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9 minutes ago, ThunderDragonCy said:

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

Give in..... Theyre beatiful.

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Hi all 

thanks Ann3x for uploading the photos ! 

Well that s what it looks like after it s first run. About 20 min of mud, wet grass, gravel and lots of jumps. And I am pleased to announce that nothing went wrong !!!! 

I haven t stripped the gearbox yet to examine the internals but no problems during running, everything worked beautifully. Managed to get the slipper clutch set just perfect (what a pleasure compared to the pain in the bum setting on the original SA gearbox). The sealed diff is magic compared to the SA geardiff, I had a lot more drive on corner exit so much so that I’ll have to change my suspension settings a bit cause the car was understeering a bit from the extra push on both rear wheels whereas it used to typically tend to oversteer due to one rear wheel spinning out cause of the more open diff. Did lots of jumps to put strain on the clutch and gears and everything held up very well, I even got a bit over enthusiastic and cartwheeled the car couple of times on bad landings but again everything held up fine. Lastly I tightened the clutch so there was no slip action whatsoever and continued jumps, hard acceleration, and full pelt driving over rough terrain to really strain the idler gear and diff, but again no breakage. So I’m very pleased with Ann3x’s gearbox print ! It really transforms the car. I m going to dismantle everything tonight and see what’s happened (if anything) inside the gearbox. 

Stay tuned ! 

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So how close do you think we are to having properly sorted 3D printed parts so I just need to buy those, a Fibre Lyte chassis plate and a Repro body and some modern unis and wheels and I have an Ultra Astute? What's missing? Toe in rest uprights? Arms? 

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5 hours ago, ThunderDragonCy said:

So how close do you think we are to having properly sorted 3D printed parts so I just need to buy those, a Fibre Lyte chassis plate and a Repro body and some modern unis and wheels and I have an Ultra Astute? What's missing? Toe in rest uprights? Arms? 

Jeze, dont ask for much do you?!

I might make arms at some point but dont intend to replicate the entire car in 3d.

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59 minutes ago, Ann3x said:

Jeze, dont ask for much do you?!

I might make arms at some point but dont intend to replicate the entire car in 3d.

Ha! Just interested to see how far this has gone. With uprated bulkheads available, your gearbox and battery straps, there are upright solutions out there, seems like you could put together a car with all the uprated parts rather than starting with a vintage model. AMPRO have done new suspension mounts and rear wishbones and uprights for the king cab. Would they work on an Astute?

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I think the orb/ampro ones are too wide (KC is different fit)  but pargu actually make dedicated astute ones in aluminium. Check out the ones on my SA.

 

I think most of the car you could build from mod parts but arms,  hubs and bumper are still needed + the little bits N bobs. 

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Gearbox Disassembly photos after 1st test run.

Some issues with bearings spinning in housings - will have to tighten up bearing hole tolerances. Also some issues caused by the layshaft and diff float - again, needs a small adjustment to bearing mounts.

However gear mesh looks good (and that's the hard bit).

26088412787_272de5fd49_c.jpg

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Some dirt /water ingress due to diff float.

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Layshaft brassing, again due to some float.

All pretty easy to solve stuff. Im just glad the mesh is ok - thats one's a b*gger to change (big remodel).

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Hi all 

thanks Ann3x for uploading the photos ! 

Well that s what it looks like after it s first run. About 20 min of mud, wet grass and big jumps. Did another 30min run yesterday. 

What can I say.... it’s fantastic !!! 

Diff action is great, big change to be able to tune the diff properly. The slipper clutch is great, 100% better than the original SA item and very easy to setup properly. It’s even better than my personal solution (custom SA main shaft to incorporate Dyna storm clutch spring to get rid of the SA ball and spring washer setup) because the Schumacher clutch has bigger pads and larger contact surface. 

Gearing is great and allows a lot of possibilities. 

It can handle my 9t 4500kv motor without anything slipping, breaking or wearing. 

A new prototype is being printed to resolve the very minor problems that we’ve found. And then... more testing !

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It took some time as both of us have been busy with work but finally, v2 of the gearbox has been thoroughly thrash tested on the astute and we only have a couple of minor changes to make:

  • Tweak to bearing housings which are a tad too tight ootb
  • Change to layshaft spacer config to reduce layshaft float

@t3garett has tested it pretty hard now and everything seems to be holding together.

Assuming the v3 print works ok (we'll test again to make sure), it should be ready for purchase in shapeways within the next month alongside a full list of the parts needed from Schumacher.

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So, good news. We have completed testing of the gearbox and it's now ready for public consumption.

@t3garett will write down his thoughts at some point but it seems ready to go now. I just need to write up a parts list and some basic assembly instructions and then it should be ready to buy via shapeways!

May need someone to experient with a KingCab / Hilux tho - think the Driveshafts on that might need some experimentation but for Astutes / SAs/ Madcaps etc it should be a drop in fit that works fine with brushless.

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Now for sale on Shapeways! Parts list & build info below. MASSIVE thankyou to @t3garett for helping with all the testing and many hours of experimentation / shimming / explaining to me minor issues. I really think it was worth it and hopefully will allow many more Astute runners.

Shopping List:

Basically you need 3 groups of items, The Gearbox, the Schumacher internals and then some generic RC parts for assembly.

  • Gearbox from Shapeways (Gearbox Halves & Plastic Layshaft Spacer are included on one Sprue). Self explanatory, buy the colour you want on Shapeways.
  • Schumacher Cougar KR / SVR Gearbox Internals:
    • Layshaft U4072
    • Idler U4037
    • Slipper Clutch:
      • Spring U4106
      • Plates U3869
      • Pad U3364
      • Spur U3351 (83t - many other sizes available but this is a good middle ratio)
      • Spacer U4083
    • Gear Diff set U4352 or Ball Diff set U7130
    • Motor Plate U4071
    • Gear Cover U4091 + U4089 (usually comes as a set)
  • Generic RC Parts:
    • 10x12x0.2mm Diff Shims (U2761 - I used 2 but shim to fit)
    • 5x7x0.4mm Layshaft Shims (U4124 - I used 1 but shim to fit)
    • 6x8x0.5mm (CR447 - I used 2 but shim to fit)
    • 2x 10x15x4 Diff Bearings (U2699)
    • 1x 5x8x2.5 Slipper Bearings (U3136)
    • 1x 6x12x4 Layshaft Bearing (U4084)
    • 3x 5x10x4 Idler/Layshaft Bearings (U2698)
    • 3x M3 40mm Countersunk Bolt (Screwz4RC sell them)
    • 1x M3 30mm Countersunk Bolt (Screwz4RC sell them)
    • 4x M3 6mm Button Head Bolts (Screwz4RC sell them)
    • 5x M3 Nyloc Nut (U1547 but any will work)
    • 1x 48dp Pinion as per ratio you want

To decide on an appropriate Spur / Pinion combo below is an excerpt from the Cougar KR manual showing what's compatible, as the Astute is just another 2wd buggy, the same ratios should work for the fine - just gear as per FDR required:

 27728408617_d8d4994fb0_b.jpg


Assembly:

1.      Check the parts list and make sure you have everything needed (I didnt show the 6mm bolts in picture below but everything else is there):

27728418757_2f1d0beaed_c.jpg

2.      Prepare the Gearbox after printing:

  • Cut the sprues neatly with a side cutter removing the 2 gearbox halves AND the layshaft spacer
  • Clean the bolt holes with a pin / small Allen key / pokey thing. After printing there will be residue present. You need to remove it (or it will end up in your car/ gearbox).
  • (Optional) Dye the parts with RIT. If you intent to colour the gearbox (recommended as the white will discolour easily) do it NOW before you get it dirty / greasy from handling. Obviously not required if you buy it pre-coloured from Shapeways but a good idea as the white discolours easily.

3.      Assemble the Diff & Idler as per Schumacher manual / your preference.

4.      Place the Diff, Idler and Layshaft along with bearings, any grease/oil you desire and any required shims in the Left Gearbox half.

IMPORTANT: Make sure all bearings are properly seated before going further / shimming. This may be a tight fit due to shapeways printer tolerances.... If it's genuinely too tight to get in, use fine sandpaper / a round file /a knife to shave off (as little as possible!) to allow proper seating. If you have loose bearings they will spin and damage the casing. If you have unseated bearings the gearbox will bind so make sure they're firmly seated (but seated....).

41695460985_6ec452a248_c.jpg

5.      Add the Right Gearbox half & bearings and bolt the halves together using the 30mm bolt / nyloc nut in the lowest hole.

6.      Place the 6x12x4 Layshaft Bearing on the Layshaft OUTSIDE of the casing (see pics).

7.      Add the VRC Plastic Layshaft Spacer & the Schumacher Metal Layshaft Spacer

27728415597_d5da3e86f1_c.jpg

8.      Assemble the Motor plate onto the gearbox using the 3 40mm bolts & nyloc nuts.

9.      Add 6x8mm Layshaft shims as required to adjust for layshaft float (which will be tested for later)

28721980518_d671c31a29_c.jpg

10.  Assemble the Slipper in the following order (for reference..... the order is also shown in the 1st picture in this thread)

  • Inner plate & pad
  • Slipper Bearing
  • 5x7mm shim
  • Spur
  • Outer plate & pad
  • Spring
  • Washer
  • M3 Nut

When assembled & shimmed correctly the Layshaft should float 1mm max and the diff 0.5mm max whilst still spinning freely. In order to get correct shimming you may need to repeat steps 4-10 a number of times whilst reshimming.

27728412677_b7f43c72d1_c.jpg

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11.  Mount and adjust mesh of your motor with appropriate pinion (48dp) to the Motor plate using 6mm M3 bolts then adjust the slipper as desired (start off quite tight then back it off as you test run until you have the control you want).

12.  Attach the Gearbox Cover using 6mm M3 bolts and insert the rubber outer plug.

28721976608_e839f0e311_c.jpg

13.  Mount the gearbox into the Astute chassis as normal (should also fit Madcap & Saintdragon). It bolts in exactly the same as stock.

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14.  Enjoy!

41878805504_db7377e0c6_c.jpg

Notes:

  • Normal Astute driveshafts / UJs have been tested to work with the gearbox just fine (my car above is using standard Astute UJs - check the fit).
  • The gearbox MIGHT be compatible with the KingCab / Hilux Monster Racer too. It physically fits these trucks fine and should be plenty strong enough to handle the big wheels BUT the standard KC driveshafts are too short to use with the Cougar outdrives. If you can source appropriate replacement dogbones/UJs/CVDs it should work ok but it might take some experimentation. If you do find a combo that works – please tell me and I will list it for others to use.

A few notes for people doing this mod:
1/ I am a hobbyist not a commercial outfit. I have designed and tested the Gearbox to the best of my abilities but I simply don’t have resources for the level of testing you might get with a commercial RC part. I *think* if anything, the gearbox is overbuilt but there’s always a chance that something might break unexpectedly. Please set expectations accordingly.

2/ Just because you now have a modern gearbox does NOT mean you have a modern car. With a hot brushless setup you will be pushing the rest of the car to it’s limits. If driven sensibly – that can work (and be a ton of fun). Just don’t expect your Astute to be an E-Revo. Noone likes breaking vintage cars.

3/ Due to Shapeways tolerances and the 3D nylon some shimming and manual setup will be required. If you are a total beginner – this might be hard to accomplish. I am assuming that you have basic knowledge of how to shim, run-in and tune a car. If not – this will be a learning experience for you!

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I hope that you dont mind but i made a note of your work in my Astute group on FB.

Regards Patrik

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Excellent work. In time I will get this gearbox. 

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1 hour ago, Pata76 said:

I hope that you dont mind but i made a note of your work in my Astute group on FB.

Regards Patrik

Go for it! I just want more Astutes running :)

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So after about 30 years of running and rebuilding my mosnter racer it's diff is now beyond rebuilding. So I seriously need this. Ordering the case is easy. How do you guys recommend I order the internals?

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You can buy internals from any model shop that stocks Schumacher. 

In the UK you can buy direct from them at http://www.racing-cars.com

Just search for the part numbers I listed above or buy a cougar kr and use the necessary parts from the kit/car. Many other shops also stock these bits. 

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7 hours ago, Ann3x said:

You can buy internals from any model shop that stocks Schumacher. 

In the UK you can buy direct from them at http://www.racing-cars.com

Just search for the part numbers I listed above or buy a cougar kr and use the necessary parts from the kit/car. Many other shops also stock these bits. 

Schumacher have handy exploded diagrams on their site, for the Cougar KR, look here http://www.racing-cars.com/pp/Car_Showroom/www.racing-cars.com/images/Technical_Info/Schumacher/Current Cars/Cougar KR/Exploded Diagram/KR_exploded.pdf

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Well, it isn't my intention to argue the wonderful work you did but, in my opinion, it would have been far better if Tamiya gears have been used (DN01, DF03, FF03 & more). I guess in UK Schumacher's parts are easy to find but around UE it could be not the same.
Last but not least it's opportune to consider that Tamiya, normally, keep in production its parts for several years ensuring spares availability.

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Tamiya stuff is quite expensive and there were limited options for 3 gear setups with both gear and ball diff options as well as a slipper, mainly due to tamiya basically giving up on race buggies. 

Schumacher stuff is also kept in production a long time with parts shared across many models, they also clearly intend to keep involvement in racing so I thought a better long term bet. 

Sorry but I can't consider specific countries parts availability. 

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