Bob's M1070

[kingbob]

OK, so even though my Optimus Prime isnt finished yet, it is close, and i'm contemplating my next build. I love the look of the US M1070 HET, so figured i'd try my hand at one.

But before I start buying parts, i want to make sure what I have in mind is feasible, at least on paper.

Obviously all 4 axles are driven, with front and rear stearable, so i'd probably use TLT1 axles at each end, unless anyone can recommend a better alternative? Can anyone confirm the internal ratio of the TLT1 axle vs Tamiya semi axles is the same, or should i use TLT axles for all 4?

Also, does the TLT1 axle have a pin/hex drive system, or a splined drive like a semi axle? That one makes a big difference to what wheels I can use, whether they are hex or pin drive.

The other problem with wheels, is the size. The M1070 has 53" tires, which in 1/14 scale is 96mm. The closest I can find to the real design is the Rock Crusher X/T from rc4wd, which is a 94mm tire. But it has a 1.55" inner size. Given that i'd have to make and attach hubcabs, i'd prefer plastic wheels, but i cant find any. Anyone have any recommendations?

Anyone have any advice?

Thanks.
Bob

[kingbob]

1/16 actually makes things more difficult when it comes to tires and wheels.

1/12 isnt too bad, rc4ws do some mil-spec 1.9"s which are close in size, so thats not an issue. Does mean it would be about 30mm wider, which may be an issue for axles. Could use wideners, but they mess up steering.

I dont really plan to build a trailer though, so matching scale with a tank isnt much of an issue.

[Finster]

I think this company has the tires you'd want although it won't be cheap.
http://www.afv-model.com/4711shop/in...ath=79_375_332

They list tires for 1/16 and 1/14 scales. If not AFV-Model, I know there is a Euro seller that has the exact tires used on the HET. Hope this helps.

[kingbob]

Thanks Finster. They have the Michelin 16R20 at almost the right size. €16 each though! Would need 9... Ouch.

[kingbob]

Far out, another €9.90 per rim, plus €11.50 per hub. Works out at about US$50 per wheel. $450 just for wheels. Might have to skip this idea.

By comparison, using rock crushers would cost $100 for tires, and $80 for stamped wheels. Big difference.

[doodlebug]

Take a look at this thread and get some ideas! http://rctruckandconstruction.com/sh...=oshkosh+m1070
Cheer's, Neil.

[kingbob]

Yeah I saw that one. That level of metalwork is beyond my ability though.

[sassgrunt]

I have just the bare bones of one of these started. I bought semijoe's frame rails and cut them to 28". I am using TLT axles, and the distance from the center of the front hub to the center of the rear hub is 22-1/2". I am using RC4WD Rosk Crusher tires (the sidewall says "HT 19") and plastic Tamiya Humvee rims, (I wanted to have something plastic to attach a hub to, as well). There is just enough spacing between tires of the 3rd and 4th axles for the 4th axle to steer. The width outside the tires is 8-1/2". I also am using a stock semi-truck front spring setup, although the spring itself is from one of the single-rear-axle trucks, so that the screws that go through the axle can also pass through the spring to hold it all together. I also bought Russ' air-ride suspension for the rear three axles.

I'm not sure yet what it scales out to, as I was trying to enlarge some drawings I found to fit these tires. But, my goal was to build something that would work with 1/16th scale tanks. As my primary reference, I bought the Hobby Boss 1/35th kit for the M1070 and M1000 trailer, and plan to enlarge the plastic parts on a copier to fit the chassis.

I am not nearly up to speed on taking pictures yet. With my kids all out of the house, it's just me and the dawg to try and figure out all this technology stuff - and, I think she's a lot more savvy about it than I am. Sorry about that. Here is a link to a photo of an M1070 that uses the Tamiya Humvee rims (and also tires from it). -Mike http://www.rc-tanky.com/jine/kracik/kracik1.jpg

[kingbob]

Originally Posted by sassgrunt

I have just the bare bones of one of these started. I bought semijoe's frame rails and cut them to 28". I am using TLT axles, and the distance from the center of the front hub to the center of the rear hub is 22-1/2". I am using RC4WD Rosk Crusher tires (the sidewall says "HT 19") and plastic Tamiya Humvee rims, (I wanted to have something plastic to attach a hub to, as well). There is just enough spacing between tires of the 3rd and 4th axles for the 4th axle to steer. The width outside the tires is 8-1/2". I also am using a stock semi-truck front spring setup, although the spring itself is from one of the single-rear-axle trucks, so that the screws that go through the axle can also pass through the spring to hold it all together. I also bought Russ' air-ride suspension for the rear three axles.

I'm not sure yet what it scales out to, as I was trying to enlarge some drawings I found to fit these tires. But, my goal was to build something that would work with 1/16th scale tanks. As my primary reference, I bought the Hobby Boss 1/35th kit for the M1070 and M1000 trailer, and plan to enlarge the plastic parts on a copier to fit the chassis.

I am not nearly up to speed on taking pictures yet. With my kids all out of the house, it's just me and the dawg to try and figure out all this technology stuff - and, I think she's a lot more savvy about it than I am. Sorry about that. Here is a link to a photo of an M1070 that uses the Tamiya Humvee rims (and also tires from it). -Mike http://www.rc-tanky.com/jine/kracik/kracik1.jpg

Sounds like you're on the same page as me. Ive got the hobbyboss kit on its way as a reference as well, great minds think alike.

I was looking at the 1.55" rock crushers as they are 94mm, and the real tires are 53" which at 1/14 scales to 96mm. At 1/16 they scale down to 84mm but I couldnt find tires that size. I assume that yours are the 1.9"s if they have 19 Written on them which are 110mm tall.

At 1/14 it should be 25.5" long. At 1/16 should be 22.3" long.
Width at 1/14 is 7.2" and at 1/16 should be 6.3" wide.

So yours must be closer to 1/10 or 1/12.

I know tlt axles are 180mm/7" wide at the outside of the hex so depending on wheel offset it should be pretty close if the tires arent too wide.

My main issue at the moment is working out the width difference between tlt axles and semi dual output axles. The semi axles are narrower so getting the wheel width to match is what im trying to work out. Would appreciate any help if you've already sorted that issue.

[doodlebug]

Originally Posted by kingbob

Sounds like you're on the same page as me. Ive got the hobbyboss kit on its way as a reference as well, great minds think alike.

I was looking at the 1.55" rock crushers as they are 94mm, and the real tires are 53" which at 1/14 scales to 96mm. At 1/16 they scale down to 84mm but I couldnt find tires that size. I assume that yours are the 1.9"s if they have 19 Written on them which are 110mm tall.

At 1/14 it should be 25.5" long. At 1/16 should be 22.3" long.
Width at 1/14 is 7.2" and at 1/16 should be 6.3" wide.

So yours must be closer to 1/10 or 1/12.

I know tlt axles are 180mm/7" wide at the outside of the hex so depending on wheel offset it should be pretty close if the tires arent too wide.

My main issue at the moment is working out the width difference between tlt axles and semi dual output axles. The semi axles are narrower so getting the wheel width to match is what im trying to work out. Would appreciate any help if you've already sorted that issue.

http://www.the-blueprints.com/bluepr...rucks/oshkosh/
http://www.the-blueprints.com/bluepr...osh_het_m1070/ Does this help any?
Cheer's, Neil.

[sassgrunt]

Bob, my first chassis was 23" long. I tried mounting TLT axles on it, but they were too close together to allow the rear one to steer, and also too wide for the length of the chassis. I agree that the rear dual axles have a good width for that length, but I couldn't come up with driven steering axles that were narrow enough to match. My scale probably IS a lot closer to 1/12, but I'm happy with the scale being a compromise; as long as I can end up with an 8x8 working tractor. -Mike

[kingbob]

Heres some sizing, the red line is the size of a stock King Hauler


And a full size actual scale version
here.

[kingbob]

Just did the maths, you said the tlt axle with hummer wheels and tires is 8.5", which is 215.9mm.
The real thing is 102", which at 1/12 works out at 215.9mm.

Cant get more exact than that.

Now to work out if its possible to widen a stock semi axle to match. May be easier to use 4 tlt axles and just lock the steering on 2 of them.

[kingbob]

Top view sizing.

[kingbob]

Can someone with a TLT-1 axle tell me the width of it?

Googling and searching i get answers between 168mm and 180mm. I dont know if thats from case edge to case edge, or hex to hex, or axle to axle.

Regular semi axles are 120mm from case edge to case edge, so if TLT axles are ~170mm case edge to case edge, then i could just use a 25mm widener on each side on regular semi dual input axles.

For 1/12 scale anyway.

[sassgrunt]

I pulled off a set of wheels to measure my axle. I am using aftermerket aluminum end pieces that lock the steering, but I don't believe it changes the width from stock. Width of the axle case (to where the shafts emerge) is 168mm. Width at ends of the hexes is 180mm. Width at the outside of the tires I'm using is 215mm, (and the tires are 115mm tall).

Thank you for the side and overhead views. I guess mine IS 1/12 - now I know. -Mike

[kingbob]

Ok cool, so it looks like 1/12 is the scale to go for then.
I looked up getting wideners for the dual output semi axles, but for the price plus axle, its cheaper to just get a tlt axle and mod it for dual output.

Sounds like the plan.

[sassgrunt]

This is a pretty neat M1070 build from 2008, if you haven't seen it before.

http://www.rcpanzer.de/apboard/threa...tart=1&seite=1

[kingbob]

Sweet jeebus thats beautiful! I hadnt seen that before at all!

Thats built in 1/14 though, which is what i'd prefer. It look like he used tamiya semi axles, and made 2 ali brackets for each side to hold a steering hub. Basically to get a super narrow steerable axle.
I wish I could see how he worked out the mechanics of that. And the black plastic wheels look familiar, but they arent Tamiya Hummer wheels.

[Bigrigger]

Hey Bob, this is a cool idea! If you need any pics or info on TLT axles, I have a few separate from frames at the moment. One of them has a straight axle conversion kit or something on it, if you needed a wider axle. Let me know if you want to see a pic!