Special tires?
 

Up to now, I've been pulling my little girl around in her wagon using my XT8 truggy. Now that she's getting heavier, there isn't enough traction to do this much longer. So, I thought I'd basically replace the front wheels/pull handle assembly with the front end of a truggy (with a little extra work to make it wide enough). This would give me steering and FWD power in one spot.

However, are there any 17mm hub tires that are not foam-filled and squishy? Her weight on the front would squash regular foam-filled tires down flat. Ideally, air filled tires would be the best, but properly sealing R/C tires would be a chore, if even possible.

I plan to use an outrunner on 5s using an extra MMPro I have lying around, geared for 8-10mph max. I was thinking of using a ERBE transmission assembly, which would give me the motor mount (need to mod for the outrunner) and the necessary gearing. I would rather use a transmission with all metal gears, but not sure what's out there, is reliable, relatively inexpensive, and readily available replacement parts.

So, if anyone has any tire or transmission ideas, let me know!

1/5 scale wheel/tire?

None that I know of. Have you considered modifying the wheels that are already on the wagon? Maybe either weld part of a 17mm socket on there or notch it and use a drive pin like older Losi trucks had in their wheels?

Hpi tera pins and change the foams...

1/5 offers some options...

http://www.aliexpress.com/store/9058...rms-L-C-T.html

1/5 scale would be much sturdier (but pricier) - you could use 23mm adapters (these work great) with some aluminum tape to fit the 24mm wheels hexes.

Any scale R/C tire would have too much "squish" IMO. And PBO, those spikes are a little extreme! I tried thinking of something that I could fill the tires with which would give them more or less the same firmness as air. I thought of spraying that hardening foam stuff, but I doubt I could do it uniformly.

In the end, I'll probably have to modify something like this: http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

5 Spokes, she'll be stylin! If you made the wagon RWD could you use the axle and wheels it already has, or does it have the shaft welded on and the wheels free-spin on them? I'm thinking weld the wheels onto the shaft and then put a sprocket on it and use a chain drive off your transmission.

Style is not exactly a prime consideration when your "ride" is a Radio Flyer. :lol:

I want to make this FWD to make things simpler. The wagon is similar to this, minus the canopy. When hooked to the XT8, it doesn't turn all that well; it kinda drags the front end until the tires decide to pivot. So, I figured I'd redo the steering scheme and provide power in one shot by making it front wheel drive.

Since the front end of a truggy has all the basic components to do this, I figured I'd use it for the base. It won't have suspension (although I may add something for this, but that's a future mod). I might need to find a way to lengthen the driveshafts for a wider wheelbase to ~19" total (the long center sliders from a Revo?) and then find a way to attach the tires to handle a 17mm hub.

The XT8 I'm using now is a bit "twitchy" at startup since it's geared for ~35mph. The 5s battery and 1717 motor are always stone cold at the end of even a 5 mile run, but the ESC running at minimal throttle tends to get warm.

Since I want to go a max of 10mph, motor choice should be easy. Geared 46/12 and with a truggy diff, a typical low kv outrunner on 5s would get my desired speed. But since it would need a special bore pinion and motor mount, I think a regular inrunner (Medusa 36-80-2000) on 4s or 5s using a Summit transmission in low speed geared 62/22-18 should be adequate.

Ah c'mon, she could be the only little girl on the block with spinner! :party:

http://www.motivationalz.com/pictures/see_me_rollin.jpg

For the center shafts, some of the big Savages and LSTs have some rather long center shafts and will hook up to your Truggy diff no problem. Only problem is that they aren't telescopic so you'd have to watch your length really carefully.

You'll probably have to put in some kind of suspension, the front "axles" on that are also the supports. Maybe cut the part off that goes into the wheel but use the rest to support it. Fitting 17mm hexes to it could be difficult, you could find a 17mm socket or something, cut it to size, and weld it on but they you still have to hold the wheel on with something.

It might be kinda cool to get her one of ^^^ electric cars and build that up. You can find them at garage sales for $50 or so and they already run on 540 and she can steer it (wouldn't that be fun? :whistle:). The Medusa should mount up pretty easily and there's plenty of space for batteries, all you've gotta do is figure out what to do with the throttle/ESC. Since she can steer it herself perhaps keep that part radio controlled :wink:

Looking closer at the steering on that wagon, that's a pretty shoddy design! I remember wagons as having the whole front end as one assembly that would rotate with the handle, that would steer MUCH better. I may have a front end you can have...

I thought about one of those Barbie Jeeps, but I already have the wagon and it's rather unique to R/C-ize a wagon.

Anyway, after doing some more research, I've settled on using the Summit as the base of this project. The transmission allows LOTs of gearing options and includes a motor mount. The wheelbase is close to 18.5", which is really close to the wheelbase of the wagon I'm using. And being a Traxxas product, replacement parts are available everywhere.

So, does anyone have just the front-end and transmission assemblies of a Summit they want to get rid of? :whistle: I could get the whole thing, but I'd be parting out and selling about 70% of it, and it's rather expensive...

I'm not sure how big your daughter is and what sort of weight they would have to carry, but my prefered tyres for my on-road buggy are Medial Pro Tarmac 2, they are not a usual thin wall tyre filled with foam, there made of tread rubber full depth hollowed out in a honeycomb lattice to keep the weight down and glued flat to the wheel to ensure no ballooning and minimal expansion, they are probably about half as stiff as solid rubber would be, I believe that the RC buggy wheel would be the weak point when you started loading it up.
http://www.medialpro.com/assets/imag..._overview1.jpg
the one on the left here is a 1/8th buggy tyre, 10th scale on the right.

thats very cool, have a link to where they sell them?

If I could only find some MT style tires like that...

I'll probably end up doing some kind of hybrid thing where I take a 17mm rim, chop it down and bolt it to some type of tire I find at Home Depot. Kind of like this:

http://www.homedepot.com/catalog/pro...349809_300.jpg

Work
 

That may take some work to get it right, but it seems as if it would work well once you get all of the wheels done. I did see a thread a while back where some guy turned his R/C MT tires into air tires. I'm not sure but I think it was one of shauns projects. He was doing something similar to what you are trying to do toeing the kid around. Anyway modding the wheel to accept the 17mm hub would be a good choice, but doing the first one may be difficult to figure out.

I was going to try to fill a MT tire with air, but figured the required pressure would make it too easy to pop if I go over any kind of sharp object (R/C tires aren't exactly thick-walled), and sealing it properly would be a PITA.

Yeah, I figure the first one will be the toughest. But I only need two (since I'm making a front-wheel drive setup), so by the time I have the process down, I'll be done.

you could use one of those arosols they have for sealing and filling car tires when flat..

How about putting an inner tube inside a tire?

I remember seeing a video on youtube about a guy with a MT floating his truck on a small lake with inner tubes in his tires pumped up all the way.

Good luck,
Nick

I'd have to find an innertube that was the exact size.

Now I think of it, I'll probably just use the wagon's front tires and mod them with the 17mm hex. Cheaper that way.

That's what I was saying. Not sure on exactly how to do it, but IMO that'd be an easier way to go than trying to find RC wheels and tires that can handle the weight.

Well, I got some parts on the way. Most of them are Traxxas parts simply because they're cheaper and it's easy to find replacments:

- Summit 2-speed transmission with 68T spur
- RDLogics Revo CVDs (more on why later)
- Trx 17mm hubs
- Revo pushrods/steering links
- Revo knuckles

Other parts I'm going to use (which I already have)
- Center diff from Hyper8 buggy (had a couple extra for some reason).
- Center diff mount from the Hyper8 buggy
- Medusa 36-80-2000 motor
- MMPro with CCBEC hardwired in for extra BEC current.
- 4s 5Ah lipo

I plan to attach a 16-18T Mod1 6mm bore pinion (have to talk to Mike about a 6mm bore version) directly to the output of the Summit tranny. That will mesh directly with the 46T spur on the CD. When using a 16T motor pinion, this gives me ~55:1 reduction ratio. This arrangement allows everything to be compact and bolt up nicely without having to use a center shaft of some kind.

I got the RDLogics CVDs because the output of the CD has drive cups, and these are the only ones I could find that had dogbones on the end. I just won't use the drive cups the kit comes with.

I'll obviously have to create a simple chassis to tie everything together, and then work out a steering setup. I just hope the Revo knuckles are strong enough to support the weight. I chose them because I can simply run the pillow ball bolts through a vertical metal "strap", which will hook directly to the wagon.

I want to spend no more than ~$150 on this project. I'm already at ~$120, but at least I have just about all the parts I need. I doubt I'll get a strong enough servo for $30, so I am thinking about robbing the servo controller from a crappy servo, adding an external H-bridge driver, and an external geared motor I have laying around. Just have to find a good way to provide feedback from the motor's output via a pot to the servo controller.

Once everything arrives, I can start going actual assembly.

Would it be easier to drive by the rear wheels and steer by the front wheels?
Could do some kind of straight shaft system for the rear or even some barbie jeep drive.
Just thoughts or ideas.

Yeah, I thought about that, but figured it would be easier to have the drive and steering in one spot.

Sorry, looking at their dealer list your out of luck if you don't live in Eurasia.

Anyone know of a 1/8 buggy rim that has a completely flat face (no curves) and absolutely no offset whatsoever)? I want to cut out and use the 17mm hex portion of that rim, and bolt it to the wagon wheels. My LHS didn't have anything and most of the pics on ebay aren't clear enough for me to see how flat the face is, or if there is an offset.