might as well hop on the bandwagon

civicsr2cool · Post by **civicsr2cool** » Sun Dec 04, 2005 10:54 pm

forgot to edit in that i fixed the 4wd on all 3 of my mt's. the problem with all of them are the driveshafts not long enough. on the two uncut chassis i just backed the gear on the draveshaft off a little more, fixed it perfect. on this one if i extend the driveshaft it extends my wheelbase, so i just put a few spacers behind the gear in the rear axle and full time 4wd.

with 4 wheels spinnin i can get through the snow ouside now!

betty.k · Post by **betty.k** » Mon Dec 05, 2005 12:21 am

i had the same prob with my old bigfoot mt. if i slammed into reverse when going forwards i'd hear the clicking of the bevel gears as they slipped slightly.
i had to use shims to prevent it from happening.

but my newer "dragon slayer" hummer doesn't have the same problem and i'm running it hotter than the old one.
that's one good thing about rs, they always take feedback onboard and redesign accordingly.
bad thing is they should just get it right to begin with!

frizzen · Post by **frizzen** » Mon Dec 05, 2005 7:11 pm

That and they NEVER announce changes to the product line, it just happens along the way so we've got to try to find out the earliest month code that the effect happened during

civicsr2cool · Post by **civicsr2cool** » Thu Feb 09, 2006 9:18 pm

had it runnin the other day and my board touched my stering motor and burned my fets for left steering. had a cool light show when it lit on fire

i was wonderin if andy of my clone boards or old zip boards that i have piled up will have a replacemnt for it?

Zenith · Post by **Zenith** » Fri Feb 10, 2006 10:22 pm

If I remember right, in another thread Maxx started, it was mentioned that a board designed with magnetic steering would need a complete steering curcuit overhaul to work with motor-type steering.

But your lucky; I just retired my ZZMT after robbing the dogbones for my Xmod EVO, so maybe we can work a deal out or something. PM me if interested.

crazydave · Post by **crazydave** » Sat Feb 11, 2006 8:08 am

Traditional bit boards with magnetic steering only use 2 n-channel trannies to pull the steering. In order to drive a motor you need to add 2 p-channels and a couple resistors to create a full h-bridge. In theory this should work, but I haven't had any success, I don't know if I'm wiring wrong or what.

Hogjowlz had once used a PCB from a Muscle Machines micro. I've gotton PCBs from those stunt cars with tank steering that would work. Newer clones like the Charg-N-Gos at Walgreens with those hard wired motors, use the same PCB as those stunt cars, but are only set up with 2 trannies. The pads to complete the h-bridge are there, though I haven't tried them to see if they work.

civicsr2cool · Post by **civicsr2cool** » Sun Feb 12, 2006 12:29 am

i was talkin bout maybe the drive fets off a clone, or maybe any off an xmod board i have a few of them too.

crazydave · Post by **crazydave** » Sun Feb 12, 2006 9:04 am

Well first off, just to clarify... FETs and transistors are slightly different, They perform the same function, but they do it in a manner that is different enough, that I believe they should be referred to separately and not as one and the same. FETs are transistors, but not all transistors are FETs.

Secondly, to answer your question, yes clones are the same. Xmods are totally different, whole different class. Nearly all 1/64th or smaller use the same transistors, BUT nearly all of them have different markings. Since the MTs steering uses a H-bridge just like a bit's drive circuit you will need to be able to distinguish between the N and P-channel transistors.

My best suggestion would be to go to the "Weird Science" forum, and the "Articles" section of the site, and read up on the FET mod. Hopefully ph2t has got his h-bridge diagrams back up. Then go to digikey.com look up the N-channel FETs IRLML2702, find the chart that show which pins are which, print it, write it down, or memorize it. Then do a search for the IRLML6401 P-channels and do the same. Then to determine which is which on your PCB, take your volt meter, put the + terminal on the + side of the battery. (With the battery installed in the car) Then take your - terminal and poke at your transistor's pins, until you get the full voltage reading from your battery. (You might want to check the battery before hand so you know what reading you're looking for) That will be the base, or IOW the ground pin. Once you've determined which is the base pin, you will be able to identify if it is N or P-channel.

But I'm telling ya, if you don't mind sacrificing the lights, it would be so much easier to pick up a $6 stunt car from Biglots or Walgreens, and do a PCB swap. An added bonus of the PCB swap will be that when you are ready to do a FET mod, the FETs will be direct swaps, so you won't have to do all the jumpering, and flipping that you have to do with the MT's PCB when you FET mod it.

civicsr2cool · Post by **civicsr2cool** » Sun Feb 12, 2006 10:26 am

hell if its gonna force me too do a fet mod ill just swap the whole board with my other mt, since there is no reason this one needs fets. and the other one could really need it.

crazydave · Post by **crazydave** » Sun Feb 12, 2006 1:01 pm

You're not really forced to do the FET mod, but if your swapping out the trannies, might as well just throw FETs in there, probably less work.

civicsr2cool · Post by **civicsr2cool** » Fri Jul 28, 2006 10:56 pm

found a 1:43 dragon slayer from walmart with a plastic body

wheelbase extention!

i still have to mount the body.

i used xmod driveshaft and antenna tube

1 tire lenght longer = way more scale appearence

modified rims to fit the tires perfectly. shown in front a flipped rims zzmt

awd?

beanoman · Post by **beanoman** » Sat Jul 29, 2006 2:15 am

The zzmt is nice.. But that last picture.. Thats the first time I've seen a 1/64 car awd front end idea with some potential! Looks like it really has half a chance unlike most.

Maxximum Attack · Post by **Maxximum Attack** » Sat Jul 29, 2006 8:50 am

Are you going to stick a ZZMT bevel gear in there and go with a dual motor setup?

civicsr2cool · Post by **civicsr2cool** » Sat Jul 29, 2006 11:51 pm

nope i have the gears from a slot car and im using a superslick motor. its almost done just need more work on the knuckles, and the time to work on it....

civicsr2cool · Post by **civicsr2cool** » Sat Nov 17, 2007 8:49 pm

UPDATE:
threw out the h1 body, scored me a willy's jeep on ebay.

redid teh wheelbase today and this is where i want the body to rest at

3-cell and back to original steering gears