crawlercrazed

I am currently building a ground up rc nitro rock crawler. i have tlt axles ( the plastic stock housing i plan to upgrade to aluminum later) with the 2.2 axle widener kit, 4 wheel steering, 4 links from a monster truck chassis kit and a scale chassis from crawlerstore. i plan on running either a .12 or .15 nitro engine with a cooling fan to a stampede tranny (geared low) with an airplane gas tank. the engine would be on the back side of the chassis like a monster truck and everything else in the front. i wanna run the gmade wheel and tires from the spider on it as well. since the chassis it self is 15 inches long i plan on cutting it down to 12 so my axles have clearence and not hit the chassis at all. my point of concern is while crawling at weird angle will the engine stall???

The Real Dogman

Crazed, It should not stall if you have it tuned properly and your in-tank "clunk" can move freely in tank to follow the fuel..But as far as running with good fuel flow, the engine will run upside down, sideways...ect

Sounds like a cool build-up, please feel free to post progress pictures, we all want to see them..

Anomie

It sounds like you have a good plan there. Post some pictures here as you make progress.

Dogman is right. If you use an airplane fuel tank your fuel flow will be ok in any position. You shouldn't have a problem running the engine at odd angles.

crawlercrazed

yea so ive been on the web for more ideas and ive decided to go with tubular chassis that resembles a sand rail along with 4 wheel steering and a nitro engine and tlt axles still with a traxxas tranny and clod wheels. i have no clue when ill have pics up tho im waitin for tax money b4 i get to crazed buyin stuff.

Anomie

That's cool. Do us a favor and post some progress here as you move along. The nitro rigs are few and far between, and I appreciate anyone with some drivetrain ideas and details in this area.

mechanicalbob

My Feedback: (49)

Well it has been awhile scince I have been here. I see the Nitro Crawler builds go on. Some of the issues I have read here are the "roll back" when not on the power. With a planeary gear set you will not have that issue. The only place that might have an issue of roll back is when shifting from forward to reverse. I am getting closer with mine I am on my 5th tranny build I hope this is the one that I like. As for the cooling issue I am going with a Heli cooling setup. It is light weight and effective. I cut about 2-1/2" off of my cooling head. this helps keep the weight down and with the forced air it cools just fine. The other issue is fuel delivery. I was going with a airplane engine but decided to make my own out of sheet metal and use a Perry Pump to feed the engne. Over all my truck is going to be basd on a 2.2 Comp rig, 12.5 WB 12" wide. It has been along road to get Nitro to crawl and there is a long ways to go to make it work right. I will post pictures smetime soon.

Steve

Anomie

Thanks for the update, and I'm looking forward to seeing pictures of your work. It seems that there are varying ideas and plans for making a nitro rig operate well, and the variety is intriguing.

The liquid cooling is still progressing for me, and I finally finished the coolant reservoir and have completed most of the machine work on the top and bottom caps. Once that is mounted to the frame, I'll run some plumbing and put up some pictures of the system. The clutch is another story, as I continue to redesign in favor of an engagement similar to a DIG. That may take a while

dude7422

reiko i see still working on this great ever think of using one of those ceramic mug heater /chillers to cool motor put under the motor mount run off a lipo battery use small spacers to hold motor up just 1mm from the ceramic chiller just a idea

Anomie

A chiller or Peltier-type cooling is a really efficient method, but I have to challenge myself with the liquid. It is taking forever, but I know it can be made to work reliably.

This is the original radiator I had planned to use, but I have recently decided to use something newer.



I found some interesting cooling system parts that are intended for PCs, but could easily be adapted for other purposes. I'll have some pictures of the reservoir and associated parts as soon as more work is completed.

hands without shadows

So are you building a clutch which engages at a certain speed or an on/off manual shaft engagment?

Anomie

I'm actually working on both. I would like a manual on/off, but a stall clutch will not require a radio channel in order to operate. A manual coupling seems like the way to go, so far.

The Real Dogman

Hey you guys aren't you forgeting, I already looked into the peltier, and found thats its survivable working temp is too low for nitro engines. Also, That's exactly like what I was talking about just as few posts back

Anomie

Yes, the Peltier would have been an interesting system, but after learning of the info you provided, it appears to be inadequate to the task. I'm hoping the liquid will be effective. I think just the surface area of the radiator and lines will provide plenty of transfer.

RC-Archer

So I just read thru this entire thread and I think that you just missed a way to run nitro in your crawlers. The worlds greatest crawlers on the face of Earth uses this technology and have been using this technology for the last 50 years. Now this technology is being used in cars and is called "hybrid power" I'm refering to Diesel Locomotives and Hybrid cars.

The way the system here works is that you have the gas/nitro/diesel engine run a generator and you use the power from the generator to run your electric powered chassis. Hook up a 550 motor to the nitro engine and use it to generate power for the 550 motor in your chassis. I would use two throttles, one for the engine and one for the ESC.

This how the mighty 3000 hp diesel locomotives work to crawl at a snails pace. THe simplicity of this method is that you don't have to have a fancy clutch or reverse transmission or braking system. And it is a perfect way to convert the high horsepower of your nitro engine into usable torque for your crawler.

subyman

My Feedback: (2)

Why not just use a battery then?

Anomie

I had considered a hybrid rig before deciding to use strictly nitro propulsion. I still plan to use a generator for some of the electronics, but not electric motors. I suppose most of the drive to use nitro is the difficulty to make it reliable and capable as a crawler.

Rat1

Is anyone going to actually build something or are you guys just going to keep this topic going for a few years?

The Real Dogman

Hey rat, we just might talk about it forever. But if you have any HELPFUL suggestions by all means lets hear them....(whispers----there are builds going on behind the scenes, you will see them when they are ready)

Rat1

Ok I was just wondering because this thread has been going on since Aug of last year and so far no one in this topic has even built a test machine. Heck no one has been able to build a capable nitro powered rock crawler in years.

Anomie

There are a few builds by RCU members that are ongoing, and the difficulty in making a reliable model can really spin the clock.

Mine is in progress, but since the thing has been all machined by me in my spare time, it is very time consuming. Plus, when I run into snags, parts need to be redesigned and made again. This is not the most efficient routine, but the challenge is most of the enjoyment... for me. Nitro-powered, liquid-cooled, and 29" long.

I have made 134 parts that are on the truck, and 50+ that have been removed/scrapped for one reason or another.

4 years, so far.

rorannerusan

Here is an idea I came up with after reading all ur post. Make a clutch setup like an automobile only set it up to work in relation to throttle response. U would need a servo for the clutch, but maybe you could wire into the same plug as the throttle. All I see is just setting it up similar to a brake. or just use the throttle servo with a different type of arm. As you give it gas it pushes the rod which would push an actuator similar to a brake like clamping giving instant clutch at little throttle eliminating some clutch burn up. With this setup you could easily experiment with clutch material. A simple fan would probably eliminate overheating. Then use a big spur gear and small clutch bell rig. Maybe this would work just an idea. Oh as for rolling forwards or back you could set the brake to grab some at idle meaning clutch disengaged. This would probably be cheap to try and could probably make your own spur gears for cheap with a dremel.
Let me know what you think of this idea. I have had this for 5 years now .
Thanx Lee

rorannerusan

Here is another idea coming off my previous post and adding to it. Has any tried a planetary gearbox? In theory you could use ur stock tranny and use gears to run a planetary type gear box. Check out the tamiya gear boxes amd maybe you could get an idea. Sing my clutch idea and spur gear idea you could set up a gear to gear setup to run a home made tranny similar to one of theres plus you would have reverse.
Nitro rocks
Just thought of this idea off of another forums on transmissions.

Let me know what you think?
Thanx Lee

The Real Dogman

lets see some pics of your setup

Anomie

I do like the idea of a scale clutch that can disengage, but the amount of control required for this while driving the truck might be tough to work out. A coupling that does not slip should need no more than a switch. Once 'on' or 'off' is selected, the coupling would stay in that position until told to do otherwise. This is just my thought, of course, as I have not completely worked out the design as of yet.

As for a planetary gear set, check out some of the posts [link=http://www.rcuniverse.com/forum/m_4641832/anchors_4731563/mpage_2/key_/anchor/tm.htm#4731563]earlier in this thread from mechanicalbob[/link].

rorannerusan

These are just ideas right now. I figured maybe when I get more money I will build a nitro crawler. Here is another thought for realism. The axle assemblies from the Kyosho madforce or nitro version could be setup probably for more realistic crawling looks. As for the clutch I thought about using either a nitro with a longer crank shaft output or a screw on one and a bearing setup to allow the clutch idea to spin with motor rpm essentially a metal plate with a hole for the rod to push and the bearing in front so the plate won't spin and a spacer of some sort to push the clutch piece or pieces together. Here's a thought make the clutch actuating plate bigger then the clutch disk on nitro engine. When the throttle returns to idle being the disk is over sized the metal plate would have a hanger that pull back on the clutch actuating disk. If anyone thinks this will work let me know. Has anyone seen the mod gears for a tmaxx tranny? There was making making a crawling gear setup as well as three speed setup somewhere. I seen that about a year ago and was going to get but could not find the site. As for water cooling why not try a trx pro .15 with a water cooling head. Maybe someone could rig it up to cool with an electric pump some kind of radiator setup and a fan to suck cool air through the radiator fan could be controlled through rpm by some kind of pick up maybe similar to a bicycle speedometer. The clutch idea would need a clutch bell with holes and a flywheel with 2 threaded holes instead of the clutch shoe rods. Just take those out and thread the holes. you would have to make sure the clutch bell holes would line up with fly wheel holes. I saw a setup like this on a nitro monster truck designed for instant movement as you touch the throttle. I was in Hawaii when I saw this on a modded tmaxx and man was it sweet. The guyt set it up for sand drags so that it would go instantly with out wasting nitro meaning less throttle for movement since the clutch grabbed quicker.
Thanx Lee