My HEMTT build

[Gregg]

Well, I have most of all the parts I need to get started so i thought I will start my thread. I am building an HEMTT M983 tractor. This is an Oshkosh
military equipment hauling tractor. 8x8 dual axle steering. This should be a fun build.

This is a picture of it. Once I am finished I will also be building a goose neck trailer for it. Something like a Trail King. I will be using this vehicle mainly as a tank transporter. Although this truck really does not have the capacity in real life to haul tanks, I still like the looks and concept of it being a tank transporter. Oh I forgot to mention I have a large collection of 1:16 scale rc tanks. Mostle Tamiya and Tamiya powered. I'll put some pics of them up in the tank section, so here we go.

[pigeonfarmboy]

Two of my favorite HEMTT builds:

http://www.rccrawler.com/forum/1-9-s...oller-8x8.html

http://www.rccrawler.com/forum/1-9-s...not-hemtt.html

[Gregg]

Hey Thanks farmboy. I really like the second build. It gave me some rally good info on how to do the suspension. I am new to this so that really helped. i will be making most of my own brackets too this is invaluable info. Thanks again.

[rc_farmer]

That is gonna be a great build. I have driven these when they were a part of my FA unit. They hauled the beans and bullets.

[Gregg]

Started the mundane task of assembling me TLT axles. I have a locker for one but havent got a clue as to how to install it. I have some pics I'll get up tomorrow.
I noticed on one of my diff carriers there is a tapped hole in one side where the axle goes through. Is it possible to lock the axle by installing a set screw in this hole and is that what it is there for? I also need to get one more pinion gear. I did not do an entire inventory of all the Axle parts bags because I knew there would be something i missed or needed so I can do 3 of the 4 axles. So far so good. Having fun. Not quite like building a tank from a kit.

[fhhhstix]

If the side of the diff with the ring gear has a hole in it, that is a ring gear for a high lift or a crawler which will work in a TLT. The only difference is the TLT does not have the hole in the shaft for the threaded lock pin. Here are some pics of the high lift axle to see how the lock works.





Travis

[Gregg]

Wow , thats cool. Thanks Travis. So does this mean I can lock the axles with this diff?
This pair was bought on Ebay because they where already set up for the troguh drive axle. Came in parts that I needed to assemble. That is why I need a second pinion gear and bearings for the second drive through axle. Cant wait to get these done so I can start on the suspension parts and then determine my frame length. This will also help with scaling it. This will be in between normal scales from what I can tell so far.

[Gregg]

I have a few pics of the parts pile.









the first pic is of the diff locker which I have no idea how to use.

[Gregg]

i know I should use bearings on all this rolling stock but at the moment the budget is shot in the A$$. I can always upgrade them in the future as well as add more lockers.

[Panther F]

It's all looking good and we all know about that dirty phrase ... the budget.
















~ Jeff

[doodlebug]

Hey Greg, read thru this thread, and it will answer your bearing question.
http://rctruckandconstruction.com/sh...=axle+bearings
Hope this help's! Later, Neil.

[CustomClod]

I love watching these builds. Cant wait to see more
Scott

[Gregg]

Thanks Niel. I am not using the Tamiya 3 speed tranny so that is not an issue. The bearings I'm referring too are for the axles. I generally would always put bearings in the roadwheels of my tanks as should be done with these axles but as I said at the moment the budget is shot so I am continuing with everything I can for now.

[doodlebug]

Hey Greg, further down in the thread Lil Giants Joe, was talking about using bearing's on the end's of the axles and leaving the bushing's next to the diff.. And Freddy Gear Drive had some comment's too! Have fun with the project!
Cheer's, Neil.

[Gregg]

I also had to make custom wheel hexes. The Panther wheels use an 8 mm hex. Try finding that one. LOL
What i did was get some aluminum 4/40 x 3/4 standoffs and cut them down to size. I then drilled them out to fit over the output shafts. Then i drilled them to accept the pin. They work great.

[Gregg]

Well, progress has been a little slow as most of this is new but i have completed my axles. i did have to make custom wheel hex's as i had said and they work great with the Robbe Panther wheels. Now tomorrow i am going to start on the suspension system. not quite sure which way i'm going to go yet but i have gotten plenty of ides from alot of you guys. I'll get some new pics up as soon as more progress has been made but things are progressing nicely.

[Msmaddie]

Its going to be a pretty impressive machine when its done.

[mazdaparts]

Will the steering radius be affected with locked diffs? I'm thinking with this many wheels on the ground you should have traction most of the time.

[Gregg]

I'm not going to lock any of them at the moment. I need to see how all the gearing ratios work first . I'm also thinking of using a motor doubler just for some added grunt. I'm not really building this as a crawler although that is what most of this build really consists of but a hauler for my RC Tanks, Some of them are over 15 pounds, so we are looking at a lot of accumulative weight.

[Gregg]

I did hit a small snag with the length of the leaf springs I have. The tire diameter I'm using is a little tall. Actually a little closer to scale from what I can see from some of the other builds like this i have seen so I need to fab some lengthened brackets or use a different type of suspension. The budget is still condition Red so anything I need has to be made. Keeps it interesting.