Super Astute Gearbox Testing

[Ann3x 222]

As some of your might have seen here, I've been working on some new parts for the Super Astute series of cars.

One of the projects I've been working on is a replacement gearbox for the Astute that accepts modern internals (ie a modern slipper and a sealed gear diff). The main reason behind this is because Super Astute TTC gearboxes are too rare, there is nothing at all that has a sealed diff and the Astute and Kingcab series are DESPERATELY delicate in the gearbox and a drop in replacement would allow far more of them to be used/raced.

I settled on the Schumacher Cougar KR for internals as it has a 3 gear setup (similar to the Astute / SA) and is relatively common.

I modelled everything up in CAD and made a test print via shapeways. Some pics below.

For a 1st prototype, it's actually gone together pretty well, the parts mostly hang together and work. Clearly there are still some issues to fix though:

• Major: Motor fouls gearbox a bit (pinion size, hence gearing options are restricted). Will cause issues especially with King Cab (where pinion need to be smaller).
• Major: Motor Plate fouls wishbone pins (I could mod the motor plate to fit but as I want this to be a drop in replacement part, I will tweak the motor plate's angle instead)
• Minor: Outdrives are smaller on Cougar than Astute (53mm for SA vs XXmm for Cougar). Doesn't look too bad (see pics) but might cause some issues when driven hard. Not sure how it'd affect the King Cab.
• Minor: Nut recesses have some minor issues (too small / too big, doesnt affect use but should be fixed)
• Minor: Chassis post recesses are ~1mm too deep
• Minor: Small amount of binding in the gearbox (this might actually run in fine, dont know until its tested, if not may need to shift idler gear a little in CAD)

Now for the reason I'm writing this thread now before the part is ready..... I NEED SOMEONE TO HELP ME TEST IT!

Confession, I do more technical stuff than actual driving and I get most of my fun from the build however it's obviously critical that my stuff works properly when it becomes available to others. Hence for a part like the gearbox which takes precision and a lot of abuse - I want it properly tested before I make it generally available on shapeways.

So Im looking for a volunteer from the community to help test my models. I'm looking for someone as per below:

• Has an Astute / Super Astute / Madcap / Kingcab RUNNER that they use regularly. Must be a runner, must be usable via some "proper" driving to actually test the part.
• Has a modern brushless / lipo setup than they are willing to test on the car.
• Is willing to test the parts I send and then post them back to me (with comments/feedback via regular TC pms / emails)
• UK based (sorry don't want to post internationally when prototyping - too slow/expensive)
• Longstanding & well known TC member who is knowledgeable about parts and has build experience (quite a few $ of kit so I want to test someone who's likely to be trustworthy (and not disappear & take my stuff!) and knows their stuff (essential for troubleshooting))
• Ideally - Has modern 2wd experience (aware of what "good" is actually like for this class and some modern 2wd parts to use, spurs, pinions etc)

If you're interested in helping me develop the gearbox and/or other parts - please let me know (and confirm the above points). I'm thinking the gearbox needs one more round of my own prototyping before it can go to my nominated tester for a thrash test (but you never know - I might mess up).

BTW - Please don't be offended if you volunteer to test my stuff and I don't take you up on the offer, my wallet can only cover so much shapeways prototyping at any one time

[Grastens 2811]

I was going to volunteer until I remembered I sold you my Astute

Best of luck with the testing! I am sure you will find the volunteers you need

[t3garett 268]

I d volonteer as I run / race a super astute which is currently brushless with standard gearbox and modified mainshaft and own a second shelfqueen super astute and also a modern trf201. But I live in France (I am a brit though, bermingham born and bred.) Let me know if you don t find anyone else. 

[ThunderDragonCy 8607]

8 hours ago, Ann3x said:

As some of your might have seen here, I've been working on some new parts for the Super Astute series of cars.

One of the projects I've been working on is a replacement gearbox for the Astute that accepts modern internals (ie a modern slipper and a sealed gear diff). The main reason behind this is because Super Astute TTC gearboxes are too rare, there is nothing at all that has a sealed diff and the Astute and Kingcab series are DESPERATELY delicate in the gearbox and a drop in replacement would allow far more of them to be used/raced.

I settled on the Schumacher Cougar KR for internals as it has a 3 gear setup (similar to the Astute / SA) and is relatively common.

I modelled everything up in CAD and made a test print via shapeways. Some pics below.

For a 1st prototype, it's actually gone together pretty well, the parts mostly hang together and work. Clearly there are still some issues to fix though:

• Major: Motor fouls gearbox a bit (pinion size, hence gearing options are restricted). Will cause issues especially with King Cab (where pinion need to be smaller).
• Major: Motor Plate fouls wishbone pins (I could mod the motor plate to fit but as I want this to be a drop in replacement part, I will tweak the motor plate's angle instead)
• Minor: Outdrives are smaller on Cougar than Astute (53mm for SA vs XXmm for Cougar). Doesn't look too bad (see pics) but might cause some issues when driven hard. Not sure how it'd affect the King Cab.
• Minor: Nut recesses have some minor issues (too small / too big, doesnt affect use but should be fixed)
• Minor: Chassis post recesses are ~1mm too deep
• Minor: Small amount of binding in the gearbox (this might actually run in fine, dont know until its tested, if not may need to shift idler gear a little in CAD)

Now for the reason I'm writing this thread now before the part is ready..... I NEED SOMEONE TO HELP ME TEST IT!

Confession, I do more technical stuff than actual driving and I get most of my fun from the build however it's obviously critical that my stuff works properly when it becomes available to others. Hence for a part like the gearbox which takes precision and a lot of abuse - I want it properly tested before I make it generally available on shapeways.

So Im looking for a volunteer from the community to help test my models. I'm looking for someone as per below:

• Has an Astute / Super Astute / Madcap / Kingcab RUNNER that they use regularly. Must be a runner, must be usable via some "proper" driving to actually test the part.
• Has a modern brushless / lipo setup than they are willing to test on the car.
• Is willing to test the parts I send and then post them back to me (with comments/feedback via regular TC pms / emails)
• UK based (sorry don't want to post internationally when prototyping - too slow/expensive)
• Longstanding & well known TC member who is knowledgeable about parts and has build experience (quite a few $ of kit so I want to test someone who's likely to be trustworthy (and not disappear & take my stuff!) and knows their stuff (essential for troubleshooting))
• Ideally - Has modern 2wd experience (aware of what "good" is actually like for this class and some modern 2wd parts to use, spurs, pinions etc)

If you're interested in helping me develop the gearbox and/or other parts - please let me know (and confirm the above points). I'm thinking the gearbox needs one more round of my own prototyping before it can go to my nominated tester for a thrash test (but you never know - I might mess up).

BTW - Please don't be offended if you volunteer to test my stuff and I don't take you up on the offer, my wallet can only cover so much shapeways prototyping at any one time

Can't help with testing, but just wanted to say this is awesome. Couple of thoughts on your fit up issues:

- If yhe kingcab needs a smaller pinion with lower gearing, is there a larger spur gear available from schumacher which would both aid the gearing down and help the motor clearance?

- Outdrives: Do you know what length and hub end bearing interface the Schumacher dtiveshafts are? Astute series driveshats are odd length anyway (although i believe you can fit up Blitzer Beetle rear uprights to use modern standard length driveshafts) so if the ends of the schumacher drivershafts run on 1150 bearings maybe that is a good way for owners to get a sustainable supply of universals for their buggy?

[Ann3x 222]

The astute driveshafts seem to fit the Schumacher outdrives fine, at least with my setup (madcap arms, super astute hubs). 

Yes, tons of spurs and pinion combos available so (assuming I can fix clearance) ratios shouldn't be an issue. 

Leslie, I'd love to have your help testing (and have bought / sold with you before in fact for the f201) but postage to/from France will get pricey I think. 

[ThunderDragonCy 8607]

46 minutes ago, Ann3x said:

The astute driveshafts seem to fit the Schumacher outdrives fine, at least with my setup (madcap arms, super astute hubs). 

Yes, tons of spurs and pinion combos available so (assuming I can fix clearance) ratios shouldn't be an issue. 

Leslie, I'd love to have your help testing (and have bought / sold with you before in fact for the f201) but postage to/from France will get pricey I think. 

Good stuff on the outdrives. Sounds like the blitzer mod for longer standard driveshafts should still qork then.

Pop to the post office and check postage to france (pop the parts in a jiffy bag and weigh it). I post stuff to france all the time and it isn't that expensive.

[t3garett 268]

Yep ! Postage would be a pain, well if ever you re stuck and can t find anyone give us a shout. 

Keep up the good work by the way !

[t3garett 268]

By the way.... I really must post something about the f201 you helped me build, its now fully carbon with 3racing chassis and brushless and goes like badword

[Boomerang_kid 18]

Looks good, keep up the good work.

I run a brushless setup on my Super astute, and a brushed setup on my madcap. The Super Astute is what I used for racing, I recently upgraded to universal drive shafts, interested how the outdrive issues can be resolved. I was using Madcap arms with the SA rear hub carriers but they kept popping. I think I need to go back to the SA arms.

When you talk about testing, do you mean track testing, eg jumps, cornering, etc as I can do that at my local track? 

[Tizer 607]

Great work! If this works out well, it will bring a lot of Astutes back on track I think.

As for testing.. Check out the Iconic RC group on Facebook. There's a few guys on there racing with Astutes regularly (and hard!). Any issues will show up in their tests.

[Ann3x 222]

2 hours ago, Boomerang_kid said:

Looks good, keep up the good work.

I run a brushless setup on my Super astute, and a brushed setup on my madcap. The Super Astute is what I used for racing, I recently upgraded to universal drive shafts, interested how the outdrive issues can be resolved. I was using Madcap arms with the SA rear hub carriers but they kept popping. I think I need to go back to the SA arms.

When you talk about testing, do you mean track testing, eg jumps, cornering, etc as I can do that at my local track? 

I mean general usage that it'd be reasonable to expect the buggy to handle (jumps, corners, hard acceleration / braking on a range of surfaces). Racing type stuff I guess.

I just want some reasonable testing done wrt durability of the parts with a brushless motor without going traxxas kid crazy (roof drops, double flips, 550 brushless etc - it isn't reasonable to expect a 20yo buggy to do that, even with new transmission - the other parts will just die instead).

[Ann3x 222]

Soooooooo..... my latest print is in and the majority of the issues seem to be resolved. I think it's ready for some testing.

As a reminder, these were the issues with the 1st print.

• Major: Motor fouls gearbox a bit (pinion size, hence gearing options are restricted). Will cause issues especially with King Cab (where pinion need to be smaller).
  • Fixed! 19t-28t pinions now fit with the standard Cougar 83t spur. Motor no longer fouls GB.
• Major: Motor Plate fouls wishbone pins (I could mod the motor plate to fit but as I want this to be a drop in replacement part, I will tweak the motor plate's angle instead)
  • Fixed! Rotated the plate 5 degrees and no longer fouls.
• Minor: Nut recesses have some minor issues (too small / too big, doesnt affect use but should be fixed)
  • Fixed!
• Minor: Chassis post recesses are ~1mm too deep
  • Fixed!
• Minor: Small amount of binding in the gearbox (this might actually run in fine, dont know until its tested, if not may need to shift idler gear a little in CAD)
  • Fixed! Runs nice and smooth now
• Minor: Outdrives are smaller on Cougar than Astute (53mm for SA vs XXmm for Cougar). Doesn't look too bad (see pics) but might cause some issues when driven hard. Not sure how it'd affect the King Cab.
  • Think this is ok for the SA, at least it fits fine on mine (SA hubs, Madcap Arms, Pargu pivots, SA UJs)
  • Tested on the KC for fit and it looks like outdrive length will be an issue. Needs longer outdrives or longer UJs / Dogbones.
    • ~5mm longer dogbones needed (KC standard is 63.5mm so needs 68mm or so dogbones/UJs)
    • or ~5mm longer outdrives to fit the Cougar Diff

Updated pictures of the Gearbox:

Nut retainers all sorted now.

Thats a 21t pinion, I tested 19-28t which is a decent range for the cars this will fit, especially when you factor that the Spur can be changed too.

Motor clearance is tight with smaller pinions but should be ok.

On the Super Astute:

Fits like a glove.

JUST clears the pivots.

A test fit on a King Cab chassis (it is a perfect fit, but outdrives / dogbones are ~5mm too short):

Dogbones definitely too short (well outdrives actually.....). I estimate 5mm extra needed.

Kinda wish I hadnt modified my chassis as the new gearbox is a direct fit.

And as a bonus the King Cab's modified Dyna Storm transmission:

Let's hope it performs ok!

My outstanding worries:

1. The outdrive length (and the fact my setup is a mish-mash)
2. The Diff & Layshaft's lateral play (might need some shimming, might be fine)
3. Bearing housings might be a tiny bit too loose.
4. General strength of the plastic.
5. Plastic permeability (will probably get stained without dying, may allow water entry to gears/ bearings - potentially might need sealing before use. Might not be an issue except with crazy wet conditions).

@t3garett Has kindly offered to test this for me. So it will be packaged up and go out to him tomorrow. Leslie - please take some pics/ vids!

[t3garett 268]

Looks great !

can’t wait to test it !

cheers

[ThunderDragonCy 8607]

Awesome job. My Yeah Racing unis which are stock fit on most Tamiya buggies are 70mm. Would that be too long? Would the Blitzer uprights giving a little more space at the other end work together to make it fit?

Plastic Permeability - i haven't had any trouble with the parts i have, but i know @Pintopower recommends clear coating parts to stop dirt grubbiness. Or go for the polished white finish and paint black. 

I found with my 3 deg rear DT03 uprights that SLS definitely isn't as strong as ABS, but beefing it up in the hotspots seems to have fixed it, for me at least. Is there room to add 1 or 2mm wall all round? Weight isn't really an issue is it?

[Ann3x 222]

Not like its a structural part like a pivot block / arm. Its mostly 1.5-2mm wall section anyway and I've put thickening struts and box sections in too - I'm just paranoid!

Are the YR CVDs 70mm from pin to pivot? Sound interesting if so.

I think the Blitzer uprights would actually make things worse wouldnt they? (dont they have further offset axles bearings cf madcap (ie need an even longer shaft to fit?))

On permeability, Im not exactly sure how permeable the shapeways nylon is and its not like the SA is a crawler after all... The concern is mainly that the bearings rust through the box. Only testable via time I guess.

[ThunderDragonCy 8607]

29 minutes ago, Ann3x said:

Not like its a structural part like a pivot block / arm. Its mostly 1.5-2mm wall section anyway and I've put thickening struts and box sections in too - I'm just paranoid!

Are the YR CVDs 70mm from pin to pivot? Sound interesting if so.

Just measured- 70mm pin to pin. They are advertised as being for the DF02/3

[Ann3x 222]

Im going crazy, I HAVE a set of DF03 CVDs (Tamiya ones not YR) and yes, they're 70mm as you say..... I thought i had tested these but will try again.

[Ann3x 222]

Yeah, they're the right length shaft but the axle is way too short for the King Cab hub (25mm vs 32.5mm axle on the King Cab).

If DF03 dogbones exist, they might fit perfectly. Alternatively longer CVD axles.

[waterbok 1284]

DF03 dogbones should be the same as for Manta Ray, DT02 and such.

Tobee used to make tougher ones that had a choice of three different axle lenghts

[Ann3x 222]

Pics:

DF03 shaft length looks PERFECT @ 70mm

Until you look at the axle end. Here is the problem:

@waterbok You're right. It looks like Mantaray dogbones will be the solution. Unfortunately I only have UJs.

A better solution would be some modern 32.5mm axles but itd take someone with specialist knowledge (or a lot of modern trucks) to find them i think.

[ThunderDragonCy 8607]

I have TG10 axles in my DT03 to widen the track, but they are only 4mm wider per side. Part is 50808 if you are interested. I think this is where the Blitzer upright comes in. It uses standard 25mm axles, but then that is going to pull the inner bearing outboard a fair way. Tricky one.

[Ann3x 222]

Ok so, Kingcab axle issues aside, the 2nd prototype Gearbox is with @t3garett now and he's mounted it to his car (looks like it fits his config ok too), he asked me to post pics as an update. Testing on Wednesday! Exciting :).

Some clearance issues near rear right wishbone, shouldnt really affect operation but again needs solving in next iteration.

Some bigger issues with endfloat of the main shaft in this prototype but its shimabble (and should be easily solved via a revision).

Big props to @t3garett for all the photos (and for the testing to come!).

[ThunderDragonCy 8607]

So excited to see how this goes.

[Ann3x 222]

Its alive!

[ThunderDragonCy 8607]

That looks gorgeous. It is not helping my astute want at all