Hand machined mechanical pencils

BV20 Lathe Quick Change Toolpost (24/08/11)

I have wanted a quick change toolpost for a long time, so at last I decided to splash out and get one. My lathe is a BV20 model, originally bought from Axminster UK. This is approximately a "9x20" size. Other people, such as Warco, do a similar lathe. Axminster originally listed a toolpost which they claimed was specifially for the BV20, but I spent over a month waiting for it to come in stock and it never did. I suspect that it was the same design as the one shown below anyway.

There is a toolpost going around which fits the Myford 7 lathe. Several people stock it, but after a few phone calls RDG Tools proved to be the most helpful - the chap actually had one there and could tell me the dimensions of it. I ordered a 5-piece set (main block, two plain holders, one boring bar holder, and one parting tool holder) and it arrived next day, which impressed me hugely. The part number is 725MYFORD, and here is a link to the product page: http://www.rdgtools.co.uk/acatalog/Quick_Change_Toolposts__Complete_Sets_.html. I thought I would put up some photos and dimensions of the toolpost, to give you an idea of whether it might be suitable for your own lathe.

Impressions. Excellent appearance - all surfaces are ground and it arrived neatly packed and well-coated in protective grease. It doesn't appear to be hardened, but I don't think this is very significant. In fact, it may be a bonus, if I ever need to drill the main block for locating pins or whatever. The locking screws on the main block were a little crunchy, but after removing them and the pistons (press the piston in towards the main block and pull the locking screw up and out) and giving things a clean, they work fine. My only gripe was the hex spanner supplied - the handle is at a peculiar 135° angle and the hex socket is only 4mm deep or so! Not a big deal - I made a quick tool with an old 8mm hex socket with a T-handle attached.

There were no problems about fitting it - the old toolpost came off, and the new one plonked straight on. The toolpost is fixed with an M10 bolt through the middle.

The holders accept all tooling I have, which ranges from plain bits of ¼" HSS bits to inserted-tip tools with ½" shanks. For the odd big tool I can easily swap back to the original toolpost. Adjusting the height and changing tools is a breeze, and makes me wonder why I messed around with packing up tools for all these years. I have ordered a set of five additional holders, because you really need a holder dedicated to each tool to make maximum use of a quick change toolpost.

I have made a drawing of the toolpost dimensions, available as a PDF here. Please note, these dimensions are not exact, they are just to give you a rough idea of suitability.


The box!

All nicely packed

Main block

A plain holder

Mounted

The rather wonky hex spanner

Very shallow hex socket

Old toolpost

Removed - held by a single bolt

New toolpost fitted

My new hex spanner - old 8mm hex socket, piece of ¼" steel, and a nail for a handle

Three tool holders with tools

The two pairs of screws allow short lengths of HSS bits to be held in both ends

Parting tool holder

Boring tool holder - note the V groove