Adaptation of the Proxxon Milling machine

Re the LED lamps: why bin them? It should be fairly easy to convert them to a low-voltage supply. Surely the mechanical hardware is worth a few bob?

Hi Kiwi Bloke,

My original thoughts were to use two of these lamps either side of the milling head in bespoke units. With more rigid arms. The Flexible arm is good in theory, but does start to droop over time. In the current set-up the head of the light unit is held by a single screw which also holds the internal circuit board of the mill.

This position affords the best option from an operational point of view, but it does not illuminate the X-Axis dial in low ambient light levels. A good point for me is I don't run the risk of the light catching me in the eye and triggering a migraine.

Regards

Gray,

Gray, did you overlook my previous post?

Hi Kiwi Bloke,

I apologise for not responding before but I did not see this post.

1. To fit a Gib adjustment strip would necessitate opening up the Keyway in the Slider. Twelve months ago when I had my other equipment this would not have been a problem. Today that would be impossible unless I subcontract the job, which is fraught with problems.

Fitting a Gib here would also mean putting the adjustment screws in from the back of the machine.

When the head is unlocked the turning couple due to the weight of the milling head. Tends to concentrate the force at the top of the rear face of the Keyway. This would be directly onto the Gib strip if it was situated here.

The ball race allows the adjustment to come from the opposite side and any droop from the turning couple is taken by a solid face. I also chose the ball race because this would reduce the drag. When compared to a full length Gib strip. It will also tolerates a slight deviation in the Key strip width, due to this being just drawn bar stock.

2. In an ideal world I would have fitted this key in a shallow groove. This does two functions in that it would take out any straightness issues from a bent Key strip. Secondly it is not going to move in use. Plus it would not matter if Countersunk screws are used.

Proxxon have had two different types of Key strip attachment from the components I have in my workshop. Some years back they were attaching the Key strip with M4 Slotted Countersunk screws. This Key strip is planted directly on the Column diameter. The Column on this set-up is of "Drawn" appearance.

Currently there is a flat machined on the Column and the Key strip is held with 3 x M3 Countersunk screws onto this flat. Even here there is a second deviation in that some columns have been turned, while the two new ones I received from Proxxon recently have been "Ground". I have put Ground in inverted commas because I am of the opinion from the finish that this may have been done with a tube linisher. The new Columns do perform better than the old ones.

I hope this helps?

Regards

Gray,

Edited By Graham Meek on 21/02/2023 11:39:21

When I say binned, they are in the scrap bin awaiting further use. I did actually modify them by cutting the pcb in the head and so getting them to work on about 20v if I remember correctly, but a refit of the main power supply took away the 20v supply, and so it was a lot easier to start again.

Gray. Thanks for explaining. It all makes sense. Instructive. Seems Proxxon equipment may be more than a bit like the curate's egg?

Duncan. Glad to hear you also have a scrap/to-be-used-later bin! I hate waste and throwing anything away. My wife tells me it's a problem. I think it's a virtue...

For some while I have been working on the Tailstock Support to be used in conjunction with the Emco Dividing attachment. I used it recently to make the Eccentric Spindles for the Emco Compact 5 and Unimat 3/4 Lever operated Clamping attachments. One of the Eccentric shafts is being set up in the above photograph.

The Tailstock body is made in to halves for ease of manufacture. The split line is easily seen in the above picture. Two Button headed dowels locate in the central Tee slot. This automatically locates the tailstock on the same centre-line as the Emco unit. Which also uses two button headed dowels in the same tee slot.

The tailstock barrel is locked by two brass half pads using the adjustable clamping lever. The barrel currently looks a little over-long, and this may well get shortened sometime in the future, once I have had a chance to use the tailstock a bit more.

The interchangeable centres uses the usual Unimat location technique but the dimensions are the same as the earlier Unimat SL. I had thought of using the U3/4 dimensions but this would have led to a larger tailstock barrel. This can be a problem when working on smaller pinion gears. Where the gear cutter fouls the tailstock barrel.

Regards

Gray,

I have just completed this revised table feed attachment. It was designed with a view to the FF 230 mill requiring no modifications in order to fit the unit. It simly bolts on where the original feedscrew bearing plate fitted.

I had some help from John Slater in the form of a small PWM board. The control and "ON-OFF" for the PWM can be seen below the motor housing.

The two knobs on the top of the unit control the direction of travel, (nearest the handwheel), and the clutch to engage the drive to the table.

Not only is there a variable drive through the PWM, but the Proxxon NG 2e Power supply can also provide additional variations. The table is really going some when the both controls are on maximum. As yet I have not had time to calculate the exact top feed rate.

Regards

Gray,

As is usual lately I have forgotten to add a photograph of the component parts of the feed attachment.

Regards

Gray,

Graham, you are a true Craftsman - Absolutely stunning work.

Joe

Plus one for Joe's comment, top quality workmanship.

Highly accurate machined parts with excellent surface finishes like those are tough enough. Designing your own specialized parts starting with a blank piece of paper or computer screen and making them good looking, functional as well as in proper proportion is something else. Very few in my opinion have that combined set of skills Gray. My best compliment I could use for anyone's work would be to say there as good as anything George Thomas did. I think you've set a new bench mark for what my best compliment would be now.

Have you given any thought about producing a volume II of your Projects For Your Workshop book?

Thank you all for your kind endorsements of my work. This project has been a test for man and machines. While the machines handled the work with no trouble. I have found this project has taken me a long time to achieve.

I was fortunate enough to call GHT my friend and visited him many times at Milton Grange. I owe a lot of my skills to his writings and his meticulous approach to planning his projects. He was a fount of knowledge when it came to engineering, and his woodworking skills with mortice and tenon joints would put many a toolmaker to shame.

As regards a volume II I regret to say that this is out of my control. Chris Deith was the instigator of the first volume, which came totally out of the blue when he rang me one day at work with the suggestion of a book. That was well over 13 years ago now and approximately 50 articles ago. I suspect with his passing that will be the end of any future volumes.

Regards

Gray,

Edited By Graham Meek on 30/09/2023 16:39:17