Emco Compact 5 Modifications

Hi Colin,

There was a time many years ago when I was not a Toolmaker, and I had to ask. There is nothing wrong in that and there is no need to apologize as I am only too happy to help.

All the black rectangular parts are Anodized aluminium. The only spare part I did not have from years ago is the one plain aluminium one. The other turned parts are Leaded BMS which were commercially blacked, but again I only had the central spindle. This is threaded M8 x 1 LH Pitch to match the tailstock barrel, or sleeve, and has a couple of flats on to take an 8 mm A/F Spanner.

You are right the collar is for repeated drilling to a set depth. The use of the Bed Stop shown above is great for returning the tailstock to the same place when doing repetition parts.

All the pivot pins are 4 mm diameter groove pins to DIN EN ISO 8745. Not to be confused with Roll or Seloc Pins which are useless for this task. They come in various lengths and at the moment I cannot remember what those lengths were. These are not hard, but tough like capscrew material. As they are working in anodized aluminium which is as hard, or maybe harder than harden steel the two will give years of service without any problems. Provided they get the odd drop of machine oil something like ISO 32.

Don't think you need to anodize the aluminium. You will get an extremely long life out of plain aluminium working on this type of pin, or even silver steel. Bushings of any description would be an overkill in my book.

I find the lever tailstock handy when tapping, or using a button die. A bespoke holder for which I am currently working on among other things.

Does this help?

Regards

Gray,

Hi Graham,

Thank you once again, your detailed information is an immense help to me on this project.

Knowing now that you've used aluminium for those rectangular pieces, it simplifies things greatly as I'll be milling them on my Proxxon FF 230 Mill.

I believe Proxxon has used the same M8 x 1 LH thread on their Barrel too, which helps as I can now dimensionally gauge & scale various items between the Proxxon & Emco.

The one major difference between our Tailstocks is that Proxxon chose to use a MT1 "short" version, which is akin to a B12 taper for Drill Chucks.

Being that I'm in Australia & having those DIN numbers for the Pins, it shouldn't be too hard to find something equivalent here or as you suggest, simply make some from silver steel.

I greatly appreciate all of your input to my questions within this thread but please let me know if you'd rather them as a PM instead.

regards Colin

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May I comment from the audience, please ?

A lot of us will be learning things from this ‘masterclass’ that would be lost to us if the discussion became private.

MichaelG.

Hi Colin,

I use the Proxxon drill chuck on my C5, as it is 0-10 mm capacity where as the Emco is 0-8 mm. I purchased a B12 to No 1 Morse taper arbor to mount this on from one of the ME suppliers.

I suspect things are starting to warm up with you while we here in the UK are getting decidedly cooler.

As regards the PM, I concur with Michael, a lot of people, including myself, benefit from other peoples questions. When I recently needed to get a new 2D drawing package. It was Michael's response to another members question on another post along the same lines that made me go with Qcad, so thanks Michael for your input. I am completely satisfied with my / our choice.

Regards

Gray,

Hi Graham & Michael,

No prob's, more than happy to keep this whole discussion open.

So Graham, with the various aluminium components, is there a specific grade you'd recommend using for this application?

It's most likely I'd be buying short drops coming off flat bar, which typically is 6060-T5 & based on using the 4mm Pins, I'm guessing these flat pieces would need to be about 8mm finished thickness?

Already had to buy a 300mm length of EN1A-PB out of the UK for the Barrel extension, as currently buying short drops over here of any suitable steel is almost impossible.

(However if I wanted full lengths then I can pretty much buy anything)

regards Colin

Hi Colin,

The Aluminium you can get hold of will be fine and off the top of my head I think it is 8 mm thick.

Regards

Gray,

For sometime I have been wanting to make some Insert toolholders for the C5. Now I have the Proxxon mill where I want it, I decided the time had come to make some.

Each Insert holder has been machine such that it is automatically on Centre Height. The main body of the toolholder completely fills the tool turret so no swarf can enter and become a problem when changing tools. A step in the underside of the tool registers on the edge of the tool turret. This means the tool can be removed and replaced with no loss of index position.

I am currently working/designing a Lever Operated Tailstock Clamping attachment. This attachment will not require any machining to be done to the existing tailstock body. Because of the similarities of the C5 with U3 & 4 this attachment will also fit the Unimat's. Of course it will need to be shortened in length but that will be all.

Regards

Gray

Edited By Graham Meek on 14/01/2023 17:00:24

The Tailstock conversion has moved down the list slightly. I have been making some new HSS tool bit holders. These have less protrusion than my original versions.

The tool bit is locked by one "Angledicular" M2.5 Cap screw and a 15 degree chamfered washer. I was a bit dubious about this being man enough to hold the tool bit. In use my doubts have been shown to be un-founded. I also benefit from only having to use one locking screw.

The old holders now get used on the Unimat 3.

Although this may be only a temporary measure as I have an idea for a better set-up on here.

Regards

Gray,

Some while back I promised a Lever operated Clamping attachment for the C5.

This shot shows the attachment fitted to my Tailstock salvage scheme. This still uses the same lever, eccentric and eccentric pad. The standard attachments do not require for the standard tailstocks to be modified in any way.

As I said earlier, what fits the C5 will also fit the Unimat. Above are the component parts to complete the conversion on both machines.

This shows the sculpting required to miss the internal strengthening ribs.

This shows the C5 parts assembled and fitted to the Unimat 3 for convenience as regards photography. Below with the tailstock body fitted. No more searching for that Allen key, or having the key foul the topslide if the key is left in-situ.

Lastly we have the Unimat base fitted to the lathe.

Because the C5 tailstock body casting fouls the Leadscrew handwheel on both the Unimat and the C5 it will not slide on and off the Bed. The Unimat tailstock casting does and the whole unit can be removed at will once adjusted. Here is the attachment waiting for the tailstock body.

Here is the Unimat tailstock completed. As these attachments sit on the bedway in their own right. When the tailstock body is fitted the whole unit slides up and down the bed with a nice silky feel. The attachment also ensures less debris can enter beneath the tailstock to bed interface as the design clearance is only 0.05 mm (0.002"  )

This concludes the Modifications to the Compact 5.

The only other item I am considering making is a Motorised Toolpost spindle, but as this is a separate stand alone attachment, it will be probably be described in a separate post.

Regards

Gray,

Edited By Graham Meek on 21/04/2023 17:12:34

Hi Graham,

That's another set of terrific modifications you've done,

I'm curious to know if you'd ever considered back-filling the inner voids within the Tailstock body with something like a metallised epoxy (JB Weld, Devcon, etc)..?

As you'd likely know, my Proxxon PD 250/E has so many similarities to your C5, its Tailstock design & construction being just one.

In use with the 10mm Rohm Chuck, my Tailstock is "nose-heavy" when sliding it along the bed until it's locked down & so I'd contemplated about "adding weight" into the rear cavity portions..?

Now having almost completed building your "Lever Action" attachment for my own Tailstock, I'm again wondering if filling those rear voids might help?

Would appreciate your thoughts on whether it's a good or bad idea?

regards Colin

Hi Colin,

Thanks for the kind comments as regards the design.

I have never considered the need for the void filling. Plus with the C5 tailstock, access is required from below to get to the two set-screws used to locate the tailstock barrel and lock the feedscrew bearing.

The design of this attachment will not allow the tailstock to droop when you move it. The lever action allows just enough clearance for the tailstock to slide when released. It is a bit like just slackening off the clamping plate on the standard set-up to allow the tailstock to slide. Unfortunately using the standard set up to do this usually results in the clamping plate jamming, due to the turning moment on the plate.

It is funny but this design actually came about because of a YouTube video on converting a Proxxon Tailstock to lever clamping. This involved machining the tailstock body, (a big No-No with me, which I have proved is not needed). Which combined with the sloping back face on the tailstock of that particular model and the oversize bore used. I considered not to be a real proposition on the C5 especially as the two internal ribs which take the camping forces would be virtually machined away.

The beauty of this design in use is that I can release the locking lever with the third finger of my Rt hand. Move the tailstock with my thumb, index finger and second finger, then re-lock again using the third finger. One slick operation which makes using the machine so much more enjoyable. Plus makes me more efficient in my work time. (By the way the lever ratio is 30:1)

At first glance I can see no reason why this type of attachment would not fit these lathes, and I had considered mentioning this in the previous post. Of course I would really need to have access to a machine, or machines in order to make a proper appraisal.

Regards

Gray,

Hi Graham,

Recently acquired an abused Emco Compact 5 and readying through the forum posts for rebuild/upgrade references. I noticed that you have 3 different C5 tailstock photographs within this forum thread: original, lever added, and machined base with lateral keyway and lever. Would you mind sharing more information on the tailstock with the lateral keyway? It is shown 2 posts above.

Best Regards,

David

P.S. 2 C5 milling heads are current for sale on eBay here in the USA

Hi David,

I my apologies for not replying sooner. I have been in the middle of a Broadband upgrade that did not go too smoothly.

I take it this is the tailstock base you are referring to.

This was a salvage scheme done many years ago when I first had this machine. This was a tailstock from a donor machine. The original tailstock was out and rocked about on the bedways. The salvage of this tailstock on my Proxxon mill appears earlier in this post.

The Donor tailstock body was modified because the tailstock barrel was running out towards the back of the machine. Plus it was also dipping down towards the bedways.

I have been intending to draw this up and write an article on how to do it. The problem there is it may be some months before the article will get published. This modification is not for the faint hearted it requires a good deal of patience to achieve the desired effect. It does combine an adjustment to ensure the tailstock centre-line is coincidental with lathe spindle.

If you will bear with me and maybe give me a nudge via a PM in about a months time I will see what I can do.

Regards

Gray,

Edited By Graham Meek on 29/06/2023 15:38:54

As promised I have made a start on the Tailstock Base Salvage scheme, as used on my own C5.

Unfortunately during uploading to this site the drawing has turned through 90 degrees.

The scheme incorporates a means of moving the tailstock laterally across the bedways. This involves one M5 grubscrew being in contact with the inside wall of the tailstock casting nearest the M6 Clamping screw. While an M6 grubscrew impinges on the rear inside wall of the casting.

Access to this adjustment is via a hole which Emco kindly provide in the back of the casting. Unfortunately this hole is in two different places on the tailstocks that I have. The newer casting has the hole lower down as shown. To accommodate the casting with the hole higher up just requires making the head of the spigot taller.

This spigot also locates the clamping plate, (which needs to be modified with a 6 mm hole), and stops this plate from jamming when moving the tailstock. The addition of a spring around the M6 clamping screw between the plate and the the new tailstock base, further refines this set-up.

The M6 grubscrew is drilled though to allow a 2.5 mm A/F Allen key access to the M5 grubscrew. This moves the tailstock towards the operator while the M6 grubscrew moves the tailstock away form the operator.

Once the optimum setting is reached the two grubscrews lock the casting to the new base plate due to the opposing forces of the grubscrews. This however does not want to be overdone as there is a risk of breaking the rear tailstock casting wall.

I have yet to dimension the drawings which I hope to complete over this weekend.

Regards

Gray,

Here are the drawings of the modification. As I said earlier this is not something for the faint hearted. It is easy to achieve provided the project is approached methodically. To make the New base I would recommend using a jig which is machined in situ in the dividing head, with tailstock support. A tenon machined on the jig will automatically orientate the base to ensure alignment. The base can be held on the jig using the two 6 mm diameter access holes for the grubscrew which locks the tailstock feedscrew bearing and the Dog point Barrel alignment grubscrew. M5 tapped holes will be more than adequate.

Rotating the dividing head will ensure a perfect 90 degrees for the Vee. Provided the bottom of the Endmill or slot drill is used. Once the Vee is established the 10.50 mm dimension can be established. This also ensures all surfaces run parallel to one another.

It would pay to leave the base oversize on thickness, say about 0.1 mm to allow for some fine tuning once all the parts are made. It is always better to have material to come off than having to put some back on or even starting again.

To machine the tailstock a set up as used earlier in the post using two Vee blocks and a mandrel will ensure the alignment of the tailstock barrel bore and the Tenon.

Regards

Gray,

I have added an additional view for those who want to make this conversion. It relates to the amount of material that needs to be removed from each side of the Vee. Please note this only applies to a 2 mm wide slot. If the slot is less or more than this then some trig will work out the different dimension.

Regards

Gray,