Member postings for Brian John

Yes, I always go up to 1.7mm when tapping into steels.

What brands of M2 taps do members use ? I never have any trouble with M3 or larger taps but I have had a few M2 taps break. Brass and cast iron are usually okay but steels often cause problems. I use plenty of Tap Magic and I go very slowly, about 1/8 turn at a time....back and forward.....but I still sometimes get a broken tap.

Pero : My current lathe was not cheap at all and I did buy from a respected seller of machine tools...and I still had problems ! It was not purchased from ebay. Many of the problems were exacerbated by that fact that I live in Cairns which is far from the supplier. Had I lived in a capital city like Brisbane than I could have just put it in the back seat of my car and taken it back. They probably would have given me a new one once they realised the extent of the problem.

Edited By Brian John on 12/07/2017 03:34:54

The Model Engineer magazine must have many articles aimed at beginners. Could not these be gathered together into a book or a special issue magazine ?

I buy what I can afford. Actually, there was nothing cheap about my lathe. It cost  as much, if not more, than a C3. The reason I bought it was because it was small and I only live in a small unit. It is mounted in my living room.

Criticism of the Vevor lathe duly noted and I will pass on it....thank you.  I had never seen it before so I thought it was worth asking about.

My current lathe has a carriage lock so I assumed that it was a standard fitting on all lathes. I find it essential for parting off.

Edited By Brian John on 12/07/2017 02:09:34

Geoff : any chance of a photo of the T nuts you made ? How much thread have you put on them ?

All points duly noted. Where is the carriage lock on these lathes ?

Does anybody recognise these VEVOR lathes ? They seem to be all over ebay in Australia but I am not sure if you have them in the UK. I know they are made in China but have the lathes been around long enough for people to form an opinion of their capabilities ?

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I doubt that I will get anywhere with the fly cutter ; I cannot get the shape correct.

Lawrie : yes, a larger diameter milling bit does make sense. A 12mm bit should do it in three passes.

The vertical mill slide for the Optimum lathe is back in stock at machinery house. What diameter end mill bit would be suitable for machining the side of this cylinder ? I was thinking of the 6mm bit. I have not done any milling at all so I do not have a clue.

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Edited By Brian John on 22/06/2017 10:10:48

Getting the shape right.

Anyway, here is what the base of the mill slide looks like. The L276 from Machinery House only has one hole in the middle of the base whereas this tool has two holes. Other than that it looks identical and It should be okay to fit to my lathe somehow.

Edited By Brian John on 24/10/2016 18:21:57

Edited By Brian John on 24/10/2016 18:22:48

I am having no luck with the fly cutter so I will revisit the idea of a vertical mill slide. This slide from India is the same size as the correct slide from Machinery House. I am not sure how it fits yet but I am sure something can be done to make it fit my lathe.

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What would be a good size milling attachment to use in the lathe chuck for this job ?

Edited By Brian John on 24/10/2016 11:48:10

Why should parting off from the rear and running the lathe in reverse be any better ? I do know that taking a facing cut from the rear with the lathe in reverse often produces a better finish on my lathe but I have no idea why.

The fly cutter has arrived after going missing in transit for two weeks ; nobody knows what happened to it.

Does this look even half right ? I have set the middle of the cylinder (marked with a black line) at the height of the tip of the fly cutter cone. Then I have adjusted the cutting tool so that it sweeps right to the edge of where I need the flat. This is my practise cylinder. I have drilled and tapped two other cylinders but I will not be using them until I get some idea of how this works.

Edited By Brian John on 21/10/2016 07:24:39

Minitech in Australia only have grade 304 stainless steel. A google search has shown this to be difficult to machine. I will have to order the 303 from ebay/Hong Kong so it will be at least a month before it gets here.

Regards the control valve : I see that Minitech have both 4mm and 6mm stainless steel rod. I might be able to make it the same way as I did with the silver steel but without drilling and tapping. I would just use brass round 3/32'' (2.38mm) and Loctite to pin the pieces together. Drilling into stainless steel with a 2.3mm or a 2.4mm drill bit seems more feasible than drilling it with a 1.6mm drill bit....and no tapping involved.

I will not part off ; I will use the hack saw.

What grade of stainless steel is best for lathe work ?

Edited By Brian John on 18/10/2016 14:54:30

Edited By Brian John on 18/10/2016 15:03:54

But it will be oiled by the displacement lubricator so wouldn't that prevent it rusting ?

There is no way I am going to try drilling and tapping stainless steel...I had a devil of a time with the silver steel...or turning it in the lathe either !

Perhaps I should have made the whole thing out of gunmetal bronze which was my original plan.

Edited By Brian John on 18/10/2016 09:46:29

I was not totally happy with my idea for the control valve so in case the retaining compound does not hold I have come up with a plan B. The control valve has been made in two parts using 6mm silver steel and 4mm silver steel joined together with M2 threaded brass rod which will be held in place with Loctite 222 (low strength). The only turning I had to do was reducing part of the 6mm shaft down to 4mm. I used the flat edged parting tool for this, taking small 0.05mm cuts while passing it back and forwards between the 6mm sections.

Drilling and tapping took longer than expected due to rubbish drill bits breaking ! I hade to remake the parts a few times. I bought some good quality 1/6'' (1.59mm) drill bits today from NQ fasteners here in Cairns. They only had two in stock but it was enough to get me out of trouble. I will join everything together tomorrow. I have screwed one together on the photo and left one in parts so you can see how it fits together. I think somebody suggested this idea earlier...many thanks.

UPDATE : the fly cutter has gone missing and nobody knows where it is at this stage. It left Melbourne 16 days ago. I am starting to think about making some sort of jig and filing the cylinder flat by hand.

Edited By Brian John on 18/10/2016 08:10:49

Edited By Brian John on 18/10/2016 08:14:13

Where are we at with 3D scanners ? Is there anything on the market for under a 500 pounds that will do a good job. I am thinking of replicating old model train parts (4mm/OO gauge).

NOTE : I am aware that there may be copyright issues involved but let us leave that aside for the moment. I want to know how good the current scanners are.

Edited By Brian John on 17/10/2016 18:11:45

Edited By Brian John on 17/10/2016 18:14:12

Where can I buy decent quality drill bits : 1.6mm and 1.7mm ? I have been using those small packets of ten that come in the plastic cylinders from Hong Kong (ebay) but the latest batch is awful : they wobble, they are rusty and they snap easily.

I am in Australia but I will buy from overseas if I have to.

Edited By Brian John on 17/10/2016 11:15:35