Half Track build

[MadInventor]

I've been quiet on this for a while, but have still been busy on it.

I've made a new front suspension bracket:

Along with a new front axle

Which attaches to the chassis via a 2 link system, and some TT-01 shocks. The solid bracket provides some up and down movement of the whole axle which is oil damped.

And the free floating axle pivot on the suspension bracket provides some quite ridiculous potential axle articulation. In practice this will be reduced by quite a bit when the steering is connected.

Getting there slowly

[bromvw]

Impressive work Martin . This design seems to be far better then the original . I like how you have managed to get the whole suspension system lower .It looks far more ' scale ' . Once the rest of the bodywork is fitted this is going to be epic - and fast too I would think .

[Skottoman]

Great work! In case you want to mount those tires on a different wheel, Just narrow a set of 1.9's and you can stretch them to fit.

Cheers,

Skottoman

[MadInventor]

Finally got the steering connected up today and was able to do a quick test drive in the garden

Put in a radio plate for the receiver:

Bellcrank is only roughly cut out to see if the steering works ok, but at least it is ballraced

5mm diameter track rod took some bending.

Left and right lock is very good, although the inner wheel should turn more than the outer.

I may need to alter this as the front tires may scrub badly because of this.

[bromvw]

Martin - great progress mate . Re the steering , I would try it before making any changes . I think that with the tracks large contact area you'll not need to change things . Having the inner scrubbing a little might actually help this beast to turn . There's a lot of mass there and its going to be light on the steering anyway so the drag on the inner may be a advantage .

[TWINSET]

Left and right lock is very good, although the inner wheel should turn more than the outer.

I may need to alter this as the front tires may scrub badly because of this.

Can't you just flip the front axle and have the steering rod behind the axle?

That was always the first mod on Clod crawlers as they suffered the same issue

[bromvw]

That might cure it Andy . I wasn't actually looking at the angle of the steering hubs but having them trailing would certainly improve the set up . Knowing Martin he'll sort it out though

[MadInventor]

Can't you just flip the front axle and have the steering rod behind the axle?

That was always the first mod on Clod crawlers as they suffered the same issue

I looked at that but the frame that the axle pivots on gets in the way. I might have to flip the axle, then add pivot arms to either side of the axle so that the track rod at the front can operate the pivots, which can then push/pull on the stub axles.

At the moment though, I'm just pleased I've got it working and can drive it . The next job is to figure out how the hold the battery in properly so that I can try it on 3S .....

[SteveU30]

Can't you just lengthen the bar and make the wheels toe-out a little? That would give you a better Ackerman angle for now even if not the ideal solution.

[MadInventor]

Can't you just lengthen the bar and make the wheels toe-out a little? That would give you a better Ackerman angle for now even if not the ideal solution.

Good idea Steve. I machined 3mm off the end of the main track rod before running it for the first time to get rid of the toe out . However, I think I'd rather flip the axle and try to get it to work that way round somehow. Now it's driving though I'm putting some effort back into the grapple skidder to try and fit the R/C gear in it properly.

[mongoose1983]

Oh, wow. Your work is brilliant.

[MadInventor]

Can't you just flip the front axle and have the steering rod behind the axle?

That was always the first mod on Clod crawlers as they suffered the same issue

Take a bow sir

I've extended the front axle pivot pin, flipped the axle over and mounted the main track rod below the axle uprights, so that it just clears the pivot pin. This now has the axle on the right way round and gives correct ackerman angles. I also moved the pivot point for the steering pivot back as far as I could to compensate for the new position of the centre track rod

Added a sleeve to the track rod for the steering connecting arm to attach to, it was easier than trying to attach it at the upright and will take the strain off the upright in the event of knocks.

I've just got 2 track rods to make now and the steering will be done. That will be all the major engineering done on it and once I've attached the speedo it will be ready for some video. It shouldn't then take too long to finish off the bonnet and side skirts. Then detailing and paint and it will be done.

[SteveU30]

Ooh nice to see some progress, can't wait to see this done, still my favourite build of yours!

[MadInventor]

Got a little bit more done this weekend:

Finished off connecting up the steering. Throw in an ESC and I can drive it

Added some side skirts to the front of the 'tank' hull to help prevent gloop and sand getting in the hull, and to finish off the look of the that part of the hull:

I've done the same for the other side of the hull as well.

I can crack on now with fitting the ESC properly, making an antenna mast holder, getting the bonnet, side skirts, detail parts, and painting done.

13/05/2014 - Got the antenna holder done.

15/05/2014:

Fitted the ESC properly and have started on building the structure for the bonnet to attach to. Gave it a quick run last night:

That was running on 2s. Tried it on 3S and almost immediately ripped the tracks apart. (one of the connecting pins worked loose, then the track self destructed. Tried it several times and the same thing happened. The tracks clearly cannot take a silver can and 3S, having been originally designed for a silver can and a 6V NiCad running on a much lower gear ratio. Still, it goes ok on 2S and has a good turning circle now I've rebuilt the front suspension and axle.

[MadInventor]

Few more pics from yesterday I didn't get a chance to post:

ESC Fitting

Machined out rear bulkhead a bit to lighten it, and help make room for the ESC.

Fitted the ESC On / Off Switch, although it is a bit low in the chassis:

Broke 4 track links executing a handbrake turn on the patio when I slid it sideways into the step under the patio door:

Front bracket for holding the bonnet and the front grille machined ready for fitment (The steel bar is just to give an indication of the angle of slope of the bonnet):

Another view of the front bracket.

Not far off having to blow the dust off the airbrush now.

18/05/2014

Cut and folded the bonnet to shape:

It's starting to look like some weird form of rat rod. Thinking about putting king tiger exhaust guards on the side skirts with a set of big bore exhaust pipes, to give it a set of side pipes.

Added some bracketry down each side of the bonnet to attach the side skirts to.

[SteveU30]

Wow this is really taking shape now, keep up the good work Martin, really looking forward to the end result now!

[MadInventor]

Armoured sidepipes:

Side panel looks well rough, but bodywork is not my strong point. The bonnet is quite flexible, so if I try to zimmerit it to cover up the cracks I suspect that it will just crack off when the body flexes.

[Skottoman]

Wow! That thing really moves across the grass! Smooth running too.

Very impressive with the body on, and it does look the part for sure.

I'd love to see some slower crawling type video of it going up hills/over rocks.

Pretty cool build!
Cheers,

Skottoman

[zomboided]

I've never noticed this build before. It's a load of old rubbish. My niece could do better.

(kidding...totally awesome how much you've built here rather than 'just' stitched bits together)

[mongoose1983]

Looks amazing! I was wondering, how much does it weight?

[MadInventor]

Looks amazing! I was wondering, how much does it weight?

Haven't had a chance to weigh it yet, but it's not mega heavy. Heavier than a hotshot, but not as heavy as a TXT-1. A positive lightweight for one of my builds

More progress today:

Painted on the basecoat and fitted the sidepipes, after painting matt black. The white silicone I used to stick on the exhaust guards will dry clear and not be noticeable. Added a drivers viewing port (Left hand drive of course), and some lifting rings off a panther turret to the bonnet.

Made brackets for 2 towing shackles from aluminium.

Just got to put on the camo coat, and add a few more detail items from a leftover king tiger, and I can call it a day on this one.

[IBIFTKH]

Armour-plated chunk of pure awesomeness!!

Amazing skills, imagination and inventiveness. I really enjoy your builds but this has to be my favourite so far. Can't wait to see what you come up with next!

[MadInventor]

Camo done:









It's more or less finished now, just got a little bit of detail painting to do and add tow ropes on.

How much better would it be though with a decent one piece ABS or lexan shell (My home made one is not v strong and v heavy for a bodyshell, a proper ally hull, ballraced jagdpanther wheels, and some closed loop tracks that don't fly apart with 3S. Would be mega quick for a scale model, and quite stable. Bodywork could do with lowering and the rear hull shortening slightly as well. Would actually be quite an easy kit to make cough cough hint hint cough.

[bromvw]

Martin its a credit to you Sir . Not only does it look excellent but the quality of engineering is first rate too . i would maybe add a machine gun near to the Commanders hatch but thats very much a personal choice .

[MadInventor]

Martin its a credit to you Sir . Not only does it look excellent but the quality of engineering is first rate too . i would maybe add a machine gun near to the Commanders hatch but thats very much a personal choice .

Thanks,

I was thinking about twin gatling guns poked out of the front of each side of the front glacis plate (The plate with the drivers viewport.). But yes, when I can pick up a cheap machine gun that would be good. Also a figure with just the head and shoulders, and a coal scuttle helmet poked out of the commanders hatch.