New zzmt build

[Smoke&Mirrors]

Very cool RRB, kinda similar to the build I'm doing - granted it's a revision, not a scratch build.

I shaved the steering box flat and glued a micro servo with a bb motor as big as the drive motor and metal gears! I have to stop and steer otherwise it draws from the other motor, but it turns like something else. I also glued the little upper steering cup holders to the side of the servo. Then I mounted to motor parallel to the gear that contacts the pinion (feel free to correct me). And I put dean plugs on it too! I don't know how vertical it can get though, I just haven't tried. I still have a lot to fine tune on it. I'll be interested to see how you end up doing the suspension, since I'm having trouble with the significant torque twist.

P.S. Oh yeah, bought something like .005" guitar wire (probably the high E) for bug antenna and use it now exclusively on my MT's. It's thin, scale looking, and gets good reception.


EDIT:
I found two better pictures that will misfiled. This gives you a better idea of what I've done and you can see where I put the dean plug.

[sidewinder]

You know, you could hook some of the wire between the two halves and it would act like a spring.

like this:

[redrustbucket]

S&M- Thanks, yours looks good. Like how you used the servo for steering. Too bad it draws that much juice. I did one with a servo like that but I made the mistake of using a plastic geared one which stripped right out. How did you get it non propo. I removed the pot in mine.

Adding weight to the front tires helps with torque twist, as does some break in time. The rest you have to tune out w/ suspension.

Sidewinder- Sweet drawing. I like that idea but I'd probably revise it some to use one wire in the center or a strip of carbon fiber. Carbon fiber would be tunable by drilling holes or simple sanding I would think.

[Smoke&Mirrors]

Thanks, I'm flattered. It does draw a lot, but I was tired of dealing with weak and unreliable steering. How did I make it non-propo... good question. When you asked I totally forgot about that. I have no idea, I guess I'll have to take a look. I'm sure I just removed the pot too. It should be plenty broken in, and the twist is really strong, it's just just a little pull - It'll roll the whole front end over till the wires stop it. I still want to figure out to make better rims, like you and Supergroup-crawler have been. I just used diets old little tut.

[sidewinder]

Carbon fiber would be cool, but at our LHS you have to by a bunch so I'd have to wait until I had another project that justified buying that much.
Wouldn't a servo work with a non propo by just turning all of the way? I never tried it but it seems like it would have to do something with the electrical input, I just kind of assumed that it would default to the maximum possible motion. --------------man, that was an awkward sentence, but I can't think of a better way to say it.

[frizzen]

I like the articulation spring idea, I was just going to take a piece of cut open round stock mounded the chassis extension for travel limiter.

What are those rims/tires again? I think I might need some for the Tatra.

[redrustbucket]

It should be plenty broken in, and the twist is really strong, it's just just a little pull - It'll roll the whole front end over till the wires stop it. I still want to figure out to make better rims, like you and Supergroup-crawler have been.

Sounds like you definitely need to get some suspension on it.

I've got pics of how I do the rims. I'll post pics when I get a chance.

Carbon fiber would be cool, but at our LHS you have to by a bunch so I'd have to wait until I had another project that justified buying that much.

Sucks, I picked up a thin piece for building planes pretty cheap at mine.

What are those rims/tires again? I think I might need some for the Tatra.

1/18th Polaris quad tires. Rims are 2 sets of modded zzmt rims. Pics coming.

[redrustbucket]

Some fake bead lock wheel how to pics. I like to use a small hand saw for this and then hand sand with a piece of 80 grit laid flat on the table to finish it off.

Start w/ one zzmt wheel.


Remove the innermost ring on the wheel.


Sand flush to second inner ring. This is your inner beadlock now.


Take a second wheel and remove the outer most bead. Then sand until the hub can be peeled out.


Then remove what would be the inner most bead as you did with the first wheel and sand flush to the second inner bead. This will be your outer bead lock.


These are the tires I like to use for this as the diameter is perfect for this mod. They're the rear tires off of Polaris 1/18 scale quads. You will need two quads to do a set of matched tires.


Test fit your wheels into the tires. They will probably need a little sanding of the outer half to get the width right. Once the fit is good, insert the outer half of the wheel into the tire and run a bead of CA along the edge where the halves will meet up. Join the two halves centering them as best as possible. I like to throw them in a vise for a few minutes to let the glue set up. To do a set of the narrow front tires simply sand the outer half to the correct width. That's it. Hope this helps.

[sidewinder]

Hey RRB, I thought you might really like this place, ot has a lot of really cheap electronics, also check out the hardware and motor sections. OH, and the gear section...they even have a small chain and sprockets. http://www.allelectronics.com/index.php

This in particular might be of some use in the future:http://www.allelectronics.com/make-a-st ... UIT/1.html

[redrustbucket]

Cool, thanks.

[redrustbucket]

Doing some testing. Added tungsten to front wheels, taped the body on and used another strip for a little bit of suspension limiting.

Climbs about a 55 degree grade. Tires are the limiting factor right now but I've got something up my sleeve for that.


[youtube]http://www.youtube.com/watch?v=eq2ZiS8kZBs[/youtube]

Side hilling isn't too bad, hopefully I can improve it a little once the suspension is done.
[youtube]http://www.youtube.com/watch?v=tJbFykI3JDk[/youtube]

Tested it out on a small ledge. The main problem I found was the motor hanging up because it's so far in front of the axle. Hopefully I can make a decent skid for it to help alleviate the problem.
[youtube]http://www.youtube.com/watch?v=bJ-3idbD2aA[/youtube]

[sidewinder]

That's pretty impressive,The tires look like they are gripping pretty well, but some tire dressing might soften them up a bit.

[redrustbucket]

Might try that, or some of this FROG SNOT

Got another set I'm working on now though.

[sidewinder]

Frog Snot--Man, that would be a great name for a micro brew.

[redrustbucket]

Yeah, make it green and sell it on St. Patrick's day.