What lathe

[SillyOldDufferModerator @sillyoldduffer]

Joshua,

Nothing personal, believe me. We're trying to tell you there are three things that go wrong with lathes:

1. The machine
2. The material
3. The operator

Many of the questions on this forum are from operators asking how to solve a machining problem. Sometimes the machine is faulty or out of adjustment, more likely the machinist is having bother with an unfamiliar job and is seeking advice.

The problem can be one of technique, or dealing with a difficult material, wrong cutter, rpm or feed-rate, or a bunch of other stuff. Turners once went through a long apprenticeship and those of us who are self-taught make many mistakes. Even the professionals have their moments!

Tracking down what's wrong involves eliminating all the possibilities. It's best not to arrive with fixed ideas! We would do you a grave disservice by suggesting an expensive lathe is the answer when the problem lies elsewhere and might be easily fixed.

For example, my mini-lathe wasn't good at threading under power, The motor was too fast and got hot if run slowly for long periods. My solution was to make a hand crank to turn the spindle manually : much more controllable, and the motor and control board aren't stressed at all.

Dave

[Former MemberParticipant @formermember12892]

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[Joshua KempsterParticipant @joshuakempster]

Look pal I totally agree with what your saying and yes I am inexperienced but if I’m saying there was a fault with the motor an it took out the board that’s what happened an the second machine had a bad lead screw an yes it wasn’t very good running at low speeds hence why I sent it back for something more suitable. But if I could produce good work on the old myford then I’d expect to be able to on the newer machine. With regards to the back and forth it’s obvious it’s not a forum for me

[John ReeseParticipant @johnreese12848]

If I were buying a lathe I would avoid any with a built-in variable speed. At some point the Chinese maker will terminate support for the lathe and parts will become unavailable. Unlike lathes with step pulleys and back gears the available torque does not increase at lower speeds.

I prefer a machine with a standard electric motor that can be sourced anywhere. I favor V ways over flat ways. Even with considerable wear in the V ways it is still possible to hold size. On flat ways the wear is concentrated in a small area near the headstock, If the gibs are adjusted for the un-worn part of the bed there will be slack at the worn end therefore it is impossible to hold size.

I have owned South Bend lathes since the 60s. They have V ways, a standard motor, step pulley drive, and back gears. I believe Boxford is a near clone of the South Bend so I would recommend it. Colchester made great lathes but I am not familiar with the smaller sizes. Emco made some great lathes. Stefan Gotteswinter uses one.

I am not opposed to a Reeves type variable speed for lathes although repair parts are pricey.

[Former MemberParticipant @formermember12892]

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[Oily RagParticipant @oilyrag]

"I bought a myford ml7 to make up some air rifle silencers an dispute it being a well built quality machine …."

What was the outcome of the dispute?

Was the problem with the 1.5mm pitch thread not picking up down to the incorrect selection of the module gear being fitted to the TDI?

Edited By Oily Rag on 22/01/2021 22:34:10

[NealebParticipant @nealeb]

Did the ML7 ever come with a metric leadscrew? If not, cutting a 1.5mm thread with an 8TPI leadscrew means the TDI is useless anyway. If it had a 3mm pitch leadscrew, then pickup could be at any point and you don't need the TDI.

Says someone who bought an old English lathe with metric leadscrews that came with all sorts of extras – except the additional worm wheels for the TDI for the full range of pitches. Imperial threads on an imperial lathe are so much easier!

[not done it yetParticipant @notdoneityet]

Posted by Nealeb on 23/01/2021 08:23:51:

Did the ML7 ever come with a metric leadscrew? If not, cutting a 1.5mm thread with an 8TPI leadscrew means the TDI is useless anyway. If it had a 3mm pitch leadscrew, then pickup could be at any point and you don't need the TDI.

…

Barrel threads for silencers are air guns are generally 1/2” UNF, so imperial. Of course one can choose any thread for the silencer construction.

[HopperParticipant @hopper]

Posted by Joshua Kempster on 22/01/2021 18:41:23:

… I don’t reverse the machine I pull it bk to my original scratch cut with the tail stock used as a stop to ensure good position

That's the cause of your double threads right there. Same starting position means nowt when the leadscrew position is not set to match it either by TDI or marking the change gears and returnnng them to that position by hand rotation until reclasping the half nuts. And even then, it only works for certain threads according to a very strict criteria. Martin Cleeve outlines it in his book Screwcutting in the Lathe if you want to learn it.

Its easier to keep the halfnuts engaged, back the tool out and reverse the lathe when screwcutting metric on imperial machines or vice versa and don't have any problem.

As for the old Myfords — who would buy a 1955 car and expect to jump in it and drive to and from work in it every day without putting a spanner on it?

 

Edited By Hopper on 23/01/2021 09:33:50

[Joshua KempsterParticipant @joshuakempster]

1/2” x20 unf for the Barrel but 1.5 pitch for the 2 end caps I use a tap for the barrel

[Joshua KempsterParticipant @joshuakempster]

I don’t get why you can’t understand that the lead screw was moving when I moved the the carriage that was the reason it was double threaded I’m not guessing this it is a fact

[Former MemberParticipant @formermember12892]

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[Tony Pratt 1Participant @tonypratt1]

Joshua, It is very likely the Myford lathe had/has an imperial leadscrew, so if you were cutting a metric thread on it you must keep the half nuts engaged at all times, after one pass stop the motor, put the motor into reverse & drive the tool back towards the tail stock to start the next cut.

Tony

Edited By Tony Pratt 1 on 23/01/2021 10:04:48

Edited By Tony Pratt 1 on 23/01/2021 10:05:08

[Joshua KempsterParticipant @joshuakempster]

I was using tpi on the myford mate

[John HinkleyParticipant @johnhinkley26699]

This site is frequented by people of all ages and sensitivities. If you can't keep your posts civil, kindly leave the forum

John Hinkley

[Robert ButlerParticipant @robertbutler92161]

I wasn't aware unsilenced air rifles were capable of more than hearing damage!

The OP should be aware there may well be Police Officers subscribing to this forum and if so I would expect them to make enquiries as to the identity of the OP and arrange for his local force to confiscate any weapons and revoke any Firearms or Shotgun permissions whether necessary for the type of weapon described or otherwise. Weapons should not be in the possession of abusive and volatile individuals.

The OP has nothing to learn from any advice given on this site, he has been unlucky with every machine he has purchased. I hope all those firms supplying machines subscribe and take note to avoid supplying the OP it can only end in tears.

If I was the dog poo referred to earlier I would be anxious to extricate myself from the shoe.

It is time the OP was invited to leave this forum .

Robert Butler

[Former MemberParticipant @formermember12892]

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[Andrew EvansParticipant @andrewevans67134]

Joshua, I get the feeling you think you know more than you actually do. If you don't want other people's advice then why bother asking. Why not accept you have made a few daft posts and apologise and move on? You would instantly get some respect back and people would consider helping you. Calling people 'mate' or 'pal' is a sure fire way to wind people up.

What I do know is that there are many people in this forum with huge amounts of skills and experience and willingness to help others – you are just not tapping into that knowledge in a respectful way.

[Joshua KempsterParticipant @joshuakempster]

Yeah your right I apologise for the posts I jus got stressed out because a few people jumped on me over the fault machines. I came on here the get some advice of some proper craftsman an engineers as iv seen some of the work created. With regards to the legality of me making custom parts for sub 12lb air rifles I can assure you I am completely in my legal rights to do this but anyway I do apologise an I would like to learn from the Group an start again

[Joshua KempsterParticipant @joshuakempster]

An I have come across like a idiot lol iv just had a expensive frustrating experience lol

[Former MemberParticipant @formermember12892]

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[VicParticipant @vic]

Posted by Gavlar on 22/01/2021 19:14:57:

Pre Charged Pneumatic (PCP) airguns are 'hurt your ears and do permanent damage' loud without a moderator. It's thevery reason I started learning to use a lathe.

It depends on the Rifle. Many of them can be “blatty” as airgun folk call them. As you know the actual barrel on these guns is often quite short. In the case of some target rifles the manufacturers fit the barrel inside a longer hollow tube to maintain the sight radius. It’s this tube that seems to cause the noise. The manufacturers claim that the pellet exiting the barrel into “clean” air inside the tube improves accuracy. You can fit a moderator at the end of the tube and it works well. I made my own once and it was basically a simple cone with a hole in it. Sadly it increases the overall length of the weapon. An easier solution I found which works fairly well is to turn a plastic slug with a conical end to fit inside the barrel sleeve. Two O rings keeps it in place and if you thread the outer end it’s easily removable by inserting a bolt. Not as good as a conventional moderator but takes a bit of the noise away. I used to love firing oil soaked cleaning pellets out of mine every now and then. They came out so fast it sounded like a small bore rifle going off!

[Joshua KempsterParticipant @joshuakempster]

Ok apologies to all

[Joshua KempsterParticipant @joshuakempster]

Iv got a hw80 which has had a custom one of 3 rosewood stock built by a absolute master also the internals have been built out of titanium which make it recoil free (almost) it’s a target rifle an shoots around 11flbs which is relatively low power but massively accurate the idea was to get quite good on the lathe an mill so in the end I can machine small parts out of titanium ie the moderator an safety catch and other bits.

[garyParticipant @gary44937]

hi joshua, what is the legal power of an air rifle now, can the canisters be charged at home, how many shots do you get from a fully charged canister,

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