Sprocket shaft bearings?

[jackalope]

I ordered these for both of my tanks however the don't fit over the shafts? They're so tight they won't go on and I don't want to destroy them any ideas on how to get them on the shafts? Looks like I'll have to machine notches for them to clear the screw heads that hold the front sides together but thats easy enough but any ideas as to how I get them on the output shafts would be VERY helpful!

[MichaelC]

Jack I think they have very specific fitting size and will only go over the one that has the exact diameters.........

[jarndice]

Jack, I had the same problem some years ago with a PANZER4 and I wrote up the way I did it in TIPS & TRICKS,(SUB PAGE 3 LINE 12) You put the hull of the Tank in the coldest part of the Freezer overnight and in the morning you put the bearings on a hot plate, WARNING not so hot that you get burned! Apply a film of lithium grease along the shaft and with a small hammer to hand place the heated bearing on the end of the shaft and GENTLY tap the bearing down the shaft, If it will not go don't force it! That means your bearing really is too small. GOOD LUCK. shaun

[sassgrunt]

I also had a problem when trying to fit bearings to final drive shafts. I found out that the shaft on a Tamiya tank, (12mm, as I remember), is a little smaller than what's on a Heng Long, and the 12mm bearings I got for the Tamiya wouldn't work on the other. I removed the oversized shafts and spun them in an electric drill; then pinched sandpaper over the spinning shaft until it would fit the bearings. I know that somebody had a thread on it somewhere - I'll try and find it. -Mike

[jackalope]

Thanks guys. Yeah the bearings I ordered are for the Taigen 4.1 steel gearboxes which is what I have but the bearings are SO tight I can only get them on a little bit of the way. The drill with sandpaper is what I was thinking as well.

[jarndice]

Jack try the freezer method first and if it does,nt work what have you lost?You will be surprised how much the bearing will expand, and you can still try the drill afterwards. shaun

[tomhugill]

Sometimes the shafts have slight buring on the ends which I've found makes the sprockets hard to get on. Maybe grinding around the edge of the shaft at the end. This might give required tolerance you need to get them on.

[jackalope]

Worth a try Shaun, it can't hurt.

They go over the end but its like the shafts are tapered and get larger the further inward the bearings try to go till they just stop and I can't move them any further. I'll get them on yet!