Replacement toolpost for Grizzly lathe

[propforward]

Howdy all.

This is nothing super extraordinary by any means, but was a nice little machining introduction for me.

Essentially, what I am going to cover in this post is the replacement of a standard 4 way tool post on a 12 X 36 lathe, with a quick change toolpost from a smaller lathe.

Here is my lathe, at the headstock end, to show you the 4 way toolpost:



It's a perfectly reasonable toolpost, but it's "chunky" - a bit big. I have found it a little awkward to mount smaller toolbits and get them close to the chuck on small parts.

Here is a close up of the toolpost:



A while ago my Dad sent me over this quick change toolpost. I believe this is a Myford toolpost, but I'm not 100% sure.



Anyway - it is much more compact, and much better suited to holding 3/8 and 1/4 bits. The 4 way post required all the bits to be seriously packed up with shims - about 3/8" worth typically.

So this is a pretty straightforward project really - it's a matter of measuring the height differences of the two posts, measuring the mounting thread of the old post, and then making a new shaft, a spacer, and a clamping nut to put the new post in position.

Let's start with the mounting shaft:

I started by machining the shaft to suit the hole in the toolpost. I had some nice 3/4" dia steel around that was ideal, so I turned down the length of shaft required, plus some extra to take a thread for a clamping nut. I did this slowly, because I am new to machining, but by taking my time got the shaft to fit really nice and close to the bore in the toolpost. I threaded the end of the shaft with an M10 thread.

Then I turned the shaft around, to start work on the end that would mount to the cross slide.

I had previously measured the mounting thread as M16 X 1.5.

So this was going to be fun - my first ever attempt at screw cutting on a lathe.

Let me just say right off, I made some fundamental errors and did not get the thread right first time. The pictures that follow are the third attempt. 

[propforward]

So, this is the start of getting the mounting end ready for threading



Here is the first pass of the thread cut:



And here it is, finished up.



Man - I really enjoyed making that!

Finished shaft:

[propforward]

Once I made that, I did a dry assembly run to make sure that the toolpost was going to be in the right place





It looks odd perched there like that, but this just assured me that I was along the right lines.

Next up was to make a spacer to clamp between the shaft and cross slide, for the toolpost to sit on.

I had a piece of scrap steel, 3" in diameter, that had been tossed out at work. I don't know what alloy it is, but decided to try and use it, as it was the right size.



I cleaned it up on the diameter, faced it, and then machined a bore and counterbore, to suit the mounting shaft.

Once that was done, I cut off the piece I needed using a bandsaw, and then faced the other side to the right length.

[propforward]

At this point, these are the components prepared, and ready to go.



Next up, a clamping collar and nut.

This is the start of the clamping nut, getting bored out to accept an M10 thread.



I am boring it instead of drilling it, because the cheapo chinese made drill bit I have is hideously blunt, and the point is ground at least 2mm off center. 

Never mind. I need practice at boring (this post is doing well in that regard  )

Here is the clamping nut - I deburred the threaded hole AFTER taking the picture.



Here are the main components, artfully arranged next to my favourite lathe reference work.



At this point, I made a short 6mm diameter shaft, and a simple knob, to thread into  the clamping nut.

And here it is, all assembled and ready for use



This is my first ever self ground toolbit mounted to it. I used this bit in the 4 way toolpost to make most of these components.



So there you are - a nice little project, and the new toolpost is much more compact, and I think it will be easier to work with. Tomorrow I will grind up some 1/4" bits, and get back to my first engine!

Thanks for bearing with me. This was a great project - it covered a lot of fundamentals - turning, facing, turning to a specific diameter, screwthreading, boring and counter boring, and a taper. I really had fun with this.

[Pete49]

Nice job I reckon I still have the clunky tool post and a box of shims but would like your style of tool post...maybe 1 day. To paraphrase 'So many tools   so little money' Anyways a nice clear write up
Pete

[Don1966]

Enjoyed it Prop, nice clean write up and great photos. Nice addition to the lathe, it keeps getting better doesn't it?

Don

[swilliams]

Nice little job Prop. Now you'll need to amass a huge collection of holders for it. One can never have enough.

Cheers
Steve

[Stilldrillin]

Prop.
That was a great project! 

Nicely done, and shown...... 

David D

[steamer]

Well Done! 

 I still need to make the handle bar nut for both of my toolposts.....add it to the list!

Dave

[propforward]

Thanks all! Looking forward to putting this into service today. Got to grind a few 1/4" bits, and then make more chips - see if I can progress that wobbler a bit.

[b.lindsey]

Well done Prop!!!  Excellent pictures too!!! That should make using the lathe far easier.

Bill

[mklotz]

Nice job.  Toolmaking is very satisfying.

Don't throw/give away the 4-way post however.  Now that you have the QC post to handle tools you change often, you can afford to load the 4-way with less used or specialty tools.  Shimming them is less of an annoyance when you know you only have to do it once.

Before I got a QC I had made about six 4-ways.  Some of them were the typical design and some were personalized to hold specialized tools, e.g. a 3-way for getting into tight corners and one set up for 1/8" bits for detail work.  I fitted all of them with integral lock-down handles so they can be mounted without the need for any wrenches.  I still use all of them and wouldn't be without them.

[propforward]

Absolutely - the 4 way is still a perfectly good tool Never throw a good tool away!