First crawler - Stock chassis - Who needs expensive stuff... 56k beware *VIDEO ADDED*
 

Finally got around to putting my little Rock Buster into a real crawler. I did everything on the cheap and used as many stock pieces as I could. The way I see it, you don't need much to make a decent crawler. As it stands now, the only rocks I cannot crawl are rocks that I doubt many 2.2's would be able to make either.

Video July 16, 2006

You will need QuickTime 7 to view the video. File is 50mb. Please Right-Click and Save As...

Video 1

On with the build.

Since I have not seen anything on how to attach the Pede yokes to the TLT axles, I figured I would document that part of the build. The rest of the steps have been done many times before. As far as chassis mods, all I did was trim an inch off the bottom and drilled a few mounting holes for the links.

Drilling the bevel gear

If you attach the dogbone yoke to the bevel gear and cinch down the allen screw, you will get a nice indent on the bevel gear in the center of the flat portion. This will help keep the bit centered.

(sorry for the blurry pic)
http://www.woodardway.com/hobby/crawler01.jpg

The next pic shows how I held the bevel gear in place to drill. I don't have a drill press, so everything was done by hand. I used the clothes pin (that is glued to the piece of ply under it, I usually use it for holding wire to solder) to hold the bevel gear steady. The clothes pin I used was just thick enough to clear the gear.

http://www.woodardway.com/hobby/crawler02.jpg

The next image shows the flat part of the gear as well as the indent.

http://www.woodardway.com/hobby/crawler03.jpg

This image shows the pilot hole that I drilled into the gear. it is a 1/16" bit designed for hardened steel. My drill has a bubble leveler on it so I tried to keep it centered. I drilled slowly with no more than the drills weight to make progress.

http://www.woodardway.com/hobby/crawler04.jpg

I then used a 3/32" bit to enlarge the hole to accomodate the pin for the yoke. The pin is actually somewhat larger than 3/32" but if you massage the hole with your bit, you can enlarge it enough to fit the pin.

http://www.woodardway.com/hobby/crawler05.jpg

Reassemble per the manual. To lock the diffs, I just used one of the three bevel gears in between the other two. One thing I did do was use one of the Traxxas diff shims (Teflon, .5mm) on the bevel gear (the one we just drilled) to take up the slack. My diffs had a ton of play in them, so I figured I would use one here. Works like a charm.

Here are the specs of my rig:
wheelbase - 11.5"
Novak XRS ESC
Old school stick radio (I like the control, used to sticks from flying)
batteries - 1050mAh 6-cell
55t lathe
Pede tranny locked with sliders
Moabs on HPI cross spokes
Links - 96mm Traxxas on bottom and 106mm on top (no I didn't saw that wrong, look at the pics)
Stock shocks work well if they are properly bled, don't use that stupid tool that Tamiya gives you. Works like garbage. I put in enough oil to allow the shocks to bottom out, but go no further (about 3 more drops of oil over the Tamiya tool).

http://www.woodardway.com/hobby/crawler06.jpg

http://www.woodardway.com/hobby/crawler07.jpg

http://www.woodardway.com/hobby/crawler08.jpg

http://www.woodardway.com/hobby/crawler09.jpg

Poser shot..
http://www.woodardway.com/hobby/crawler10.jpg

Looks good.Thats exactly want I what to do when I finally get my TLT.

The only thing I had to buy other than the Pede parts and links was a few extra 3mm screws. I think I bought some 35mm long ones and cut to fit. Other than that, I used all parts from the TLT kit.

I think I saw that Hobby People had the kit for $70...

thats exactly what i did 1+ yrs ago... i loved that chassy setup ... ya kno what works really well if you take the upper links where they are attached to the chassy and move them down to the same skrews that hole the lower ones in place.... torque twist and suspension geometry will be much much better...

he he ALSO sleeve your steering links... go to the autoparts store.... 3/16th's break line works like a freakin charm.

Why should I sleeve the steering links? They are the stock ones...do they bend or something? As it is now, I only get a tad torque twist, but it is hard to really tell without the body. Also, as it stands, my axels stay horizontal throughout the travel within say 5 degrees.

ya they bend quiet easily espically when runnin up agains rocks and what not... i actually had my fron link bend up in a "U" shape when the tire opposite the servo link got really good grip...

As for links what ever works for you... i just kno i had pretty much the same exact link setup and when i moved the upple links down to the lower ones skrews, articulation motion became alot better and it got rid of torque twist...

another lil pointer is to rotate your rear axle up so the pinion angle on the axle side is pretty much flat when looking from the side like the seventh pick, so that your not puttin as much stress on the u joint but mainly to get the drive shaft up and out of the way of the rocks.

I had it that way at first. I think I will go back to it since I have nixed the 4WS idea I was going to go with (hence the neutral angle).

I hope to have video up later tonight. Still sans body, but I think the video does it justice. I am really happy with it and my neighbors thought it was pretty cool.

lol i was just gettin mine to work good and i tore it all down:twisted: thats lookin real good though cant wait to see it finished and if ya want to see some detailed pics on how to convert to a laid down tranny since i have my chassis just sittin there pm me only if ya want those pics;-)

Sure, go ahead and send them. I am not sure if I will go through the effort though. As it is now, I can almost balance it on the back wheels with the nose almost pointing on the vertical. Also, with everything inside like it is, its lateral balance is superb. I took some of my airplane knowledge and applied it here. So far it has zero bad tendancies and its pretty rare that I flip it over without it being a dumb-thumbs mistake. My crawling spot is pretty much flat, but it is all large river rock with most rocks being around 13" long and wieghing around 6 - 10 pounds. I had a rock today that I could not get over and when I readjusted my position to get over it, I ended up pushing it out of the way. Not bad for a truck that is about 6 pounds. I hope to swing by the Post Office to get an accurate weight, but I am guessing under 6.

How's the tigermoth? Is it the 400 version? It looks good, keep up the good work

Heh, I have gone through 7 Tiger Moths, both the IPS and the 400. I have also had 13 Slow Sticks in varying configurations. Also had a Formosa, DC3/C47, Dragonfly heli... I have also had 6 of the Alfa birds. I got out of planes for a while as it was being way to time consuming and expensive.

Alrighty folks... Check the first post, I have uploaded a video I shot today. Still doesn't have a body yet, but I hope that comes soon.

Those are big words! Have you crawled with other 2.2's? I've got some rocks here for you to try. ;)

Good job on the truck, you're on your way! Nice high-quality viedo too.

have fun,
ryan

Crawled with them no, seen them do it yes. From what I have seen, patience, line, traction and speed are the keys to crawling. Most objects are conquerable if you take your time. You see what I have to work with in the video, it is very easy to get hung up if your line is bad. I probably should have worded the sentance you quoted a little differently, but I am confident that my little rig would be capable of going anywhere a similarly setup 2.2 could go and get stuck or flip at the same places others would as well. I think the stick style trucks have an advantage over conventional chassis, so I am not really looking at those.

Video is the first time I have tried to shoot something of that sort. I have filmed R/C planes/helis and touring cars at the track, but getting nice shots of a crawler is a lot harder. I like shooting from the perspective of the truck, so its easy to get blocked by rocks etc. Believe it or not, I shot that video with my basic digital still camera that only shoots @ 15 frames per second. There is one section of the video that it looks like the tires are not moving (even though the truck is) because of the frame rate. I cut the video in Adobe Premier Pro 2.0 and outputed in H.264 (codec) QuickTime video, 50% quality and audio is Q-Design Music 2, 22050kHz, mono. For the web, this is about the best you can get for quality of picture/sound/time for filesize. If you ever watch a trailer at Apple.com, this is the video codec they use.

my neighbor wants to build one cheap but good. This is a perfect example.... saved in my bookmarks!

i feel your pain, i get head aches from building crawlers too. lol

I agree, Many are, but there does come a point, as you will most likely find out, when a more capable truck will leave you behind simply because your truck wont work as well. I'm not talking sticks, I'm talking verticle plate TLT's. I see it endlessly here, and it's an important part of evolving as a crawler. Lots of guys come out with modified stock-TLT chassis trucks, and they work ok, but as soon as you see a refined comp TLT climb something like the 'waterfall,' you end up back on the drawing board. No amount of line picking will get a truck up that if it is physically incapable of climbing that grade, then high-centering at the top...

My truck was exactly like that and then I got an SW2 huge diferince.

Are you talking about chassis like the SW2 or something different? As my ride sits now, putting it next to an SW2, my mounting points are about the same. Ground clearance is the same. My tranny isn't layed down and I don't have shocks like a Maxx, but for all intents and purposes, the rigs have the same atributes. if I need more mounting holes for something, all I have to do is drill them.

Knowledge is power and if you wouldn't mind explaining your rationalle more, I would appreciate it.

"Who needs expensive stuff"

you

Well, many of the chassis up here are custom, and there are a few Bulus running around.

1) the stock TLT chassis has too much unneeded material. If you compare yours to a Bulu 2 for example, Id guess that the Bulu has half the aluminum footprint. Less weight, less to get hung up, better performance.

2) run a 60/40 split or more. Your chassis is centered, and I'll tell you right now that move it to 60/40 or more and you'll be able to climb stuff you couldnt before.

3) High-clearence links. Moving your chassis forward will create longer links, which you'll then want to high-clearence. This will give you more ground clearence under all of your truck as opposed to just the center.

4) When you can afford it, change shocks. The stock tamiya's arent great, and smoother, more predicatable suspension is a good thing. You dont see many, if any, experienced guys running stockies.

5) some people will say lay down your tranny for better COG, but I've seen standup setups work just as well... I perfer standup.

6) How much weight is up front? This makes a huge difference climbing. How much is in your front wheels? Is your battery as low as you can make it?

7) Add 'newfangled technology'. My TLT has 5" of center clearence, and it's a verticle plate chassis with a Pede tranny. (I run a carrier setup) How about dig? It'll open up a new world of maneuverability. How about a lifter sysytem, where a 3rd servo lifts your chassis to free you when you're high centered? These setups, although very optional, prove themselves out there on the rocks and leave 'normal' setups behind in some instances...

8 ) When you start running 'the hard stuff,' You'll probably go to a 12" - 12.5" wheelbase. I've seen lots of people try going shorter, but 12.5 seems to be the hot setup, but again, it depends on where you crawl.

Your truck may have the same basic measurements as another, but remember that these little things will add up and make a difference in what your truck is capable of doing, regardless of driver. Up here, we push each other every week in an attempt to get the slightest edge in performance, and we've learned over the years what works well (for our terrain) and what doesnt. A lot of this you'll figure out as you drive your truck more and more, and make little changes. Thats part of the fun of crawling!

Ryan

PS: (Please dont take this as anything negative toward you or your truck! It looks a probably drives a heck of a lot better than my 1st TLT!)

Well thats not very helpful is it...?

rbgerrish: I don't take it negatively at all. You have been crawling longer than I have, so every little bit of knowledge helps. I don't know how much more I will do to the truck, but I have this bookmarked in case I do. Being a totally broke father/college student makes it hard to do upgrades.