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Member postings for Graham Meek

Here is a list of all the postings Graham Meek has made in our forums. Click on a thread name to jump to the thread.

Thread: Chris Deith
25/05/2022 16:39:45

I am deeply saddened to hear about the loss of such a kind and helpful man. He was instrumental in getting me to put pen to paper and bring to the Hobby my designs. He also took me by surprise when he said he wanted to put my articles into a book, but he obviously knew his business.

I shall miss being able to catch up with him at the exhibitions.

Our thoughts are with his family at this difficult time.

Jean & Gray,

Thread: mini grinders
21/05/2022 10:08:15

I have had a 12v Proxxon for over 10 years, it has done a lot of work and is still fine, never gets hot and is above all quiet compared to some I have used.

Regards

Gray,

Thread: Emco Compact 5 Modifications
20/05/2022 16:47:32

Work has ground to a halt on these projects for a short while. I need to spend time getting the larger machines out of the workshop.

As a taste of what is coming I have enclosed one of John Slater's 3D views of the Retracting Topslide attachment.

c5 retract john slater.jpg

Since John has made this drawing I have moved the Operating handle to the other side of the unit. That way it does not foul the Tailstock.

Regards

Gray,

19/05/2022 10:06:14

Dear Jouke,

The leadscrew engagement on the Handwheel conversion is carried out by the lever on the left-hand side of the carriage. This lifts a cylindrical half nut via an eccentric into engagement with the leadscrew. The cylindrical half nut is keyed to stop it rotating so alignment with the leadscrew is always assured. (One half nut has been used on numerous occasions in the past by various lathe manufacturers).

While your C5 powered cross feed sounds an elegant design. I think if I were trying to do this I would start with a C5 CNC cross slide and carriage assembly. These regularly come up on the Internet for sale. I think this would be an easier starting point. A plus point is these parts are, I believe, made from Cast Iron.

With regards to my design modifications. I pride myself in that I do not modify the existing machines in any way. I always make use of existing tapped holes for attachment points. No existing Emco part was modified in this recent design and my C5 could be put back to standard in a matter of minutes.

Regards

Gray,

18/05/2022 10:22:33

Dear Jouke,

Stops on the trip rod running along the front of the machine can be set to any desired thread length, with-in the limitations of the machine. The trip rod moves to the left or right depending on the operating lever position. Which dictates whether the the thread is a RH or LH. Moving the operating lever to the right means the trip rod moves to the left and visa versa.

The operating lever works the banana shaped plate, at one end of this is the trip rod and at the other is the dog clutch selector. Thus any movement of the trip rod directly affects the dog clutch selector.

As the carriage moves along the bed during screwcutting it makes contact with the stop, 2.5 mm later the dog clutch is disengaged. Moving the operating lever in the opposite direction, after withdrawing the tool, returns the carriage to the start position.

As there is only one tooth on the dog clutch it can only pick up the drive at one pitch intervals.

Regarding the hand wheel position, this end was chosen so as to utilise the existing leadscrew nut fixing position and to retain the original operating force position on the carriage.

In my experience there is always a dead space at the headstock end of the bed due to the chucks, faceplate and catch plate attached to the mandrel. I therefore did not consider there would be much loss of travel. However in this instance I may be wrong.

I hope these notes help,

Regards

Gray,

PS

I have just completed a new topslide feedscrew using the above attachment, I hope to post a photograph soon. Which is for the next phase of the mods, a Retracting Topslide.

17/05/2022 09:21:01

One thing I did forget to mention is that the gears were made using the Emco Compact 5 Dividing attachment and are all 1 MOD.

Regards

Gray,

16/05/2022 11:02:07

Hi Kiwi Bloke,

Thanks for your kind comments, there were times when I nearly abandoned the whole idea. Thankfully things are now on the up and life goes on.

I'd like to take the opportunity to mention that I don't think a lot of people realise the cross-section of the C5 Bed ways are identical to the Unimat 3/4. I recently posted on here, about the restoration of a Unimat 3 that was given to me. It was a bit of a basket case and was fitted with a large induction motor all suspended off the headstock.

Despite the obvious abuse to this machine in it's life, there was zero wear on the bed ways. The Tailstock and Cross-slide assembly were worn but the wear was nothing like I was expecting.

Fortunately Emco saw the light with my C5 as this one comes with an adjustable / replaceable cross feed nut. The Leadscrew nut also benefits from a backlash adjustable feed nut. The trip-rod bracket is anchored off this adjustment screw.

Thus I think given my intended use for these two machines I don't see wear being a problem.

I did draw-out such an apron attachment some while ago, but as yet I have not got around to making it.emco compact 5 handwheel conversion p1.jpg

emco compact 5 handwheel conversion p2.jpg

Whether I ever will, is another story, I might if I get the chance to obtain another C5.

Regards

Gray,

Hi Joe,

As mentioned above things are on the mend now, so I am doing OK thanks. The C5 project has been a God send really, if a lot of very hard work given the timescale I set myself.

Unfortunately the FB2 is going as well. While it will be hard to see both of them go, it has to be done sometime. Better to do it while I am able to. The machines will make someone else happy and I hope they get as much enjoyment out of them as I have had. I am really looking forward to using the smaller machines, I started out with a Unimat SL 64 years ago.

As regards the CNC, sorry appearances can often deceive. Everything was done by first principles and the trusty Emco Rotary table. Total machining time was just over two days.

Regards

Gray,

15/05/2022 11:16:37

After deciding to downsize my workshop in January, the need to get the Compact 5 (C5) up to a standard I was comfortable with became a priority. The use of my larger machines would be of benefit while they were still here.

Having had the luxury of the Screwcutting Clutch on the Maximat Super 11 it was something I was not happy to do without. The C5 had always been tempting me to do this mod, so during my recuperation in February I set about designing the attachment.

gboxbody john slater.jpg

The above view shows the Mk1, and it also shows you really need to be in the workshop more. The reason being I had forgotten to allow for the dis-engagement of the Leadscrew. This being a necessary requirement on the C5, other wise in Manual mode the operator has to turn the banjo gears as well.

gearbox components.jpg

This need to retain the C5 disengagement Knob meant the Operating lever would need to move from the chosen site where the knob was to in front of the headstock. Thankfully during the need to do a complete redesign of the main body it was possible to have both controls in the one place.

compact 5 main body 1.jpg

compact 5 main body 2.jpg

The keen eyed amongst you will notice the main body is now in two halves, or parts. Again had I have been a more frequent visitor to my workshop at the time, I would have noticed the Bracket welded to the inside of the Headstock cover, which takes the cover locking screw.

compact 5 screwcutting clutch.jpg

Had it been possible to retract the leadscrew with drive key attached through the bearing in the lathe bed, then the original design would still have worked. Unfortunately the key stands proud of the shaft and this cannot happen. Thus there was nothing to do but start again with two halves, and yes this was after I had machined the main body in one. Of course I could have cut the bracket off, but that is not how Graham operates.

dog clutch assembly.jpg

The redesign also threw up another problem, in that the Dog Clutch, because of the split line needed to sit higher in the upper part of the main body. Unfortunately this brought the dog clutch selector into conflict with the drive belts when changing to the lowest Mandrel speed. This was eventually overcome by machining a flat on the selector similar to the flank on a camshaft. An eccentric balance weight is yet to be made and fitted to the outer end of the selector shaft.

A new bearing assembly was also made for the Leadscrew handwheel which has some Radial ball bearings in. The housing was extended towards the Headstock to provide the anchor point for the outer Trip Rod support. The ball bearings will eliminate wear to the leadscrew end face and give better repeatability when screwcutting.

While I have used this lathe for screwcutting in the past, it was a rather hair raising experience. This attachment now completely eliminates the heart stopping moment as the tool approaches the chuck jaws.

I will in due course go on to describe other attachments for the C5, two of which get the benefit of the screwcutting clutch. I hope you have enjoyed my rather long winded post.

Regards

Gray,

Edited By Graham Meek on 15/05/2022 11:20:55

Thread: making spindle bearings
03/05/2022 09:55:27

Hi Jamie,

That is a lovely piece of work, you should be justly proud of that.

Using an H7 reamer will give you the same size hole as the Oilite bush. These are normally supplied to give an H7 bore when they are pressed into a hole which is itself H7.

Hopper has the best option and it is something I have done in the past. That being to machine a custom Oilite bush. Billets of solid Oilite used to be available and this would give a better self lubricating bearing solution.

Torlon in my experience takes on moisture so you might have problems with this material. Especially if it is machined in a humid atmosphere and then lives in a relatively dry environment.

Regards

Gray,

Thread: ER16 Collets from Ebay
23/04/2022 10:46:32
Posted by B Tulley on 22/04/2022 20:46:05:

. Not sure how else I can check the collets though?

When I recently made a new spindle for my Proxxon milling machine, (posted elsewhere on the Forum). Knowing whether any run-out I was getting at the spindle was due to the Collet, or my workmanship, was a primary requirement. I checked the collets before hand in the following manner.

A ground dowel of nominal collet diameter was gripped in the lathe collet chuck. The dowel was checked to see if it was parallel to the lathe centre-line, in the vertical plane. The subject collet was then placed over the dowel and abutted against the collet holding the dowel.

A DTI was then set to indicate on the cone diameter and the collet rotated by hand whilst gently urging it against the "holding Collet". The collets I had obtained from Arc showed no signs of error with my 0.002mm division clock.

Admittedly this does assume the two end faces in contact are perfectly square. However if this is this problem it will show by a progressively low spot reading. At both locations of the clock on the cone diameter. Turning the collet end for end on the dowel should eliminate this sort of error. If it persists then I would say the error is run-out

When I installed the new spindle and checked with one of my collets. Using the same dowel, and DTI, TIR was less than one division on the clock. Which for milling is good enough for me.

Regards

Gray,

Thread: Hello from Gloucestershire
12/04/2022 20:27:00

Greetings from the other side of the County, (Forest of Dean),

Always plenty of advice to be had here, whenever you need it.

Good luck with the lathe purchase.

Regards

Gray,

Thread: Unimat 3 Restoration
11/04/2022 20:48:02

Thanks for the kind comments Howard,

I have been putting the lathe to use today on some bearings for my Compact 5 screwcutting clutch. I am really pleased with the smoothness and quietness of this machine. It has been well worth the effort, plus I saved it from the skip

Regards

Gray,

Thread: Adaptation of the Proxxon Milling machine
11/04/2022 10:05:57

Thank you Michael,

Getting to this stage has been a bit of a struggle. Trying to keep several projects in the air at once is proving to be a tall order. As I am currently trying to finish a screwcutting clutch for my Emco Compact 5. Once this is finished I can complete my downsizing by retiring my FB2 and Maximat Super 11.

Regards

Gray,

10/04/2022 17:17:31

Having already posted the above spindle modification I thought it might be as well to start a new thread as there are now quite a number of additions to the milling machine.

fig proxxon tooling.jpg

The above photograph shows the dedicated tooling to suit the ER 20 Spindle Nose. A new Spindle Nut which has a bayonet fitting allows the various tooling to be removed and added in an instant. Some of the early CNC's used this type of fitting but with ISO 30 & 40 tapers.

The Spindle nut is so designed as to self eject the taper when removal is needed.

fig proxxon.jpg

The Bayonet design can be made out in the spare Spindle nut on the table in the above view.

proxxon machine vice.jpg

I have also made a new vice for the machine, which is based on a Thiel design. John Slater was kind enough to do a 3D view of the design.

fig vice.jpg

There is a variable table feed under construction and I will be showing this at a later date.

Regards

Gray.

Edited By Graham Meek on 10/04/2022 17:19:49

Thread: Unimat 3 Restoration
10/04/2022 17:03:03

Following a period of post-Op recovery I have at long last been able to take some photographs of what has been happening in the workshop.

fig unimat restoration.jpg

Apart from a coat or two of varnish on the woodwork this project is complete. I am very pleased with the outcome. The machine is much quieter than I remember the Unimat to be with its AC Motor.

There is an added bonus in that the lathe toolholders for my Compact 5 will fit directly into the topslide toolpost without any alteration to centre height.

Regards

Gray,

Edited By Graham Meek on 10/04/2022 17:03:53

Thread: Determining/measuring sub-micron displacement
03/04/2022 10:54:38

Clearly my simple solution has upset a few.

The principle is based on the Galvanometers used in my College days.

Above all, there is no need to manufacture anything to achieve a fairly accurate result, the materials would I suspect be readily to hand.

Silly me, I thought this was the purpose of the post.

Regards

Gray,

02/04/2022 11:07:06

Hi Joe,

I have been giving this some thought and think that a horizontal lever which is suspended vertically preferably by a thread. At one end mount a small mirror at an angle. Have a fixed stop for the lever to butt up against when at rest. Shine a Laser pen at the mirror and have the spot somewhere convenient on the workshop wall.

If you move your probe into contact with the lever and mark the dot on the wall. Move away to break the contact and mark the dot again. the difference should be simple trig to sort out.

We used to use a similar technique when setting up the lasers on the Radiotherapy treatment machines.

Regards

Gray,

Thread: Gib missalignment
24/03/2022 10:28:42

Some observations from reconditioning more machine than I care to remember.

If there are dimples in the Gig strip then spherical ended screws are best. Pointed screws will quickly loose there adjustment, they dub over like a bent nail. This is due to the too and fro movement of the Gib as the feed changes direction. This is one of the reasons for doweling the Gib.

Grub screws with a cone to match the angle of the Gib, avoid the necessity to dimple the Gib and are best used with a flat surface on the Gib, but the Gib must be doweled. Or some other form of constraint used to stop endwise movement. They also give line contact rather than point contact.

Regards

Gray,

23/03/2022 19:51:02

I am currently working on an article for Neil on Gib Strips.

One thing I have pointed out at the beginning of the article is to check the angle of the Dovetail. This is something that varies from 45 to 60 degrees. Each manufacturer having their own personal favourite.

Regards

Gray,

Thread: Over 70 Driving Licence Renewal
18/03/2022 17:50:17
Posted by Graham Meek on 14/03/2022 17:57:34:

I will ask my GP about the driving past 70 waver on Friday. I suspect from what I have read this only applies provided the renewal application is with the DVLA.

Regards

Gray,

Well as promised I posed the question to my GP, who was only too happy to help. His reply was it is up to the Driver to ensure he or she conforms with the law. This requires them to complete an application form if they wish to continue to drive.

The only time my GP has been involved with the DVLA as regards the over 70 licence is to do a medical, or complete a questionnaire issued by the DVLA concerning a particular driver.

I hope this helps future readers,

Regards

Gray,

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