ThunderDragonCy

Thunder Dragon - Ongoing Chassis Development - now with TRF suspension

Recommended Posts

Because of the question about carbon double layer cassis. My Dyna Blaster does have the same weight as the original one now. So no weight reduction because of carbon. 

  • Thanks 1

Share this post


Link to post
Share on other sites

@CollinBecause of the gearbox design on these it would be more likely a twin side plate type which would need a bottom deck to mount everything on. I have worked up a design but it would be very, very stiff (not ideal) and probably heavier than the plastic tub (also not ideal, and the plastic tub is actually pretty good) so not worth it. I like having at least some original kit parts on the buggy too! 

Share this post


Link to post
Share on other sites

Ran it! Beautiful conditions at lunchtime today. Bright and sunny and dry grass. 

20190305_135232

The new steering is pin sharp with the bearings. Possibly need a slower servo or get used to it! The front carbon tower and the new body mount were spot on and survived several grip rolls, which more than can be said of my aerial whip!

I was back to a lot of front end, the perennial issue with this chassis, but grip rolling is new. Seems the longer stroke shocks allow more travel which in turn allows more weight transfer. I had my drag brake quite strong and the grip was pretty high so I was rolling it during off throttle turn in. I have the same springs as before, but as these are borrowed shocks the damping might be a little light. However I suspect the main thing is the extra travel. I wound on a bit of preload to reduce the droop which helped a bit, but after reading my setup guide it suggested lowering the rear ride height and roll centre. I did that and it calmed down. I was still having to be a little careful of turn in bite but it was fast and fun, with more rear grip and less weight transfer. I am sure with some damper tuning it would calm down a little more. 

Otherwise though, very nice. I love this buggy. 

  • Like 2

Share this post


Link to post
Share on other sites

Anyway to fit an ARB on the front? That might help and allow you to free up the rear a bit & add back a bit of droop.

  • Like 1

Share this post


Link to post
Share on other sites
16 minutes ago, Ann3x said:

Anyway to fit an ARB on the front? That might help and allow you to free up the rear a bit & add back a bit of droop.

I has occurred to me to have a look. Main think I need to figure out is the arm end attachment. It uses a 4mm moulded in ball instead of a screw 5mm ball screw so I don't have any rod ends that fit. Any pointers to part numbers would be most appreciated. 

Share this post


Link to post
Share on other sites

After about 2 weeks of not running anything due to awful weather, I finally got to run again at lunchtime. Bedding in the lovely new DF02 universals I have now fitted to the rear, and also a revised suspension setup. After finding the car very 'on the nose', I rebuild the rear shocks with a 2 hole 1.4mm piston to match the front 2 x 1.3. This gave much less damping at the rear and more balance front to rear. I also tried some much softer rear springs, as I was still running the DF03 Gold rears from the original suspension setup, which are pretty stiff. I also lowered the roll centre at the rear as well. All up combined to make it much more balanced and loads of fun. I did buy a couple of bits to make a front roll bar, and I might still do that, but for now I think it's in a nice place. Be interested to see how it fairs on higher grip surfaces when it dries up a little more. And I have a track day booked in about a month.

Share this post


Link to post
Share on other sites

New parts!

20190403_131651 20190403_131651

Having swiped the aeration dampers I was using from my TRF201 and now having the carbon towers which committed me to 75mm long front dampers (so too long for regular cva dampers) I needed another set. I have been hanging my nose of the 53926 DF03 aluminium dampers for a whole so when @Juls1 fantastic buggy damper thread extolled their virtues over and above the aeration buggy damper set, I caved in and got a, set from a Japanese vendor on ebay.

They really are lovely. Easy to build, really smooth, with lots of spares and everything you need in the box, plus a set of the medium gold springs from the DF03 spring set 53927. If you are considering these I would say dry build the rears and check the fit. They build up at around 100mm eye to eye, which is much longer than the 94mm long eyelet option cva short shock, and the 93mm of the aeration dampers. At full length they lifted the rear of the buggy waaaaaay too high. I put the supplied spare black o rings and the 3mm spacer from the damper parts sprues in there and they fitted up just lovely. I built them with the 2 hole pistons and 500cst rear, 800cst front, gold front springs, soft rears as before. 

Ran it for the first time today and it runs really nice. Balance is good, but possibly a bit over damped. I think I will rebuild them with the same oil but with the supplied 3 hole dampers. Can't wait to run it at the track weekend after next. 

 

  • Like 3

Share this post


Link to post
Share on other sites

The poor thing has been laid up since the last track day. It was ace on track, the best it's been, but a cartwheel broke the rear upright again. Thats track 2 - uprights 0 as the first iteration broke the time before that. New one did last longer though, but cracked right down the body of the upright. Finally got the replacements today

20190515_191218

Not only to these use smaller 1050 bearings and thicker walls, i also stumped up for the new pa12 with glass material. This is a strong plastic with h glass beads in it that fuse during the sintering process. Hopefully these are keepers. Gave it a run out on fresh cut grass once back together. Just lovely. love this buggy. 

2019-05-15_08-50-08

 

  • Like 1

Share this post


Link to post
Share on other sites

These uprights REALLY don't like me! Cracked one of the above sliding into a kerb just having a quick hack in the street. Very frustrating, but possibly the glass bead reinforcement was a bit brittle? Also been chewing through gearbox outdrives at the rear and some binding. I think it was because of the angle they run. The TRF arms have quite a pronounced back sweep so the driveshafts run at quite an angle out of the gearbox. Add in my 3 deg toe in uprights angling them forwards again and there is a lot going on. 

Anyway, a mate of mine was doing up his brother's Terra Scorcher wondered why they were two sets of holes olin the rear pivots. He flipped the block and got toe in! So all you Thundershot chassis runners can easily improve your cars handling by flipoing the rear suspension so the wider holes are lower. Like this

Tamiya Thunder Dragon with TRF suspension and rear uprights from CTE RC

This has massively helped. It sweeps the arms forward, and has allowed me to do 0 deg uprights so angles are much better all round. 

Tamiya Thunder Dragon with TRF suspension and rear uprights from CTE RC

 

I changed things up again. The symmetrical nature meant i could simplify them but also add material. They keep the 1050 inner bearing, but i went for the 1350 outer bearing from the XV01 uprights i used to use on my TRF211. The bigger bearing won't catch or bind on the drivepin. 

I also tried a new material just introduced, PA11. It's said to be tough and softer, more rubbery. It certainly feels less stiff and brittle than other materials i have tried, but it's not flexible. Fingers crossed! 

Share this post


Link to post
Share on other sites
11 hours ago, ThunderDragonCy said:

These uprights REALLY don't like me! Cracked one of the above sliding into a kerb just having a quick hack in the street. Very frustrating, but possibly the glass bead reinforcement was a bit brittle?

I also tried a new material just introduced, PA11. It's said to be tough and softer, more rubbery. It certainly feels less stiff and brittle than other materials i have tried, but it's not flexible. Fingers crossed! 

You are right, the PA12GB is stiffer because of the beads but also more brittle. The glass beads don't adhere to the plastic really, they just make it less flexible. PA11 should be a good choice, it's a little bit more flexible. Should be able to handle impacts better. My favourite still is just the normal PA12 SLS nylon (Versatile Plastic). Works well as long as it's designed beefy enough. Orientation makes a huge difference though, so make sure you set it to the correct orientation. You can lock the orientation on the Shapeways 3D tools.

  • Like 2

Share this post


Link to post
Share on other sites
4 hours ago, Tizer said:

You are right, the PA12GB is stiffer because of the beads but also more brittle. The glass beads don't adhere to the plastic really, they just make it less flexible. PA11 should be a good choice, it's a little bit more flexible. Should be able to handle impacts better. My favourite still is just the normal PA12 SLS nylon (Versatile Plastic). Works well as long as it's designed beefy enough. Orientation makes a huge difference though, so make sure you set it to the correct orientation. You can lock the orientation on the Shapeways 3D tools.

Good to know. I never ad some much trouble with an upright before these. Maybe orientation is a thing, but I don't know which is best. For a rear upright, how would you suggest I set it? Building with the bore vertical, or horizontal? 

Share this post


Link to post
Share on other sites

Ran it tonight at the park. Runs really nicely, and the gearbox outdrives stayed put too so i am calling that a win. 

Share this post


Link to post
Share on other sites
On 7/12/2019 at 1:31 PM, ThunderDragonCy said:

Good to know. I never ad some much trouble with an upright before these. Maybe orientation is a thing, but I don't know which is best. For a rear upright, how would you suggest I set it? Building with the bore vertical, or horizontal? 

Orientate on it's side, with the bore for the kingpin vertical. That way every layer of the print is around the kingpin. Otherwise there's a good chance it will just split between layers and pull the kingpin through. At least that's what I do :)

  • Thanks 2

Share this post


Link to post
Share on other sites
7 minutes ago, Tizer said:

Orientate on it's side, with the bore for the kingpin vertical. That way every layer of the print is around the kingpin. Otherwise there's a good chance it will just split between layers and pull the kingpin through. At least that's what I do :)

That would definitely explain a couple of the failures. Hopefully these hold together, but i will definitely change the orientation now. Thanks. 

Share this post


Link to post
Share on other sites

Having had so much fun with my DF01 with GF01 wheels, i picked up a cheap 13t pinion and fitted the GF01 wheels to the Thunder Dragon. It was nice keeping the handling good but having more ground clearance. The wheels also highlighted my camber and toe settings were all to ****, so i sorted that out too. The GF01 are too big, but i am now on the lookout for some 2.2 truck wheels to fit schumacher tyres to. Running the road also highlighted the turn in over steer due to having a lot of droop at the rear. I rebuilt the shocks with 3 more o rings inside so they are now about 85mm long and droop is 5mm instead of 10. Hopefully should improve things

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now