Thread: Vicmark 100 chuck snapped thread

1. Vicmark chuck - contact Vicmark as the chuck is still in production & parts will be available. Depending on how old the chuck is & what the break looks like they may even replace it for free if you are lucky, otherwise consider it 'wear-and-tear'.

2. Speed change. This really only works correctly when the lathe is running. If its still stiff when the lathe is running, open up the headstock - there is an access panel with a bunch of screws. Take a look at the interlocking pulley - some batches have suffered from a corrosion problem which leads to the alloy pulley failing. If its failed (= stuffed) you should be able to get parts from Carbatec or Hare & Forbes - H&F have/had a rough scan of the disassembled lathe with the part numbers on their web site. Otherwise clean it out, don't splash lube everywhere & see how you go.

Originally Posted by neilb

Also I find that my speed selector lever on the MC900 is really stiff, and hard to move. What would this be ?
Thanks.

Lack of lubrication. With the motor running spray WD40 into the lever sides ,front and back, and gently move the lever Keep spraying and moving until it moves freely, but don't force it. That's how I fixed one a while back.


Peter.

Originally Posted by neilb

Also I find that my speed selector lever on the MC900 is really stiff, and hard to move. What would this be ?
Thanks.

I recently acquired a second hand mc1100 which I believe is similar, adjustable speed type. I believe the one i acquired had not been used in a while. the speed adjustment was very tight and hard to move. As Bsrlee said it should only be operated when the lathe is running. I found that after moving it from fast to slow and back again several times it started to free up. I also opened the cover and sprayed the springs and things liberally with CRC.

I also noticed that the edges of the belt are fraying a bit so I made a mental note to buy a replacement belt or two in the near future. Once you get the cover off and watch the mechanism work as you change speed you will see why this type of speed control is probably rather hard on the drivebelt so a spare or two on hand would probably be a good idea.

Doug

Originally Posted by neilb

I went to use my MC900 with a Vicmark 100 chuck after about 2 yrs non use but all was covered up and nothing had any surface rust anywhere. I checked everything and I found that there was a small loose metal item rolling around in the center of the chuck when I turned it by hand.
It was the part of No. 4 jaw that the fixing screw screws into under the actual jaw plate. It had snapped clean off lengthways down the thread.

Can this part be bought seperately and if so , what is the proceedure in fitting it ? I had a look at the other 3 jaw screw threads and I dont see how they come out easily.

I think the part you refer to is called a slider as it slides in and out as you open and close the jaws?
I needed one once and they only came in a set of 4. $60 seems to ring a bell.

First step is to mark the slider numbers on the chuck with a texta. This will help when reassembling.

To fit, remove insert, remove backing plate, remove large circlip (circlip pliers make this easy), lift the scroll out and the sliders can be removed and replaced.
Clean all the parts in solvent a reassemble in reverse order.
The fun bit is getting all the sliders to close at the same time.
One point to remember is No4 jaw has a slot in the back. There should be a roll pin in the chuck which locates in this slot and restricts how far the jaws can open.

If this advice fails to fix the problem then the chuck is stuffed and you should send it to me

Cheers

Tim

Contacted Vic at Vicmark today and he reckons he's got spare parts for it and can do it while I wait. Only thing is , you have to replace all 4 sliders as they come in sets and hopefully the pin is not sheared off .
As for the hard to move speed selector lever, I will open the headstock up and have a nosey into it. I have replaced a belt on it once before and it may be a good time to inspect everything while Im at it.
Thanks for all the replies.