unversal drive shafts

[3series takumi]

latest project i yanked out the stock dogbones and put in a set of xmod universal drive shafts. they work great and will never pop out but they are plastic. i am not sure how long they will hold up.

...only one way to find out i guess. there was some modding involved of course but now i can use xmod wheels with out having to drill out the center of them. oh and best part of all is no more wheel pins. i lost way too many of those, good thing they were easy to make out of paperclips ;p

here is my bad picture

[cdog4w]

takumi, gotten any closer to posting a little howto on the xmod shock/wheel upgrades you have done?

[3series takumi]

oh crap i forgot about them, i have been way too busy lately
i will get to it

[cdog4w]

Takumi, you ever think about grinding down the edge of the mini-x wheel shafts so that the axle portion that attaches to the wheel is D shaped? This would ideally allow you to put XMod rims on your x as you already have. Even better, it would let you do it without having to resort to either drilling out the rim and adding the pin groove or using the plastic xmod universal drive shafts (not to mention modding them to fit). I've got a dremel tool, but I need to get a vice so that sucker doesn't shoot through the window or my head.

Out of curiousity, even the threaded part of the xmod universal drive shaft is D shaped correct? And theres no problem getting the wheel nut on and it staying tight? (I don't have an xmod or parts yet)

Lemme know if you think this won't work, otherwise I'm trying it as soon as I can get to RS to get some xmod rims and a vice to do the grinding.

Oh, I'm also going to put up a video of my (sadly) stock mini-x sometime soon. There isn't enough video available for people to see what the X is like, so I thought I'd take advantage of my new digicam.

[3series takumi]

um i modded not so i could use xmod wheels, i didnt it to get rid of the dogbones. unversials let you turn sharp and not worry about them falling off. and the screw part of the the axle is not D shape, it is just a smaller diameter. they use the same wheel nuts as miniz i think.

[3series takumi]

if i had a good camera i could film it, but the one i have would get blury tryin to capture the speed of my baby ;p serious though my camera sucks. i want to get a video of a gas scooter goin with it. the scooter can go 20mph, i sould be able to keep with it if the ground is smooth. just hope it doesnt get ran over.

[cdog4w]

I'm slowly planning out what I want to do with my car. I'm taking my time since I'm new to hobby RC and am trying to avoid making mistakes. I just ordered some extra drive shafts from tiny along with some overland tires, so I'm hoping to have a set of xmod capable shafts after grinding as well as my original set of mini-x shafts. I'm hoping to raise it with the overland tires. I run on an extremely rough asphalt, so I'd also like to go for a smooth suspension to keep the tires on the surface as much as possible.

I'd been using the stock medium springs and you can see it bouncing all over the place. I'm going to try the soft springs next, which I've installed, and man are they soft. This thing is going to bottom out and get a bit scratched up, but hopefully it will run better. How is the motion/travel on your xmod converted suspension - would you say a large improvement on the stock springs, in the context of rough asphalt?

Anyway, whats the deal with "zapped" cells? Most cells include the mAh rating, so I'm assuming its either current or voltage that is more than standard?

Finally, how did you squeeze your 5 2/3A cells on, takumi?

Thanks for being so patient and answering my never ending stream of questions.

P.S. I just got a pentax optio s4 (xmas) and I love it. Unfortunately it only shoots in 320x240 (a lot of newer cams will shoot 640x480), but it should be fine. I am editing the video and will post soon.

[cdog4w]

So since the threaded portion of the xmod axle is smaller diameter and not D shaped, do you think my intended mod of grinding the whole mini-x axle into a D shape (threaded bit and all) will hold a mini-x nut?

Does anyone have experience with this type of nut/bolt situation?

Thanks in advance.

[3series takumi]

zapped cells are.. i dont really know, but they can push 30amps on load and most cells like aaa can only put 7amps on a good day, a very good day. plus they are 1050mAh @ 1.2volts each. i have it set up saddle pack style, but that chassis is not runnin yet. 3cells on one side with the servo and 2 cells on the other side with the esc. as for the suspension, the xmod suspension (air dampers) dont bounce as much. but the only reason i use them is because i got tired of having to take the suspension arms off just to change the springs. a spring swap now takes under a minute for all 4. i have glued a set of warn overland tires on it b4 and ran the diffs tigher, almost locked, that was serious fun. the tires to add alot of clearance over the stock ones, especially the gpm tires. i drove over gravel, it was a blast. i tried to run in sand but i think i may have too much torque to do that. i also ran and a bad street, that was great too, i still do with regular tires and medium springs. the gravel was the best to watch. you can really see the suspension doin its job. i would love to see a miniz or dtm or xmod go where i went.

i raced a miniz with "soft" springs on the bad street and spanked it. all it did was bobble over the street. it was a sad sight.

[sawhit4]

hey cdog4w, i wouldnt advise grinding the bolt that holds the wheel on with a dremel. if you mess the threads up then the bolt wont go on good, wont go on at all, or wont come off if it does go on. Im not sure how soft the metal is that its made out of but if its soft enough the threads would get messed up easily. Im not saying it wont work for sure but its risky. anyway thanks for all the help with the charger i got one ordered from my hobbytown

EDIT: i have an xmod and i dont see how yall use their wheels. its gotta give yall really low ground clearence cuz they arent as big as the mini x wheels.

[3series takumi]

there is like a 1mm difference between the minix wheels and the xmod wheels. the rims are actually the same size just the tire is a touch thiner. that is a small price for the great look of new rims and even greater grip over the stock ones. the tread pattern is pretty effective as well, its even directional.

forgot to add it made no difference on mine because it as raised anyways ;p

[sawhit4]

oh my bad i was lookin at the foam tire rims aganist a mini x rim and neither one had a tire on it. woops

[cdog4w]

Well, I picked up some xmod rims yesterday and I got a sweet suction vise today. The suction is strong enough to pull paint off a wall (showing off to the woman, she didn't appreciate the suctioned paint) oops...

I got out the dremel and threw on one of the silicon carbide grind stones that came with my kit. While I was in home depot getting the vise, I also picked up some machine screws with matching nuts to practice on. I tried to match the diameter of the xmod axle, but of course thats a metric 2mm (from what I've read) and home depot is not even remotely metric when it comes to screws.

Anyway, I ground it down to a D'ish shape and low and behold, the xmod rim slid right on (it hadn't before grinding). Next I screwed the bolt on and it threaded like I hadn't touched the screw, silky smooth. Seemed to hold ok too. Next I slid the rim back on and locked it down with the nut. It worked great for holding it on the axle, but I think I was too zealous with the D shape and it wasn't a perfect grip that way. I also chalk some of that up to the screw diameter not being an exact match.

And yes, I took pictures :P Tell me what you guys think.

P.S. I'm going to try on my mini-x axles as soon as my replacements come in from tiny.

[cdog4w]

shoot, i accidentally hit new thread instead of post reply for the second image, it should be the thread right below this one :P Sorry mods/readers.

heres image 3

[cdog4w]

and finally secured to the "axle"

[sawhit4]

nice work. i stand corrected. so are you gonna use those nuts on the mini x axles or is that just for that bolt cuz its too big?

[cdog4w]

That nut is just what came with the bolt. It's my "test axle" since I don't want to do it for the first time on my real axles and screw those up. So I'll use the standard mini-x nuts when I do the real axles. Even though I ordered spares, if I don't make any mistakes, then I can have a set of axles for xmod rims and a set for mini-x rims...

I also picked up a set of small hobby hand files. 6 dif. shapes/levels. I might try doing a bolt by hand to see if its any more accurate than a dremel. I'll let you know.

EDIT: Oh yea, and just because it seems to work, doesn't mean it will. The real test will be if the wheel nuts stay on after a few runs...

[cdog4w]

Hand file worked great on my test nut/bolt. Going to try on my real axles tonight.

[3series takumi]

the trick to griding the D shape is to not grind too far back. grind just enouph for the wheel to barely reach the hub bearing. if you dont, when you put the wheel nut on, it will squeeze the against the bearing. that will be no spinning then. time for a cheap picture!! hand drawn ;p

[cdog4w]

Yea, if you see my other post, I ran into this problem. The weird thing is that before I filed it down that far, there was more wheel slop than when using the pin. Ideally, both methods should be able to provide the same ability to tighten the wheel nut before rubbing if done right... I guess I didn't check enough steps in between maybe.

I was thinking about using a dab of "Krazy Glue" on the end of the nut to kind of cap it off so that it won't come off. This glue is supposedly like superglue, has the warnings about bonding skin etc, but it turns out to not be as effective as other super glues I've tried. I think if I did this, I could probably break the glue off with a good twist on a wrench when it came time to remove the nuts.

[sawhit4]

i wouldnt do that because i did the same thing on my stampede (1/10 scale monster) i tried to install a stub axle from a different model and when i did it would spin the nut on the wheel while it turned the wheel. So one nut would get tighter while the other one came off. i tried lock tite and the nut with the nylon in them to keep them on and neither worked.

when you ran into this problem was it with one of the axles or a test bolt?

[cdog4w]

It was the mini-x axle. I couldn't find the bearing in the daylight, so I have to wait for parts now anyway :(

It's really unfortunate that this didn't work, it would have been a good solution.

So takumi, how much modding/effort did it take to get the xmod universal drive shafts on your car? Can you give us any details?

[3series takumi]

its not too hard, but it is kina hard to explain. i will draw up a picture tonite to explain. if i had the machines i would make and sell adapters for this thing, it worked out pretty good

[cdog4w]

Cool, I'm guessing the shafts can be ordered without having to buy a whole xmod. Looking forward to the guide/tutorial :P

[3series takumi]

sorry people i am lazy. i never got around to it. lets say i will do it tonite ;p. i promise. i gotta get my scanner up and rinning though

[cdog4w]

Haha, no problem. No need to apologize since you're the one doing us the favor. You could also do more of your MS Paint art instead of fixing your scanner :P

[3series takumi]

im almost done. haha that wasnt ms paint ;p that was me tryin to write on my handheld screen. (pocket artist) :D

[cdog4w]

Ah cool. I'm seriously considering picking up a tapwave zodiac soon to game/mp3/anime on the bus to work :P Pretty sweet handheld.

[3series takumi]

ok here it is. this is one jank picture but it was the best i could pull right now. anyways. i picked up an xmod all-wheel-drive uprgrade. took it all apart ;p. the parts that need modding are the cups that come out of the dif that is there. on of the cups has a shaft that is longer than the other. i just pulled that extra piece off. now take one of the many yellow bushing and glue it to the shaft of the cups. i put them as far up to the cup side as possible. after that you need to devise a way to put little stumps on the sides of the bushings so it will fit in the minix dif just as the dog bones did. oh and i put a spring in the diff to get the cup assembly pushed towards the drive shafts. i am sure this is too confusing.

last step is easy. normally the front wheel hubs have one bearing each. all ya do is put in a second bearing just like its is in the rear hubs. so all wheel hubs have 2 bears (that fixes the wheel wobble problem too :) )

thats pretty much it

[cdog4w]

Cool, thanks takumi. Crap, after losing that bearing and ordering a pair of extras, I'll STILL be one short for this mod. The price paid for failed innovation...

[3series takumi]

i hope everyone understands that stuff. i would take a picture of my actual work but i cant find my good camera. the digi cam i have near me sux at taking macro shots :(

[cdog4w]

Yea, its really tough taking shots of small parts.

So what did you do with the rear or did you just install the universals up front only? If you did it in the back too, I assume you had to buy 2 AWD kits to get enough parts?

I think once I get the replacement bearing I'm going to try to tweak my modded axles and see if I can make them work. This time, testing will occur in the kitchen! I might have to fish under the fridge (ew), but at least it won't lose anything this time. By that time I should also have the OL tires which should be hot. I ordered some GPM's with my last tiny order, but I was a tard and didn't notice that it was only a set of 2 tires as opposed to a full set of 4.

Oh well, I finally convinced my friend to get a mini-x and I just added those bearings and OL tires to his order (woo, save on shipping) . Actually, all it really took was giving him the Tx for 5 min outside :P

[sawhit4]

hey cdog4w, what do you have to do to the ol wheels for them to fit? that sounds cool. does the mini z use an axle with a pin like the mini x?

i got one question that has nothing to do about this but i dont know where to put it. ok here it is. can i solder two wires to the battery pack so i can charge it without taking the battery out or would that run electricity through the esc and receiver? and if i cant do this then can someone tell me a way to make it easier to get the batteries out?

[cdog4w]

I got the GPM mud tires:
http://mini-zracer.com/shop/product.php?pid=562
(tho i got the last 50 degree pair apparently :)

I dunno anything about the mini-z axle, but the tires fit on the mini-x rim. The only real issue is that the OL tires have a hollow space so that only 2 small edges touch the edges of the rim. I haven't run on it but I would guess the tires could slip off due to low surface area contact to hold them on. What I plan on doing is finding some kind of foam tape or something and cut it to the width of the gap on the inside of the OL tire and just tape it to the center of the mini-x rim to hold the tires on.

As for your second question, if you have the stock 5 cell pack, then it has no wires at all and the ESC has leads with battery springs attached that you slip in to the spring holders on the battery case to connect to the batteries. What I do when I'm not using it is pop the red battery spring out to disconnect the circuit. For charging, I still have to pull the batteries out, but I plan on putting a deans connector on the pack at some point. Anyway, you should be able to solder leads onto the pack, but you'd either have to solder them so you can still use the springs from the ESC leads or replace the ESC lead springs with something that will attach to the leads from the battery pack (ie. a deans plug). I haven't done it yet since one of the ESC leads is short and I'm not confident enough to solder on the PCB to add a longer lead to the ESC.

Sorry, lots of rambling but hopefully you can get enough info out of it :P

P.S. yea, the OL tires LOOK hot, and I'm guessing will RUN even better. Especially since I run on craptastic asphalt. Mmmm soft springs + OL tires...

[cdog4w]

heh, forgot I had a picture of the tire :P VNC'ing to home to submit this. PS over VNC = fun!

Left to right...
1. Stock mini-x rim/tire
2. xmod rim/tire from kits
3. xmod rim/GPM OL tire

The tire laying down on the left is also a GPM OL tire, so maybe you can see what I mean about the tire being hollow.

[sawhit4]

yeah i get what your saying. how do you plan to get those tires on? wont they rub on the chassis? or have you done some mods to solve this?

[cdog4w]

They don't rub up front, but they do in back. I'll either get out the dremel or those hobby files in the back. I do need to make sure they don't rub at full turn in the front, but I don't think they do.

[dgilpin]

A Dremel is the Mini-x's best friend!

[3series takumi]

amen to that!