Grasshopper II 'send off a cliff'... Restoration

[Kol__ 3377]

Hi guys,

I recently stepped back into the world of RC (with a new purchase of a Mad Bull - see my other build thread) and my 4 year old son was so enamoured with the car and the concept of RC that I purchased a battered to bits Grasshopper II rere from eBay for him (nothing but the best for my son). It was heap as chips and came with the running gear and a little transmitter. The owner said it had been used by his son and I quote 'Not sure what else to say, could be good for spares or sending off a cliff'

So I plan to rebuild this little puppy, although it'll probably cost near on the price of a new one (of course that wouldn't include the rx/tx or the uprated Core RC 21T motor, nor all the extras I got with it), but it'll be great fun and have the 'I' built it factor... brought it back from the edge of certain doom. The seller included a lot of spares, including the rear wheels (new), 2x 380 motors, 1x 540 motor, set of road wheels and tyres and a variety of plastic spare parts and driver figures etc.

This was the spec info from the seller...

Surprisingly rebuilt recently but has been well bashed since…Full bearings / Red wheel nuts / Desert truck rear tyres / 12mm rear hex adaptors / Core RC 21t motor / FTX ESC / ACOMS steering servo / Carson 2.4ghz reflex wheel and receiver / Rear shell clip mounts worn away / Bumper long gone / Steering rods straight as a roundabout / Bumper bracket broke / Shell ‘A’ pillars down a drain probably / Will include any spares I have

Re reading the above from the seller, errr.... why did I buy this?

Anyway, so here's how she looks now....

[Kol__ 3377]

Took the wheels off and cleaned them up along with the ball raced bearings...

Front wheels are pretty battered, think I'll take some sandpaper to them to try and carefully smooth out some of the worst areas of damage...

Shell cleaned and I would say it's beyond repair, however a new one is over £23 for some reason! Considering a repair to the A pillars with some metal rod, but how durable that would be is dubious, plus the time involved may just not be worth it. Plan B is to pick up a Mad Bull shell (£7) as the mould is the same, just with different cut outs around the front shocks (no bother there) and different mounting holes (simple enough to line up the Grasshopper body over the Mad Bull and mark the mounting holes and drill some new ones).

Parts purchased so far...

New chassis 0335092 - on the chassis that came with the car the rear mounting points for the body shell had been ground down to nothing, level flat with the rear wing (see pics, amuses me to think of how many meters it must have slide upside down to grind them down, must had been on some real adventures!). The front bumper mounting points had also snapped off.

New bumper 0445007 - not included in sale

New rear tyres 9805183 - to go with the unused rear wheels that came in the deal

Snap pins 50197 - rear of shell was held on with a cable tie and good to have some spares of these for general RC use anyway.

Still to decide on how to proceed with shell and stickers... any thoughts?...

[Superluminal 3750]

If it was me and If your going to use it as a basher rather than a shelfer id probably aradilte some cut down lengths of brass or aluminum tube as new A pillars, remove the decals, sand down the worst of the road rash, a bit of filler , sand again and a respray to make it look more presentable. I quite enjoy the tinkering side - obvs more effort than just buying a new shell it can definitely be saved with a small amount of hobbying.

[TurnipJF 9192]

Agreed - especially since the A pillars on a new shell will probably go the same way as the current ones before long if the car is driven and crashed enthusiastically.

By all means get it a new shell - I think it deserves a good looking one for the shelf - but give restoring the current one a try. Even if it turns out "nice from far, far from nice", it will be good for bashing around with, preserving the new one for display. 

[Kol__ 3377]

Thanks @Superluminal and @TurnipJF I had similar thoughts about the possibilities of reviving the shell and fabb'ing up some home made A pillars etc. I also really enjoy the tinkering side of things. I love a project and I like bringing things back into use, rather than binning them. I just have to spend my time more wisely these days with the little kiddies running about! There is some moulding underneath the roof where some rod could be glued/screwed into. I've used Araldite quite a bit in the past and haven't found it to be very flexible (particularly in colder weather) and the glue often breaks away from the plastic, even when using the old cloth soaked reinforcing method. Any other suggestions for a more flexible plastic glue once set? My real concern is going to all the trouble of restoring the shell, only to have it bashed to bits on the first outing in my sons hands!

[Kol__ 3377]

Ok, so I've been investigating the shell and making some progress towards a refurb...

Removed all the stickers, was a bit painstaking, but RC stuff on YouTube on the TV helped!

Measured the A pillars on the shell I'm yet to paint for the Mad Bull

This is what I'm left with underneath...

Having researched some more flexible plastic glue, the current plan is to glue in some 6mm plastic rod, just need to be clever how I do it to ensure it has a strong fixing at each end.

[TurnipJF 9192]

4 hours ago, Kol__ said:

Ok, so I've been investigating the shell and making some progress towards a refurb...

Removed all the stickers, was a bit painstaking, but RC stuff on YouTube on the TV helped!

Measured the A pillars on the shell I'm yet to paint for the Mad Bull

This is what I'm left with underneath...

Having researched some more flexible plastic glue, the current plan is to glue in some 6mm plastic rod, just need to be clever how I do it to ensure it has a strong fixing at each end.

Which glue have you decided on? I have had success with styrene cement, plastic pipe joint goo, styrene offcuts melted in acetone, and plastic welding with a soldering iron. Any solution that melts the plastic and makes the new pieces homogenous with the old seems to work well. 

[Fabia130vRS 2098]

I use super glue and baking soda.

put some super glue to hold it together… then add glue layer per layer… glue, soda, glue, soda let it dry and voila.

I repaired that way my plastic stand for my camera on the tripod. And it still hold.

[Kol__ 3377]

Thanks guys  Glue wise I've bought some 'Loctite All Plastics Glue' -

• Loctite Plastics Bonding System is a two-part cyanoacrylate adhesive that sets in seconds
• develops tremendous strength with just one drop
• The activator primes hard-to-bond surfaces such as polypropylene and polyethylene
• Loctite Super Glue Plastics Bonding System dries clear and sets without clamping
• It is resistant to water, most chemicals and freezing temperatures

Hopefully that'll do the trick, what do you guys reckon? Would that be as good as the options you mentioned @TurnipJF? Not sure if it will melt the plastic like you've mentioned.

@Fabia130vRSThat baking soda idea interesting. Why baking soda? Is it just something that can act as solid to soak up the glue and give it more substance?

[TurnipJF 9192]

29 minutes ago, Kol__ said:

Hopefully that'll do the trick, what do you guys reckon? Would that be as good as the options you mentioned @TurnipJF? Not sure if it will melt the plastic like you've mentioned.

The activator sounds like it might do something similar. Worth a try. Please let us know how you get on!

[alvinlwh 5894]

A little late to this party but just to share my experience with my very trashed Lunchbox. After sitting in storage for 12 years, I dragged it out a few months ago, sanded it down, sprayed it with all the intention of restoring it to its former glory. But when I was baking the final coat of paint, I set the oven temperature a touch too high, and it became a meltbox instead. So I got fed up and bought a new shell, slap some free sticker I got from Kent Models on and just use it as a rough basher. Needless to say, it rolled on its first run and put some deep road rash on it. 

[alvinlwh 5894]

37 minutes ago, Kol__ said:

Thanks guys  Glue wise I've bought some 'Loctite All Plastics Glue' -

• Loctite Plastics Bonding System is a two-part cyanoacrylate adhesive that sets in seconds
• develops tremendous strength with just one drop
• The activator primes hard-to-bond surfaces such as polypropylene and polyethylene
• Loctite Super Glue Plastics Bonding System dries clear and sets without clamping
• It is resistant to water, most chemicals and freezing temperatures

Hopefully that'll do the trick, what do you guys reckon? Would that be as good as the options you mentioned @TurnipJF? Not sure if it will melt the plastic like you've mentioned.

@Fabia130vRSThat baking soda idea interesting. Why baking soda? Is it just something that can act as solid to soak up the glue and give it more substance?

The activator is fine, we static modellers use it all the time and Tamiya hard RC shells are the same plastic as the static ones. 

Baking soda is a filler, super glue is kind of liquid. Static modellers uses baby powder or plaster to the same effect. The last time I play with food when model building was using the salt chipping method and that is now superceded by chipping fluid. 

[Kol__ 3377]

@alvinlwh do we have any pics of the melted blob!?

I didn't realise you could bake these plastic shells, what's the technique and correct temp? are you just using the Tamiya paints?

[alvinlwh 5894]

1 hour ago, Kol__ said:

@alvinlwh do we have any pics of the melted blob!?

I didn't realise you could bake these plastic shells, what's the technique and correct temp? are you just using the Tamiya paints?

There you go.

Baking them is a technique some static car model makers do, but the problem is how low can your oven go. Mine is marked 80C but can probably go as low as 70c. I think that time I did not turn it down low enough/left it in there too long/placed it too close to the fan causing it to become a melted mess. The way fan oven works is the fan blast the heat at 200+c until the oven hits the target temperature and it stop blasting heat, kicking back on again when the temperature falls below the set point.

The temperature of 100F(37C) to 120F(48C) had been floated around in some forums but that is just the temperature of a drying booth, which you can build one out of 2 x 60-100w light bulbs (depending on size). It had been claimed that baking can also help to make the paint tougher. 

 

@about 4m mark, 60C bake to harden the paint to allow sand and polish. 

Bottom line is, I experimented with it some it actually failed on my last and final coat. Try at your own risk. AND DO NOT BAKE PC BODIES! 

[Kol__ 3377]

@alvinlwh, thanks mate

Woah, that poor shell, looks like it would be a cool looking body with that paint scheme

[alvinlwh 5894]

22 minutes ago, Kol__ said:

@alvinlwh, thanks mate

Woah, that poor shell, looks like it would be a cool looking body with that paint scheme

Nah, I was just going for a rusty white van look since it was already quite hammered underneath, easy to paint in the rust spots. In the end, I just got a replacement shell and didn't bother to paint it anymore. Hard shell hides road rashes poorly compared to PC shells. 

[Willy iine 18805]

@Kol__ That body to me appears fully repairable.  For the missing front bars, I would take a thin-ish styrene sheet, heat it and wrap it around something near that diameter to get the curve.  Cut it to general size and cement it, putty, sand,  repeat putty/sand as needed.

 

I use general off-the-shelf Tamiya cement (orange cap for plastic) for gluing hard shells and they work very well on Styrene sheets.  As for heating, I use an emboss heat gun (my automotive grade heat gun I use for vinyl / clearbra installs, etc on 1:1 cars gets too hot and pushes air too wide).  

Good luck with the restoration!

[Kol__ 3377]

Parts have all arrived now, so full strip down and cleaned all parts...

Going to clean up the gears properly with some break cleaner

I wasn't surprised to find another bent part on the car when I found this rod that holds the gearbox to the chassis was bent - popped in the vice, couple of knocks with the palm of the hand and it was straight. Also straightened the steering rods at the same time

 

[NWarty 1325]

As a GHII nerd, this thread is great!

[Kol__ 3377]

So the main build is done...

Cleaned the gears with brake cleaner

Built up the bulk of the car

Front wheels were pretty damaged

Carefully sanded them down with 80 and then 120 grit...

Car rebuilt...

Now onto the body shell next, wish me luck!...

[InsaneJim69 1584]

Front wheels turned out great !! 👍

James.

[Grumpy pants 4474]

Impressive work on those front wheels, they’ve come out really well.

[Kol__ 3377]

Thanks guys, I'm pleased with the results so far Still uming and ahing at the mo about what material to use for the A pillars on the shell and how to fix them in place. Thinking styrene solid rod at 5.5mm might do the trick. Just got to figure that out and get on with the shell. My son's birthday is 27th Oct, so haven't got forever to get this thing finished! 

[TurnipJF 9192]

21 minutes ago, Kol__ said:

Thinking styrene solid rod at 5.5mm might do the trick.

Sounds like a workable plan!

[IoMTom 149]

On 10/9/2021 at 10:39 PM, Kol__ said:

Thanks guys, I'm pleased with the results so far Still uming and ahing at the mo about what material to use for the A pillars on the shell and how to fix them in place. Thinking styrene solid rod at 5.5mm might do the trick. Just got to figure that out and get on with the shell. My son's birthday is 27th Oct, so haven't got forever to get this thing finished! 

I just used some left over sprue bits from one of the parts trees, gone for the contrast look! It’s not as pretty as yours looks to be going, but it is original (ish)

 

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