Project best X frame saved thanks to cman_1500w

[NeoSlayer888]

cman_1500w: Thanks for posting the pictures for me.

I also want to see some movies of TXTFUN's crawler. I think there was a 1:1 crawler called Tiny that had its drivetrain offset to one side so the driver could sit lower. Im not 100% that its name is/was Tine though.

[NeoSlayer888]

Link to Tiny: http://www.pirate4x4.com/comp_rigs/bundrant/index.html

[cman_1500w]

No prob!

I like your new idea there! Never thought about that one before. A bit complicated and I don't see any reason why it wouldn't work but the main driveshafts would have to be really short. My brain hurts just trying to think of it!

Rbgerrish had some kind of wierd setup on his latest rig with a short driveshaft connecting his gd's to the tranny. May wanna go back and find out the skinny on that again.

[NeoSlayer888]

Nuther Tiny link

Once I learn Solidworks I should be able to work out all the driveshaft problems. But for now time to research Rbgerrish.

[NeoSlayer888]

Click for pictures of Rbgerrishs very cool crawler. It has two gd's inline after the motor.

[TXTFUN]

Here's an old vid, shot it at night so it wasn't the best quality but the camera man takes a spill at the end so I had to save it

http://www.rcpics.net/view_single.php?medid=29760

This was when I was running 15" wheelbase, slightly lower, Std tyres and had still not sorted my spring rates properly. You can still see it's pretty stable but it just keeps getting better as I tweak it.

I have it apart at the moment cause I'm making new servo mounts, but I'll get my act together and take some footage of some better obsticals for you on the weekend.


I'm running 22 turn singles I think (Kyosho Monster 360's) on 9t pinions and find it to be low enough still with enough punch for areas that cant be crawled.


I haven't thought of a sideways tranny because this one worked out pretty perfectly for me, everything fit very snug and worked, could be and option where you could still use a std battery as well which would be good.

I remember seeing rbgerrish's crawler on Outer Limits a while ago, Very nice and unique looking rig. Has it been in action yet? How did it fair?

[cman_1500w]

Neo, I'm pretty sure I've seen that rig before in some of my magazines! Cutting edge stuff! Now that's thining outside of the box! Us r/c crawlers could use a few things from him!

Rbgerrish's rig is pretty cool huh! Nothing like what i've seen before! Some really neat ideas there, especially with the stacked gd-600's. Haven't heard any updates lately just a few pics from one of their latest meets.

TXTFUN, you know I actually already have that video of yours! Never realized it was you until you pointed it out! heh heh! Sometimes I download vids when I'm just barely still awake at night! It's kinda dark but I can see the capability in it. I did notice you still had some torque steer but you said you've pretty much gotten rid of that. Can't wait to see an updated video!

I've never tried a dual motor setup so I haven't seen the advantages to it in person.

The sideways tranny was just a brainstorming moment....trying to think any other possible ways. I'm still for yours though b/c it places everything(motors/battery) down low.

If 2 22turn singles are enough then I really wonder what 2 of those 55t motors that everyone's been raving about would do!

I've noticed from reading on here that lighter weight rigs...like clods...don't seem to need as much gear reduction as the heavier ones. When I added reduction (just last night actually) to my 12lb+ crawler (x-axles, bb's and all) it has made a TON of difference. How much would you say your crawler weighs?

[TXTFUN]

I'm not sure on the weight, when I get it back together I might sneak it into the fruit and veg shop and sit it on the scale and check it out .

Clods also have the advantage where they can spin one set of wheels first when the other stalls so you can gradually put power on and it wont jerk so much when the motors arc there way out of the stall.

My understanding on motor windings was the less number of turns the more power it draws so the more power it produces and the shorter the runtimes. And single, double or triple was the number of wires together in the winding eg 22t double has 2 strands of wire held together as 1 and wrapped 22 times around the armature and a single gave less speed but more torque where as a triple gives higher top speed and less torque, So 55t would mean not much punch but really long runtimes. Is this correct, I cant remember who told me now, might have been the guy at the LHS.

[cman_1500w]

Cool, I'm really curious as to all the ins and outs of your rig TXTFUN! A clodkiller from Oz is sure to upset just about any clod in the states! The next chapter in rc crawling will be known as........ "The Age of the Shaftie"

Yes Clods can also do their little wheelspin thing too.....which helps but can also hurt depending on the situation of course....more often than not I think it helps tho.....damn clods!

I believe you're right on the motor topic too....That all sounds familiar to me in my very general understanding of it. Kaetwo and Pinchflat both run those motors with like 9t pinions and I've heard they get ~1hr of run time so you are probably right there also.

[Grizzly4x4]

Hey Muzz, Cman,
I thought I'd put some useful info into this thread.
You are right on the motors. Lots of torque, not as much punch as a Mag Mayhem but not terrible either. The throttle control is what I noticed most about them. Very nice.
Actually, last I knew, Pinchflat was running the motors with 9T pinions and Kaetwo was using 13T pinions.
BTW, I love your rig Muzz, very innovative. I do hope you can get some comp wins with it.

[NeoSlayer888]

Update on the reducers:

Picture wont last long so please don't tell me that it is a red X.

I tried drawing the Traxxas joints in AutoCAD. I only have my digital caliper so the angles might be wrong. I think they are because 14 degrees of movement per joint seem low to me. What does everyone else think?

[cman_1500w]

I see the pic

looks good to me. Only thing I can think of is for you to clock the 'reducer' or the part that connects the upper part to the lower part that has the outdrives for the driveshafts.

Like in 1:1 where they clock the t-case to gain better clearance.

Maybe turn it ~70degrees so it's more flat on the bottom.

[NeoSlayer888]

Dont people clock a 1:1 t-case so they have a flat belly? I should have drawn a mock frame but if you look at the pic I posted and the one you posted for me than you will see what I am talking about. Since the E-Maxx tranny is inverted the driveshaft angle is not good and requires a longer driveshaft. With the reducers the driveshafts are droped down to hopefully where they would be if the tranny was not inverted. Also they move the driveshafts closer to the axles so the driveshafts dont have to extend as much thus making the driveshafts stronger. I am a little confused about what I just said so if you dont understand anything just ask.

[NeoSlayer888]

I just had a brilliant idea! At least I think it is. The idea will even work for non inverted trannys. It would work better for them infact. Looking at the back of my E-Maxx tranny I relized that the moter is ~.830" higher than it needs to be. I want the top of the motors to be flush with the top of the tranny (or bottom if it is inverted). The only things needed to drop the motors would be a new motor plate and the frame would need to be widened to fit the motors. The only cons I see are that the frame has to be widened creating more contact between the frame and rocks.

[cman_1500w]

Yes that is the exact reason they clock a 1:1 t-case.

Ya know, i forgot there about that last pic and just didn't tie it into your new pic. Now I get it!

So yeah, inverted tranny, reducers......gotcha!

So if you're doing this to reduce the angle on the driveshafts to make them stronger you'll have to beef up the mount for the 'reducers' to gain any of the strength benefits your'e talking about. If the mount for the reducers isn't strong then all that goes out the door....know what i mean?


Here's a question, Do you think the increased length in the chassis will be a problem. With the much shorter driveshafts....do you think they will have more of a chance of binding at full flex. Say you build it to have ~70 articu.......will the driveshafts bind up?

Also what about the increased bulk/weight from this setup? The X-axles are some heavy mofo's already. Is lightweight your goal?

[Grizzly4x4]

Originally Posted by cman_1500w

Here's a question, Do you think the increased length in the chassis will be a problem. With the much shorter driveshafts....do you think they will have more of a chance of binding at full flex. Say you build it to have ~70 articu.......will the driveshafts bind up?

If you put a limiting strap in the center of the axle to stop the axle from dropping vertically, that would help if the u joints are on the edge of binding but would still allow articulation. I have seen some 1:1 buggies that have the ujoints nearly maxxed out at ride height but limited with the center strap.
BTW, I did not mean to imply that there is no useful info in this thread, I just meant that alot of what I say is useless banter. I reread my post and thought that you might have got the wrong impression. Sorry.

[NeoSlayer888]

I see what you mean about the reducer strength. The current plan in my mind is that the reducers will tie into the frame just like a cross brace. I have no idea if the driveshaft will bind. I need to turn out more ACAD drawings to be sure. I am hopping that it will not bind but think it will be a serious problem to overcome. As for lightweight question that is not what I am going for. I am going for the best X-Factor frame I can make. To me this means crawler ratio, adjustability, and a low CG. I am hoping that dual motors and the correct gearing will be able to overcome the added weight. Thanks for the info Griz; I will go research that now. Also I didn’t take any offense to your previous post I just thought it was some CLOD humor.

[cman_1500w]

Hey Grizz this is a shafties only thread! Keep your spying clod self away!

LOL j/k! man!

Good idea with the lim strap! I shoulda realized that....whenever we have a prob, then look to the 1:1 rigs! Nice ingenuity there!

Oh and Neo you need to finish this design b/c I might copy it! Seriously tho, can't wait to see what you can come up with here! What you have in mind sounds like a solid design!

Part of what makes crawling so intriguing to me is the challenges we face it creating our machines. So different from other types r/c vehicles! All those weekend racers simply don't know what they're missing!

[TXTFUN]

Muzz is back again, I know I said I'd have some vids for everyone but what started as a bit of a clean-up ended in a stripdown and overhaul, made some new combined servo, shock and link mounts, trimmed up the chassis, had to make up some new links with bends in them, should be finished soon, just gotta rewire my motors and fit some body mounts so maybe this weekend.

Neoslayer, my maxx uni's run pretty close to 30-35* and they dont really bind, I think because they are plastic they can stretch a little.

With the reducers I would probably try to run the first gear straight off the output shaft on the tranny to keep it simpler, I can get 5" of centre clearance with the latest tweaks so I dont think you would need to drop it down too much.

Cman I hear you on the on road guys missing out, I can stay up till 2am trying to achieve what is seemingly impossible with some scrap aluminium and a drill.

No offence taken Grizz, after a while you can kind of get an idea of what everyones sence of humoour is like, I'm pretty cruisy anyway so can take a bit of a joke.

Now back to the tools, I gots to get playing on the rocks again

[NeoSlayer888]

With the reducers I would probably try to run the first gear straight off the output shaft on the tranny to keep it simpler, I can get 5" of centre clearance with the latest tweaks so I dont think you would need to drop it down too much.

Can you elaborate on this please? Because I drew up my idea and it is 8.616" long.