Lookin to build a crawler from scratch.

[TheModfather]

Well, I have an old Clod in teh garage that's just itchin to get some runtime. That being said, I'd like to build a crawler. To the next level, I'd like to build the chassis from scratch.

I'm looking for a starting point here. Not exactly sure where to begin. I have the clod, and an old-school ESC canalever chassis. It has a real short wheelbase, and very little articulation.

So to those who have built crawlers from scratch - can you provide some input as to where you started - what things you tried that didn't work, and what worked nicely. This won't be competitive - it's gonna be strictly for recreation and fun.

Thanks in advance.

[willyrocket]

Heres a tip. If your gonna use aluminum sidepates for a chassis, use wood at first till you get it the way you want. Doesnt waste aluminum and you can tweek it. Most people dont have the equipment to cut aluminum, (to make it easy) so this way you only have to do it once. Same goes for your link rods. Use wooden dowels or just plain threaded rod to get your lengths right. Hope it helps!!!!

Take your time so it looks pretty at least once!!!!!!!Because it doesnt last.

[TheModfather]

Originally Posted by willyrocket

Heres a tip. If your gonna use aluminum sidepates for a chassis, use wood at first till you get it the way you want. Doesnt waste aluminum and you can tweek it. Most people dont have the equipment to cut aluminum, (to make it easy) so this way you only have to do it once. Same goes for your link rods. Use wooden dowels or just plain threaded rod to get your lengths right. Hope it helps!!!!

Take your time so it looks pretty at least once!!!!!!!Because it doesnt last.

Great tips here! I would have never though of that.

For the chassis, i will be using titanium. It's lighter than aluminum, and more rigid. I am fortunate in the respect that I have a buddy that fabricates ATM surrounds - out of aluminum I have a cache of aluminum working tools and machines at my disposal!

[Gimbal]

Figure out what you want the specs to be
-Wheelbase?
-Track width?
-Ground Clearance?
-Gearing / speed?

Then devise a plan to git-r-done. A good rule of thumb is to always keep your weight as low as possible, reguardless of what kind of rig it is.

Take a look around at how link geometry works. Best to keep your links all about the same length. So that will dictate where they get mounted on the chassis. I also like to keep my links parallel top and bottom. But that's not altogether necessary with a crawler. Also you want to keep everything tucked up, nothing hanging down under the truck, to snag on stuff.

Another thing to consider is make your link mount points as free as possible. Ball ends will only rotate so far before they bind...

Good luck

A Zilla chassis is an excellent platform to start with.

[TheModfather]

Thanks for the reply! So many things to take into consideration.


-Wheelbase - I am in the dark here - what are the advantages to longer vs. shorter?
-Track width - I would like to go a little bit wider than stock.
-Ground Clearance - Would like to keep a low COG while maintaining decent clearance.
-Gearing / speed? LOOOOOOW gears is the only way to go!

I wont' be using ball ends - but I am not sure what they're called exactly. They are "like" ball ends, but they have a hollow metal ball in the middle of them that a bolt fits thru.

[Reflection]

Originally Posted by TheModfather

I wont' be using ball ends - but I am not sure what they're called exactly. They are "like" ball ends, but they have a hollow metal ball in the middle of them that a bolt fits thru.

I'm not using "ball ends" either. I'm using 1:1 scale heim joints/rod ends in the 1/4" flavor. They are a little more expensive than your RC scale "ball ends" but they are a thousand times stronger and look more scale to me.

This is VERY simular to what I've got on the ends of my links............

[TheModfather]

Originally Posted by raptorman57

I'm not using "ball ends" either. I'm using 1:1 scale heim joints/rod ends in the 1/4" flavor. They are a little more expensive than your RC scale "ball ends" but they are a thousand times stronger and look more scale to me.

This is VERY simular to what I've got on the ends of my links............

Yeah! Those are what I have on that ESC Chassis in the garage!

EDIT: Um - but mine are 1/10 scale LOL

[ChevyPedeCrwlr]

Finish Project as fast as possibile. I wanna see Pics

[Gimbal]

14½" wheelbase seems to be about average for a crawler.
On the other hand, I run about 12½" on my racer.
So you decide. Shorter will be more squirly, but fun. Longer will climb better.

[TheModfather]

Originally Posted by Gimbal

14½" wheelbase seems to be about average for a crawler.
On the other hand, I run about 12½" on my racer.
So you decide. Shorter will be more squirly, but fun. Longer will climb better.

This gives me a GREAT starting point.

Can anyone tell me if someone makes extenders for stock Clod axles?

[TheModfather]

This is the chassis that I have on the clod curnently: http://www.clodparts.com/images/?fil...s/esp048-1.jpg I am not too much a fan of it because as I stated before, the wheelbase is too short, and there is not much articulation. But I will try to use this as a starting point for designing my chassis.

[SR5Dave]

14.5" wheelbase is a hair short.. My clod is 15.5" and it climbs great. I'm thinking about moving up to 17" once I get larger tires.

Try to keep your first frame real simple, Mine consists of basically a box in the center with aluminum channel bolted on the sides, works great! My next one I'll go a bit more in depth though.

If you've got a clod, you'll have trouble getting lower gearing. Its either fancy machine work or 80$ an axle for reduction :(

Try to keep your link angles relatively flat, everything just sorta works better. Use an upper link mount (like where the stock steering goes) that way you'll get plenty of triangulation in the links when you mount them. Don't forget about steering, servos, etc.

As for links.. if you can swing it, using the metal heims is the way to go! The plastic ones will hold up for a good amount of abuse.. Just have spares cause they can and do go! Search around on here for everyone's buildups, lots of good ideas and great results

[PinchFlat]

Originally Posted by TheModfather

This gives me a GREAT starting point.

Can anyone tell me if someone makes extenders for stock Clod axles?

Well, there are wheel wideners. They basically extend the axel.
Here are the ones I use: http://www.inetrc.com/shopping/html/...inueSubCatID=2 I am very happy with them.

There are also these: http://rc4wd.com/shop/product_info.p...roducts_id=549

[TheModfather]

Everyone who has posted here has been super helpful! I can't thank you guys enough.

The plan is to build a mock up this weekend, and then hopefully start production next week or the week after. I am sure that I'll be calling on you guys for input and/or suggestions. This is a great resource, and I'm very fortunate to have found it!

[PinchFlat]

Originally Posted by TheModfather

Thanks for the reply! So many things to take into consideration.
-Wheelbase - I am in the dark here - what are the advantages to longer vs. shorter?
-Track width - I would like to go a little bit wider than stock.
-Ground Clearance - Would like to keep a low COG while maintaining decent clearance.
-Gearing / speed? LOOOOOOW gears is the only way to go!

Here is what I run.
Wheel Base: 16" (15.5" would be an excelent all around WB)

Track: I use the inetrc.com wheel wideners

Ground Clearance: I'm at 4.5" with the 16" (anywhere from 4-4.5" would be good with 15-16" WB)

Gearing: Alot of my crawling pals and I use the Integy 55x1 lathe motors($20-$25ea.) with 9 tooth pinions, in our clods with great results (you will have to use a motor plate or modify your gear housing with 9t pinions). You don't even really have to gear the clod down with the 55x1 motors. You can use the stock 13t pinion and not have to worry about motor plates if you choose, and they perform good.

-PF

[TheModfather]

Originally Posted by PinchFlat

Here is what I run.
Wheel Base: 16" (15.5" would be an excelent all around WB)

Track: I use the inetrc.com wheel wideners

Ground Clearance: I'm at 4.5" with the 16" (anywhere from 4-4.5" would be good with 15-16" WB)

Gearing: Alot of my crawling pals and I use the Integy 55x1 lathe motors($20-$25ea.) with 9 tooth pinions, in our clods with great results (you will have to use a motor plate or modify your gear housing with 9t pinions). You don't even really have to gear the clod down with the 55x1 motors. You can use the stock 13t pinion and not have to worry about motor plates if you choose, and they perform good.

-PF

If I recall correctly, one of the Clod motors runs forward, and the other in reverse - but since the lathe motors are sealed, how do you 'time' them properly?

[Gimbal]

Link
This is the motor I bought. They are adjustable timing and have bearings. So to make 1 reverse, it's the standard loose endbell and flip 180°. Remember that on the reverse motor timing will be backwards, I have mine set to zero right now.

[TheModfather]

Originally Posted by Gimbal

Link
This is the motor I bought. They are adjustable timing and have bearings. So to make 1 reverse, it's the standard loose endbell and flip 180°. Remember that on the reverse motor timing will be backwards, I have mine set to zero right now.

Perfect! That is exactly what I was lookin for! What is the RPM on these motors?

[PinchFlat]

Originally Posted by TheModfather

Perfect! That is exactly what I was lookin for! What is the RPM on these motors?

mine are adjustable/rebuildable also... but I just wired one backwards with the same effect. Since they are set at zero. Oh... and if I remember right the RPM is about 8000.

[TheModfather]

Originally Posted by PinchFlat

mine are adjustable/rebuildable also... but I just wired one backwards with the same effect. Since they are set at zero. Oh... and if I remember right the RPM is about 8000.

Perfect! I can't imagine needing to gear lower than that - a 9 tooth pinion + the 55 turn motor should be just about right.