Member postings for ega

See advice at:

https://www.directplastics.co.uk/about_plastics/post/all-about-delrin-as-an-engineering-plastic

Ingenious use of cheap ratchet spanner to lock and unlock tailstock!

Patrick *lathes* are listed; perhaps a different Patrick?

Daniel

Thank you.

A favourite jingle comes to mind:

Dare to be a Daniel,
Dare to stand alone!
Dare to have a purpose firm!
Dare to make it known.

No doubt we shall be prosecuted together for copyright infringement!

Nice lathe, by the way.

Might someone rotate these interesting photos so that they can be viewed in comfort, please?

Further to John Hinckley's information, the test sheet with my machine says "60W cont. 100w 15 min".

My vintage Warco 6 x 4 machine came with a 240mm x 260mm sheet steel table for use in the vertical mode which is quick to mount and remove. It would be easy to make one for a similar machine which didn't have one.

My experience generally supports the comments by Perko 7 and Richard -. However, I don't find the swarf a problem in practice; I am cutting without lubricant and clean up with vac or brush.

The other day I made a 400mm straight cut in 3mm steel sheet without difficulty. Curved cuts are limited by the fixed width of the blade on my machine and, of course, there is always the limitation of the arm which restricts the throat by comparison with a conventional vertical bandsaw.

Neil Lickfold

Thank you. That looks both simple and ingenious.

I think your point about tube length would also apply to car exhaust systems.

PS I am a fan of Rocol slideway lubricant; expensive  in aerosol form but very effective.

Edited By ega on 07/06/2019 11:24:40

Your system sounds interesting. Might you post a picture? (If only to get the image of a pot *under* the bed out of my mind!)

The Barker lathe - see lathes.co.uk - used round bed components in a rather different way and was also "triangular".

Is the wedge in fact a taper pin and does it project from the bar? If so, this seems another disadvantage to this design as it will constrain the projection of the cutter - the bit that matters!

Whatever method is adopted, it will be much easier done on the bench rather than with the door already hung.

Hiring the router and buying the jig rather than the other way round seems doubtful policy. If routing, aim to use an up cutting-bit.

Presumably, one of the OP's "cutters" was a wedge. An easy mistake to make and one easily avoided by the seller.

John Haine:

GHT gave instructions for a screw-adjustable boring bar which he intended for use on the Quorn castings.

Sounds defective but is there an axial push rod that secures the cutter?

Here's one I knocked up recently from a couple of pillow block caps:

This extract from Cliff Bower's Book of the Lathe (1955) is probably more applicable to flood coolant users:

PREVENTING WEAR

One of the main causes of deterioration in chuck truth is wear of the scroll bearing, and usually very little has been done by chuck manufacturers to minimize this. Wear in the scroll bearing arises from the ingress of swarf and other abrasive particles between the rotating surfaces, and these are often washed into the bearing by the action of cutting lubricants. One way to minimize the ingress of harmful material from outside the chuck is to pack the inside of the body with thick grease. This can be packed in by removing the back plate and the back cover plate from the chuck body. A better way is to force the grease into the body under fairly high pressure from a grease gun, and a means of doing so is to drill and tap a hole in the body for the insertion of a high-pressure-grease nipple. So that this will not be hazardous to the machine operator by projecting outside the body and catching in sleeves and other parts of his clothing, a recess should be machined so that the nipple is completely sunk below the body surface. The grease hole can be closed by a screw plug suitably shaped, to restore the smooth exterior of the body.

When grease is forced into the body under high pressure from a gun, it penetrates the clearance space in the scroll bearing. Since the pressure within the body will be fairly high, the passage of harmful material into the bearing will be blocked. Alter a time, the grease in the bearing will be washed away, and it can be renewed by applying more grease by means of the high-pressure nipple. The grease flowing through the scroll bearing will force out any harmful material which has penetrated into the bearing. The grease should have a fairly high viscosity; if it is too thin it will tend to be flung out of the pinion holes by centrifugal force, particularly if its temperature should rise for any reason.

The idea of using lubricant to scavenge foreign matter from a mechanism is also used for cycle hubs.

Sounds like a good tip; can you confirm that it is the book by Claire Davies that you recommend, please?

(There are a number of titles with similar names).

Could the slit be left incomplete to prevent the casting closing up too much due to released stresses?

MichaelG:

Thank you; you are the master of the LINKing art!

Mike Poole:

Tap and test should not be necessary with the Smith gauge but if needed the GHT-style adjuster is a great help:

(The "topslide" in my picture is actually an ML7-style cross slide which is good for longer tapers).

You could if you made and used a Smith taper gauge; see my posts in this thread:

https://www.model-engineer.co.uk/forums/postings.asp?th=85534