HURCO VM10i Bellville Washer Replacement

[Sam I]

I'm currently going through a Bellview washer replacement after having issues with cutters breaking prematurely and some spindle fretting. The drawbar force is below spec so I've decided to replace the Bellville washers. I've spoken to HURCO and they don't have a procedure for this and I'm wondering if anyone has any words of wisdom?

Per the drawing below I'm currently trying to remove item 40 however it appears to be loaded so as I'm loosening the M5 cap screws holding it on it's starting to come away. Is there a tool to compress this or should I be doing this with a tool in the spindle? UPDATE - yes, popping a tool in the spindle allowed me to remove this cap. Had to put a tool in, move the knockout piston out of the way, remove the cap, reinstall the knockout piston, remove the tool then re-remove the knockout assembly. Now I'm trying to work out how to remove the full drawbar assembly - it moves freely up and down about 2" but won't come out the top.

The next problem I'm not sure how to overcome is removing the 1 off precision nuts (Item 38) from within the assembly or does the whole lot just slide out of the top? So there's an 8mm allen key inside the spindle from the bottom securing the actual collet to the spring stack. It was super tight but it came undone with a bit of force and the drawbar assy just slides out the top of the spindle.

Any words of wisdom from someone who has done this before would be greatly appreciated. I'll try and update with my progress as a resource for anyone else in this situation.

 

[bigjon61]

We had our Hurco tech come out and he changed them out in an afternoon. I believe there are 74 washers and they cost $4 each from Hurco.

 

[Sam I]

We had our Hurco tech come out and he changed them out in an afternoon. I believe there are 74 washers and they cost $4 each from Hurco.

Thanks, already got the washers. Just need to know how to get them out. Had an independent guy due to come out and do it but not heard a peep from him so doing it myself now.

 

[Sam I]

Right, that's it done. All in it took me around 3-4 hours including the faffing and working things out. It was actually pretty easy and I'd guess it would take me around 1.5 hours next time with half of that being removal and reinstallation of the sheet metal. If anyone is going through this in the future this is how I did it:

Remove the sheet metal surrounding the spindle. The first step is to remove item 40 in the drawing above. The thing is this part is preloaded. It's held on by 6 cap head screws. You could back them off a tiny bit at a time until the preload is gone but I found it easier to put a tool in the spindle which relieves the preload. Once I had done this I removed the knockout assembly. This is held on with 4 nuts and it sits on some standoff bolts. I lifted the whole assy off of these and moved it out of the way leaving it perched on just two standoffs to gain access without having to remove anything. Once Item 40 was removed I then moved the knockout assy back in place to remove the tool before putting it to one side again.



With the knockout assy out of the way and Item 40 removed.



At this point I put a wooden dowel in the spindle taper pushing up on the clamping collet and the spring assembly began to lift out of the spindle. I wedged a spanner on the spring assy nut and against one of the standoffs and removed an 8mm hex head cap screw from inside the collet.



That was really tight to the point I doubted it was meant to come off. On my spindle at least it was a standard RH thread.



Now the whole drawbar assy could be lifted from the top of the spindle.



I already had the replacement washers but I noted the orientation of the washers in the stack. I also measured the height of the preload nut and noted this down. All washers were replaced and coated in high temperature grease.

Assembly was a straightforward reverse of the above.