Milling machine varispeed pulleys

[scottmk1]

I’ve stripped the top end of the head on my Semco mill and found the that the key and key way in the stub shaft are both gubbed so I will be replacing these. But what about the varispeed pulleys? Is there any way to determine obvious is the wear on the pulleys? I can’t feel anything with my finger nail and they look ok apart from some small marks.

 

[Agroshield]

I guess you will check the bore is OK.

To me, the only thing to check on the pulleys is that they do not close too much so the belt is forced off the outside or they do not open too much such that the belt bottoms out on the shaft. The outside looks good from the pictures; you'd have to assess the inside yourself. In any case, if there is a problem, you'd have to solve it by stops or travel limiters on the vari-speed mechanism.

 

[Pete.]

Usually they dish on the angled faces. If they are not badly fished then they are good.

 

[scottmk1]

The bore looks ok but I haven’t measured it yet to make sure.

The bearing on the upper one is dead so I also need to figure out how to get that off as well.

Ok @Pete. I’ll check with a straight edge.

 

[Brad93]

Can repair shafts and open jetways up to next imperial or metric size in the oulley

 

[scottmk1]

Can repair shafts and open jetways up to next imperial or metric size in the oulley

I think the key way is a bit too wallered out for that.

 

[Brad93]

I'd braze that or even spray it

 

[scottmk1]

Wouldn’t braze be too soft and wear even quicker than the steel? I think a new part is around £140 so not sure how that would compare to the cost of a repair.

Cheapest way I guess is just to machine a new key way and make a new key if the pulley bore is ok.

 

[Seadog]

Silicon bronze is quite tough.

 

[scottmk1]

Silicon bronze is quite tough.

Ok, any recommendations for rods? Or are they all the same?

 

[Johnnybravo]

Wouldn’t braze be too soft and wear even quicker than the steel? I think a new part is around £140 so not sure how that would compare to the cost of a repair.

Cheapest way I guess is just to machine a new key way and make a new key if the pulley bore is ok.

No brainer if a new one is £140

 

[scottmk1]

No brainer if a new one is £140

Well, £140 plus vat and delivery

 

[Brad93]

Blimey by the time you machine it that is a no brainer. You'd be looking at an hour machining time, hour allowance for welding, plus cost of the rods. Be £100-120 job. Might as well have a new one.

 

[dan.taylor.1]

What model mill is it?

 

[scottmk1]

What model mill is it?

It’s a Semco MasterMill 800

 

[scottmk1]

No welding rod cost or welding time for me. Just a fresh keyway on t’other side of the shaft - as long as what appears to be another key is not positioned importantly.

Repair cost depends on who is doing it. Contracted out or in-house.

It might be possible to widen the keyway and make s stepped key if you are a machinist and have the kit to do it (that doesn’t seem likely from the thread, or it would have already been done by now).

I do have the equipment but I don’t have the time right now. So looks like buying a new part along with new belts and bearings, or putting it on the to do list