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ThunderDragonCy

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

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On ‎30‎/‎05‎/‎2017 at 7:55 PM, TurnipJF said:

Can't find the build thread I was thinking of, but a photo of the vehicle (belonging to Terz1) appears in this thread:

 

 that's cool, thanks for the link, I do actually have a very hopped up wild dagger with an old beetle shell (shell was a one off vacum formed by a friend of my brother over 25 years ago at school! I am not sure what was used as a mould, probably a sand scorcher).

 

since this I have bought and built a blitzer - couldn't resist, but also ordered a DT03t which arrived today, so lot's of options 🙂 

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Hello, and thanks for such an informative post. I enjoyed reading it whilst deciding on a Neo Fighter.

I've recently dug out my vintage Thundershot and Grasshopper with my 5y old boy, and we are having a great time. The GH chassis was quite damaged and eventually broke enough to justify a new car. The DT03 is superb, light years ahead of the Grasshopper. I like it as much as the TShot: great handling and plenty fast for us.

I was expecting to change a few bits here and there, but so far no need. I'm running it stock with a 2000 mAh LiPo.  I sanded the front edges off the output cups to help with clearance for the swing arm, fitted the cups into my drill and spun them up on some sand paper. I fitted ball bearings.The suspension springs need pre-load (with some yellow plastic collars from the late 80s) but then work amazingly well. Might fit some street tyres or just wear out the stock ones and get some new off roaders.

My needs are not demanding, and this buggy did the trick more than well enough. If you fancy one, I recommend it highly.

Ben

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Little update - the 7.2V pack was getting a little short of run time, and having run an 8.4 in my Thunder Dragon I thought I'd try the same in the Grasshopper. Overlander were brilliant - they built be a hump pack 8.4v battery with the 7th cell 25mm from the cable end of the pack. As you can see it fits perfectly

8.4v hump pack in the grasshopper dt03. Custom one by overlander. Put the 7th cell 25mm from the cable end and it fits perfectly.

The buggy now has nice bit of pep, and plenty of run time. Added bonus is some more weight towards the front which has helped turn in too. 

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New shell done today with the custom "Dress Up" decals modified from the Grasshopper2 Junior. I have been working on these for months! 

20171203_18561920171203_18560720171203_185551

Full story on the post over in the Vintage forum 

 

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Beautiful Thunder. Lovely car. The mod to front suspension mount and the use of that mad bull/gh2 shell is a very good call. The new paintwork shows off this bespoke concept beautifully. 

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40 minutes ago, ALEXKYRIAK said:

Beautiful Thunder. Lovely car. The mod to front suspension mount and the use of that mad bull/gh2 shell is a very good call. The new paintwork shows off this bespoke concept beautifully. 

Thanks dude. I do love a 'hopper2, but only in loud colours!

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Hi Thunder

It looks as if your running 8.4v on a TBLE-02s I did think it would handle it - (I was concerned for my own TBLE-02s's when I started using 7.4 LIPO)

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10 hours ago, gizard said:

Hi Thunder

It looks as if your running 8.4v on a TBLE-02s I did think it would handle it - (I was concerned for my own TBLE-02s's when I started using 7.4 LIPO)

Yeah, I have given it a go. It works perfectly with the TBLE-02S and the Speed Passion MMM 13.5R motor (3300kv). I was running 8.4 on 10.5t/3800kV in my thunder Dragon for a while, but even with the fan fitted it kept tripping the thermal shutdown. I don't have a fan on this buggy and it runs no problem at all.

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Setup chronicles continged....

Mini spikes

Car is now permanently on truck wheels. Recently found a great place near work to run on grass as they keep it cut. Massive field with a gravel car park, trees to run around, leaves to drift in. Lovely.

Car has been setup up with as much rear grip as possible in the setup because I used to run on gravel before finding this new place. Front anti roll bar, low front/high rear heights. Was running cut stagger front and vee4 rear. Since running on the grass, especially since gettng the 8.4v pack the car has been oversteer central. Hardly any rear grip! Sorted the diff out and filled with 300000 cst oil for limited slip, stiffened front springs, increased advance in the motor to maximum to reduce torque, and heavier front damper oil but to no avail. The tyres didn't look very worn, but had seen better days. 

Fitted the mini spikes you see above. I have never (in my admittedly limited experience) known such a massive change in balance from a single change. From so-much-oversteer-i-don't-want-to-drive-it to just grip and go. Power understeer in cornering, taking absolutely everything on the throttle from standstill. Now It's borderline boring! I wanted a bit more grip but some powerslides are what 2wd is all about, right? Maybe I should have got mini pins to keep some drift!

Anyway, had 5 minutes this afternoon so motor advance is back to minimum for max torque, and the soft springs are back on the front. I'll be swapping out the front anti roll bar for a rear at this rate! More when i have some more running done and got a setup dialed in. Anyone else run some other Schumacher truck tyres? Maybe some mini spikes on the front too? Or some vee2 on the rear?

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Popped my site cherry(!) (1st post) just to say I really enjoyed this. Most went right over my head but after umming and ahhing for days I’ve just order a DT03 (Racing Fighter) to dip my toe into RC. 

Will be pinching some ideas I think 👍

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36 minutes ago, Man1c M0nk3y said:

Popped my site cherry(!) (1st post) just to say I really enjoyed this. Most went right over my head but after umming and ahhing for days I’ve just order a DT03 (Racing Fighter) to dip my toe into RC. 

Will be pinching some ideas I think 👍

Welcome and a great start. Grab a camera and start a build thread when it turns up. Feel free to ask as many questions as needed. There is no stupid question, but the answers may well be :P

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Hey Thunder, did you ever try fitting a brace between the two front shock mounts? You could potentially fit something with standoffs and/or spacers that could utilise the existing mounting holes, and this may still allow for the nose of the body to fit below the brace. Could be an ideal little Shapeways 3d printing project!

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11 minutes ago, Nobbi1977 said:

Welcome and a great start. Grab a camera and start a build thread when it turns up. Feel free to ask as many questions as needed. There is no stupid question, but the answers may well be :P

Thanks. 

I’ll certainly detail my journey. Total newbie at this so be good to document it although it will be a slow process  literally bought the kit and bearings so still need a fair amount.

And the questions will be coming soon enough!

Already having to resist blue bits and carbon bits. Like a magpie attracted to shiny 😂

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2 hours ago, Man1c M0nk3y said:

Popped my site cherry(!) (1st post) just to say I really enjoyed this. Most went right over my head but after umming and ahhing for days I’ve just order a DT03 (Racing Fighter) to dip my toe into RC. 

Will be pinching some ideas I think 👍

Glad you're inspired. I have had a lot fun tinkering. Hope you do too. As the guys have said; ask questions. It's part of the fun.

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1 hour ago, ALEXKYRIAK said:

Hey Thunder, did you ever try fitting a brace between the two front shock mounts? You could potentially fit something with standoffs and/or spacers that could utilise the existing mounting holes, and this may still allow for the nose of the body to fit below the brace. Could be an ideal little Shapeways 3d printing project!

No I haven't. Any brace would make getting the body on and off a pain. I got the metal GPM shock mount mounts (if you see my point, the parts that screw into the side of the chassis which the top wishbones and the shock mount attach too). Before I got the metal ones the plastic kit parts used to creak. Now thry don't so that's good enough for me. I reserve all my mad 3D printed parts for my Thunder Dragon 😂

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Little bits today. Running on grass seems to put more stress on the rear suspension so I have nearly lost the screw pins a couple of times. Got the TL01 shaft set and 5.5mm shims to de-slop it. As I have some spare new wishbones I replaced those too

20180107_20122820180107_20114420180107_201122

Also, following the mini spikes tyres giving so much grip it just understeers all the time on grass I have put 600cst oil in the rear shocks (up from 500cst/40wt) and gone from the medium gold DF03 spring to the hard silver. This should help turn in and take a bit of grip away from the rear. We'll see this week if I get to run.

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15 hours ago, ThunderDragonCy said:

Little bits today. Running on grass seems to put more stress on the rear suspension so I have nearly lost the screw pins a couple of times. Got the TL01 shaft set and 5.5mm shims to de-slop it. 

Hey Thunder, weren’t you running, or at least testing, 54395 Suspension shafts for outboard front wishbone pivots previously? It’s an interesting concept, I hadn't really thought about this until seeing all the discussions about tapping screws being ‘invasive’ into plastic, versus a concept such as yours using a  shaft with an e-clip to achieve the mechanical restraint (which is obviously ‘non-invasive’ to the plastic of the suspension arms.)

Having looked at the manuals of a few other non Tamiya kits it’s seems quite common to go for the mechanically restrained, non-invasive methodology wherever possible for various fixings, but I guess this adds complexity and cost via increased number of components. 

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2 hours ago, ALEXKYRIAK said:

Hey Thunder, weren’t you running, or at least testing, 54395 Suspension shafts for outboard front wishbone pivots preciously? It’s an interesting concept, I hadn't really thought about this until seeing all the discussions about tapping screws being ‘invasive’ into plastic, versus a concept such as yours using a  shaft with an e-clip to achieve the mechanical restraint (which is obviously ‘non-invasive’ to the plastic of the suspension arms.)

Having looked at the manuals of a few other non Tamiya kits it’s seems quite common to go for the mechicaycresttained, non-invasive methodology wherever possible for various fixings, but I guess this adds complexity and cost via increased number of components. 

Yes, the front wishbone has shafts (again replaced due to screwpins backing out) and I also drilled through my c hubs to put a shaft in as the kingpin for the steering after the supplied screw came out within 5 mins.

The shafts are more of a faff and more expensive which is why you Don't see them on basic kits. Another good thing is that they are stainless and polished. The screwpins I took out where rusted up and rough after a year of use. The shafts should be smoother and last longer

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More updates. Long winter has got me reading and thinking there were lots of things i would like to improve about the rear uprights. Slimmer design with no fouling the wishbones for a start, taking out the slop on the axle and on the lower wishbone pivot, and having looked at the TRF201 rear hubs, add some toe in and adjustability. After an abortive effort due to mucking up a measurement, these bad boys arrived today from Shapeways

20180219_204342

First things first, a quick recap of the basic kit part. Massive opening around the driveshaft to accomodate the fat plastic driveshafts means it fouls the wishbone before the shocks reach full extension

20180219_204120

No toe in here

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Install the bearings. They are a snug fit so i needed to use the axle end and hex to pull them into position usibg the wheel nut. I jammed a slim screwdriver in the drive cup slot to stop it turning. 

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Cleaned out the lower pivot holes with a 3.1mm drill bit. Then m3 threaded the ball mounting holes on top

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Trial fit. Snug between the wishbone ends and some toe in!

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I tried to position the innermost ball in the same place as the original upright but didn't quite work out. I needed to open out the tutnbuckle 2.5mm to 27.5mm of exposed tutnbuckle to get about 3 deg camber. What was more successful was to clearance to the wishbone. Loads more droop!

20180219_211039

All installed and looking sweet!

20180219_213324

Got toe?

20180219_213339

These are 3 deg toe in. I have some 1 deg as well just to see. Not getting a chance to run much at the moment but really pleased with these!

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Beautiful day here so charged up the batteries and headed to my favourite running spot on the way to work. Car was working great until a bottom out to cartwheel to this......Ooops!

2018-02-20_11-54-42

That section is same size as the kit version so the ABS must be way stronger than the SLS 3D printed nylon. Back to the CAD screen later to add lots more material to that section. Worked nicely whilst it lasted though. Put power down nice and cleanly, and the rear suspension seemed nicer. 

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I wonder if CNCd alloy would be better for this than 3D-printed nylon? 

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57 minutes ago, TurnipJF said:

I wonder if CNCd alloy would be better for this than 3D-printed nylon? 

It would definitely be strong enough in aluminium but would cost a lot to get them made in anything less than huge quantities. I don't think the SLS nylon is necessarily a problem here, I just need to add much more material. It's also a worst case setup too - I ha ve the TGX axles and 10mm hexes on the truck wheels to widen the track so there's a lot of leverage on there.

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