Tool post milling attachment

[shipto]

Not sure what the proper name for these is but I think toolpost milling attachment will suffice but I am making one anyway.
I had the motor from my old Clarke mini lathe lying around for ages so decided that would be good for this project. While I am primarily making this for small milling cutters I may make the gears changable so it could double up as a grinder too.

Started off by welding a old bit of stock from lathe tool to a 115mm bit of 45mm round and drilled out 1" right through before boring for a bearing each side.
Also ordered a controller for the motor.

I am currently working on a nut to hold a seal and clamp the front bearing securely in place will update as I go along.

[shipto]

Not 100% happy with front nut but it will do.

[shipto]

Rear locking ring.

[shipto]

Easier bit done.

[shipto]

This bit I am not looking forward to because I have to make the plate something like pictured.

[shipto]

Got the basic shape made with a plasma cutter at work and smoothed off a bit with the belt sander.
Could really do with a boring head now but as this is a side project already I am not eager to start a side side project.

[shipto]

No pulleys yet but a few pics of it in place on the lathe.

[efrench]

On a Rose Engine, it would be called a drill frame.

[vtsteam]

  

[shipto]

On a Rose Engine, it would be called a drill frame.

Thats a new one to me but a search showed me some similar items.

[shipto]

Well its working but its really slow going, I have slowed the lathe vfd down to 6hz and still only feel confident to take tiny nibbles each cut.

[vtsteam]

Still, that looks cool! 

[shipto]

Thank you VT however not long after this pic was took I ran into a problem, not with the attachment but with my lathe there must be a broken tooth inside the screw cutting gearbox and it started to jump. Luckily I was not leaving it unattended and managed to withdraw the cutter before it did any damage to the part but it would not do another run without jumping so the finished part is not quite as deep as I wanted but it will do the intended job well enough.
If I wanted to make another the next option is 2 1/4 tpi which would still do but I only want one for my quornish project.

[vtsteam]

Can you fix the gear in the gearbox, shipto?

[BillTodd]

Could you try driving the spindle via the screw cutting box , rather than driving the spindle directly (as normal). This should take a lot of the load off of the SC gears, which might (with luck) just be springing apart?

[shipto]

Can you fix the gear in the gearbox, shipto?

Probably but it would require stripping much of the front end of the lathe I think for a gear I will probably never use again. If it was something more important then I would give it a go but for this probably not.

[shipto]

Could you try driving the spindle via the screw cutting box , rather than driving the spindle directly (as normal). This should take a lot of the load off of the SC gears, which might (with luck) just be springing apart?

I am struggling to get what you mean, are you suggesting driving the screw cutting shaft? if so not sure how I would do this.

[BillTodd]

Yes.  The problem cutting low tpi (long pitch) screws is that the gearbox has to spin faster, or almost  as fast as, than the spindle . This puts an enormous load on gears that are primarily designed to reduce the speed. If you can turn the lead screw and let the gears drive the spindle,  the gears and shaft are loaded far less.

[shipto]

Yes.  The problem cutting low tpi (long pitch) screws is that the gearbox has to spin faster, or almost  as fast as, than the spindle . This puts an enormous load on gears that are primarily designed to reduce the speed. If you can turn the lead screw and let the gears drive the spindle,  the gears and shaft are loaded far less.

makes sense, will bear this in mind if I ever need to do this again. Thinking about it an extension to the end of the leadscrew run from a wormgear box would do it.