Toughbox Assembly

[BJT]

Warming the bearing a little, even by just holding it in your hands for a while can help. Just make sure someone hasn't been holding the shaft too. A friend of mine used to rebuild electric motors, big ones, and when it was time to put the bearings on he would grab them out of a hot plate and drop them on. without heat they went on tough with a hammer.

[EricH]

Originally Posted by Kyle Love

My team had the same problem. You can use a deep well socket and lightly tap the gear down onto the shaft. You can also lightly scotch brite the shaft of the CIM.

We "persuaded" them with a mallet. Working carefully, of course.

[ghebinkim]

Our team found that sanding down the large output shaft helps to get the large bearing on. To sand it evenly, we put a belt sander face-up on a table, and then rotated while pressing it onto the sander.

As for getting the gear onto the CIM shaft, we just used a padded hammer to lightly tap it in.

[GUI]

Today we assembled the transmissions, and they had several issues. First, the roller pins did not go in very easy (i think the hole was a tad bit too small) and they "unravelled". We got the first one in with some persuasion, but it had some "mushrooming" that we had to squish back so the gears would fit. The second transmission was even worse. The fist pin bent, and when trying to remove it, we accidentally broke it off. We drilled out what we could, then tried another one in hopes that it would push out the remains of the first. The second one got bent, but we got it out and finally got the third to work.
The second issue we had was the small gear for the second stage in one of the trannies wasn't quite big enough to fit on the shaft, so we had to sand a little on the shaft, but it is still a press fit.
Our third problem was one of the pinions was way too tight to fit on the cim. It was so tight we had to put it in a vise and persuade it (i know this is bad for the motor, we were already planning on ordering extras. We were in a bit of a hurry, we wanted to finish our prototype drivebase.).
Other than these assembly problems, i really like the Toughboxes. They are simple, and plenty strong. They are also an improvement over the older AM single speeds, being symmetric and all. I think our current plan is to reduce them to single stage gearboxes for the competition drivebase.

[MrForbes]

Why didn't you ream the gear?

(oh yeah...Matt knows about the reamers, he was working on something else)

[GUI]

now we think of that...

[Wayne Doenges]

We have had similar problems with the roll pins and large shaft.
We bent two pins trying to get them inserted. We were using an arbor press to insert them. When the pin was flush with the opposite side they would mushroom. We went and inserted spilit roll pins.
The large shaft was .002 too big. We put the shaft in the chuck of our drill press and used emory cloth to get it down so it the bearing would slide on.

[scottydoh]

we had similar problems too, to get the bearing on, we used a peice of pvc pipe the same size as the shaft and hit it with a mallet numerous times.

we also had problems getting the gear on to the CIM shaft

also, did anyone else notice that the larger gear that is supposed to "rest" against the roll pin is very loose on the hex shaft?

It seems like these transmissions are just all around crap.

[usbcd36]

Ugh…

Trying to put in the roll pins today was very frustrating.

We tried putting the first pin into one of the output shafts, and the shaft caught the end of the pin and unraveled it a bit. The second pin went in, but the top mushroomed and eventually fell into pieces, leaving us with a plugged hole and only two roll pins left (the ones from the second gearbox).

After completely destroying two titanium carbide bits trying to drill the pin out, we went out and bought a new 3/32" bit and enlarged the hole in the second shaft. The metal the shaft is made of is easy to drill with a good bit and drill press. The pin went into that shaft with a more reasonable amount of force, and it's also plenty secure.

We're going to have to do something else to clear the hole in the first shaft, though. There are fragments of one of the drill bits left in there, which makes it nearly impossible to drill out with anything we have, and nothing budged when we tried to punch it out.

Any ideas?

[Joe Finkel]

try to drill a new hole

[Muktar Ali]

Hi we also had some problems with getting the roll pin into the output shaft. It broke in the hole and we had serious problems getting it out We fixed it with brute force and now it's in position.

But i need your help. One of our gearboxs is rattling when we run the motor. The large cluster gear is knocking against it's bearing and making a bad noise. We've greased it up and done several refits. Any suggestions?

PS anyone going to the florida regionals?

[DDAwg3]

We found the gearbox to fit very poorly and then a more detail inspection determined it had not been deburred and many of the components were not square and out of round........

in the process of re-machining everything!

[moonwatcher211]

I haven't actually read all these posts, so someone may have already pointed this out, but there is an assembly video for the toughbox on youtube

I'm from a rookie team, and that's how we did it (while in our school's LRT/special ed office using their computer and a table we dragged across the room)

[cjtenny]

Originally Posted by moonwatcher211

I haven't actually read all these posts, so someone may have already pointed this out, but there is an assembly video for the toughbox on youtube

I'm from a rookie team, and that's how we did it (while in our school's LRT/special ed office using their computer and a table we dragged across the room)

It worked mostly for us, like Seti said, but we did some small part wrong so now we've run into bulging-gearbox-syndrome. We took it apart, since bulging clearly isn't right, but our teacher had to leave, so we couldn't be at school anymore, so it'll have to wait till our Tuesday meeting.

[Justin M.]

Did anyone else have problems with the holes not lining up? The piece of extrusion interferes with the bolt path just a little. Looks like I'll have to go at it with a file.

First one of our gearboxes comes without 4 holes drilled, now that one fits after I drilled them myself, but the one that I thought was fine doesn't line up. I never had this many problems with kit gearboxes, ever...