Member postings for Tony Pratt 1

Blowlamp, just read your post. Another principle I picked up along the way is that you do not need two registers to do the same thing and is incorrect and adds extra cost .

Tony

Of course a threaded only spindle will and does work but I would imagine was only chosen for cheapness. We then move up to parallel register/thread and then the most expensive but prefered option is tapered register and either a screw or cam locking system, I'm sure if a thread only spindle was acceptable the large machine manufacturers would not spend a fortune making the fancy tapered location varieties?

Tony

In the first case perhaps the register diameter is not undersize right up to the shoulder. In the second case without a register, it's obviously pulling up on the thread, but I would still suggest it isn't the best way of locating a chuck to ensure concentricity?

Tony

I agree Michael Williams is correct. I always undestood and practiced that screw threads are not an accurate form of location or register but only a means of fastening parts together.

Tony

Hi Joe, that is seriously "inexpensive" for a British made product! I can't see any profit for anyone at that price if they are made in Britain?

Tony

I can't see how "made specifically to fit Myford 7 series lathes" or something similar could offend anyone?

Tony

Hi Graham, I don't think they exist as threaded shank cutters in the small diameter range come with 6mm, 10mm, 1/4" & 3/8" shank diameters.

Tony

Hi Michael, Myford was actually brought by RDG tools last year after they went out of business? As far as I know Myford never actually made lathe chucks but I may be wrong. I thought Toolmex and HBM were actually eastern imports but the Toolmex site is saying it is a US company but I doubt if the chucks are made in America but I stand to be corrected. It's a pity you are having shall we say file to fit but that is par for the course on a lot of tools these days.

Tony

Good luck Neil! Sounds like you have done all you can, I am always amazed when people go to bed and in the morning they are suprised when their wordly possesions are floating down the road, after a week of flood warnings. If I was in a flood area I certainly wouldn't sleep a wink and would be monitoring the situation hourly.

Tony

I have always had fair results knurling with a scissor type tool and all the good advice above is relevant. I must admit to never calculating knurl/work diameter and it always seems to come out ok in the end.

My view is also being covered with adverts using IE8, comp view on or off makes no difference.

Tony

Hi Mark, get as close to centre height as you can that's your reference, then try all the other suggestions above.

Tony

Would be good for all types of heat treatment of metals, tempering oil blacking etc. Also melting certain metals. It needs a temperature controller to be really versatile.

Tony

Michael, the 3 gentlemen you quote are of course no longer with us to defend themselves so we will have to accept your word on what they did or did not say. The truth of the matter is that obviously flatness is the preferred option, then concave and the worst case scenario is convex.

What I will say is that Tubal Cain (the REAL one), GHT, Dennis Chaddock were I believe highly qualified engineers and also extremely skilled and practical machinists etc. In my experience having this combination of skills is not all that common.

Tony

The idea behind a new lathe facing concave is to prolong it's useful life. As it wears it will face concave, then flat and then finally convex which is the least desirable condition.

So buy an expensive lathe and it only cuts right for 1/3 of it's life? So if you buy a second hand one, make sure it is half way through it's lifespan and maybe it will cut correctly.

Something wrong with that way of thinking.

It's not a way of thinking it's a fact and a properly made lathe will face correctly until it cuts convex. I have only owned a Super 7 but worked on many lathes in industry and I must agree that Myfords are vastly over priced, under powered and short on specification. They are a joy to use and feel nice to the touch but if I ever change my lathe I will seriously look at the far eastern products.

Tony

The idea behind a new lathe facing concave is to prolong it's useful life. As it wears it will face concave, then flat and then finally convex which is the least desirable condition.

Tony

If you don't have a good fit between pillar and the body you will be relying on friction to stop the body pushing away from the work when cutting. I know the tool will still be able to pivot about the pillar but I would still go for a good fit.

Tony

Hi Allen, just a word of caution, if you do decide to use a draw bar[which is a good idea] do not over tighten it! If you do you may have trouble releasing it.

Tony

Hi Jan, have you got a copy of the S7 manual? if not it is a good idea to get one and well worth the cost! I have set my S7 several times using the cut and try method described in the Myford manual with no problem. don't worry about how much shim you need as the stand etc is only a welded box and cannot be expected to be a reference surface. When the lathe is cutting parallel the lathe bed isn't twisted. Obviously a used lathe will be worn to a certain extent so you will have to get the best out of it you can.

Tony

Richard, I know grinding lathe tools is a basic skill to learn as I have been doing it for 40 plus years! You are missing the point in that the OP paid for and wanted a screw cutting form tool and thats not what he got. For a beginner that is a serious issue, it's just not acceptable to buy a form tool which isn't to the correct form. I also agree that carbide is a bit OTT for home workshop screw cutting and you can buy HSS screw cutting tools from the usual suppliers ready ground hopefully to the right angle.

Tony

This tool doesn't need to be "touched up" as some people quote, it's a complete regrind if you have a Silicon carbide or diamond whel to hand. I'ts also irrelevant if some of you guys can grind a screw cutting tool in 5 minutes, a lot of people can't!

As has been said before I really don't think in some far eastern factories quality control exists, perhaps just a printer knocking out inspection certificates to assure us the tools we buy are within specification.

Tony