[zetran]

We had to have our spindle on our Mori MV55 (1985) reground after a tool pulled out and spun in the taper. After the grinding the tech put a force gauge on it and it pulled at 1700 lbs. My boss said that's to low so he wanted me to take out the drawbar and check the Belleville washers. there was 3 broken washers in the stack. One of the questions I have is that there was a lot of play in the stackup of the washers before I even took off the end nut. Like 3/4" or so. I would think that there shouldn't be that much play (or any at all). Even if the 3 washers wasn't broke it would still be loose. I took off 135 washers. Is the nuts suppose to make contact wiht the washers or can there be slop in it? Does anyone know how many washers are suppose to there? Theres no telling if the proper number of washers were installed the previous times.

[underthetire]

Don't know for sure on that old of a drawbar, but typically on the ones ive done there is no play. Im assuming thats a 50 taper machine? If so it should be ~4000lbs of force. I never replace just broken springs, i do the entire stack when I did them. Why choose us? has them pretty cheap.

[zetran]

It is a 50BT. I did buy new washers from McMaster Carr and when I put the 135 washers on it was still loose so I put 6 more on. When I tightened the first nut (flange??) it made contact about .120 thousandths before reaching the same position it was before I removed it. So I tightened it down the .120 to the original position. I don't have a force gauge yet (the tech took his home). I put the machine back together and the drawbar seems to be working fine. I'm just trying to make sure I don't FUBAR. Was there any preload (I'm guessing that would be what I call that) on the other drawbars you worked on?

[underthetire]

Yes, but typically the but tightened to a shoulder