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Re: Scorpion 4x4 Build project

Posted: Fri Mar 24, 2017 5:25 pm
by Dadio
I hope my last post didn't sound dismissive of people working with more basic tools , I'm in awe of what 1300GT achieved with basic tools on his 4wd SRB custom build ,that was the inspiration for this car in the first place .
Anyway i finished the the second king pin this evening so it's just the second drive shaft to extend (I've made a sleeve and have the silver solder ready ) then it's steering time , i think i know what I'm going to do .

Re: Scorpion 4x4 Build project

Posted: Sat Mar 25, 2017 3:27 pm
by Dadio
Today I extended the second drive shaft and silver soldered the sleeves , after fitting and testing i was still worried that they might pop out at full lock so i decided to add springs in the diff drive cups , those drive cups are supprisingly hard steel ! I had to deepen them to make space for the springs and the only thing i had that would touch them was diamond dust dremmel tools ,took a little time but it worked and the shafts are now satisfyingly secure , they even click into place when fitting them so I'm a happy man and i can move onto the steering.

Re: Scorpion 4x4 Build project

Posted: Tue Mar 28, 2017 12:38 pm
by Dadio
I had a little time this afternoon so made up the chain guide pulleys , i also removed a single chain link and i think i got lucky as the tension is just about spot on :D i can still add a tensioner at a later date if it's needed ,pictures later .

Re: Scorpion 4x4 Build project

Posted: Tue Mar 28, 2017 2:35 pm
by Dadio
Pictures of the finalised transmission ,drive shafts extended , chain guide pulleys fitted and chain length shortened, there's a second guide pulley up front but its kind of hidden , you can see the screw that it runs on in the side of the tub in the second picture also a scratch in the tub i'll have to clean up before painting:(.
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Re: Scorpion 4x4 Build project

Posted: Fri Mar 31, 2017 5:36 pm
by Dadio
I made a start on the steering this evening , it's going to be tight but i think its going to work , looks like I'll have minimal bump steer if all goes well .

Re: Scorpion 4x4 Build project

Posted: Sun Apr 02, 2017 3:46 pm
by Dadio
I got started on the steering system , there are a few areas that need attention as yet , i have a slight binding issue on the track rod ends with suspension compressed but i have a couple of ideas to overcome it , clearance is tight as the links go under the diff out drive cups and there's only 3mm so they are just over 2.5mm thick , bump steer is acceptable and probably less than stock , its not clear in the pictures I'm afraid , the top part of the top crank for the linkage is over size at the moment as i was not sure of the relative alignment of the top and bottom arms as its not 90 degrees so i thought I'd fit it and then mark the position for cutting later .
the really good news is that it all fits under the body.
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Re: Scorpion 4x4 Build project

Posted: Sun Apr 02, 2017 9:53 pm
by 1300GT
Really nice work. 8)

Re: Scorpion 4x4 Build project

Posted: Mon Apr 03, 2017 6:50 am
by Lonestar
I can't wait to see this thing finished :)

Re: Scorpion 4x4 Build project

Posted: Mon Apr 03, 2017 1:43 pm
by DennisM
Hats off 8)
On a note - when You build mine, I´d like double decked trailing arms up front, instead of the link :mrgreen:

Re: Scorpion 4x4 Build project

Posted: Mon Apr 03, 2017 3:04 pm
by Dadio
DennisM wrote: Mon Apr 03, 2017 1:43 pm Hats off 8)
On a note - when You build mine, I´d like double decked trailing arms up front, instead of the link :mrgreen:
I had thought of a top arm , easy enough to do by replacing the top link mount and making a top arm mount,as it is i should really make a taller mount to raise the ball joint as the steering hub is taller than the 2wd version anyway , it would also reduce the load on the flanged bearings in the king pin assembly , i have to admit to being worried about the 6mm flanged bearings not lasting too long but the move to double trailing arms is a big cosmetic change from standard that I'm reluctant to make , what i may do is go to 7mm flanged bearings and make a slightly bigger king pin assembly , there's space to do it and it would be all up stronger with possibly less play .

Re: Scorpion 4x4 Build project

Posted: Wed Apr 05, 2017 12:27 am
by Coelacanth
You could narrow your track a few more millimeters...Kyosho made some hexes that were 3mm thick, about the thinnest I've seen...they have taper-fit holes for the axles, mind you...you need Optima tapered axles. I wish I could remember the part number! I used a set of those to narrow the track on my CYANide on-road Optima car.

Other than those Kyosho units, the narrowest 12mm hexes I've seen that use cross-pins are 4mm thick. Those are easily available on eBay.

Re: Scorpion 4x4 Build project

Posted: Wed Apr 05, 2017 2:58 am
by isobarik
Coelacanth wrote: Wed Apr 05, 2017 12:27 am You could narrow your track a few more millimeters...Kyosho made some hexes that were 3mm thick, about the thinnest I've seen...they have taper-fit holes for the axles, mind you...you need Optima tapered axles. I wish I could remember the part number! I used a set of those to narrow the track on my CYANide on-road Optima car.

Other than those Kyosho units, the narrowest 12mm hexes I've seen that use cross-pins are 4mm thick. Those are easily available on eBay.
those are for the sp cars and have been used on the front of the lazer zxs / evolutione

and the part number is sp-62

mvh isobarik

Re: Scorpion 4x4 Build project

Posted: Wed Apr 05, 2017 3:10 am
by Dadio
If i need to i can mill a couple of mm off the hexes that are on there , I'm going to have to remove the blue anodising as it's glaring at me as not looking right .
I've ordered up a set of Schumacher full spike tyres as they look fairly retro in a 2.2 size .

Re: Scorpion 4x4 Build project

Posted: Tue Apr 11, 2017 4:19 pm
by Dadio
She went for a brief test run this evening , there are two little issues .
1 it has the turning circle of an ocean liner .
2 There is a little clearance issue with the chain .
I was kind of expecting the poor turning circle and have a cure , I'm going to drill and tap the steering hubs so i can fit the ball studs for the track rods closer in ,this will increase the turning angle ,probably increase it too much but i can reduce it by end point adjustment.
The chain clearance will be easy ,either adjustment or removing a little material .
This sounds bad but this is the kind of stuff you have to expect in a project like this , I'm actually pretty chuffed that it worked as well as it did first time out .

Re: Scorpion 4x4 Build project

Posted: Wed Apr 12, 2017 12:47 am
by mugenbulldog
Two words: 4 wheel steering. Problem solved!