LongRat 616 Posted March 28, 2020 Here's my Avante that I started working on for the 2019 Revival. I'll document the modifications here. It's a 2011 rerelease, with mods to improve performance and durability but the intention is to keep it as an identifiable Avante. I don't want to wrap the body around a modern chassis or transform it into an Egress etc. Mods Increased suspension travel so the chassis grounds out before the shocks. This is using small bore TRF aeration shocks and custom made carbon towers. Adjustable caster front end to mount the suspension arms at various angles, using a machined aluminium bulkhead. Slipper clutch to allow locked permanent 4WD but with some stress relief on the gears. The clutch is quite heavily ventilated as it is in a very confined and sealed space in there. There are plenty of other changes I will likely make, but I would like to get some racing under its belt first to see how these changes perform. 12 1 Share this post Link to post Share on other sites
GTodd 1350 Posted March 28, 2020 Please provide pictures and explanation on how you got slipper clutch to work!!! 2 Share this post Link to post Share on other sites
Grastens 2795 Posted March 28, 2020 Love the paint on this one! I too look forward to reading your findings. 1 Share this post Link to post Share on other sites
LongRat 616 Posted March 28, 2020 1 hour ago, GTodd said: Please provide pictures and explanation on how you got slipper clutch to work!!! The pressure plates are machined to key directly with the shaft, so they can't move rotationally relative to each other. Compression of the spring washers is achieved via the screw in the end of the shaft, just like in the standard ball diff option. I used a modern Schumacher 48DP slipper spur gear and pads, although the gear had to be machined slightly to fit and the central bore enlarged. The whole thing is an extremely tight fit! 6 Share this post Link to post Share on other sites
GTodd 1350 Posted March 29, 2020 2 hours ago, LongRat said: Installed. DUDE!!!!! That is the answer for EVERY Tamiya 4WD made from the Avante until the Durga. You need to market this!!! How much for two of them? Need them for my Rere Egress and 1989 Avante. 3 Share this post Link to post Share on other sites
LongRat 616 Posted March 29, 2020 I've been talking to a few people, especially Top Force racers who are really interested in this concept. I need to test it properly and work to make it easier to make if I go forward with this. As it stands the clutch is too difficult and time consuming to make in any quantity. 6 Share this post Link to post Share on other sites
Jonathon Gillham 4607 Posted March 29, 2020 Just now, LongRat said: I've been talking to a few people, especially Top Force racers who are really interested in this concept. I need to test it properly and work to make it easier to make if I go forward with this. As it stands the clutch is too difficult and time consuming to make in any quantity. I was going to ask if this could be adapted to a Top Force. I guess it would be possible with the standard spur setup (separate drive gear). But looks like a tight fit. I'm definitely interested in one for the Top Force if it happens 1 Share this post Link to post Share on other sites
ruebiracer 1046 Posted March 29, 2020 Just a beautiful design. Played with the same thought and tried to do it with some Tamiya parts, but got stuck due to machining possibilities. Also the other tweaks on your Avante are so cool. Totally with you in keeping the Avante charactre, and not just doing another Egress. If the clutch slips, can the front axle rotate differently than the rear axle? Or did you design with permanent 4WD and just let the spur gear slip? My thought was always to let both axle slip to each other, to be able to take out tweakings in the drive train. (just as is intended by the centre diff) Hats down on your very professional looking solution, will follow this thread for sure! Kind regards, Matthias 1 Share this post Link to post Share on other sites
ruebiracer 1046 Posted March 29, 2020 Sorry, just read that you keyed the shaft. Didn´t read properly enough. So you use permanent 4WD already... I´m not in the buggy racing business since the mid 90`s, but probably it´s the std. 4WD Setup nowadays, if a slipper is used? If you oneday show us the tear down of your invention, that would be cool. What I found hard on the Avante ball diff design is that the bevel gear position on the axle is influenced by how much the pressure discs are screwed down. 1 Share this post Link to post Share on other sites
matisse 1581 Posted March 29, 2020 8 hours ago, GTodd said: DUDE!!!!! That is the answer for EVERY Tamiya 4WD made from the Avante until the Durga. You need to market this!!! How much for two of them? Need them for my Rere Egress and 1989 Avante. Indeed, if this could be made to work on the TF.... Game Changer Share this post Link to post Share on other sites
LongRat 616 Posted March 29, 2020 20 minutes ago, ruebiracer said: Sorry, just read that you keyed the shaft. Didn´t read properly enough. So you use permanent 4WD already... I´m not in the buggy racing business since the mid 90`s, but probably it´s the std. 4WD Setup nowadays, if a slipper is used? If you oneday show us the tear down of your invention, that would be cool. What I found hard on the Avante ball diff design is that the bevel gear position on the axle is influenced by how much the pressure discs are screwed down. Thanks Matthias. In practice I've found that the spring washers move such a small amount when the clutch pressure is adjusted it doesn't have a significant effect on the gear mesh. On the subject of decoupling the front and rear axles, to achieve this you could modify the standard centre diff with friction pegs instead of balls. The issue when racing is that this would slip the front under braking and so the rear under acceleration and I think handling might be inconsistent. Basically most modern 4wd transmissions are locked 4wd and slip the whole drivetrain together, like my design. Take a look at the machined components here: 7 Share this post Link to post Share on other sites
GTodd 1350 Posted March 29, 2020 3 hours ago, LongRat said: Thanks Matthias. In practice I've found that the spring washers move such a small amount when the clutch pressure is adjusted it doesn't have a significant effect on the gear mesh. On the subject of decoupling the front and rear axles, to achieve this you could modify the standard centre diff with friction pegs instead of balls. The issue when racing is that this would slip the front under braking and so the rear under acceleration and I think handling might be inconsistent. Basically most modern 4wd transmissions are locked 4wd and slip the whole drivetrain together, like my design. Take a look at the machined components here: WORK OF ART! 2 Share this post Link to post Share on other sites
ruebiracer 1046 Posted March 29, 2020 Thank you so much for your explanations and pics! It´s truly a work of art with the ventilated design. Also to swap the axial bearing to the front side is clever. One problem I had with not keyed design was unscrewing under some circumstances. In fact only some track experience can show the advantages of centre diff function or permanent 4WD. Would love to do those tests for myself on a proper offroad track. Keen on your track tests! Great ideas in this project, and love the Vintage-Tamiya paint job. I still have a wing with the same decal from back in the days... 2 Share this post Link to post Share on other sites
Howards 457 Posted March 30, 2020 That slipper looks the business. If they made it into production I'd be on the list for one. 2 1 Share this post Link to post Share on other sites
ruebiracer 1046 Posted May 2, 2020 Any News on your fantastic project Longrat? You just sparked my ambitions, and I was working again on my slipper solution based on the original diff. I fiddled a bit and shimmed, I was able to clear my 82T DF03 spur gear the lower gears down in the gearbox. So I ordered a 25T pinion and got my first 1,5 batteries on it, using my Avante 2001 as test rig. So far I could only run in the garden on higher grass on 13,5t brushless. But some jumps and hills it cleared perfect. Although I ran it with nearly no slip for the beginning, to see if it can hold the torque or would maybe loosen up. Next step will be running it on a looser level. Hope the weather gets warmer and dry again... Kind regards, Matthias 4 Share this post Link to post Share on other sites
Avante2001R 305 Posted May 3, 2020 On 3/28/2020 at 11:17 PM, LongRat said: The pressure plates are machined to key directly with the shaft, so they can't move rotationally relative to each other. Compression of the spring washers is achieved via the screw in the end of the shaft, just like in the standard ball diff option. I used a modern Schumacher 48DP slipper spur gear and pads, although the gear had to be machined slightly to fit and the central bore enlarged. The whole thing is an extremely tight fit! Looks great are you planning to release a kit? Share this post Link to post Share on other sites
ruebiracer 1046 Posted May 3, 2020 12 minutes ago, Avante2001R said: Looks great are you planning to release a kit? He did an Incredible good job on the design, the air channels are also the notches, where the bevel gear snugs in and is transferring the torque to the plate. The step on the Alu part is to center the gear. He just thought of everything. But he wrote already, that it´s to special and time consuming to make in any quantity. So no hope for a kit at the moment. But there would nowadays be a market in the Vintage racing scene and for technic lovers for sure.. Share this post Link to post Share on other sites
LongRat 616 Posted May 5, 2020 On 5/3/2020 at 6:05 PM, ruebiracer said: He did an Incredible good job on the design, the air channels are also the notches, where the bevel gear snugs in and is transferring the torque to the plate. The step on the Alu part is to center the gear. He just thought of everything. But he wrote already, that it´s to special and time consuming to make in any quantity. So no hope for a kit at the moment. But there would nowadays be a market in the Vintage racing scene and for technic lovers for sure.. Thanks for noticing those small but essential features makes the time to design it all the more worthwhile! I'm really happy to see your slipper solution, please let us know how it performs long term especially slipping a bit. If it works well it would be a much easier solution to the problem for a lot of people. I haven't had a chance to run mine at all, no tracks open and no time or places within range of me to test it properly. That time will come. 2 Share this post Link to post Share on other sites
Ann3x 220 Posted May 6, 2020 I also had a long attempt to make a slipper spur (for a Topforce actually). In the end found this as a simpler option: https://www.modelsport.co.uk/carisma-m40dt-slipper-pinion-set/rc-car-products/381157 As you say its VERY snug fit for any useful spur based slipper design. It's probably possible but will have some inherent issues i think due to the spring throw. Ive come to believe a slipper pinion is a more universal option for older buggies. 1 Share this post Link to post Share on other sites