mr-e-maxx

OK First of all I would like to lay down some guidelines. #1, I would like this thread to be for the purpose of discussion of nitro rock crawlin and not that of electric (and yes I have both nitro and electric crawlers ) I have nothing against electric crawlers but that is like discussing apples and oranges and their are other threads on this forum that already com pair the two. #2, I would like to ask everyone to please stick to the topic of nitro crawlin. #3, Please no flaming or bashing and please keep it clean.#4, The reason I am starting this thread is because i like things to be as realistic as possible ( and we all know in the real world there are no electric crawlers or at least none that I am aware of ) and scenes in the real world the crawlers have loud, fuel burning engines then I guess are RC's should have loud fuel burning engines to.

So this is for all you nitro heads out there that want to build a better nitro crawler. I am not sure where everyone is from but I live in Tucson, Arizona and I can always fine a place out somewhere that won't bother anyone. Anyways I have been in this hobby for over twenty years,I have seen this hobby do many things over the years but, the last time crawling was tried it just didn't take but this time things are allot more advance than before and I think even though electric has taken I still think nitro crawlers will take to It seems that there are allot of people that are still interested in nitro crawling also. SO lets have some fun and discuss NITRO CRAWLING.

I will start. I just started getting into rock crawlin a few months back When Hobby People sent a sales e-mail well in that e-mail they had the TLT-1 on sale for the grand total of $69.95 or $79.95 so I said what the heck bought one well of course unable to leave things alone I had to buy a JunFac Tracer conversion chassis for it and we all know how the rest of the story go's. Also I have a X-Factor-2 those are the two rc's that I am working on for rock crawlin.

Ok lets have fun.

f150dan

My Feedback: (18)

a big 4-stroke nitro engine would be cool in that X factor. It would probably have a little more torque and power at low RPM's that a regular 2 stroke would lack. The you still gotta gear it low as crap and try not to burn up clutchs after every run. It would really help you if you can figure out how to run the nitro motor through one of those airplane 250:1 or even the 500:1 gear reduction units.

mr-e-maxx

Hellow f150dan You just read my mind, Im in the process of ordering a couple of airplane gear reduction drives like they use on the electric crawlers. http://www2.towerhobbies.com/cgi-bin...&I=LXJFB5&P=ML

http://www2.towerhobbies.com/cgi-bin...&I=LXVY65&P=ML


http://www2.towerhobbies.com/cgi-bin...&I=LXHUV5&P=ML
I have ordered those three units and I believe I will be able to come up with something out of it all. I am looking to try and get into the 200:1 range first and see how that works, I think though with the units I have ordered I should be able to get into the 300:1 range if need be. I ran the X-Factor-2 with the 24.7 in it and it not a bad engine and with the lower gearing it will probably work fine. Before I tore the Factor apart I stuck a ST'S D.28m in it and boy let me tell you that thing has got some serious power and it does not mine running in the high 280 at all Ive also run the STS in my TNX and one of my maxxes and one of my revos and in those the STS only runs in 235 range, but =with the crawling the hottest it has run is 286 and it did not seam to mine at all. So this where I stand right now the Factor is apart` for re-build. I have a extra chassis that I am working on right now tiring to find places on the underside of the chassis within the protective confines of the links and skidplates plates that I will be fabing for it to displace some of the C/G lower and forward of its original C/G. [8D]

mr-e-maxx

Also I have not forgotten about the four banger and if the two stroke won't cut it then that will be the route I will take. But for the time being this project will be for the two stroke engine and the four banger will be another chapter later on down the road. Although now you have my mined wondering because there is just something about the sound of the four stokes that just demands the attention and respect for that little bitty engine. I would also like to invite anyone who has or is building a four stroke crawler to join this thread to. [8D]

littlehammer

First of all I like to say, I was just thinking about this and am glad to see this thread. I have a few ideals that I wanted to throw out.

1) How about putting the power-plant forward, shifting some of the weight onto the front axle? The four stroke sounds good to me. Maybe a heavy flywheel to help with the climbing.

2) How about going to a four channel or higher radio, that would help with independent four wheel steering and also allow the control of the brake separately.

3) Also thinking about setting up a series of (let's say Savage) transmissions. Reasons being:
A - gear reduction.
B - the last transmission could also incorporated the reverse mechanism.
C - somewhat more durable than the airplane reduction gears.
D - Can still leave the 2-speed mechanisms in, Awesome to hear it shift 4 or 6 times right after coming off of a rock crawl. Simulating real life, some people do drive to the crawling spots. Not many, most people trailer their trucks in.
(Drawbacks I see so far: The power-plant and transmissions would have to be transversed and the use of dual spooled diffs for the center drive-shaft outputs, the first to reverse the engine tranny position and the second to reorient the center output shafts. Also the weight will be an issue. But if positioned correctly that might come out to our advantage.)

The first three ideals are based on staying on the 1/10th - 1/8th scale and that I am using tools I have around. I don't have access to any machining equipment. If I had the proper equipment I am sure I can think of some less cumbersome ideals.

These other ideals I have are if the scale is changed to 1/4 or 1/3rd scale.

4) The use of Go Kart Live axle for the front and rear. This would allow the use of front and rear disk brakes, and the rim and tire combos are greatly increased. This could open us up all the ATV tires out there. We would lose the lexan bodies but I like the tube frame look much better anyway. Again weight will be a factor, so what do we need? More power!!! This brings me to my next ideal.

5) Power-plant - Love the sound of a thumper (4-stroke), I love churning out of thick mud on my motorcycle, but I have to admit I have never rock crawled with my thumper. I figure there are a lot of kart motors out there most of the high performance ones are setup for speed though. I think a 5 hp motor will have enough torque for what I am thinking. There are also torque converters designed for these motors as well. But again there is the problem of reducing the gear ratio again.

Let me know what you guys think

mr-e-maxx

Hello littlehammer I just read your post and you have some very interesting ideas there. First I would like to comment on the scale idea and remember these are just my personal thoughts and preferences. For me i would like to keep to 1/8 to 1/6 scale and the reason for that is of course money. I thought about going bigger and looked at it from many different views and it all comes back to money. If I where to go's say 1/4 or 1/3 scale then I am going big enough to say to my self why not just a little bit bigger just big enough for me to get inside it and drive it myself and forget the radio. SO that in it self but me back into the 1/8 to 1/6 scale. but some day I just my go the route you talk about, it would be very interesting to see 1/4 or 1/3 scale radio control rock crawler in action.

As you know I am using X-Factor-2 which has a 2 speed tranny and I have also installed reverse in it, so far this tranny has prov-in to be very durable and like you do like the fact of having a 2 speed tranny so when I do come off the rocks I can kick up crap and let it ripp. I would like to see your out come with the Savage 3 speed tranny, if it works out well then I would have no problem switching trannys to have the option of three speeds.I also am looking in it having the gear reduction unit operate on a separate channel so that way when I come off the crawl out go's the reduction and here comes the speed. How does that idea sound?

I do agree with you as far as moving the engine forward over the front axle or close to it. This one of things I am working on right now, what I have decided to do is to move the engine further back on the chassis. By doing this I will place the engine as close to the rear axle as possible and heres the beauty of it, the rear axle now becomes the front axle. With the X-Factors tranny it will run just as fast in ether direction, so now we have achieved two goals. The first just like the big boys we get our engine out front and we get the weight advantage. I have had my X-Factor for almost a year now and I always just bashed around with doing very little crawling with it until now but , I have run over a gallon of 20% through it in reverse in the last few months with no adverse affects on the tranny so I know it will work without problems.

Well it getting late and I have to go for now but will return later, keep the good ideas coming.[8D]

mechanicalbob

My Feedback: (49)

I am glad to see a thread on Nitro crawlers. I have been workin on the design of my Nitro crawler for about a year and a half. Some of the things that I have came across during my designing and bulding is the cooling issue, clutch and also the gearing to start with. To overcome the cooling issue I went with a Raptor .30 heli cooling fan and shroud and also the clutch came from a heli as well, the reason for the heli clutch is that it is made of steel ands it will not burn up as it is heated up. As for the gear box I am making my own custom tranny with a quick change F/R. here is a few links to where I found my gears. http://www.qtcgears.com/ and http://www.maxonmotorusa.com/ . I also am going to run with a airplane fuel tank so if my truck does end up on its lid it will still run. Some other things that I have built/ designed for my Nitro crawler is a solid axle Mono link suspention. There is one link on the axle, two to the chassis, One shock on the link to the chassis and two torsion springs on the axle that go to the single link. The other issue I had was with steering, to solve this I am going with a [link=http://www.bpesolutions.com/rcequip.html#anchor710345]linear action servo[/link]. My Nitro project BBT crawler should be done in about a month and a half or so.

Feel free to ask any questions.

Steve

savagecommander

hey mechanicalbob, didnt you build a sweet twin engine tuber with machined axles? i saw pics of one and i swear it was you..... dont forget that hpi is making a reverse module that engauges reverse only when the brakes are applied for five seconds. i know that may be an issue, but it frees up the third channel on the radio for the proposed "transfer case".......... this idea has been in my head for years and i'm glad somebody came thruogh all the hype and made a good board..

mr-e-maxx

Hello mechanicalbob. Hey I like what you are doing I cant wait to see the out come of your project. Thats why I started this thread, so all of use nitro heads could come together and toss all of these ideas around and help each other out. Again I cant Wait to see how yours comes out.[sm=shades_smile.gif]


P.S. I just checked out the site with the linear servos and I think,no I know I will defiantly be buying and using some of them on my crawlers. I also checked out the sites witrh the gears and will attempt to pick your brain for all the help you can give me on trying to set-up a gear reduction transfer instead of using the airplane gear reduction unit.[sm=shades_smile.gif]

mr-e-maxx

Hello savagecommander. Thats a great idea about the reverse module I was unaware that HPI was coming out with one. I have used the one Xtm has had out for quite sometime now,also Dynamite has had one out for a while to. I love the idea transfer case, that is what I am trying to do using a airplane gear reduction unit although I'm sure it will not be very durable at all. I'm just trying to go the cheap route first.
Thanks and Keep the great ideas coming guys. I know I need all the help I can get.[8D]

savagecommander

http://www.hpiracing.com/products/en/307.html---- thats for the reverse module, i dont know how much it is but it cant be that much.... the airplane reduction is an outstanding idea but i just cant imagine those holding the torque....its that little white gear on the out shaft... looks kind of sissy to me... maybe finding another gear the same size and pitch but metal.... whats the deal with the linear servo? a standard one wont be good enough? maybe i'm missing something here... and hey, who said your just the one needing the help? i'm going to be on the other side of the rock buddy i'll try to draw up some ideas and send them out...no sense in hiding the good stuff..

STYLES is my name

One day we will all have Nitro Crawlers.... Mark my words. Remember back in 85 when the RC-10 was the only car to have? Well its going to happen to Crawlers too, as soon as some one ( the Japanese) figure out the clutch problem, Nitro Crawlers will be everywhere. And Yes I currently own a Clod and TXT. But I would love to bolt a Saito 4- stroke in-line twin to one.. pa-thump pa-thump pa-thump. ..... Good luck guys, sonds like you've got some good ideas.

mechanicalbob

My Feedback: (49)

I see I have a few questions to answer.

I did not build that one, I do belive you are talkin about the PIE WAGON. It is a sweet truck but I do not remember who built it. The only twin engine car I built was a NTC3 with twin OS .12's with a three speed.

With the reverse that I am using I will not need a third channel. I will be using a Airplane "Mixer" to shift from forward and reverse Basicly I will have the throttle trigger set at 50/50, when I pull the trigger it will be in forward and have full throttle control, when the norm would be pushing on the trigger for brakes, mine will shift to reverse and have full throttle control. That leaves the third channel for full brake control.

For the Linear servos, the reason I went with these is that they put out 1 FT LB of torque, that should be enough to turn any tire on the rocks I think.


From STYLES is my name

One day we will all have Nitro Crawlers.... Mark my words. Remember back in 85 when the RC-10 was the only car to have? Well its going to happen to Crawlers too, as soon as some one ( the Japanese) figure out the clutch problem, Nitro Crawlers will be everywhere. And Yes I currently own a Clod and TXT. But I would love to bolt a Saito 4- stroke in-line twin to one.. pa-thump pa-thump pa-thump. ..... Good luck guys, sonds like you've got some good ideas.


I do argee that the RC-10 was the car back then. As for the clutch it is not a problim I use a Heli clutch to get the get the job done, and the cooling is another one to look at too from the Heli world. The real problim is getting the gearing down to a crawl at a cheep price. So far my custom tranny is just over $500.00 and going, but it is a prototype. I hope to get the price down to a more affordable price for people. And Styles when I do I will let you know and I will build one for you.
Feel free to ask Any questions

Steve

savagecommander

ok, 50/50 on the trim is cool but will you have any brake control or will it be like an all or nothing type. you must have a good radio, mine only allows yes/no control on the third channel....... the gear issue is a problem for me as well.... i would have had somthing by now but they are all really expensive and im on a small budget...

mr-e-maxx

savagecommander I totally agree with you about the airplane reduction being very wimpy,I am using it as a proto type once I figure out what I want to do with it I will have my son (who is a machine shop Foreman ) manufacture up something for me. I am still not sure if I can keep it as small as it is and accomplish the type of differential gear box I want( something like on the lines of a Army 5 ton truck diff box) and keeping small,lightweight and feasible. Why can't we have it both ways???????????? Original gearing and deep reduction????????????????? Why Not Why Not???????[sm=idea.gif]


mechanicalbob I have some questions for you about the heli clutch? First things I have a electric heli but in this case that doesn't mead jack. Please enlighten me about the heli steel clutch I would really like to give it a try.[sm=confused.gif] You really have my interest up on the custom tranny you are building, will it incorporate a internal reduction or external?[sm=shades_smile.gif]

mechanicalbob

My Feedback: (49)

To explane the heli clutch setup I have a few pics to help.

The first is a .39 heli engine with the cooling fan, the cap screws on the right is where the clutch mounts.


Here is what a Heli clutch looks like.


The clutch liner is replaceable.


When the clutch is installed then it is time for the fan shroud


This is what the clutch bell looks like.


Then there is the aftermarket cooling fan and clutch mount.


As for my tranny it will be an internal reduction. There will be NO external gears at all. All there will be on the outside is the Heli clutch bell, the gearing will be attached to the output of the clutch bell. The reverse is a basic dog bone type of selector. There will be two shafts in the tranny, An input and a output with all the gearing going between both shafts with one way bearings and a tranny ratio of about 64:1 and with axle ratio of about 2.86:1, the final ratio of my truck should be about 183.04:1. All I am waiting on is a custom housing and one more set of gears.

As for my braking control I am customizing my radio to have a variable adjustment switch to control the brakes, basicly adding a throttle switch where the on/off switch is at with out the spring.

Steve

hands without shadows

I'm not into crawling at all but Ive been following debates like this for awhile and I just thought of a way to solve your rollback, gear reduction and clutch burning problems all at the same time. Worm gear drive, This will offer a massive gear reduction, your car wont move at all when the clutch is disengaged, and because it wont roll back or forward your clutch wont burn out as often. A reverse wouldnt be any harder to install than on any other rc car if you want it, and you wont need brakes. If anyone decides to use this idea let me know, I want to see it. And if anyone ever brings this idea to the market I want Royalties lol.

mechanicalbob

My Feedback: (49)

I have thought about going with worm gears. The problim comes with putting them in reverse. What I maean about this is that the "worm" likes to try to "walk" out of the housing under load in reverse. It can be over come but it is not a cheap way to go (about $150.00 per diff) and adds alot more fab work too. Also the worm gears can bind under load if not set just right. It can be done but I decided to go with out the worm at the bottom end.

Steve

hands without shadows

Couldnt you make the reverse mod after the worm gear? I wasnt thinking a worm gear drive on each diff, I was thinking more of a worm gear drive straight of the engine and conventional drive to the diffs. You would only have to pay for one and because it would be larger it would be cheaper. A larger one also wouldnt walk out as easily? Im not sure. I want to make a steam powered crawler this winter, Ive always wanted to build a steam engine and it would be so cool to have an rc steam vehicle, a rock crawler would put all that torque to good use.

mr-e-maxx

mechanicalbob Thanks for the info it will be very helpful. Now what engine are you using this set-up on? Are their any issues adapting this to a regular car engine(things like shaft size or anything like that?) Now I will at least have some idea what I am looking for. Thanks again bob.[sm=confused_smile.gif]



hands without shadows I think your idea of the worm drive is great, but for me I am going for something different. If I where going strictly crawler then I would say worm drive would be probably be one of the best ways to go. But I just want something that I can keep the original drive and have deep reduction to, but thats just for me on my first nitro crawler who know what the next build will be?

Again thanks everyone for all of the great ideas and keep them coming I'm sure someone will always be able to use them( I know I will) again Thanks.[sm=shades_smile.gif]

savagecommander

hey!!! no fair using a machine shop!!!

mr-e-maxx

savagecommander Let me be the first to tell you that you are right. In over 20+ in this hobby anything that I have ever modified for my RC's by me have been made by my in my work shop by me. But as time moves on and things change I will still continue to make my own mods and if I like the out come then I will have my son spit out afew for me at the shop, also if and when I have him do that for me the parts will come with a program on a disk so if for some reason I need another one and my son does not live around me anymore I can always just take the disk to any shop and have them run the pieces for me at alot less cost (because the parts are on disk and they don't have to create a new program.). So no it is not fair and yes I still like doing it the old fashion way.[sm=bananahead.gif]

savagecommander

yeah, the extent of my shop eqip is a mill...... works ok though... i was finalizing some ideas a had and the only trouble i'm running into is how to have a functioning reverse.... i cant use clutches and getting gears to slide and mesh is a wee bit tricky..as soon as i figure that out i should be able to start building..

mr-e-maxx

Yeah I think I'm so bad I really don't think I have ever bought one metal working machine for my shop. Everything in my shop is for wood and then if I need something for metal (thank God aluminum is very soft ) I will first try one of my old wood bits or blades, if they don't work then I will breakdown and buy a metal blade or bit or what ever it is I need to get it done.[sm=what_smile.gif]

savagecommander

so i was thinking.... what is the best setup for suspension? should i go with four link, or try somthing else..... if four link what angles should i use? and is it really the best way or does everybody just say that because its what they do... i was thinking about a fast and slow chassis.. you know, crawl over the rock but then pop a wheelie and scream across the flat... i just dont see a super travel suspension holding me upright... i might go with a indy front and a solid axle rear..... what do you guys think???[sm=71_71.gif]