Super Build: The "TiCrawler" ...with added Titanium!

[Erik D_lux]

Build looks cool. I look forward to what you come up with.

I always hated a single servo. I would either to dual or here is another option

http://www.rccrawler.com/forum/axle...ervo-strengthener-make-7980-twice-strong.html

 

[Cogent]

Thanks Erik ...I think I'll get a couple of these off you (assuming you're still selling them).

I just discovered the 7980 servo is slightly bigger than standard - lucky to find that out before I designed the servo-mount I talked about above.

 

[Cogent]

Have just ordered three pairs of super-soft Panther Plowboy tyres. Oh, and some glue as well.

Man, almost as much in shipping as it was for the six tyres + glue ...I really envy you guys living in the US sometimes :sad: ...ah well, it is what it is.

Plan is to cut and glue these to fit 5" wheels and narrow them too.

 

[tweak6]

Build looks like its going to be a good one. What I find funny though, I was thinking about buying them axles off of ebay, but they sold before I could. But I am glade to see someone is putting them to good use and doing a build with them.

 

[Cogent]

Yeah - was pretty lucky these were on eBay in the already-widened form.

Have just ordered a set of shocks.

There seems to be a big variety on what people are using on their Supers in term of shocks.

I just ordered a set of fours thread-adjustable 130mm (around 5") eye-to-eye shocks. That length is the minimum I want to go for.

My feeling is that they will be too strong/stiff and will have to change out the springs (and then test different oils weights).

 

[tweak6]

I noticed that also when I was looking around and building my super, I ended up going with traxxas big bore shocks with the shock cap mod and losi mini t springs. I have not been able to test very much because of snow but I from what I have been able to I like this set up better than my old crawler which have axial shocks on it. but I think it really all depends on your own driving style.

 

[Cogent]

I noticed that also when I was looking around and building my super, I ended up going with traxxas big bore shocks with the shock cap mod and losi mini t springs. I have not been able to test very much because of snow but I from what I have been able to I like this set up better than my old crawler which have axial shocks on it. but I think it really all depends on your own driving style.

One fairly common theme I've seen with shocks is that a small spring is used relative to the length of the whole shock.

The ones I've order have the springs pretty much the same length as the entire shock.

It sounds like yours are the small-spring setup. Pretty sure I'll have to go that route.

The thing is...

These are pretty much the only shocks I could find that were in the 130mm range ...unless I jumped up to 200mm+ (eye-to-eye) range. :shock:

 

[tweak6]

A 4" traxxas big bore with the the cap mod done can give you 5" eye to eye.

M3 Long Straight Plastic Rod End (20x)

Those rod ends are 1" long, which should give you that 5" eye to eye.

When I did my shocks I used these rod ends:

M3 Plastic Bent Rod Ends (20x)

I have them on both sides of the shock, I put them on 4" big bore and it gave me a 4.75" eye to eye length.

If you do end up going to a shock set up like this that will give you some idea on to what rod ends will give you that 5" eye to eye

 

[Erik D_lux]

A 4" shock is a lot of travel to deal with. I run severely limited 3.75" big bores and I only run those because I had them. I really want to throw some limited 3.5" on there.

 

[Cogent]

A 4" traxxas big bore with the the cap mod done can give you 5" eye to eye.

M3 Long Straight Plastic Rod End (20x)

Those rod ends are 1" long, which should give you that 5" eye to eye.

When I did my shocks I used these rod ends:

M3 Plastic Bent Rod Ends (20x)

I have them on both sides of the shock, I put them on 4" big bore and it gave me a 4.75" eye to eye length.

If you do end up going to a shock set up like this that will give you some idea on to what rod ends will give you that 5" eye to eye

Thank you for explaining your setup - it sounds like the kind of thing I've seen around.

I had considered the Traxxas Big-Bores ...but most Supers I have seen had them skimmed-down slimmer. Wanted to keep it simple for now.

I'll wait for these current shocks to arrive and see how they fit.

 

[Cogent]

A 4" shock is a lot of travel to deal with. I run severely limited 3.75" big bores and I only run those because I had them. I really want to throw some limited 3.5" on there.

Man, I've just gone for 5"! :shock:

Although, in saying that, I do plan for this thing to be a bit bigger than most others.

The other reason I went for 5" was to edge on the side of too big rather than too small.

I can get smaller shocks locally (by this I mean in my country) but difficult to get larger ones. This way I can try these larger ones ...and if they don't work I can get some smaller ones locally - should be able to get Traxxas Big Bores if I need to.

 

[Cogent]

Received acrylic pieces yesterday.

The chassis prototype went together like a dream.

Holding it together is custom-made, anodized titanium posts/screws.

I countersunk the screws a little ...but doubt I will do that for the final carbon fiber/titanium chassis.

The screws are M4.

Pretty happy with how it's looking - but can't do anything else until I get the shocks, rod ends and find somewhere that can supply 4mm aluminium rod (it's unreal how difficult it is to get 4mm aluminium rod ...I thought it would be ridiculously common ...apparently not).

There's already a number of design changes I know need to be made. Nothing major though.

 

[tweak6]

McMaster-Carr


It might not help you much considering where you live but there is a link.

 

[Cogent]

McMaster-Carr


It might not help you much considering where you live but there is a link.

Cheers for the link. I'm trying to get it locally - but I might just have to get it from there (or at least somewhere in the US).

 

[Cogent]

Was initially planning on having the wheels glue-on for the sake of simplicity (only two parts).

However, I'm thinking beadlocks will be the way to go ...BUT, it will require five parts to build the wheel.

Initial idea is to have the main part of the wheel in carbon fiber and then the bead-locking part in titanium as a "lip" that run around the rim.

A very crude mock-up:



Yes, will require eight screws (compared to the usual six I've seen on most others). The thing is, these are going to be around 130mm (5") diameter.

The other thing is...

I may get one wheel made-up in acrylic for a prototype before going straight to carbon fiber. If I miss something obvious then it's a few hundred dollar "mistake".

 

[Cogent]

Drove 90 minutes yesterday on the chance my "local" hobby shop would have some sort of aluminium (or anything else) rod.

Couldn't believe it! They had 4mm aluminium rod. Only five pieces of 300mm ...so I bought them all.

Funny thing - this rod had to come from the US anyway (Chicago, apparently):

 

[Cogent]

Set out the axles and chassis to a rough position then measured the lengths of rod I needed to cut.

Cut all the rod (can't believe it ...the 5 pieces were exactly the amount required - I think my Guardian Crawler Angel was looking down on me ;-))

I got busy on the grinder and slimmed-down the ends so they could slide into the Revo rod ends. I don't have any way of threading the rod -- but wouldn't have anyway -- this is purely for getting the layout right.

It's amazing...

I've only ever seen pictures and videos of crawlers ...never one in real life!

This mock-up/prototype is the closest thing I've seen in person. There's no shocks on it yet - so when I pick it up it's like picking up a very sleepy octopus!

The labels on the rod left that horrible, sticky stuff when I peeled them off ...so I took all the rods to the polishing wheel.

Here's how it's starting to look:

 

[Cogent]

I know, I know...

There are a bunch of changes I need to make to the links and how they're positioned. Hell, the shocks (they should be here next week) won't even fit on as it is ...the links are completely in the way.

It's funny...

I read these other build threads and the crawlers seem to just come together ...but it's very deceiving how much work goes into getting one of these things together. And doubly-so for my amateur attempt ...can only imagine what it's like for the real pro Super builds I've seen!

Oh, and one thing I didn't realise...

The complexity and number of variables is incredible. I'm only as far along as mounting the chassis to the axles and only now seeing the how the articulation works ...and all the little (and big) changes that can be made ...hundreds (literally) of them!

 

[Cogent]

Just received Vanquish hubs. Was able to get the layout/sizes from them so I know the dimension to make the center of the wheel (this is what was holding me back from progressing further with the wheel design).

Diameter is 150mm (around 6"). So, with the PlowBoy tyres, should be looking at around 8" (or just over) total diameter.

Below is pretty much the final design for the wheel and beadlock part.

 

[richo119]

hey bud great work so far "thumbsup", takes some guts to start putting one together without seeing one first.