GV (Great Vigor) Hunter 1:8 4WD Nitro Buggy?

[morrisey0]

Anyone know anything about this? Interwebs search does not produce all that much. Edit: I am realizing this is the same / similar to a Robbe Panterra. And the fact that Panterra is mentioned, makes it more awesome!

I am picking up this little beaut tomorrow, although I know nothing about it and I know nothing about nitro; I love it for its age, its patina, and its yard sale price. Don't know whether to scrap it and use the parts, flip it on the bay, or convert it to electric.

OR, I have been wanting just a little bit of nitro action in my life. I want to tear an engine apart and rebuild it, and hear it roar again. I have never been near nitro since I was a little kid and my dad flew planes. I always loved that smell. So, this may just be my open door to the nitro world.

GV Hunter 1:8 4wd Buggy. I don't think the GTP has anything to do with it, but I am sure hoping it comes with it.

[GoMachV]

Also sold by Hobby Lobby (not the modern hobby lobby) as their own Hunter. Was also sold as a monster truck called the Skyward Labs Mean Mudder.

[Dadio]

I've always loved the look of the old 1/8 caged nitro cars, lil bit jealous.

[silvertriple]

I didn't know that Hunter...

[morrisey0]

Some of my favorite words, "I brought something else that may interest you." So, ended up with the Hunter and a Graupner RC-Rally Buggy. All for exactly what I am selling a WlToys buggy for later today.

The original owner was a machinist, so there are some trick pieces on the Hunter, mainly the body panels. The Hunter also came with a parts car which is complete save the engine and the rear diff gears (the reason he needed the parts car). He also had a bit of an imagination in regards to making a GTP-bodied offroad car??? I didn't think the body had anything to do with the Hunter until I noticed the wheel wells were cut to match. Its a shame almost because I would love to build a car around the body, but the paint graphic goes lower than the cut line, so to cut it to fit a car would destroy the graphic.

[GoMachV]

Graupner was a distributor that added their name to several other brands. That should be a Kyosho Group 20 Baja buggy under the Graupner name

[silvertriple]

One Graupner catalog from that period... It's on page 48. Very few of those cars do have their original manufacturer branding in the catalog, actually...

http://www.dirt-burners.com/rcdox/Catalogs/Graupner/1984.09%20-%20Graupner%20Mini%20Catalog%20%28ES%29.pdf

[morrisey0]

Thanks guys!

Unlike the Circuit 20, which the engine connects directly to the gearbox, the Hunter drives through a spur gear as I am used to with an electric setup. Which brings me to my dilemma. I have close to no money in the car, I have a parts car that is 80%+ complete (including a chassis plate so I won't feel bad for extra holes), and I absolutely love the car except it is nitro, so am I going to piss off the vintage RC gods if I look into converting this thing to a 1:8 brushless set up? Part of me wants to sell it to someone who will love it for what it is, how it is, but the other part of me is saying just do what I want. I am almost certain I am just going to go forward with looking into a conversion, so maybe I just need a little encouragement that I am not being stupid.

If I do move forward, I am going to have all kinds of questions as I don't know exactly what version OS Max 21 this is, so I have no idea on specs on it yet. I am thinking it is a FSR-B?

[morrisey0]

I think a typical Arrma 6S center diff and mount is going to fit nicely in this. I think I can get it all mounted up with no mods to the front driveshaft. The rear ds is a one off piece with a specialized bevel gear in the rear diff, and as it came with a coupler on the shaft stock, I will continue that theme and couple the rear 6mm shaft to a 5mm shaft with a correct dogbone end for the Arrma ball cup. The engine/motor swap isn't going to be a big deal I think. Nicely fitting the rest of the gear may be a challenge.

[Dadio]

As long as it's reversible then I don't see a problem with the conversion , just keep all the swapped out parts together for any future owner . I like what your doing as I'm no nitro fan either .

[morrisey0]

Looking through the parts a little deeper, I think the PO tracked down an entire parts cars because he could not find two planetary / side gears for the rear diff. I will tear down the front to compare, but I think the spur and sun gears are fine; it is just the planets. Now starts the hunt for replacements.

[morrisey0]

Well, after disassembling a known good differential, all of the gears in the bad one have at least some wear and aren't work reusing. I have found, what I believe is, a NIP differential for a Robbe Panther in Germany. It is hard to visually inspect it based on the internet pics, but by description, it should be correct. So, now have to wait for that to come.

So, with a new differential (hopefully), I think I have enough parts to build two rigs, one nitro and one electric.

From what I can see, the stock OS 21 is a FSR-B, and from an article I read, it was rated at 1hp @ 24000 RPM. So I am just guessing here, but I am going to shoot for a drive set up that will give me the same driveshaft RPM as the stock assembly created with a 24K RPM engine. The stock P/S was 12/50 on the OS, and the stock Arrma is 18/46. Can someone please check my math attached and make sure I am not doing something stupid? The plan is just to run 2S lipo, and 2000kv motors are relatively common. There is a barely used 2200kv CC setup locally I may get just to save some money. I don't think I can go smaller than the 18t pinion with the 46t spur in the stock mount, but maybe I can just limit top speed through programming.

[morrisey0]

Still just mocking things up, but not seeing any reason why this drivetrain shouldn't place nice. The rear driveshaft coupler I found is actually completely thin-walled spiral cut, so will act as a fuse if things get out of hand. Hopefully not too rated of a fuse.

Also found out my favorite el-cheapo 2S lipo packs come in a shorty style, which should be just perfect for this rig as fitting a full length pack wasn't working out well.

[morrisey0]

These guys just showed up late. Gearbox output bearings. 12x28x8mm!!!

[Dadio]

Hate to be a doom munger but that coupling on the shaft looks like a 3d printer coupling , not too sure how strong they are , if you know anybody near by with a lath they could make you a solid coupler , I could but I'm over in England , still if it comes to it then PM me and I'll spin one off for you .