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Member postings for Andyf

Here is a list of all the postings Andyf has made in our forums. Click on a thread name to jump to the thread.

Thread: Power feed transformer wiring
17/06/2013 09:49:47

I think I've devised a circuit which would work for you. It's here.

It won't work if you wind an electronic speed control down to zero to stop your spindle, but looking at Warco's catalogue it seems that the VMC has no speed control, so I assume you stop the spindle by pressing the big red button. Nor will it work if you stall the motor (unless/until that blows the existing fuse), and as has been said, a stall is perhaps more likely than a power failure.

The current for the relay coil goes through the existing fuse, but the coil in a mains relay only draws 0.3A or so, so is unlikely to cause an overload.

If anyone spots a flaw, please say so!

Andy

Edited By Andyf on 17/06/2013 09:54:30

Thread: Anyone wear Vari-focal specs?
15/06/2013 07:15:33

Fair point, Ray. My near and far vision must be nearer to overlapping than Mrs Lyons's. Through the distance part of my varifocals, I can read this with my eyes 15" from the monitor. Standing and looking down at my toes through the reading section, I can see obstructions on the floor - a bit blurred, but perfectly distinguishable, so tripping up isn't a problem for me,. I suppose it all depends on the .individual, and I'm just lucky in that respect.

Varifocals are expensive and prescription only, so unfortunately you can't try before you buy.

Andy

Thread: Silver Solder.
15/06/2013 05:08:38

Not too old a storage heater, though - see **LINK** .

Andy

Thread: Anyone wear Vari-focal specs?
15/06/2013 03:13:03

When I first got varifocals 12 years back, Ithey took a bit of getting used to. If I looked at a fixed point on a tiled floor and swung my head from side to side, the perswpective of the grout lines seemed to change. After two or three weeks, that stopped but I still have trouble with things like holding a saw so it will cut vertically. I have a cheap pair of reading specs to my prescription, which I use sometimes and they seem to help. They certainly assist with overhead jobs like wiring a ceiling light fitting, where I would otherwise be trying to look up through the long-distance section.

Since my mid-fifties, my prescription has changed little; presumeably the lenses in my eyes reached the point where they couldn't get any stiffer.

So, if you do get varifocals, persevere with them. Then you won't have to go through the sort of pantomime I did in art galleries, admiring a picture through a "distance" pair of specs, then exchanging them for my reading pair so I could read the explanatory label attached to the wall beside the work.

My lenses are also "Variolux" so they darken in bright light. That helps when driving and reading in bright sunshione.

Andy

Thread: measuring thread depth
13/06/2013 08:02:06

NB The Little Machine Shop calculations cover 60° threads (US and metric) whereas BSF is 55°.

Andy

Thread: Bulk Metal Removal, Any suggestions?
12/06/2013 22:27:41

I might try getting a core drill into it, then attack from the side with a parting tool.

But with so many teeth in action at the same time, a beefy motor might be needed, and core drills can have problems with clearing chips from a deep annular groove.

Andyye

Thread: centering the chuck
09/06/2013 04:08:11

Becky, some decent quality 3-jaw chucks came with a mark against one of the key sockets indicating which should be used last when tightening up to get best accuracy. My Chinees lathe came with a chuck marked like that, though I suspect it is just cosmetic .

Mark or no mark, it does no harm to use all three sockets in turn at the end of tightening up, just as you would with a keyed drill chuck..

As has been said, any self centring chuck will exhibit runout unless you are very lucky, and even then you may find that though it might hold one diameter with tolerable accuracy, other diameters will be held out of true.

Andy

Thread: BA and MOD D.P. change wheels for modern boxford lathe
07/06/2013 18:14:53

Steve, the overall (toothtip to toothtip) diameter of a Mod 1 gear is equal in mms to the number of teeth + 2. So a 50T will be 52mm (maybe a fraction less).

Other module sizes work in proportion, so a Mod 1.5 50T would be 52 x 1.5 = 78mm OD.

Andy

Thread: Proxxon PD400
06/06/2013 04:02:10

I am not sure where Karlas lives, but he may be able to find a dealer nearer to him on the Optimum website here.

Andy

06/06/2013 00:13:38
Posted by Karlas on 05/06/2013 14:50:06:

...I have been surfing the net a lot ( still a bit confusing ) came across this link for lathes and mills: **LINK**

a German controled Chinees manufacturer , should be relyable quality ?

Karlas, I think you may find the Optimum machines are pretty good quality. There are two factories (or two departments in the same factory) in China making the same machines. One is Weiss, and their lathes are shown here . The other is Optimum. Like you, I understand that Optimum is under German control. Weiss is under Chinese control, though they seem to be using a German-sounding name..

I have a small Weiss lathe, which worked pretty well from the start. Optimum machines may be better, because of the German control..

Optimum machines are not regular imports into the UK, but Weiss lathes, milling machines etc are available from UK importers such as Warco, Chester and Amadeal.

Andy.

05/06/2013 01:29:20

Having regard to someone's experience with a (brand new) PD400 as detailed on another forum, the quality of fit and finish, though much better than the Chinese minilathes, is not superlative. Of course, he may have received the last one to be assembled on a Friday evening.

He also found that the design of the spindle flange is such that the register diameter (and perhaps the PCD of the mounting holes) is exclusive to Proxxon, so it's either buy chucks etc from them or make up suitable backplates if you want to use cheap minilathe items.

Andy

Thread: Short thread-cutting
04/06/2013 17:02:17
Posted by JamesF on 04/06/2013 16:49:51:

Where does the spring loading come in? I can't work that one out.

James

My guess is that Nobby is avoiding the problem I have with my simple crank. If I forget it's there and turn the motor on, the imbalance makes the lathe try to do somersaults while the crank takes vicious swipes at my elbow. I guess Nobby's crank is loose on the shaft until pushed bodily inwards against a spring, to engage a dog clutch.

Andy

Thread: Taps and Dies
02/06/2013 05:08:41

Get some decent ones for best, but for simple hold-things-together jobs those occasionally found at Aldi and Lidl are surprisingly effective.. I've bought M3, 4, 5, 6 sets which include crude tap and die wrenches there for £5 or £6, and once got a set for M3 to M12 plus 1/8" and 1/4" BSP and all the tapping drills for around £15. You only get one tap (second cut, by the look of it), of each size, so they aren't much use for short blind holes, and the dies aren't split.

Andy

Thread: Installing a new lathe chuck
01/06/2013 20:15:37

Dunc, I too have seen it somewhere, but can't remember where.

There is a similar but less complicated method here: **LINK**

Andy

Thread: Mill plus power-feed circuit protection
31/05/2013 06:08:54

Sid, all I can think of is what you suggest near the end - use the downstream side of the 6A breaker (or fuse) to feed not only the spindle controller+motor but also the coil of a relay which has a separate mains supply to its contacts (with a fuse/breaker appropriate for the power feed upstream of those contacts). This means that your 6A breaker will have to carry the additional current required by the relay coil, but on the 230V UK mains that would only amount to something like 30mA, or 0.03A. If you are on 110-115V mains, it would be 60mA or so, but that ain't much - check the specs of relays with mains voltage coils available in your area which are capable of switching the power feed current .

A simple thing to make up if you are confident with wiring up mains voltage contraptions and earthing/grounding any metal box containing the relay.

Andy

Thread: 3D printing Harold Hall's Grinding Rest
30/05/2013 10:07:04

My compatibility button usually does the trick, Jason, but not when images are side by side, as here.

A work-around is to highlight the text of the message, copy it, and paste it into the Reply box below, without actually sending it, of course.

Andy

Thread: Organising tool drawers
29/05/2013 22:07:56

A bit off the cataloguing topic, but for organising delicate items within drawers:

**LINK**

Andy

Thread: Hard felt alternatives for wipers?
27/05/2013 11:19:17

You might buy a hard felt buffing wheel, and cut it up.

My Chinese lathe has synthetic rubber wipers, like windscreen wipers, and they seem to have worked OK for the last 6 years.. You could try cutting up lengths of wiper blade, if you can devise a way to mount them.

Andy

Thread: Adjustable Tool Rest for my 8" Bench Grinder
27/05/2013 11:00:43

The system used in cheap transistor radios might work; a cord (you might want to use something stronger) round two pulleys, and moored to the one with the knob/crank on it. In a radio, the pointer is moored to the cord, so it traverses a linear dial between the pulleys as the knob is turned. On a grinding rest, moor the moving table to the cord or cable. The circumf. of the driving pulley has to be equal to the table traverse, though, which might make for a bulky contraption.

Andy

Thread: Spindle Speed Control Board availability
25/05/2013 00:07:53

I'm not sure it's a speed control board itself that Andy wants, Bazyle. It looks to me that he is after a board to sit between that and his computer, to get the speed pot under computer control. I'm not into CNC, but I imagine that this involves inputting his desired speed, after which his software compares the blips from a tacho on the spindle with the desired rate of blips as generated by the software, and adjusts the speed pot until the two coincide, through something like a phase locked loop.

(another) Andy

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