homemade 3.1 gearboxes
Posted: Sat Dec 06, 2008 2:11 pm
hi guys
this is how i done my 3.1 gear boxes, its cheap to do, you dont need to buy aftermarket gears, you use all HL gears. nigel and myself did our gearbox conversion at the same time, our two efforts our similar but quite different, unfortunatly i cant find the photos of nigels so you could compare. the main differences in our 'boxes is i cut and welded the motor mounts on the gearbox casings nigel didnt, here is a link to PK where i 1st posted this conversion http://www.rc-panzerketten-forum.com/wb ... 4a31cee95f as you can see from these photos nigel an my boxes are a little different.
right, the 1st thing is to strip the boxes and remove the support bar at the back of the boxes drill the hole out so it can take a bush, you may need to slightly altar the position of the hole so the gears mesh properly, i got nigel to solder all the bushes in for me, this does make a big difference, after this i cut of the motor mounting points and welded them farther back on the casings and i put a little gusset in on the tall motor mounting point for extra strengh, the lower motor mount i cut it out and turned it around then welded it in. this may sound daunting to some, to cut and weld, but it is really very easy, you can see from the photos where the cuts and welds are. now the fun bit :-[, the way i made my 3.1 gear was to cut up stock HL gears and join the relevant gears on one shaft, the photos show what gears i cut up and used, origanally i glued the gears on the shaft, but this soon proved unreliable, they kept slipping under load, so the solution was to drill and pin them on, which is much easier than it sounds, once i done this i put the boxes back together, the 2nd outing my Tiger was hungry and promptly lunched the gears in one box, the problem was i had not aligned and spaced the gears properly, so i got nigel to do this for me, this made a hugh difference. my boxes are similar to the asiatam boxes in lay out ( i have a pair of asiatam boxes).
well what are they like?, much much better than the asiatam boxes (and cheaper) with the jamara motors these boxes are just brilliant, if my Tiger can grip the surface it will go up it, i have posted video clips of her on this site else where, and you can see how steep a gradient they can go up wth no trouble.
i have seen other 3.1 conversions on the forum we wont mention, and i'm sure they work well, but there is no need to buy after market gears which cost money, the way i have done it does require welding , and if you dont want to or cant do this, have a look at the link above, and see how nigel done his.
the ratios on the 3.1 gears seem to be perfect, more by luck than anything, i just looked at the gears and thought those look right, so i used them,(very high tec'
) the only downside to my boxes, is the bushes, in the future i will be taking them out and replacing them with proper bearings. thats about it really, if you have any queries let me know, iv'e probably missed something(i'm going senile)
Tony
this is how i done my 3.1 gear boxes, its cheap to do, you dont need to buy aftermarket gears, you use all HL gears. nigel and myself did our gearbox conversion at the same time, our two efforts our similar but quite different, unfortunatly i cant find the photos of nigels so you could compare. the main differences in our 'boxes is i cut and welded the motor mounts on the gearbox casings nigel didnt, here is a link to PK where i 1st posted this conversion http://www.rc-panzerketten-forum.com/wb ... 4a31cee95f as you can see from these photos nigel an my boxes are a little different.
right, the 1st thing is to strip the boxes and remove the support bar at the back of the boxes drill the hole out so it can take a bush, you may need to slightly altar the position of the hole so the gears mesh properly, i got nigel to solder all the bushes in for me, this does make a big difference, after this i cut of the motor mounting points and welded them farther back on the casings and i put a little gusset in on the tall motor mounting point for extra strengh, the lower motor mount i cut it out and turned it around then welded it in. this may sound daunting to some, to cut and weld, but it is really very easy, you can see from the photos where the cuts and welds are. now the fun bit :-[, the way i made my 3.1 gear was to cut up stock HL gears and join the relevant gears on one shaft, the photos show what gears i cut up and used, origanally i glued the gears on the shaft, but this soon proved unreliable, they kept slipping under load, so the solution was to drill and pin them on, which is much easier than it sounds, once i done this i put the boxes back together, the 2nd outing my Tiger was hungry and promptly lunched the gears in one box, the problem was i had not aligned and spaced the gears properly, so i got nigel to do this for me, this made a hugh difference. my boxes are similar to the asiatam boxes in lay out ( i have a pair of asiatam boxes).
well what are they like?, much much better than the asiatam boxes (and cheaper) with the jamara motors these boxes are just brilliant, if my Tiger can grip the surface it will go up it, i have posted video clips of her on this site else where, and you can see how steep a gradient they can go up wth no trouble.
i have seen other 3.1 conversions on the forum we wont mention, and i'm sure they work well, but there is no need to buy after market gears which cost money, the way i have done it does require welding , and if you dont want to or cant do this, have a look at the link above, and see how nigel done his.
the ratios on the 3.1 gears seem to be perfect, more by luck than anything, i just looked at the gears and thought those look right, so i used them,(very high tec'
) the only downside to my boxes, is the bushes, in the future i will be taking them out and replacing them with proper bearings. thats about it really, if you have any queries let me know, iv'e probably missed something(i'm going senile)Tony
