame dialed in they'll handle quite a fast motor. One of mine has a Mura Gp20 and another has an X12, both are controlable and fun to run.

[Jimbolina]

Here’s an image of that odd spur gear showing the allen heads being sized differently. I attempted to swap this smaller allen on the spur with the more typical size available, but the whole set screw itself is smaller. Not simply the drive access hole.

 

Anyway…

 

 

[Bill from NH]

Jim, that's a Slot.it gear from Italy. I notice in the above photos it's a beveled gear rather than straight-cut teeth. As I previous stated, it's probably not 48P.

 

Can you sometime post a photo of your complete chassis? I've seen the Parma brass Intl 32s but don't recall ever seeing an aluminum anglewinder chassis like yours.

[Jimbolina]

Bill, this is actually a stamped steel chassis (I do wish it was aluminum, as I prefer that particular metal in many applications, where possible). I really loved its overall design, and found this chassis quite accidentally on this forum a couple of years ago while checking-out 1/32 stamped chassis configurations. One of our members kindly let me procure one of his nice examples.
 
Please note I cut (with a Dremel tool) the oval cutouts where the front wheels are situated, to provide a bit more clearance for slight wider wheels. I also wanted to give the chassis a bit more visual interest by introducing these handy curves, to better play esthetically with the front wheel protector extensions, and contrast all the other straight lines of the chassis.
 
That is just the old, professional designer in me, I guess. I can’t leave well enough alone on anything, it seems! Ha!

 

 

[Bill from NH]

Thanks for the photos Jim. In the early photos, the steel looked like aluminum to me, sorry for the mistake. Your chassis appears to be an early predecessor to the Parma 1/32 brass Int. 32 anglewinder. The center sections are very similar, the pans tips in front are different. These chassis would have been made to fit Parma's 16D motors. These chassis are made for 1/32 scale racing, rather than womps, which are neither 1/32 or 1/24 scale. To fit a 16D motor, you may have to modify the chassis mounting bracket &/or grind an axle clearance slot in the back of the motor can. These chassis were designed for smaller rear tires. Your orange ones will probably provide 3/32" or more chassis clearance. I believe your chassis is about 2 1/2" wide. This means the myriad of womps bodies will all be too wide. Their use will require making some sort of pan wideners & attaching them to the pans. There are some 1/32 scale bodies that are narrower & will fit r ight on your chassis. Locally, we once ran FK motors (Falcons) in the Int. 32 chassis. Those cars had plenty of speed &handled well.

 

The motor in your chassis photos is an RJR C-can with some sort of arm. Is the arm tagged?  Your modification to fit the wider fronts looks nice. If you ever want to build a pure womp, Mid America sells new womp chassis, but you can often find good used ones on eBay & Facebook Marketplace.

[Dominator]

Back in the day when scale racing was at it's peak in the US we used run these type's of chassis with c-cans and Super Wasp arms.  Gearing at the time was 72P 6/42 (difficult to mesh).  I generally geared 7/44 because i could get a better mesh and just ran more choke.  We also cut the motor bracket off to allow for easier motor installation.  I'll see if I can find an example later. 

[Pablo]

Why didn't you just say it was a Slot.it?   

The grub screw size is 0.9 mm.

 

The gears have their own special pitch and you have to use a Slot.it pinion with Slot.it spurs.

[Jimbolina]

Thanks Bill and Dominic!

 

I think my end-goal with this little project is not necessarily building an authentic Womp car, but a ‘hybrid’ example. My intention is to use one of my old Parma home track bodies, and have the overall look be somewhat scale in its appearance, and just kinda cool.

 

I just fell in love with this particular chassis design, with the predominant ‘solid’ metal pans (no obvious cutouts to speak of) and frankly,  I also always preferred the chassis style that featured the integrated, extended wheel protection aspect that many chassis don’t seem to offer. Something about that ‘solid pan’ look has always appealed to me, no matter if it’s 1/32 or 1/24 scale.

 

All to say, a work in progress.

 

I am going to take all these excellent tidbits of advice and suggestions and see what I come up with over the course of these next few weeks and keep you folks updated.

 

Thanks all for your kind help!

[Paul Menkens]

Parma made beautiful Ferrarri Testa Rosa and Corvette bodies, among others, to fit these.