Rear mounting a parting tool ... if you can

[mickri]

Jeff sorry for the late reply to your post about a parting blade holder that holds the blade horizontal. I made one for my QCTP. I followed videos from Winky's Workshop adapted for my Norman style QCTP.



For maximum rigidity you want the holder to sit on the compound. My blade came with the rake. The main problem occurs when you regrind the blade the tip is no longer on center line. This requires a shim to bring it back up to center line.

 

[Karl A]

... If I had registered off the back, there wouldn't have been enough cross slide travel to bring the cutter to center. ...

My Sherline lathe has enough cross slide travel, to have the tool mounted even with the end of the cross slide.

Another idea is to make the ledge register against an edge of the dove tail groove in the cross slide. The ledge would need to be interrupted for the t-nut.

By "easier to make", I meant achieving the correct blade height.

 

[mikey]

Would a ledge that registers against the rear edge of the cross slide, instead of the left edge, work as well? A tool designed to have a ledge-machined-in-situ-at-the-rear seems easier to make.

I don't see how the location of the ledge at the rear makes it easier to make but as long as your cross slide has enough travel then I don't see why you can't put the ledge back there.

As for making something that uses the T-slots, that seems to be more complicated than it needs to be but I'm sure it will work, too.

 

[Karl A]

I don't see how the location of the ledge at the rear makes it easier to make but as long as your cross slide has enough travel then I don't see why you can't put the ledge back there.
...

Including a ledge on the side in situ (as opposed to a later add-on) seems to require obtaining an accurate measurement of the distance from the bottom of the ledge to bottom face of the tool.

 

[mikey]

Including a ledge on the side in situ (as opposed to a later add-on) seems to require obtaining an accurate measurement of the distance from the bottom of the ledge to bottom face of the tool.

That's true. If that is an obstacle, just make the tool post and add on a ledge as a separate piece. I did it that way on my prototype because I discovered that under heavy parting loads the tool post can move (bent a cobalt Eclipse tool) so I came up with the ledge. Since then, I've made several of these posts and just integrated the ledge. It is a bit more fussy to do it that way but it makes for a nicer tool.

 

[jwmay]

Another idea is to make the ledge register against an edge of the dove tail groove in the cross slide. The ledge would need to be interrupted for the t-nut.

My cross slide dovetail isn't accessible. Your idea sounds much more complex to me. But I think you know what you're planning. And I don't think you'll have any trouble. The most important part is to get started. You won't regret it.

 

[Karl A]

My cross slide dovetail isn't accessible. Your idea sounds much more complex to me. But I think you know what you're planning. And I don't think you'll have any trouble. The most important part is to get started. You won't regret it.

Thanks.
To me, placing the ledge in the dovetail slot seems easier than placing it at the side edge of the cross slide, but I will see.
For some weeks, I was unable to find the cutting blade that I purchased. This hobby is driving me to improve my organizing practices.

 

[Bazer_20002000]

Hi I have just seen your post re a rear toolpost on a 1024 and would be happy to send you or any others the dimensions and pictures of the original S&B rear tool post as I am luck to have one. It works well but I have found it best to remove when doing taper turning and from the perspective of safety its another tool post to watch out for when turning with a chuck. Cheers Barry

 

[Beckerkumm]

I'd like to see an original 1024 rear toolpost. I have to admit I don't use it a lot . Parting takes a feel and I see what is going on better using the front multifix rather than the rear. Dave