Harrison Horizontal/Vertical Mill Restoration

[Mark Davison]

My original plan was a hollow draw bar but as the INT30 on the harrison is only M12 it wasnt an attractive proposition, hence the Schaublin style one. With an M16 drawbar I'd go the hollow bar bar route.

Yes I milled a 4mm keyway the full length of the straight shank and there's a corresponding one In the sleeve of the face plate

I still need to shorten the straight shank by an inch as there isnt enough height in the INT30 taper to accept it as is

 

[Carl Wilson]

Fantastic work. It would be worth starting your own thread about it. I for one would follow it.

It can get confusing when another topic comes into an established thread. Not least for me.

 

[Carl Wilson]

Remind me, these are nuts for the change wheels on the table feed gearbox?

Yes that's right, these nuts hold the change wheels on.

 

[Mark Davison]

Apologies, didnt mean to hijack

 

[Carl Wilson]

No problem. I really like what you are doing. I'd love to see more and follow the project as it progresses. Mainly because I'd like to build one too!

 

[Carl Wilson]

Had an idea to slightly modify the retaining nuts.

This scratch shows the basics. Instead of having a grub screw threaded through the front of the nut which then opens the slot to tighten the thread, have a pan head screw threaded into the rear of the nut which closes the slot, giving the same effect.

That way the thread for the locking screw is tapped into the thicker part of the nut. A pan head screw is desirable since there is not much space inside the change wheel enclosure when the cover is fitted. If you look back through my thread you'll see that there were witness marks inside the cover where the old nuts had been fouling.

I have some small pan head screws so I might give it a go. If it doesn't work I can soon make another nut.

 

[Carl Wilson]

Bit more work on the nuts this morning. I parted the first one off. Have to drill and tap the hole for the 10-24 grub screw - I've chosen to keep it standard - then tidy up the parted end.

Feels like I'm serving my flippin' time on these nuts...

 

[Carl Wilson]

Sigh....slot being cut in the second nut...

 

[scottmk1]

Nice work as ever Carl, I know what you mean about feeling like your serving your time on those nuts but it will be worth it when you are back using and enjoying that machine.

 

[Carl Wilson]

Thanks very much Scott. I enjoy doing things properly (or as best as I can) so it doesn't matter how long it takes.

There is still a lot of work to do. I haven't even started on the main gearbox yet, or the vertical head. I got a little transfer pump (Lidl recent special) which has solved my problem of getting the main gearbox oil out without making a big mess.

 

[Carl Wilson]

Set up the first special nut to drill and tap the 10-24 UNC thread.

The nut is sitting so that the thread will be positioned at the mid point of the slot, and their axes are orthogonal.

 

[Carl Wilson]

Drilling the holes for the 10-24 UNC screws.

To support the nuts I made the world's cutest jack!

 

[Carl Wilson]

Yes!! I finished one!!

 

[Carl Wilson]

Got a Lidl special bore scope yesterday. I put the probe into the mill gearbox through the top oil fill point.

Here you can see a couple of gears and their oil delivery tubes. They look in decent condition.

We will find out for definite soon enough.

 

[Carl Wilson]

Two peas in a pod:-

I really should have checked the threads on the gearbox shafts. One was a bit rough from the earlier wire wheeling. Ran a 3/8-24 UNF die along it. Had to remove the diestock handles for access. The die didn't cut, just cleaned the thread. Then the nut went on perfectly.

Both nuts span on beautifully, and the merest nip of the grub screw locked them. Here are two change wheel retaining nuts, well, retaining change wheels.

The grub screws are flush when locking the nuts.

The now completed gearbox with the cover on. There is now no fouling of the cover interior.

Now I can get on with refurbishing the saddle and table. I have a lubrication nipple repair to do and some sheared bolts to remove.

 

[Carl Wilson]

Nice little care package just arrived from my brother.

Some centre drills, Dormer Super Cut and Aviation grade two part Loctite with cleaner.

I've just sent him back some tools I've had of his for 30 years...fair trade!

 

[Mark Davison]

Looks better than new!

 

[Carl Wilson]

Thank you very much. Hopefully it will work just as well.

 

[Carl Wilson]

Moving back to the saddle and table. This is a rough sketch of the repair for the damaged lubrication nipples I removed up thread.

 

[Carl Wilson]

I'm thinking about VFD's. As most of you know I do have some experience of them.

Specifically I'm looking at what small one to get to drive the Gryphon motor on the feed box. It's 1/8hp ie 0.1kw. I know all about what power requirements I need etc. I'm just wondering if anyone has any experience of the cheap small Chinese vfd's on eBay?

I have been looking at a Siemens Sinamics vfd. The price is reasonable but it has a lot of features I would not need. I've experience with Siemens drive kit at work and obviously it's excellent. However if I can save a bit with the Chinese one then I will.