Project: Darkhorse

[rx78gp02]

hey ya'll.
this new rcmt board is quite nice.
well i'm just gonna copy some stuff from my old thread on rcmt and continue the build up here
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i'm rx78gp02, you may call me Ve or what ever you like. I'll be your hosting for this build up and this time i'll have a camera handy.

dont mind that purse... its my girl friends purse. She just asked me to hold it.

First a little back ground
As some of you know, I've built a clod, a concours RSX, and two robots.
First up, the robot. Dubbed "Sir Scrapalot" was built out of scrap parts lounging around our school, hence the name. It was designed to shoot tennis balls into a bin and to retrieve tennis balls that have missed. We placed third in our city on our second year. No pics of the first robot though.

The concours rsx. What can i say? It certainly has fooled some people into thinking that it was a real rsx. Work of art if you ask me. I'll just let the pictures explain itself.

The Atlas Clod
Luckily i had a shop with access to free material to build a robot. Co-incidently enough i was also in the progress of building a custom clod, hehe. Well you guys pretty much know of how this came to come. From left to right, Version one, Version two, and last but not least, Atlas.
[image noborder]http://i12.photobucket.com/albums/a217/rs4ricer/DarkHorse/atlas.jpg[/img]

And now the buildup begins.
I introduce the clod for the project.

A comparison: old vs new

The project guideline:
Well i'm dubbing this clod "dark horse", so the theme is going to be dark, duh. Every part i'll be making will be in black polypropolene. I've used the same stuff in the Atlas and the stuff is brilliantly tough. I'll probably be using the set of Giant tracs i've acquired recently, it'll make good use of them i think. Right now i'm actually looking to get a nice set of shocks. As for bodies, i'm looking to get the proline streamliner or the proline humm-vee militia. Thinking of a white and black theme sort of.

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post #2

I've decided to make a design change, well more like a vehicle change to the other clod i got for cheap that had a tire missing.

Turns out this one has ball bearings in it already but has something playing round inside the diffs. Oh well though.

 

[rx78gp02]

here we go:

Thats more like it. A set of axles ready to be modified. Those motors are gonna have to go.
As i was taking the chassis apart, i noticed that the original servo mount (center) for the 4ws makes a good servo mount that can be mounted to the axle with a little modification.

I'm thinking of mounting this peice on the side of the axles much like the r/c guy steering set.

Oh and that material i got for my last truck was polypropolene but what i didnt' tell you was that it was actually a cutting board. As in kitchen cutting board. The idea sort of popped in my head when i was shopping at superstore (canadian grocery store). Just think about how much abuse it gets in it's whole life time. Yes it'll arc/ curve eventually, but you have to look at how much surface area that is.
Oddly enough the new piece of material i got isn't polypropolene, but this time polyethylene. oh well.

well here we go.
what i have today is a prototype drawing of a bumper i plan on cutting out of the polyethelene. These are gonna mount right next to the diffs, much like in my Atlas Clod.

now i really need opinions on this one.
oh and if anyone wants to borrow my plan to make their own bumper be sure to credit it with me eh? but your welcomed too.


With that compliment i decided to get my rig into motion by building the first peices for it. I finally cut out the front bumper. Here's a how to.

First i photo copied several copies of the original plan and cut out the silhoutte of each peice.

After that i glued it to the polyethelene using rubber cement glue.

 

[rx78gp02]

I used a hack saw to get a rough chunk out of the cutting board then followed up using a dremel with a cutting bit to get it a little more to shape.

To make sure the pieces will fit perfectly when i mount them to the truck, i place them in the axle and vice them together then drill the mounting holes right through the existing holes on the axles.

A preview/ test fit picture.

The test fit was perfect. I didn't have much time today to work on the clod so i could be bothered to mount them to the atlas clod but i did the next best thing. Mock up what the darkhorse will look like. sort of.
Well here's the rest of the bumper build up.

To install this kind my bumper, you will have to take apart the gear box and file or grind out this part on the axle tube to make it fit (circled in red). And hey as long as you got that gearbox open, might as well give it some maintanence. The previous owner of this clod didn't grease up the gear box much and i also found 2 set screws inside!

Here's what it looks like done:

 

[rx78gp02]

This next part makes me very excited. I'll be using the orignal tub chassis with axle mounted shocks. Probably going to be savage shocks. A 4 link suspension of some sort and the giant trac tires are going to be on this guy!

 

[Spoon37]

I like it!! :kudo

savage shocks are pretty long, but if they are angled to reach out from the chassis to the axles like you have it mocked up it should work out fine...

:truck

 

[rx78gp02]

Spoon37 - Thanks dude. It's inspirational to here praise from vets like you. Yes i do plan on mounting the savage shocks al the way into the axle.

well anyways, this is a tutorial of sorts for the servo mount to my bumper. The servo mount plate is made out of 1/4" thick aluminum and is 3" from left to right on the bumper. The tools i used was a dremel with some sort of cutting disc, a drill, a 10mm drill bit, a 2.5mm drill bit, a ryobi hand drill, and an M3 tap.

First i drawn up the peice i wanted in 1:1 scale and cut out a photocopied version of it and glued it to the aluminum like i did for the bumper.

After that i vised the piece and drilled holes in the corner to make cutting the thing with a dremel many times easier when i get down to the corner. It was also filed and test fitted to see if my 645MG servo fit.

While that servo's there i decided to marked the holes for the M3 screws i'm going to use to fasten it down with. Drilled it and tapped it with an m3 tap.

A preview of how its going to look when done from the top view and how its going to really look when its finished (servo horn down).

Next update i should have the suspension links done by then. I'll be using 3/16" steel instead of the popular 1/4" aluminum.

comments and criticism welcomed!

 

[Rapko]

Looks like its coming along nicely. I like that stance in that pic with the body and the giant tracs.

 

[Spoon37]

Good work! coming along nicely! :kudo

think you need a proper workbench tho.... the carpet isnt ideal for metal chips! :lol j/k

:truck

 

[jagg]

Looks like it's coming along nicely, and I agree with Will on the stance. My only concern would be the weight. Steel links and 1/4" aluminum plate is going to slowly add up. Most of the fabricating I do is with 1/8 aluminum plate. Don't get me wrong, it looks great, just an observation.

 

[kevin107]

Are you holding a purse? It's nice.

lol, just messing. All kidding aside, your buildup looks pretty good so far. Cant wait to see the end result! I myself am toying with the idea of revamping a clod.. but I may just sell it and get something else.. I'm not sure yet. Keep us updated.

 

[rx78gp02]

Sorry for the super late reply. I've been really busy.
anyways, here we go:


Rapko - thank man. After building the atlas clod i've decided to shorten the length of this guy. Oh and the giant tracs where nip! locally!

Spoon37 - I do have a work bench. It's my old computer desktop but i work better when i'm sitting cross legged actualy. I get alot more ideas that way. And no worries, i do vacuum the carpet after. thoroughly... sort of lol. And besides, there's no room to work on my desk anyways, see:

jagg - yah i know. Weight is a concern on my truck. Looks like after all i wont be using the 3/16th steel rodding. There's just no way of me making it work. As for using the 1/4" plating, it'll only be used in the front there and maybe a little in the back. The rest of the chassis willt he stock tub and some 1/8th" aluminum plating. Your post definetly got me thinking bout the weight, soo thanks!

kevin107 - Yes i am holding a purse. It's my girl friend's! i swear!

Right now i'm stuck at the point of find a set of rod ends that are beefy. I've been tryin to get a hold of the same ones i used on the atlas clod, but no one around here locally carries them. In about a week or so i'll have the template for my chassis out and finished with some other odd parts.
One thing i'd like everyone to look out for is a nice set of shocks if you guys got some because no one around here has any!

 

[rx78gp02]

Alright, an update. Not much of an update really. but here we go.

To install the mount onto the polyethelene guard, i marked the servo mounts with mounting points in each corner using a center punch. Drilled the holes first with a 2.5mm drill bit. Afterwards i vised it to the gaurd and drilled the pre-holes for my 3mm screws. After that i re drilled the holes on the mount with a 1/8th drill bit and called it done.

Top and rear view:

And from the corner view:

What do you guys think? i think i'm gonna have to redo the steering links and angles. But i'd like to hear your opinions! Thanks!

 

[Spoon37]

:kudo

the only criticism I can find is the steering links/positions but you said you are gonna redo that anyway...

:truck

 

[rx78gp02]

Spoon37 - As requested, i've changed the steering set up. And look what your comments have done:

Its much smoother now actually. I'll be replacing the rod ends in the days coming. Onward bound to the build up:

Time to build the upper center mount link. I've had it with the aluminum circular one and have opted for similiar ones to the one on the atlas clod. They'll have the same design and shape. Ony difference is the front one is gonna be cut down a little short and bolted to the sevo mount plate.

Using the same "CAD" design as i did for the bumper, i did the same with this and then proceeded to cut each piece out roughly. After that was done, i had refined each peice to the right shape like so:

Front axle:

Rear axle:

well now i'm stuck again. I should have my shocks later in the week, and i'm looking out for a set of nice rod ends and ball. Plus i'll be finally gettin some real tools in the coming week (my gf says if i keep good behaviour i'll get a real drill press this time)

keep those critism coming! Oh and if anyone wants the blue prints for any of my peices, i'll be oblige to release them to yah.

 

[rx78gp02]

Update time, i have found myself a machinist who is willing to mill me out some of my parts in metal. One part i'm having trouble with is the shock mount, but i've drawn up a design and i'm curios to how many of you would buy this product if it became available. And what material would u like to see it in?

Now this will mount onto the top of the steel mounting braces. Each peice will have the hole corresponding to the side of the axle it's on.
Another one is, He's also CAD'ing up an advanced version of The Atlas clod chassis with a few refinements. It'll be almost similiar to the TXT one but would there be any interest in that?

In other news, i've ordered a set of shocks seen below:

These guys are 5 3/4" long with resevoirs! You can just imagine how massive these guys are. I think it'll suit the project. what do you think? Oh and points to the person who can first guess what these shocks are or where it came off of.
See ya'll later!

 

[Jim511]

Project is looking good, and those CEN Genesis shocks should work well with the project!

 

[rx78gp02]

bingo you got it jim!
anyways, I've decided that picture was confusing, soo i made a prototype for you guys to see

And here's a CAD rendered version:

so how about now? what do you guys think? yah? no?

 

[jagg]

Interesting design, do they bolt up on the inboard side of the mount.

 

[rx78gp02]

yes, the shocks bolt onto the inside part of the mount. Mind you that my prototype design wans't that good, but the cad version one should have enough space to do so.

 

[rx78gp02]

well scrap the mounts. Looks like its gonna cost a huge amount to have these manufactured. soo looks like i'll be making them myslef once again.

Anyways, i finally got my shocks in and man they are massive!
Here's a pic of one of them and a 6" caliper"

Steering links are done as well. Compared to the orignal steering links, these are beefy enough.

As for chassis, design i'm thinking of scrapping the tub chassis and going with a tube frame chassis i've designed a while ago for the atlas clod. It was a full chassis then some where along the line i took it apart and never had enough peices to finish it.

What do you guys think?