Grasshopper (DT0)3 - Adventures in getting back into RC - Now with Proline truck shell

[ThunderDragonCy 8616]

Shifted this thread over here as I posted in General Discussions as my first post before I knew about how things worked. Also, work on the car escalated and I wanted to keep a note of ongoing upgrades/changes. Hopefully of interest to DT03 runners/buyer.

I have an original Thunder Dragon from 1988 which has had a bit of a restomod, but getting that sorted recently led to the purchase of a cheap Racing Fighter from Germany as I've never had a 2WD buggy before.

First buggy full build in about 30 years, although the Thunder Dragon has been torn down and rebuilt several times. Really enjoyed it. 

I had an old Grasshopper2 shell in my bit box from back in the day, and I'd never painted a shell before. I don't like the modern look of buggies, being a child of the 80's I love the older buggies so I decided to have a go and some light body mods to fit it to my DT03. It was already slightly modified around the front shocks to fit on my Thunder Dragon. Here's a couple of trial fits with the primer on, trying to figure out the mountings and proportion. Couldn't resist getting the wheels on to see what it might look like:

Figured out the body mods, enlarging the front hole to use the central front mount on the chassis, and adding holes in the haunches for the large l-shaped body mount towers that came with the kit. I ended up going narrower than I could have got away with on the front cuts. I chopped the DT-03 suspension mount in the centre to get the front of the shell on and off. Not bothered about the nth degree of wheel control and can always get the fancy TRF carbon one if I feel the need in future. 

After a couple of aborted attempts at orange from Tamiya and Halfords, and neither before strong enough for my liking and went for it with neon orange. 

Stickers are from MCI Racing, with red replaced with black, and yellow replaced with dark grey. Pretty pleased with how it came out.

Another modern look I'm not keen on is the super short front overhang. I like the big 80s bull bars, so inspired by AMPRO Engineering on Youtube I knocked up a bull bar bumper in 3D CAD and got it 3D printed from Shapeways. Only cost a tenner! Sets the stance off nicely, I think. I do love the kit black star dish wheels though. 

 

As for the car, I loved building it and it seems solid. I've never had brushless before either, so I went for a 13.5R Speed Passion MMM motor from Modelsport who also did my some leads with tamiya plugs, and a steel 17t pinion and a bearing set to start with. The kit came with the CVA dampers with the fixed solid plates on top of the shafts. 

Initially I was a bit disappointed. I'm certainly no expert and have no plans to race, but it was very understeery and bottomed out a lot. Due to older equipment I have already, I still use ACOMS 27MHz radio and NiMH batteries to keep costs down which I've since learnt are on the heavy side, but they work fine in my Thunder Dragon! 

So, after going down the rabbit hole of what mods to do where, trying not to spend a fortune on hop ups and learning as I go, this I think is my basics for getting the DT-03 to somewhere near it's potential and also hopefully help some newbies looking at getting their DT-03 running nice in my opinion:

1) Junk the stock tyres. The deep rib fronts that come with the Racing Fighter in particular are useless on hard surfaces and I generally muck about in the street or at the yard at work. With the fiesty motor I started tearing through the rears too, and have ended up with Schumacher Mini Pin Yellows on the stock rims. Works great, and the yellows last longer than the blue counter-intuitively, because the blue is harder it span up too easily on hard surfaces and wore out. On things like the pump track in the pictures, the mini pins are immense. 

2) Connected to 1 - Be honest about where you drive. Having burnt through cool looking buggy tyres I now have a second set of wheels (Schumacher Flexlite read, Tamiya Dish Front both in black) with Schumacher RT1s and medium inserts for tarmac. 

3) Suspension - I'm using the DF03 (not a typo, the 4WD car) setting springs, hard rear, softest front. Both are firmer than the kit springs. The DT-03 settings springs were right out because the colours would have looked rubbish if I'd needed the red ones. Yes, I am enough of a tart for that. Plus, couldn't see the point of a softer set of springs if the kit springs were in the middle. I saw the DF03 springs suggested on a thread on here I think. Great call.

I got the TRF 54043 piston rods for the rear shock and standard CVA mini shock shafts 50601 for the front and used the kit sprues and some e-clips to convert the dampers to proper pistons. After some experimentation I'm running single hole pistons with the kit Soft Tamiya 400 CST oil

4) I got the anti roll bars, but have ended up not using them. Now I have the suspension firm enough to hold the car up it handles fine without the anti roll bars. IMHO.

5) I used the leftover ball studs from the unused roll bars to replace as many of the step screws in the damper mounts as possible. Much nicer and less rattly I got a bag of ball connectors (50591) to finish the job off, although the fronts need a bit of filing to get them to fit the wishbones.

6) Turnbuckles - Don't be a cheapskate like me and pick up a cheap DT02 set, as the steering arms don't fit! These do seen good for getting the grip up though. 2-3 neg both ends.

7) Driveshafts - I had no issues with the toughness of the plastic driveshafts, but I couldn't believe how much they restrict suspension movement. I didn't want to spend out on Universals as I'm not racing. I ended up taking a leaf out of the Sand Viper book and went to the metal driveshaft and cups. Only cost about a tenner for the parts, and the car stands up at the rear about another 10mm! They look better too, IMHO. Parts are:

Shafts - Tamiya 9805551

Outdrives - Tamiya 9804237

Hub end cups - Tamiya 50823

8) Geared diff with the kit seems fine. I stuffed it with grease as advised somewhere on the internet and does fine for me. 

9) Kimborough servo saver was a fiver well spent. Much more crisp steering.

10) Not sure if the Hop Up servo mount was £18 well spent, but it looks pretty and does look into the chassis and servo much more firmly. I'm open on this one as it's pretty expensive. 

Hope you like it, and hope that helps anyone looking at getting a DT-03.

Cheers!

[Saito2 7985]

Very nice. I like the paint scheme. The Grasshopper 2 shell fits the longish DT03 chassis surprisingly well.

[Mad Ax 10843]

Great write-up and nice-looking buggy.  Looks factory and I love the colour scheme.

[ThunderDragonCy 8616]

5 hours ago, Saito2 said:

Very nice. I like the paint scheme. The Grasshopper 2 shell fits the longish DT03 chassis surprisingly well.

Thanks! I'm a sucker for orange on things, it's my company colours too. Getting the MCI Racing tip off was the key so the stickers could be keyed in. I was a little unsure about the shell because of the wheelbase, but I measured up my kids Rising Fighter (GH2 chassis-ish) and tried to keep the proportions of the overhangs the same. Mad Bull has similar wheelbase to a DT03 as it happens so I just tried to keep it in line with the proportions of the existing buggies with a similar shell. The proportions and look are really helped by the bull bar bumper giving some front overhang to the shape.

[ThunderDragonCy 8616]

So rather predictably I haven't been able to stop spending money on what is fast becoming my favourite buggy. Here's the latest round of mods:

GPM aluminium uprights. As I've cut the cross brace on the front suspension to get the Grasshopper2 body in, it was a little bit flexy. Plus the plastic ones were creaking once I put the harder DF03 front springs in. The aluminium parts are lovely, but the fasteners are garbage.

Man maths at play here. The shop with the uprights had the c-arms in as well, so I saved on postage. As most people seem to break the plastic ones in fairly short order I thought I'd get them. They look pretty and they are stiffer which helps as the turnbuckle upper links offer no stiffness compared to the kit upper arms because of the ball joints.

The eagle eyed might also spot 'not Tamiya' steering arms. After my error in getting DT02 turnbuckles, I spotted some GPM ones for the DT03 for a couple of quid so got them to make tweaking the front geometry easier. They have been good so far.

What did I say about GPM fasteners being garbage? This is the in tact side of the car. The other side lost it's king pin. Just unscrewed itself, because the allen key hex was badly shaped and I couldn't tighten it properly. Luckily I had a couple of shafts left over from a kit I bought for my Thunder Dragon.....

Drill out the threads with a 3.2mm drill.

Install 25.3mm shafts with M3 plastic washers to space it out I got off ebay for £1.20 for 50. Much cheaper than Tamiya aluminium spacers!!

Final thing, which I'll admit is completely frivolous: Carbon gear shafts. Saw them on ebay for £7. Couldn't resist.

One in:

Bit of a mess having to crack open the gear casing

And the other....

Stuffed the diff with more grease whilst I was at it.

All back together and a little damp after a quick shakedown on it's street wheels.

(Missing bull bar due to breaking two already and giving up on it, however much I like the look!)

[Jason1145 4688]

Nothing wrong with frivolous spending here, it'll be hard to gauge the benefit of those shafts but who cares, you know they are there and that's all that matters

 

[ThunderDragonCy 8616]

They are a LOT lighter which is nice. Can't be a bad thing on such a rear heavy car. Fun way to decompress after work too.

[TamiyaBB 49]

Very cool!

I've two GH 2 shells.... hmmm

[ThunderDragonCy 8616]

9 hours ago, TamiyaBB said:

Very cool!

I've two GH 2 shells.... hmmm

With the DT03 kits so cheap (in Europe at least) it's too tempting. My Racing Fighter kit was £70 and I got £20 back selling the shell and decals! 

Here's the cut and painted shell before decals

If you are accurate you won't need to cut away as much as I did behind the front suspension towers. The larger front body mount hole is drilled pretty much bang on where the original.small hole was. You can see the extra holes drilled in the creases of the rear wing tops for the rear body mounts.

[ThunderDragonCy 8616]

Might have been a little rash about the kit tyres being garbage......

Popped down to the local gravel car park to run a couple of packs through the grasshopper. Having seen most of the serious 2wd guys seem to use some variation on rib fronts I stuck the Racing Fighter deep rib fronts onto some spare front wheels and gave them a go after running my mini pins for a few minutes. On loose surface these tyres are really impressive. More bite than the mini pins to the point where the whole balance got pretty oversteer. More tyre testing to be done. Think I need some deeper tread rears to balance out these fronts.

[gary1365 90]

I haven't tried the rib tyres off round yet I used my carson all terrain on the front and they were good. The stock spikes were rubbish on the rear but they were 3/4 worn. I haven't had the chance to try the mini spike with the receiver broke but I'll try them with the deep ribs next time I'm off road.

[ThunderDragonCy 8616]

I agree the stock rear are rubbish! They were junked at the same time as the rib fronts for mini pin yellows all round. Rib fronts i have are quite different to the ones that come on the neo fighter. Narrower with much taller ribs. 

Mini pins have been fun on the gravel too, but I am still learning about tyres on the car so thought I would throw the ribs back on last night. Was surprised how much more front end it gave the car in the loose stuff. I have a pair of schumacher yellow cat blocks on the rear of the Thunder Dragon which I might try on my next run in the gravel to see how that evens things up. 

Be interested to know how you go with the mini spikes. Now I have the street wheels for hard surfaces I might be tempted with something deeper tread than the mini pins when they wear out.

[ThunderDragonCy 8616]

A lot of fun running on grass yesterday resulted in this. Time to learn about repairing (thanks to Willy Chang for advise over on General Discussions)

And as I had the shell off, I realised I hadn't done a pic of the finished chassis. This is the current status:

 

[TamiyaBB 49]

Ouch!

[Jason1145 4688]

What's that black wire thingy wrapped around the MCDonalds straw then?

Looks good with the shell off, I'm about to fit my alloy servo holder too... the turn buckles look race ready and mean... I just did the cardinal sin of fitting alloy upper arms but I'm a sucker for looks ;p

 

[ThunderDragonCy 8616]

1 hour ago, Jason1145 said:

What's that black wire thingy wrapped around the MCDonalds straw then?

Looks good with the shell off, I'm about to fit my alloy servo holder too... the turn buckles look race ready and mean... I just did the cardinal sin of fitting alloy upper arms but I'm a sucker for looks ;p

 

Ha! Old school like the Old School. ACOMS 27 MHz yo! 

Actually, turnbuckles, that reminds me. I flipped them to the front for easier access. You need to put a couple of M3 washers on the body end mountain to push the ball end out so they clear the springs. Looks better on the front too IMO.

[ThunderDragonCy 8616]

Bit of love for the broken shell. Thanks to all the fantastic advice I got over on the other thread I'm hoping for a positive result. 1st stage

 

 

 

Sanded back the paint on the underside and measured up. Those white rub tell marks are where the shell contacts the suspension mount lugs so needed to be inside those.

Scored the surfaces and got some poly cement on the job. We will see.

Also got the car wheel weights off ebay for adding a bit to the front. Saw someone using 45grms so was aiming for that.

Stashed a pair of 5 grams in front of the servo saver and another pair, one either side of the chassis

Stashed a couple of 10s on top and on the servo mount

Be interesting to see how it handles now, but I don't want to run it without a shell.

Thoughts and advice always welcome. 

Cheers!

[ThunderDragonCy 8616]

Front section on

Fingers crossed!

 

[gary1365 90]

Are you planning on filing and sanding down the join on the nose. 

[Biz73 603]

If the poly cement breaks off, try silicone as someone mentioned earlier. It probably won't be as clean a fix, but it is slightly flexible and may help it from cracking off again. Hopefully the poly fixes the problem this time and you won't have to worry about it.

[ThunderDragonCy 8616]

Don't know yet. Going to see what it looks like when it's done

[ThunderDragonCy 8616]

Looking promising. Second strip now for good luck

 

[ThunderDragonCy 8616]

Fixed! Seems solid. Can't say I'm too bothered about repainting given wear the body pin is. This is my runner shell now. I have a new plan for a shelf shell....

 

[ThunderDragonCy 8616]

Also, this lot arrived today. Let Project Mad Hopper Bull Shot 2 commenced!

 

[ThunderDragonCy 8616]

Well this is just stupidly fun!