I had a visitor to the workshop recently come bearing gifts. In the form of a much used Unimat 3 less original motor. The visitor said he had been given the machine some years ago and only came across it while clearing out the garden shed.

If I could make use of it, then it was mine otherwise it was heading for the skip.

After removing layers of swarf which had congealed with oil and formed a shellac work was started on stripping the machine. While everything was red with rust the bedways were in good order with some slight staining. Clearly the oil on the bedways had done its job in protecting them.

After running a clock over the working surfaces of the Bed there as no more than 0.01 mm maximum wear.

The tailstock working surfaces and the carriage working surfaces were not so good. while there was only about 0.05 mm wear the surface seemed to be filled with abrasive.

Thus yesterday I made a start on machining the faces back to new. The Vee ways can present problems. Thus I opted for using the Dividing Head to guarantee an exact 90 degrees. Which also made machining the flat easy.

Having the Headstock with an undamaged surface it was easy to establish what height the flat was relative to a roller in the Vee way. Machining the two items on a common mandrel ensured that alignment would be maintained.

Before the parts were removed from the mandrel a check was done on the Bed to ensure the mandrel was true or parallel to the bedways.

The last operation on the Headstock was to put Helicoil inserts in the tapped holes which hold the motor mounting plate, apart from painting.

More to follow.

Regards

Gray,

Edited By Graham Meek on 26/10/2021 16:44:17

Well after much prevaricating I decided to set the lathe up with a slight cant. It amounted to a quarter of one division on my 0.01 mm clock.

Running a further check over a hardened dowel pin on the un-worn portion of the Master dovetail on the cross-slide showed on error. Thus I concluded I must have hit on the original factory setting, first time round.

While the machine was on the milling table I also cleaned up the front face of handwheel boss. Just in case I need a flat face to reference off at a later date and also to remove the wear. Swarf at sometime had been trapped there and produced anything but a good running surface.

Regards

Gray,

Hi Dave,

I have been pondering over what to use for the new Gib strips. One of the previous owners had overtightened the adjusting screw and split the Moulded Glass reinforced plastic Gibs. My first thoughts were for steel, as the Taper Turning main body is made of steel. Tufnol also came to mind, but given you have had a good experience with Brass I might opt for this material.

Regards

Gray,

I have made Brass Gibs today and have so far fitted the cross-slide only. The cross-slide feels silky smooth now. However the taper turning attachment is going to need a bit more work. Holding the slide up to the light the Master dovetail on the toolpost is not matching that on the slideway.

Regards

Gray,

Thanks Howard,

You will probably be right on that score.

Having set the Taper Turning slide up on the mill this morning to skim the Master dovetail. I found whilst clocking the flat of the slideway that the slide had suffered some damage. In that the handle end was dipping away by about 0.15 mm. Where the slideway was bolted to a slave cross-slide in the machine vice there was no deflection.

Using a small screw jack off the bottom face of the machine vice I was able to rectify the error. Just to be on the safe side I machined 0.025 mm off these faces as well.

It is not an easy part to rectify as the feedscrew is fixed in relationship to the dovetails. Luckily my 0.05 mm off the dovetail did not affect this alignment.

The damage was not restricted to the slideway. When I assembled the feedscrew the handwheel end was running out by about 0.15. A few judicial taps with the nylon mallet in the Maximat lathe chuck soon had this part running true.

All is now well with the slideways and I shall be moving on to make a new spindle and tailstock barrel. Apart from both parts being extremely rusty the threads to take the chucks have worn a lot.

Regards

Gray,

Edited By Graham Meek on 29/10/2021 18:24:17

Edited By Graham Meek on 29/10/2021 18:24:48

Hi Dave,

This is where my memory plays tricks with me. I was convinced Emco called it a Taper Turning attachment, but on checking the Parts List it is indeed referred to as the Top Slide. Which is what I would normally call this part of the lathe. Although it is referred to in other circles as the Compound Slide.

Sorry for building up your hopes on a Taper Turning attachment.

Regards

Gray,

On Monday the parts went to the Paint Shop, (aka the Summer House). This being warmer than workshop. I will be first to admit I am no good at paint spraying, but I am pleased with my efforts.

I have also taken a photograph of the Cross-slide and Top-slide. The Brass Gib on the cross-slide is easy to spot.

Lastly yesterday was spent on a salvage scheme for the Longitudinal feed nut. The original die-cast nut had worn quite considerably with 0,25 mm backlash. The new Phos Bronze Cylindrical nut has reduced the backlash to 0.05mm. Which is not bad considering it is the original feedscrew.

Tomorrow hopefully I will make a start on the new Spindle and Tailstock Barrel.

Regards

Gray,

Hi John,

I have acquired quite a bit of "shop soiled" original Emco tooling to go with this lathe, so I will be sticking with the standard spindle. I shall however be making the Spindle and Tailstock barrel from something a little more exotic. Which I hope will be more durable than the standard material.

Regards

Gray,

Hi John,

I shall be sticking with the circlip arrangement as I have the parts for the Power Feed attachment, but currently no housing. The feed attachment needs the pulley groove in the original spindle. Hopefully Emco Austria will come up with a drawing for this part, so that I can make a new housing. Otherwise I shall be adding a variable DC drive to a home designed housing.

Regards

Gray,

Hi John, and Jason,

Please excuse my tardy reply, the past two days have been a bit hectic.

Thanks for the info on the Tommy bars and the additional clarity on the Power feed attachment. I was convinced it was on a slight angle, that is my memory for you.

It is interesting that you made a rotary table out of the drive. Many years ago I made a dividing head using the same items. With its 40:1 ratio it was ideal, I may still have the original paper drawing of the main body. I will try and look it out.

Today I finished grinding the new Spindle and Tailstock barrel. The manufacture of which has been a bit of a trial in that the M14x1 gauge I made years ago left my threads oversize and I had to pick-up each thread and re-screw cut to size. The Moral here is to use the 3 wire system first, not last. The gauge is now in the scrap bin.

Hopefully I will have some more photographs over the next few days.

Regards

Gray,