e's ExMT

[ekd]

The cam, a landing gear retractor for it's crane, and some shocks from my boneyard.

I was planning on traxxas shocks, but was curious if anyone knows what kind these are, and if they are worth trying?

[Abavuso]

Sounds like you're making some good progress. I'm still waiting for my toasted servos to come back from service so that i can finish my testing. Then I'm going to tackle the Transe brace and I'm also working on delrin Tubes to replace the stockers! This should give me the ability to make them any length i need to swap in some CVD's but then again, the dog bones arn't all that bad, it's just the axle stub!

[ekd]

Yeah, and I'm having a bunch of fun figuring this all out.

I think you're right about the dog bones. An easy way to get some idea of the quality of unknown steel is to drop it on a hard surface and listen. These ring at a high and sustained pitch. I've put a lot of power through smaller and weaker ones... the diameter isn't as important as the steel. Time will tell, but I don't see putting the kind of power in this rig that it would take to wrap these bones up.

At some point, if CVDs aren't in the picture I'll be trying hardening the stock stubs. They are so cheap, I have to see what they can be turned into.

I'm checking in here a lot, and looking forward to seeing what's next in everybody's plans. Running the "red headed step child" of MOAs has turned out to be a lot of fun for me, thanks to this crew.

Anyone have a guess as to the degree of improvement in steering CVDs can give this rig? I can't yet decide if it is vital, or a good later upgrade.

[BentMetaL]

Originally Posted by monkeyracer

The 4-link gives a little bit of rotational stability. That and there is a lot of slop in the 3-link connector that comes with the EXMT.

Also, I want my links to have the same axis of travel as the axis of rotation in the rod end to provide unhindered movement and better stability. (The lower links already do this.)


I'm looking into the GT3 hack to get easy proportional dig and 4ws functionality. I have a 6 channel radio modded into a pistol case, and it can work for that function, but it is much harder to accomplish. Also switching between the Super, my 2.2 TTC 4WS/Dig/winch Trail Rig, my drifter, rally truck, monster truck basher, and two other scalers, it is a lot easier to do with the FS-GT3 than with the FS-T6A that I have now.

Heres my thought on four link. and servo mounts. Plan to mount split packs on front axle. Sorry! can't figure out how to add pics.

[ekd]

Originally Posted by PHAT2011

Heres my thought on four link. and servo mounts. Plan to mount split packs on front axle. Sorry! can't figure out how to add pics.

The only reason I'm possibly interested in 3 link is that it would allow using the upper links in a "pan" config, to hold stuff low but protected.

Converted to stick, and set up rear steer (on left stick for now).

Turns out... I'm lousy at sticks. Big surprise. I'll get it figured out...

Edit: Couple pics of phat's rig. Nice and clean.

[tucan]

I'm really new to crawlers , have a Redcat but after finding this one my son maybe gettin a used redcat!! I have a couple questions what is clocking the axles and cloding?

[monkeyracer]

E - get that stick battery off the chassis, that will help with weight a whole lot. Stick driving takes a lot of practice. You should check out the "twin stick tech" sticky if you haven't already.

Phat - nice rig, good job on the servo plate/4 link mount. To post pics, just use photobucket or any other photo hosting service and post the [ img ] link in the threads. Only thing I would see as a potential problem is the short drag link possibly causing issues. A lot of the berg and bully guys bend their servo horns with them that short.

Tucan - clocking your axles refers to rotating them so the motor goes further up. This is called clocking since you are taking something at the 3 o clock position and moving it to the 2 o clock position.

Cloding, well, never heard of that term, but clod axles are part of the Tamiya Clod-Buster monster truck that a lot of guys use as axles for the Super Class crawlers.

[ekd]

Originally Posted by tucan

I'm really new to crawlers , have a Redcat but after finding this one my son maybe gettin a used redcat!! I have a couple questions what is clocking the axles and cloding?

Welcome!

Clocking is changing the relationship of the axle housings/links, and the transmission and/or Cs to accomplish caster choices, and how far the trans/motor hang down. I'm thinking of building an adjustable setup to experiment (incrementally) with caster, and later to mess with the ground clearance/CG compromise.

Clod stall is a result of 2 motors sharing a common power supply. Electricity always goes the path of least resistance, so if one motor sees more load... it gets a little less of the power. I found that on paper, it sounded interesting... but, learned recently that it can really mess with fine control.

Your kid needs a redcat.

[ekd]

Originally Posted by monkeyracer

E - get that stick battery off the chassis, that will help with weight a whole lot. Stick driving takes a lot of practice. You should check out the "twin stick tech" sticky if you haven't already.

I tested with that to take a last look at wheel speed on 7.2V. I'm going to mount the A123s as soon as I get the axles sorted out. They just seem to give the thing more punch... it chirps the tires on concrete.

I keep hoping one of us finds cvds. I'm having no luck.

[tucan]

thanks for the info, i can see how the 'clockin' the axles would help, that Cat drags the motors a lot. For a couple of weeks I have been torn between a Nite crawler or ax-10, but not really excited about either. but i knew i wanted some thing better than the cat.
the clod stall makes sents too, I was wondering why the front wheels would spin, while the rears did nothing. I figured it was something wrong with the motors or esc.
I've been R/Cin for 10 or 11 years now, its fun getting into something new. Almost like starting all over and learning everything again!

[monkeyracer]

Originally Posted by ekd

I keep hoping one of us finds cvds. I'm having no luck.

I've been thinking the axial wraith long universal might be long enough for the long side, and a standard AX10 universal might be short enough for the short side, but they are expensive if they are wrong.
I've also been looking at 1/8th scale buggies and monster trucks, because the outer stubs are a little beefier, and already ready to take 17mm hexes.
It might end up being that we have to modify some existing ones to get it to work, but as you said, I'd rather find an existing solution first.

[ekd]

Originally Posted by monkeyracer

It might end up being that we have to modify some existing ones to get it to work, but as you said, I'd rather find an existing solution first.

Given that we have options in tube length, this should work out well... someday. It would make it easier for the next guys, and although modding axles isn't out of my range... every mod I make has to be considered a possible future family fleet mod.

I hope it's worth it. Any guesses as to the degree of steering improvement we may see?

I'm practicing stick on my couch, I can now turn around at the ends (12 point) and make laps. This is good, for me...

[monkeyracer]

Originally Posted by ekd

Given that we have options in tube length, this should work out well... someday. It would make it easier for the next guys, and although modding axles isn't out of my range... every mod I make has to be considered a possible future family fleet mod.

I hope it's worth it. Any guesses as to the degree of steering improvement we may see?

I'm practicing stick on my couch, I can now turn around at the ends (12 point) and make laps. This is good, for me...

This will give us a lot of steering improvement. I'm expecting about 40-45 degrees of steering with CVDs or Universals.

with dig and 4ws that should allow an almost 0 turn radius.

[Hyde802]

I like seeing people put some love into the exceeds.

Sub'd.

[ekd]

Originally Posted by monkeyracer

This will give us a lot of steering improvement. I'm expecting about 40-45 degrees of steering with CVDs or Universals.

with dig and 4ws that should allow an almost 0 turn radius.

Then there really isn't an option here. Starting the hunt with Monsters and buggies sounds smart. I wouldn't mind also finding something that could be used in a shortened setup for smaller rigs.

Originally Posted by Hyde802

I like seeing people put some love into the exceeds.

Sub'd.

Sub'd to your thread as well.

I've been hunting 7" auto monitors for a while, to use on a more portable radio setup. Just won a DEI RVM700 on ebay for $8.28 + $15 shipping. http://www.avenuesound.com/index.php...2869e074805d88

This should be good enough for just sittin' on a rock, and scouting around a bit. I'm hoping I don't end up putting nose prints on it, though.

The USB vid card shows tomorrow. Time to test the cam. I'll know a lot more about that end soon.

[BentMetaL]

Monk the drag link has been tested and so for we're good. EKD, to get rid of the stick battery, run a split pack on the front axles or a small 1200MAH lipo mount on the front axle.

[ekd]

Originally Posted by PHAT2011

Monk the drag link has been tested and so for we're good. EKD, to get rid of the stick battery, run a split pack on the front axles or a small 1200MAH lipo mount on the front axle.

I was just messing with the stick battery. This is how I'm running the A123s atm. They'll be on the axle when it's all done.

The vid card is giving me problems. My desktop (XP Pro, sp2) recognizes it, but my laptop (7 Pro) doesn't. And neither can read the disc supplied. Can't use it on either until I find drivers. WTH?

When I bought this thing, I picked up some spares, including # mad-mm2009 axle stubs.

http://www.hobbypartz.com/mad-mm2009.html

I just noticed they are set up for regular hexes. The rig comes with mad-mt2038 parts.

http://www.nitrorcx.com/mad-mt2038.html

Only hobbypartz sells both as MT parts, I wondered what the deal is, so I pulled mine down. They fit just fine, and will allow standard hex wheels to be used. I'll order more, and start trying some of my Maxx stuff on it. Turns out, the stock tires are absolutely perfect... for my couch. I want an idea of what it will do with bigger tires before I choose what windings I'll be shopping for in motors.

I haven't heard a word from Punk. I decided to try mixing my ESCs by "lying" during endpoint setups. I'm looking forward to doing it right... it makes a difference, even crudely done.

Also, starting to like controlling the R steer with the left stick. The plan was to save the left 3 channels for the cam, but there is simply stuff you can do this way, that a mixer can't. I'm clumsy still, but getting the beginnings of hand/eye coordination. Now I'm unsure of how I want to set all this up.

Still haven't broken anything, and I have to say this about crawling in general: The focus needed tends to make it very easy to ignore discomfort. These damn things are therapeutic. As it sits (not including the growing experimental parts pile) w/batts, I am at <$200. And, this is becoming fun for all.

There may be dupes in the near future. My sweetie wants one now... and I have no qualms about these rigs.


edit: Phat, there is more to monkeyracer's suggestion than simple durability. A long drag link, from as far as you can get from the DL/tie rod joint, will stay far more parallel through its throw. This gives you more linear steering, and loads the ends and arm in the way they are designed to take the most punishment.

[ekd]

After going over the list of things I want to change on this rig, and the parts I already have... I have reached a point many do. I want to keep this one as a rover, and I want a more capable crawler... so, I am going to build a MT from the axles up. Coming soon are the remainder of the parts needed to build 2 custom transaxles... minus CVDs.

I like this rig. I have only had to open it up to get measurements. I want to mess with all the facets of tuning these things, and I can't see tearing a running, and fun rig apart every time I want to try something. My bashers get upgrades when they break... which means it won't be long before I can try something new. Not the case with this thing.

I'll get needed driving practice, while I enjoy building something somewhat unique.

I'll be using OTS parts wherever I can, so it can be duped reasonably. I'll keep a list of costs and part #s going, per my sig.

Axles are the only issue for me, and I don't have an LHS to poke around in, or an R/C crazy friend with a comprehensive boneyard, so...

I am offering $15 paypal to the first person who gives us the part #s for readily available cv/universal axles for these things... and $10 more if they find me #s on the same thing, but for 8mm ID outboard bearings. These can be up to 10mm shorter than stock.

We're never going to know what these things can do without them... and I can't wait to see what you guys come up with when this hurdle is past.

[ekd]

After looking at literally every CVD on ebay... researching miniature universals (and sub-miniature)... I came up dry.

To use heavier bearings (Stone bits), I'll have to make my own. So, I bought 8 pr of Integy cvd axles for the Savage 21/25 on ebay. For $51. I have read little about Integy that is good, but I'll harden the results, and hope for the best.

http://www.ebay.com/itm/230650808028...84.m1439.l2649

My offer stands for the bounty on the standard replacement parts, for stockers.... but, I won't need the 8mm.

edit: found HPI hexes : http://www.ebay.com/itm/270823015650...84.m1439.l2649.

They have 17's for the same price.

The evil twin will be running (3) 8 x 16 x 5mm bearings at the outboard ends of each axle. They should last.

[monkeyracer]

Looks interesting... Waiting to see what you end up with.