6x6 1/10 Off Road Truck build

[MadInventor 3884]

How about a motor for 1:8 scale? They're about 750 sice AFAIK

Like an Xerun 4274 2000Kv brushless system. Was thinking about getting one for my TXT, but it would ideal for this I think. Only issue is that the shift servo would have to be moved forward to make room for the bigger motor.

[MadInventor 3884]

could you use some sort of mini counter balance hydrolic suspention to keep it level or air bags in the rear for when its loaded ?

Far too compicated I think. Perhaps just a big lump of steel on the front bumper would be more my style (maybe the addition of a working logging blade to the front.)

[Percymon 2184]

You could add some strips of lead to the rails at the front, hidden under the logs as a test

Also have a look at Graupner motors, they do some quite beefy brushed units, this oe looks like silver can speed wise so perhaps a bit too quick but it weighs in at 195g and the longer can and magnets should help the torque.. Graupner Speed 600 7.2v Electric Motor (G1793)

[MadInventor 3884]

You could add some strips of lead to the rails at the front, hidden under the logs as a test

Also have a look at Graupner motors, they do some quite beefy brushed units, this oe looks like silver can speed wise so perhaps a bit too quick but it weighs in at 195g and the longer can and magnets should help the torque.. Graupner Speed 600 7.2v Electric Motor (G1793)

Thanks, I will look it up. I won't be posting on here for a while now, as I've just had it confirmed I'm going in to hospital for a chest operation tomorrow. Hopefully be back on here in a few weeks or so.

[IBIFTKH 1369]

I hope everything goes well, look forward to seeing you back here soon.

Something to ponder while you're recuperating. I'm sure I've seen twin motor adaptor plates for 3-speeds (or with your skills I'm sure you could make your own). Another possible motor option might then be a pair of 540s or 550s. I bought a pair of cheap 550s for my TXT, much more torque and everything runs cooler, though it pulls wheelies on 2s lipo!

[bromvw 744]

Thanks, I will look it up. I won't be posting on here for a while now, as I've just had it confirmed I'm going in to hospital for a chest operation tomorrow. Hopefully be back on here in a few weeks or so.

Hope all go's well . All the best .

[djmcnz 754]

Thanks, I will look it up. I won't be posting on here for a while now, as I've just had it confirmed I'm going in to hospital for a chest operation tomorrow. Hopefully be back on here in a few weeks or so.

All the best!

[MadInventor 3884]

Hi guys,

Just thought I'd let you all know I'm back out of hospital now. The hospital staff cut my sturnum in half and I had an 800gram (1.8lb) gram tumour taken out of my chest. Have got 6 weeks recovery time now while my sternum grows back together during which time I can't get in the workshop or the loft . Also got a 3 week wait to find out if it's cancer or not. Hopefully all will be well and I will get a chance to complete this project after my recovery.

[speedy_w_beans 4272]

Hi Mad, I hope your recovery and test results go well. Will keep you in my thoughts.

[Skottoman 306]

Wishing you the best. That is a tough pill to swallow...

[bromvw 744]

Bit lost for words . I'am sure everyone wishs you a speedy recovery and the all clear . Stay strong mate .

[wolfdogstinkus 1893]

Only just seen this Madinventor. Hope you get good news and I wish you a speedy recovery.

[IBIFTKH 1369]

Wishing you all the best Mad, I hope your recovery is swift and the news is good.

[Bigwheels_inc 11]

Hope your recovery runs smoothly & the news is good

[MadInventor 3884]

Thankyou for all the messages of support everyone. I think a positive mental attitude is key for me now and it helps having positive messages from you all.

Many thanks

[Percymon 2184]

Best wishes for a speedy recovery - invasive surgery is never nice, but you appear to be in good spirit and well enough to log in here  

[lupogtiboy 454]

Wishing you all the best and a speedy recovery!

Wow what a project! As others have said, I wish I had the skills to make something like this from nothing.....

[Kevin_Mc 411]

just checked in on the thread again Martin, best wishes and i hope you have a speedy recovery

[Wild Willy Speed Shop 73]

Very cool indeed.

[MadInventor 3884]

I've started to do a little more work on this model. I've been recently redesigning the transfer box I built to bolt to the end of the 3 speed gearbox. The new design replaces the end plate of the gearbox with one to support 2 extra pinions, which are then used to drive the output shaft to the front and the rear. It should enable me to increase the ground clearance under the transfer case and / or lower the gearbox back into the chassis slightly. I'm also considering replacing the steel chassis rails with aluminium to lighten the weight of the model, but I will see how things go with the rebuilt gearbox when it's done. I've also had an idea for improving how the gearbox is attached to the chassis, as the MK1 version was very heath robinson. As soon as I have some pics of anything worth showing I will post in here. I've also discovered that TLT-1 wheels and tyres just fit on the walking beams, so I now have a set of 4 of these fitted on the rear axles which should improve the grip considerably.

[MadInventor 3884]

I've started on the mk2 version of the gearbox. I have replaced the rear gearbox plate from the original gearbox, with one I made myself from 5mm plate. This has the bearing holes machined straight into the plate, so no need for the plastic mounts used on the original gearbox. I also added 2 extra bearing holes, which will support the extra gears added, so that I can have a front and rear drive shaft output. Here's some pics:

I've had to cut away the bottom of the gearbox housing to accommodate the front universal joint, but tucking it up close to the gearbox helps greatly to improve the ground clearance under the final output shaft and its casing. It should be fairly straightforward to make the hole dustproof with a piece of contoured plastic which I can glue to the original casing. The original casing is going to get glued together, this will help seal it as well as make it easier to fit the plastic I'm going to use to cover the hole up. Once the gearbox casing has been doctored, I then just need to make a fresh transfer case cover, and the gearbox can go back in the truck. I've done a dummy fit, and about half of the universal joint protrudes from below the chassis, so this will be a great improvement over the MK1 version.

Edit 05/02/2013

I've got the transfer case cover and the cover plate for the bottom of the gearbox finished now:

The bit that gave me the most grief was attaching the cover plate to the gearbox. First I tried sticking it with silicon, but that did not seem to want to attach (I was proabbly too impatient), so I tried humbrol model glue, and that did not want to stick either, so in the end I put 2 3mmx8 slef tappers in to hold the plate on the bottom of the gearbox. I'm quite pleased with how the transfer case cover turned out, it is considerably lighter than the previous version, and gives better ground clearance as well as using one less gear. The only down side is that there is now no reduction in gear ratio through the transfer case, so now the truck is geared 25% higher in all gears.

I'm just trying to decide now how to mnount the gearbox in the chassis. I can put it in at the original height at which it was fitted, which will give excellent ground clearance, or I could drop it about 5mm which would bring the bottom of the gearcase in line with the bottom of the chassi rails. This would reduce ground clearance, but also lower the cente of gravity as the motor would be lower, and overall I think it would look better with the gearbox lower. Here's 2 pics of the alternatives:

High position (As it was previously)

Lower position (Better CoG, but reduced ground clearance)

Here's some pictures of the TLT tyres and wheels fitted to the rear end. They look a lot better than the F350 items I think:

[MadInventor 3884]

Just got the gearbox mounts rebuilt. I've added a horizontal mount to the front and rear of the gearbox, the rear one mounting onto the end of the transfer case cover, and the front one mounted directly to front aluminium plate (Which I had to drill 2 holes in). This new design gives the benefit of getting rid of the old unsightly aluminium side mounts, which used the original tamiya mounts on the gearbox casing, providing a much stronger mounting for the gearbox (the new mounts also look better, and have also lowered the gearbox slightly, which will improve the CoG). Thanks to the redesigned transfer case, the ground clearance is still better than the MK1 version as well.

Rear mount

Front mount

Front mount

Rear mount

[djmcnz 754]

<jealous> <- not sure that's the right emoticon!

But wow, just wow. I wish I could do CNC magic.

[MadInventor 3884]

<jealous> <- not sure that's the right emoticon!

But wow, just wow. I wish I could do CNC magic.

Hehe, I wish I could as well.

None of this was made using a CNC machine, it was all done on a manual mini milling machine winding the handles by hand. The only other specalist tools I used were a rotary table with a chuck mounted on it, and a boring head to precisely cut the bearing holes. I had to make Jigs for the rotary table to bolt the gear cover to, to rotate the gear cover around the centres of the bearing holes to cut the circles and arcs on the gear cover.

[djmcnz 754]

Hehe, I wish I could as well.

None of this was made using a CNC machine, it was all done on a manual mini milling machine winding the handles by hand. The only other specalist tools I used were a rotary table with a chuck mounted on it, and a boring head to precisely cut the bearing holes. I had to make Jigs for the rotary table to bolt the gear cover to, to rotate the gear cover around the centres of the bearing holes to cut the circles and arcs on the gear cover.

Okay, refined:

I wish I could do metal magic!

You still have my respect!