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ThunderDragonCy

Thunder Dragon - Ongoing Chassis Development - May 2024 Potential Ball Diff upgrade

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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. 

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@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! 

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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. 

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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.

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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. 

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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.

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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. 

 

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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

 

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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! 

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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.

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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? 

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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 :)

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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. 

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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

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Not posted about the Thunder Dragon for a while. Following on from the last post the reduced droop and cured the turn in/off throttle oversteer, and it is handling super nicely. I went back to 2.2 buggy wheels after the big wheel experiment and it ran brilliantly on track the other week. Here it is tonight

Tamiya Thunder Dragon with TRF Suspension by CTE RC

I converted the rear to pin drive using DB01 axles, spacers between the bearings, schumacher 5mm shims and some leftover 850 bushings. It's winter and i have these full spike tyres glued to pin drive wheels for my TRF211. These plus some mini spike ftonts should be great. 

Also cured the slight bump steer with 3mm of spacers under the ball studs on the steering arms

Tamiya Thunder Dragon with TRF Suspension by CTE RC

Looking forward to getting it dirty again. 

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Great you made effords with handeling. Lucky you dont need original spares for your runner :lol:

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12 minutes ago, Collin said:

Great you made effords with handeling. Lucky you dont need original spares your your runner :lol:

Thanks, although TRF suspension parts are getting thinner on the ground. Still uses tub, bumper, driveshafts and gearboxes from the original. 

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So when (if) you finish this thing what’s the next chassis you reckon you’ll obsess over and slowly but surely overdo it?
 

Making Tamiya sorta faulty designs work half way decent is lots of fun isn’t it?!?!? 

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4 hours ago, Juls1 said:

So when (if) you finish this thing what’s the next chassis you reckon you’ll obsess over and slowly but surely overdo it?
 

Making Tamiya sorta faulty designs work half way decent is lots of fun isn’t it?!?!? 

I have had a play with some others, but i am pretty content right now. 

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After some great running at the weekend at the track i found that the steering was pretty sloppy, but also really asymmetric in terms of throw. At one point i had the left end point at 100% and the right at 60 to even things out! I decided to tear down the steering and replace all the balls. A lot of these were brass and they wear easily. 

As it stands

20200226_183615

I pulled it all apart and the bearings were still ok, so that's good. I used the steel 5x5mm hex drive balls and the new hard open adjusters

20200226_184916

They are super tight, but that's good! I put the new ball for the servo saver in the centre instead of off to one side (don't know what i was thinking there!), but it was still a little loose, and was still asymmetric. I found the servo saver is worn, so i have ordered a cheap alloy servo arm to replace that. I also put a 2mm spacer under the ball on the servo saver to straighten out the first link. You can see its quite angled. This definitely helped even up the steering side to side so when i get the new servo arm i am going to use a 5x8 ball screw and try and get it really straight. I also ordered a new steering arm from. Shapeways. I tweaked the design with the ball attachment 2mm closer to the servo. That will be a few weeks though. 

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Got the new arm from Shapeways this week. 

20200307_085034

I used a cheap alloy servo arm and cut the top two holes off so it clears the bumper. I tried moving the servo forward but there's is no room on the inside of the tub. A 2mm spacer has lined everything up nicely and it's all pretty even left to right. I have about 10% less endpoint on the right. 

20200307_085026

I also shimmer the steering knuckles qnd uprights as these were contributing to the looseness in the front end. It's all pretty tight now. Not bad for a 33 year old buggy! 

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The efforts you go to with this car honestly embodys the nature of a true Tamiya rc enthusiast. The one thing about Tamiya’s is that they lend themselves to be modified. Either with other Tamiya bits. Or custom made parts, or even other brand parts. It’s all in the name of making the Tamiya car something it was never ment to be but everything you dreamed it could be.. and cost be damned, it’s fun doing it!!!!!

keep up the efforts!

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@Juls1Thanks! I am continually surprised at what can fit what. I mean, it did not take much tweaking to get the whole TRF suspension to work on a vintage buggy! I guess cost is something, but these small 3d printed parts aren't much, and i don't break bits as much as i used to with kit parts! 

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Nearly a year since the last post. Ran it few times last summer and really enjoyed it on cut staggers and mini spikes oj grass. Not done anything to it.

Fitted front mini spikes yesterday to have a go at racing by post on wet grass. Possibly it's not having some better suited rear tyres, but the off throttle turn in oversteer was back. I was re-reading this thread to see what setups i had been through and someone suggested a front anti roll bar might help. I now have lots of arb spares from my touring cars, so i rigged up some dropper links using the instructions in the TRF511 manual as a guide, and laid on a few spare bars. In the end a rear bar from the FF03 kit did the trick. Because i have lots of material in my Super A5 i drilled and tapped it for some clamps. Worked out pretty well. 

20210221_203635

 

20210221_203644 20210221_203709

Looking forward to giving it a run! 

 

 

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