THANK YOU!!! some1 atleast gets my idea cept i would prolly do the white gear and a custom 2:1 ratio for more speed just cause the car would be already moving when the 2:1 is ingaged

i have a concept idea for how it could work but i need more minds to help me work on the concept design. i got ideas that need refining and criticizm. anyone interested hit me back.

What you need to do is make the damn thing and show us. The reason I am against this is that it would be very expensive, and the cost would negate any performace gains. If you can do it, and do it cheaply, then more power to ya. But I don't think it's possible.

yeah, bleak
ill be interested in hearing your idea, tho i wont be able to do any work till after christmas. ill try coming up with some ideas myself, too. i think that a centrifugal force tranny would work best, for the size.

http://img137.exs.cx/img137/7908/tranny5sr.png

idea: the first pinion drives first gear, duh
the same driveshaft has 3-4 little springs with a little weight on the ends (4 black deals on the pic.) that move out ward as the motor revs up.
the 4 weights engage the teeth on the outer pinion, which turns the secondary gear.

i dunno if this is a good idea, but if somebody has a mill or machine shop, they can probably make one. getting it small would be the trick.

just another thought to put in the arena is a torque converter, like for an automatic transmission... not sure it could actually be used for anything, but it would be pretty easy to make.

I like your idea capt.

The only problem I can think of so far is how to disengage first gear after second gear is engaged. But yes that is a good idea. I was thinking a centrifigul clutch would work best. When I was in the pit crew for mini road bikes, we used centrifigul clutches on the machines because the way you sat on it, there was no way to shift using a clutch...
Anyways, I would really like to help with this idea. I think it would be worthwhile and having been thinking about it for awhile now...
Those people who say that the weight of the whole system would make it not worthwhile have a point but I believe that if done right it could mak a big difference.

thank you for the support

i lack the supplies and machines to try it, but i can offer a tip on how to disengage the first gear. i figure that if you had a one-way bearing, once the second gear kicks in, then the wheels will outspin the first gear pinion. dunno if that helps.

imagine a mountain bike. pedals catch the chain going one direction, but not the other. the pinioin will drive the axel, but when the axel gets to the high rpms in second gear, the first pinion will not be able to catch and will just spin in idle.

size is the only issue i see. most of the parts can probably be milled aluminum, which probably won't wiegh down the car THAT much.

wow it seems as if everyone who is for this cant read. you say that we said that it wouldnt work. No one has posted on this forum if a two speed on an electric motor would work or not. anyone who says it wont just has to be shown a picture of an emaxx. What we have said is that there is no need for one and that building one that would actually fit in an xmod would be very very difficult.

Anyway now that thats out there lets look at capts idea. It would probably work but you would have to play with different types of springs to get it where you wanted. Also jon.jon wants to use a two speed in an xmod with larger tires so he can offroad. The connection made by the springs would be weak and might not connect if a wheel was stuck. Especially if he was using a locked diff since they are harder on the motor.

Also making something this small would require very precise machines. Remember not only does that have to work it has to spin perfectly true.

Oh and as for flaming others ideas, no one here is flaming anyone. No one has been rude or disrespectful besides some stuff from the people that are actually supporting this idea. The is a public forum. If they werent ready for positive as well as negative responses they shouldnt have posted here.

I think the best way to do it would be to make it like a centrifical clutch, with a very long motor pinion. When the gear spins enough, it'll move out, off the bevel, engaging another gear which would go through a set of gears to get back the the bevel gear.

This right here is where this project will be made prohibitively expensive.

If you know what your doing it wont be expensive :D

I've been doing a little research... unless you've got free access to a really nice CNC machine the cost would be pretty high. Unless you're willing to spend $70 or $80 for a 2 speed tranny then I don't quite think it would work. I think what we need to concentrate on would be finding a cheaper alternative. I'm not syaing it's not possible at all, it's just finding a happy medium between cost, quality, and weight/size. I'm wokring with a couple of ideas, but nothing has really stuck out in my mind yet...

Check out this article though...it's pretty good. I find the drawings a little confusing, but if you think about it it all makes sense.

RCTek Article

Jeremy

that article is good. i think it is a similar idea to mine and probably works a lot better, especially if you want to offroad like jon.jon.

as for parts, the outer gear car be standard gearstock with the center drilled out. the plates to contact it ouldn't be too hard to make either. i bet any mill machine could do it, if you know how to make one. also, a lot of high schools have mills, and if you just get permission they'll probably help you out.

im not even sure if a large mill like one a highschool or local machine shop would have could do it. It would need to be very small and i dont think that most of those machines can do that. I think a mini mill like from sherline might be the best way to do it but at close to $3000 a pop they arent exactly cheap.

Also the people who run places like local machine shops dont know what your making or how its supposed to work. They just see a drawing and they make it. They cant say well since this is a two speed tranny i know that this should be here and that should go there so whatever it is you show them has to be exactly what you want.

Sawhit and Capt make a good good point. Standard gear stock would work but you would need a quite detail oriented machine. But also we would need to have the drawings perfect in order to get it to work. It's great to have the ideas, and I think everyone here has great ideas, but we need to work on some specifics. Either today or tomorrow I'm going to start taking some measurments of the rear end of the chassis where the tranny would be.
Also, I've been tring to think of the material to use for the contact area for the second gear. I'm not sure if was mentioned here but someone had said to use sandpaper. I don't think this would work because a) it would wear down the inside of the gear, and b) the sandpaper would wear out pretty quickly. I think since the weight and materials we are dealing with are fairly small scale that some kind of rubber would work best. Maybe even some of the material from the XMods tires. This way it wouldn't wear down the inside of the gear but would be easy to replace when the rubber itself does wear down.
I think all of the ideas are really starting to make sense! Everybody seems to have really good ideas and people seem to be seriously thinking about this. I am willing to spend some money to make this work, but we need to solidify our ideas first. So, let's sum up what we have so far:

The basic principles is to use a centrifigul transmission. Any other kind of system would be too big and too heavy. So, the way this would work is there is a standard first gear the spins on a one way bearing. This means that when the motor is spinning the first gear the bearing acts like any other bearing, but once the clutch shoes engage the bearing it basically just works as a free floating assembly. The second gear is larger so the same amount of rpms=more wheel rotation. So while in first gear, the rpms rise and the clutch shoes move out until they press against the inside of the second gear. Once the second gear engages, the first gear just rotates freely without having an effect on the actual wheel rotation.

Now, as I was writing this out I've come up with a few issues. The motors we use for the XMods rev up to max rpm almost instantly. So the first gear wouldn't be engaged very long. I'm not sure if this would actually be an issue, because the short amount of time that the first gear is engaged would probably be enough to get it up to a great enought speed that when the second gear engages it would basically just take over for the first gear and continue rasing the speed.
Also, before we send this out to any machine shop we need to determine exact gear sizes to make sure that we are getting the most out of the system.
Later on today I will be breaking out my old engineering books and trying to figure out some gear sizes. Also I will try to get some measurments on the rear end of the chassis and start to mock up a non rotating assembly.

Anyways, we seem to have the right group of people working on this so let's get cracking and see what we can do. I definitely think we're making some progress. I should be back later on today or first thing tomorrow with some of the calulations i've come up with.

Take it easy everyone.
Peace
Jeremy

Okay, here's a crude drawing of the space we have to work with.

Red = Space for tranny
Blue = Black shock/rear plates mounts
Green = Front of motor

ok, if what i imagine this thing's size to be, then 19mm should be enough. i have to check with some friends to see how small the high school's mill can go, but if it works, ill be glad to have a prototype milled. i'm good for ideas, but when measurements and specific designs come in, i fail... can sombody else try and do that?

yet another thought:
has anyone seen a governor(sp?) for a steam engine? it operates on a similar idea as a centrifugal tranny, but has fewer moving parts. that may be an easier thing to make. explaination later.

Hey capt,

I am currently woking on some drawings right now. I think they should work. The only thing is the motor needs to move forward in the car if we want to keep all the rear components in the same place. It really shouldn't be a problem but I have to think about it for a bit. Anyways hopefully by the middle of the week I should have some preliminary drawings. I'm starting to think that this could really work....

Anyways, keep thinking on it and we'll see what we can come up with.

Jeremy

ok, im working on a slightly different idea on the side, one that i can do at home. I got a question about some parts.

motor shafts, can i geat an armature with about 10mm extra length on the shaft? where + how much?

also, pinion gears. i heard of pinions with different numbers of teeth, how many and how few teeth can you get? are the gears the same diameter, even though they have different numbers of teeth?

hopefully, if i can get these parts, i'll be able to build a tranny that won't require power machines and alot of $ to make. don't give up on that one though, jeremy, that is a much better design than my new idea.

btw, is there an easy way to cut key grooves in motor shafts? i need to get a metal collar to slide along the shaft without rotating or slipping at all... thanks for the help.

the mini X uses a motor shaft that extends the length of the car. Kinda like how the xmod uses that shaft that goes the length of the bottem of the car and connects the front to the back but through the motor instead of the gear drive. Ill search the mini x forum and find the dealer website so you can order one. You could just cut it to whatever length you want.

As for pinion gears being different sizes yes their are different size pinions but i believe they differ in diameter though. If it had fewer teeth but was the same diameter then it wouldnt mesh properly.

The motor shafts and pretty small so cutting a key knotch would be pretty hard. A dremel might do it but you might try making the ring out of something like brass and soldering it on.

The site here has all the parts.

Those who says a 2speed transmission is possible in an xmod are dumb b*stards. 1st, if it was possible, why doesn't radioshack do it? 2nd, why compare emaxx to xmod?(they serve different purpose. show me a onroad ep if u can) 3rd, if you were so good, u would most probably be on the design team of radioshack or some company and not discussing it here.

LAST

Prove me wrong if you can. If you insist that i'm wrong, how much time do you need to complete this project? All u guys do is say it's possible it's possible... and it dies off eventually or warps into another thing like the dual motor project. :mad:

heck, you guys dont even have cad drawings.

ok ben, ill give you that we're not designers for RS, but why cant we try? nobody has proved that it cannot be done.

And what was the point of your post? if we want to "waste our time" or whatever, that's our deal. what you just did is a great way to start a flame war. please dont post unless it is constructive to the topic.

I agree with Capt. We are working here trying to improve something and also trying to be creative. Your argument about "if it will work, why doesn't RS have it?" doesn't make a whole lot of sense. Here is a small list of upgrades that RS doesn't have but do work:

1. Lithium Ion battery upgrades
2. Carbon fibre drive shafts
3. Metal lugs and shims
4. Aluminum brackets and suspension pieces
5. Carbon fibre chassis'
6. Aluminum chassis'
7. Stacked FETs
8. 130 and 180 size motors

And that's just a list off the top of my head. I know there's more but that's just without thinking about it too hard. The point you made about it not being at RS is moot. If people like us listened to people like you where would we be today? Maybe our idea won't work. So? If you don't have any constructive criticism, then don't say anything. You say that it will be like the dual motor and warp into something else. If this does work or ends up turning into another upgrade that makes your XMods faster are you going to buy it? Have you bought anything for your XMods that doesn't come from RS?

I'm not trying to start a flame war I just don't like it when people jack other people's discussions just to flame or put down their ideas. He didn't once say why it wouldn't work or even offer any thoughtful ideas. Just picture however many years ago someone said "I want to make a small car that you can control via a radio signal". I bet there was someone just like little ben here who said "You guys are dumb b*stards... it will never work and you're just wasting your time".

you forgot some of the stuff ive done, 260 size motor, regulator, wide rims, independant rear supension, plate type lsd diffs. heck i was tellin the r.s. by my house about we nut jobs do and they were in awe, so keep shootin for the 2spd its possible just gottra think

WOW ben1112 you are narrow minded.

If people had not tried to fly, where would we be today?

Let them alone already if they want to try it so be it, it wont cost you anything and if this thread bothers you then just dont read it.(I find this thread interesting myself)

I myself think it can be done but it may take a lot of trial and error before it works but I think it can be done.I also think it can be done more than one way.

my thoughts are also that centrifical force is almost the only/easiest way to go.
I'm also thinking that it will take a completely new motor mount to house the 2 speed tranny.
my thinking is a custom tranny and motor mount that can be switched out fast if need be and will not change/mess with the stock spur gear on the center shaft.

Ben, I've lost all respect for you. The fact that these guys are just TRYING something new and being creative takes some thought. The fact you come in here, rake a quick look and write "It can't be done" is straight up bs. It might not fit under a stock body, but it can be done. People thought a brushless xmod was impossible. Brickmodder and I both have brushless xmods (just gotta finish the gear and it's done).

thank you, guys, glad to know people are watching this and think it'll work. as i said before, i have been sitting on a new idea based on a governer for a steam engine. my mom is hiding something in the basement till chistmas ;) , so i can't work on it, so i'm gonna thorw it out here so ppl can help me refine the idea while i wait to be able to get to my tools.

http://img75.exs.cx/img75/4302/tranny29ov.jpg

the idea is that the metal collar is fixed to the shaft, the pinions are free to slide along the shaft, but the spring keeps them at the end. those weights spin and the centrifugal force pulls them outwards, compressing the sring and pulling the pinions toward the motor. if the pinions have different #'s of teeth, then this will act similar to the one jeremy is designing. only the pinions change, not the second gear.

the problems i have with this idea is that where the two gears meet, the teeth will not line up, and there will be problems with the sliding. also, the bevel gear probably won't allow for too much if any sliding anyway, because of the placement and general design.

give me any help you can, this version is simpler and even i can build it, so long as the design gets worked out. i really wanna get my hands dirty, not just sit and think!:D

That's a great idea Capt! Very clever :eek:

I do have a problem with it though. Not saying it won't work, just something to think about. The different sized pinions would cause a problem... the teeth need to match for this type of gear to gear system. Unless there's some kind of magic ratio (who knows maybe the Fibonacci sequence?) then there would be some major gear grinding..
Also, the transfer from one pinion to another might be problematic. Although it may not, there's really no way to tell without trying.
Also, with the two different pinions, how would the smaller pinion contact the drive pinion? I'm stumped...
I think it's an amazing idea with loads of potential, it's just a little hard to figure out how to apply it successfully. Please don't think I'm trying to bash your idea, I think it's great!!
Hmmm....I'm defintely going to think on this one...
Great idea though.
Hmmm...
I think I might have an idea to elaborate on your design...
Hmmm...

Here is a interesting link.

how stuff works

Now that I'm really looking at this problem, your best bet to make a gearbox would be a CVT. You'd need 2 cones and a belt and a pulley to replace the gear with. A bit motor could move the set of cones back and forth, raising and lowering the gear ratio, or you allow the pinion-mounted cone to move, then centrifical force could make them move out, making the ratio larger, and attach a spring to the arm and bevel, so as it slowed down, it'd get pulled back in. This setup would be fairly small, too, and make a fully variable tranny!

wow people like ben should be banned. I still hold my ground in saying that this is not worth it but fully understand that yall can spend your time doing whatever you want. Oh and as for his question about if it needed a two speed why didnt radio shack put one on it? even if the car needed on radioshack wouldnt put one on it. Look at their other rc cars. Their toy level not hobby level and the xmod is kinda on the line between the two. Come on ben lets try to think things through before we open our mouths huh?

Now thats a nice idea capt. Very creative. But since one gear is smaller in diameter when the larger gear disengages the car would stop because the smaller one would not be able to engage the other gear. Get what im saying?

good idea viperdout, but isn't the controller 2-channel? how will you control the bit motor?

anyway, the more i think about the governor, the more i believe that ill need a super-special pinion made. this will fix ya problem sawhit
the pinion would have more teeth on one end than the other, and the odd teeth tapering out, to smooth the transition. like this.

http://img138.exs.cx/img138/3032/pinion6xg.jpg
even so, it may grind. ideas?

Well, I'm leaning towards a spring idea, but the bit motor could either be wired through a regulator to the fets or possibly on a time-release mechanism. The spring simplifies it, and just uses centrifical force. I'll draw a diagram tomorrow.

Well okay, i know that for many things that are created are thought to be impossible. Like einstein and the the electricity stuff. People thought he was crazy. Okay i admit i was harsh. But a project like this would be very costly as it needs to be very small and precise. it might be possible on a bigger scale.
Have you guys find a way to overcome the problems posted? Some said you need Cnc workshops and very precise tools.

Let me be your motivation. Prove Me Wrong OKAY?

I will buy your product if it works and is effective.

I Hope you guys will have the last laugh at the end of the day. which i still think is difficult.

(I take back the vulgar terms i used. Im sorry)

What im trying to say that the community is very important as they come up with many ideas for aftermarket mods. But one must be realistic. I don't want to burst your bubble but in order to make a successful project you must know what are you trying to acheive? Like many have said, Electric motors make max torque at 0rpms. IT can be done. You can make a 2 speed. but at the end of the day what purpose does it serve? have you guys thought about it? It's good to be innovative but please do not waste resources and regret later.

wtf is up with this mastermod dude flaming everyones ideas then giving us his life story for the past couple of days then giving us a list of everything he owns? oh wait did he not get the memo? NO BODY CARES!

***start mastermod impresson***
Ah dude your xmod sucks, im gonna run it over with my smaxx, or maybe i'll use my rc10gt, or maybe ill shove it up my *** cuz im doin your dad, blah blah blah blah blah
***end mastermod impression***

oh and by the way if i know what your talkin about its for taking off very small ammounts of the comms of electric motors. All it can do is remove a small ammount of material from the round comm i seriously doubt without serious modification that it would be much help here. And since they cost usually around 300-400 dollar range i wouldnt want to screw one up.

And one more thing about emaxxs sucking, I guess thats why they were the best selling electric monstertrucks for a heck of a long time and are still in the top. Funny how that stuff works huh?

Ben i bet theres no harm done. The guys here have shown no regret or desire to stop what their doing and i bet they will keep going with this until they get something like a two speed.

Now back on topic ive been thinking and i believe the only way this will work and be robust enough to last is to make it like the two speed in a larger scale rc. All mechanical linkages, no spinning weights, nothing like that. Kinda get what im saying?

http://img.photobucket.com/albums/v1...ut/diagram.jpg

CVT.