Beefy Scorpion

[ron]

No I do not yet, its a pain putting up pictures, all my pictures are like 1mb +, so I have to resize them, save them and then put them up, if you know an easier way, please let me know. Mean time here is what I have done so far.

[ron]

progress of the restoring and rebuilding the ishipla shocks. I have used alloy wheels for the tires, typically gearhead for the rear and tamiya phoenix for the front, both have been machined to size on the circumference to look the part!

[ron]

OK, about the top spring collar, yes the grub screw literary scares the shock body and destroys the anodizing. So here is an idea, either get a collar that is of the clamp type OR make a small grove inside, cutting 1/4 around the inner circumference of the collar, making sure the top and bottom surfaces are not cut and intact, get a strip of steel and cut to size and put it in the grove, when you tighten the grub, it will push against the steel strip which will uniformly press against the body of the shock, there should be no mark if the strip is nicely polished around the edges. Very complicated and tedious work, I know but it should work if you have a steady hand and the right dremel tool. I got the idea from the old camera lens hoods, the ones you slip-on and screw a knurled screw on the side, it pushes against a metal brass strip that pushes against the lens barrel and pulls the hood in.

The clamp option is the better way to go, but I like the look of the one with the grub screw!

[GoMachV]

They also have soft tip grub screws, nylon or brass tip

[DennisM]

That´s a very cool build You´ve got going there, Ron.
Nice job on the shocks, just give me a shout when You´re done using my lathe

I´m resizing my images as well, so no clever tips here.

That rear shock strut - which Tamiya buggy is that from, looks like it was never meant to be any other way
Thanks for the tip on the shock "clamps" which is easy for a guy with a lathe but surely will end up in agony and tears in Denmark

Think I´ll try the suggestion with the soft tip grub screw

[ron]

Thanks! Ha ha ha, yes, that is an option, Dennis, as suggested by Gomachv.

The small sherline lathe is a great tool!! Bought it with my pocket money. Cost me close to $800 with parts and tools but well worth it. Just yesterday I bought a 'boat load' of tooling and all for $50 only from an estate! Included was bench press drill for $35! They had a real sized lathe (south bend lathe) - maybe I might get it for $50-$100! But I have no space for it .

Oh the rod ends are from tamiya hilux, blazing blazer, or suoer champ. These 3 cars had them for steering. So they were part of the steering linkage system. So real scale like and all METAL construction too! , nice! The ball hole dia is 2mm while the rod end dia is the standard 3mm. The stainless steel tube was cut to size and I tapped both ends with a 3mm tap and inserted grub screws too receive the rod ends. Lightweight and efficient. I doubt I needed the strut cause the chassis is pretty stiff as it is. But because in the latter design, kyosho had a one-piece trailing arm mounts and so I made this mod to mine, looks cool so I will keep it.

those rod ends are popping up on ebay and not that rare, there are 2 sellers right now selling a pair or so but around $8/piece. I have slowly acquired about 32 pieces so far, all new. I did pay a fortune for some though, the rest I got for cheap to average price. They are a great addition to any vintage project.

I have a lot of ideas for my build, the major changer will be using a belt drive system and a smaller 380 brushless motor, the motor will really look the part on the buggy. I am planning to use 1/12 - 1/16 scale radio gear as well. I really want the buggy to show its mechanical components. Initially the radio gear it had hid them all with their large size and and all.

[DennisM]

I´m familiar with the rod ends - the part that intrigued, me was the upper rear shock mount.
I´ve never seen it in one piece - a split verision with a piece of rubber tube inbetween can be found on ie Avante.
Where does Your´s come from?

I think You should buy the full size lathe and resell it to me for twice the amount, just put it on the ferry and I´ll do a pick up in port

That belt drive sounds very interesting, any pictures?

[ron]

Oh, I should hav my glasses on! I misunderstood, yes, indeed, they came from the Avante! I was fiddling with them when I got the idea of actually using them. I did not like the rear shock towers or the fronts because they are too 'showy'. I wanted a stealth enough tower so that the only thing the eye catches are the shocks, I am thinking of doing something with the front towers.

I cut half way through the round/ cylindrical portion on both the pieces, filed the ends with a round file into a concave half moon shape until the holes of the pieces aligned with that on the gearbox, they are fixed with 2 screws and the hafl cut ends with the half moon cut in them interlock against each other. So thats how I modded these up. I know the shocks are t too much of an inclination but they work well. Same configuration can be found on the avante, 1/8 scale rat dune buggies, AYK super trail etc.

Yeah, I should get that lathe!! It is complete with its own metal table with tooling compartments and all, I don't think, anybody will be able to get it out of the shed and across to the street, no room, so only thing is to leave the table and unscrew the lathe, its a shame but at $80-$100, its a bargain. I know what you mean!! ha ha ha, there are so much things here and sometimes they get scrapped cause the younger generation don't care.

The belt drives an idea, I have no hardware yet BUT, it is soon going to turn into a reality. I am going to eliminate the center gear and have a direct motor to counter gear drive, I am nervous how this might turn out. I can't increase the size of the belt drive lager than the counter gear dia as it will interfere with the gearbox axle. It will turn out to be too fast of a runner and heat up the motor with what I am thinking. I went with the belt idea because with the stock configurtion, there is too much noise and for me personally, it looks bulky. (Just compare the design of this to the rowdy baja buggies gearbox, all the gearing is beautifully packed inside the gearbox)

[DennisM]

The following is taken from the thread where I fiddled with a belt tranny,
where Phin named the gear ratio on the Scorpion and came with ideas.

ron wrote:
...
What is the pulley ratio on your setup? You know with the stock setup, the trany had 3 gear reduction in sequence, 2 outside the gearbox and one inside to achieve that speed at the wheels. With the pulley setup, won't the motor be putting out a lot of rpm on the wheels and getting pretty hot doing so? I am not trying to be a smart ass here, just asking if you don't mind.

Love the pulley with the belt, you have made a scale-looking scorpion more real with the belt drive, man that is just real. I am so doing that too. I think you can employ chain drive too, for that wicked look, but won't be as smooth as belt drive.


Phin wrote:
....

It helps that the internal transmission ratio on the Scorpion is 2.8:1. I believe the V-One pulley Dennis is using is 32T, and a pulley for the motor can be found as low as 10t or 11t, so the belt setup should handle gearing for a stock brushed motor.

The real potential of the belt drive though is to reach the gear ratios you need for the torque of a 17.5t brushless.

[ron]

yes, I remember, But what does Phin mean by internal ratio? Inside the gearbox? and than you got the ratios outside (2 ratios). So is it the overall ratio? (r1 x r2 x r3) = 1: 2.8

I am going with the 308 motor on my setup as I said before, I have seen the traxxas 1/16 scale 4x4 truggies with this thing powering it, very powerful indeed and for a light scorpion chassis, it should work just fine.

So how did your belt setup work, Dennis?

[Phin]

2.8:1 just for the two gears inside the trans case. Diff gear is 28t final drive gear is 10t.

[ron]

Got it Phin, thanks, so you are saying, as long as the internal ratio is 1:2.8, it is OK no matter what power you apply to the gearbox, there will be no to minimal damage?

I hope with the direct belt drive and a torquey motor with less rpm, I am able to drive at a moderate speed, I don't want this thing to turn out in a 'dash' buggy that is too fast everytime. I will experiment but it is good to get ideas.

thanks guys.

[Phin]

Got it Phin, thanks, so you are saying, as long as the internal ratio is 1:2.8, it is OK no matter what power you apply to the gearbox, there will be no to minimal damage?

I hope with the direct belt drive and a torquey motor with less rpm, I am able to drive at a moderate speed, I don't want this thing to turn out in a 'dash' buggy that is too fast everytime. I will experiment but it is good to get ideas.

thanks guys.

It definitely still matters what power you put through the gear box. You should be able to find pulleys in the right size to gear a 21.5T or 17.5T brushless but I wouldn't really go to a faster motor than that with a belt.

You'll have to look at the roll out recommendations for the 380 can you want to use and see if you can find pulleys in the right sizes. From what I understand 380 motors have less torque.

[jwscab]

I use fast image resizer to change all my pics. It's a small application that you can put on your desktop, set the file size(resolution A x B) initially, then just drag and drop the pics it will resize and place in the folder of your choice. very easy and straightforward.

[ron]

Thanks, Phin! I will have to do a bit of research and see the diff 380 motor specs. I want to use some of my vintage receivers and servo with the brushless ESC that I will buy with the 380. Going to go with the smaller servo that is used with 1/12 scale race pan cars. Hopefully it has enough torque for steering! I don't plan to go bashing with my buggy or go very fast, making it as a RTR as well as a shelf queen . I don't want to keep it all closed up as a model but really enjoy it by running it. It already is light and with the 380 setup, it should fall in the featherlight weight category, ha ha ha.