M548 tracked vehicle

[cooper_xl]

Originally Posted by Mike Flea

Looks nice Cooper, keep going!

Originally Posted by smog

You've got mad Skills Cooper, this thing is too cool. Someone pass the popcorn over...

Thanks guys!





Another step:





Detail,with the M2 bolts



All assembled:







were made in 4mm stainless steel rod, TIG welded and the brackets are from 12mm square tubing. Ran out of M2 nuts in the middle of the assembly

[Mike Flea]

Off topic, but what's with the control tower in your backyard?

[4wd4ws]

Awesome build and buildthread.

Subscribed!

[cooper_xl]

Originally Posted by Mike Flea

Off topic, but what's with the control tower in your backyard?

Now that I see that in the pic, it's a strange looking tower...for me, it was always there... Is a tower that receives high voltage and convert to "standard" voltage for the houses in the area....








By the way, I was thinking to put a sound generator so I had to see how a M548 sounded like. I was expecting a big diesel truck sound but...

https://www.youtube.com/watch?v=BbDY3GwjrO0

...holy cow, it's like 100 angels riding chainsaws


Talking about motors, adapted the 2nd one to the gearbox. The first was straightforward, this one was harder



Next is assemble everything and setup the radio again now with twin motors,twin ESCs and 1 battery

[Mike Flea]

Detroit diesels have a little different sound than other diesels, as they are a 2 stroke engine compared to a 4 stroke

[cooper_xl]

Originally Posted by Mike Flea

Detroit diesels have a little different sound than other diesels, as they are a 2 stroke engine compared to a 4 stroke

Exactly! I wasn't aware of being 2-stroke until i start digging for this. Scale truck are amazing!! For most are just toys but are a great way to learn stuff




First test:



https://www.youtube.com/watch?v=P-LzyysaeVU


The setup is: 2 55t on 60A ESCs and a pistol radio that allows more than one mixing. Basically there's 2 mixings, one for throttle and one for steering and they work together

[cooper_xl]

I'm turning my attention to the tailgate now. Added the steel tow cable with all it's mounts











Sure it will look better all painted(and without excess glue) but i want to show it earlier. For the curious, there's aluminium for the half circles and hooks , copper on the middle mount, brass on the cable ends and the cable itself it's steel(a bike brake cable)

[Mike Flea]

Looks good

I don't think I've ever seen a tracked vehicle on a pistol type transmitter

[cooper_xl]

Originally Posted by Mike Flea

Looks good

I don't think I've ever seen a tracked vehicle on a pistol type transmitter

I'm not a regular guy . The truth is because,like you,never saw anyone using a pistol radio but I never used a stick radio before so I borrow a friend's stick radio(he's into planes) to try...well, couldn't get used to it so start thinking in how to make it work with a pistol radio....








Well, back to cosmetic stuff:


Working on the ring mount and legs for the .50.It's a notorious feature that had to include..





The ring it's a 2 piece part that I've machined earlier. Could do it in 1 piece but this way, rotates 360º.


First, the front legs










Then,could do the rear ones






The asymmetry on these is on purpose.For some reason the 1:1 it's like this...


Waited to next day to allow to epoxy to harden and added reinforcements,steps and cleaned the "welds"
















Only needs a bit of sanding,colour and better looking(and shorter bolts). I think I'm doing the .50's mount next...

[j0e]

Too cool, man. Too cool!

[cooper_xl]

Thank you!





Slowly working on the suspension but not happy with the results, the spring look too soft. I'm afraid I'll have to do all the the suspension arms to see how they cope with the weight


This weekend had to work hard on my future house and feel like i was hit by a train...to relax,added 2 new things:




First, the cutoff handle ( someone can help on this? I caught a small reference to this, saying that's a handle on a chain for the fire suppression system on the engine)





And then, the handles(?) to help enter the cab




Some creative liberty to make them work with the door handles





Also...painted the last 5 road wheels

[Mike Flea]

Yep, that's what it is, it's the outside handle to the fire extinguisher Cargo Carrier M548, scroll down to the 5th picture

[cooper_xl]

Originally Posted by Mike Flea

Yep, that's what it is, it's the outside handle to the fire extinguisher Cargo Carrier M548, scroll down to the 5th picture

Exactly! I saw in the Operator's Manual,available on Google Books

One of the things I've got to do now are taking care of the tracks. Stock, look too clean and being all black,don't seem scale. So i tried to weather them to look metallic and worn







this is the first one, used a rust red, and 2 different grays



because the red was too "red" for rust, on the second track applied a bit of dark brown and seems better








Stock and weathered:





Far from good but it's my first time weathering...

[Mike Flea]

Looks good, and from 10 ft, may look real. However, if this is going to be more than a shelf queen, running on anything other than grass, it will wear off, and you'll be back to the black

[cooper_xl]

Originally Posted by Mike Flea

Looks good, and from 10 ft, may look real. However, if this is going to be more than a shelf queen, running on anything other than grass, it will wear off, and you'll be back to the black

Nope...no shelf queen...sure that some of the paint will wear off but time will tell how it will look







Do you guys know when we hit a bump in the project and affects the motivation?

I was struggling with the suspension, discarded the 1st idea, the 2nd with torsion springs looked good but because i couldn't get cheap springs, decided to went "full builder" on this and try to copy the system on the 1:1:torsion bars.

This is the first prototype :




https://youtu.be/74heCE7kXm8


From what I'm seeing right now:

The tension can be tuned. First, by the wire diameter. It's spring steel, started with 2mm and now changed to 1.5mm. Then,moving the piece that connects the spring to the axle, changes the stiffness. Another advantage it's that the ride height is set and locked with a screw. In the ride height, the positive and negative travel it's the same

[Mike Flea]

I can't help you there, I have a hard enough time with 4 shocks on a crawler, TT, or SC truck, lol. But the suspension on that video looks promising.

[cooper_xl]

Suspension know-how is another different hobby .


Small update. Working on the suspension arms. The are steel bar with one washer welded at each end to add that 3d look and help to round the ends. Machined a bit on the center to make it thinner. Then, filed all the edges to look a cast piece. On the holes at the ends, will be a axle for the wheel and on the other, the suspension pivot










In the end, they'll be almost invisible. Half-hidden by the wheels and the tracks


And now,the "bones" of the suspension:

First, the blocks that will be bolted to the chassis and will hold everything





In place:









The arms are attached to 4mm steel rods that offset from each side like the real one. On the 1:1, the arms are connected to torsion bars. I opted to this system instead because is more adjustable. The photos show spring wire but I've replaced for 4x2mm spring steel bar.

[cooper_xl]

And this 2 videos of the suspension working

https://youtu.be/fJzAY2Z3FZ8

https://youtu.be/PTvrInCnxOc


Ignore the fact that only was 4 wheels each side. Both front wheels will work on a different system because of drivetrain being there

[Mike Flea]

Appears to work smoothly, good job!

[cooper_xl]

Thanks!

My take on the tension wheel:

https://youtu.be/Bx81uLoozFc


Not complicated as the real system but I'm confident it will work. Is basically a arm, rotating on 2 bearings and a shock with a spring inside to push the wheel against the tracks