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Member postings for Dave Halford

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

Thread: Dropping 12v dc to 6v dc
25/05/2018 21:11:28

Sorry,

Posted by Rob Rimmer on 25/05/2018 18:27:36:

Posted by Speedy Builder5 on 25/05/2018 17:49:40:

Dave H, I can't see a 12 to 6volt dropper on that site/link Am I missing something or did you mean buy 2 x 6volt batteries ?

BobH

Possibly Dave H is suggesting using one of their 12V batteries and tapping off the exposed connector to get 6V? But I'm not fully sure whether vintageengineer needs 12 AND 6 volts?

Sorry, I was suggesting centre tapping the 12V battery, it's the simplest system, but possibly a bit 'old school'. For me Vintage and electronics don't mix

Thread: Are we Luddites?
25/05/2018 16:44:28
Posted by BDH on 25/05/2018 12:43:00:

I'd have to disagree about us being Luddites, we don't go about smashing machinery (usually).

Brian

Only when we go moving mills about on tiny wheelssad

Thread: Dropping 12v dc to 6v dc
25/05/2018 16:42:00

One of these maybe?

https://www.tayna.co.uk/car-batteries/classic-car/

Thread: How to adjust the alignment of the head-stock on a BG1224 lathe
19/05/2018 15:46:29

You don't say how much use the machine has had.

Is the saddle too loose? If the back lifts try tightening the clamp till it drags a bit.

Will a dial gauge on the tail stock run parallel? If so it's likely bed wear (assuming you move the saddle a lot less than the tailstock.)

Does it run parallel if you just use the top slide?

Thread: Myford Super 7 Motor Pulley
17/05/2018 21:06:41

There's a genuine new Myford motor pulley on the Bay - buy it now (confess I just put it there)

If you want it now's your chance, if you don't never mind.

Thread: Ceramic disc regulator
14/05/2018 20:55:55

Suggest you dismantle one and see the way they are built.

Thread: Back gear repair
10/05/2018 16:18:52

Beware of cast iron welding rods - you need ones almost entirely Nickel otherwise it will not machine with HSS gear cutters.

Thread: How to remove a chuck from a Boxford model A
01/05/2018 11:39:21

Posted by Ian S C on 01/05/2018 11:13:31:

I'v got a copy of a hand book off the web, and their suggestion is to lock the back gear, put the key in the chuck, and give the key a bump with your hand. I prefer to put a bar across the jaws and tighten the jaws on it, and I tried that to no avail, what next?

Ian S C

Edited By Ian S C on 01/05/2018 11:21:23

Hi Ian,

What normally comes next is the substitution of 'hand' for hammer which is how the key holes get cracked.

Generally, how gummed up is the rest of the lathe? Old oil sets like glue over time so if it's been undisturbed for tens years or more there may be old oil acting like thread lock. heat will loosen it, you only need 50C then it should come off normally.

Thread: coaxial indicator
30/04/2018 10:18:46

Try a hair dryer, old oil goes gummy and sticks thing up. The heat loosens it enough to get some WD in there to dissolve it.

Thread: Phone Scam
25/04/2018 20:54:14

If you type these numbers into Google the search results can be very illuminating.

Thread: Heating Tapes for Machine Tools
24/04/2018 12:46:07

Green house heater 60w per foot

Thread: Maching flats
23/04/2018 20:19:43

Roger,

Pretty much as Ian Parkin says.

I would clamp your round at 90 deg. to the mill table using an angle plate (assuming as you have a small Horizontal mill you will have neither a vice large enough to hold 1.5inch dia, nor anything to hold an end mill vertically.)

Mill the first flat at what ever your required depth is by adjusting the knee height.

Rotate the round 180deg and reclamp with packing in the flat just milled (a piece of square lathe HSS will do) so that it is above the table. the untouched end needs packing with the same size HSS + the gap left between the table and your round so that the round is parallel to the table as before.

Adjust the table height for the correct depth of cut

Mill your second flat.

Thread: Home workshop fatal tragedy
21/04/2018 11:46:30
Posted by Ady1 on 21/04/2018 09:20:41:

There's an upper and lower explosive limits table here

Even stuff like propane is pretty limited at 2 to 10%

Acetylene is right up there at 2.5 to 100%, one reason it's still used a lot is the temperature it burns at with O2 is around 2500+ degrees and it can be used in steel work

Saw a cabin cruiser go up due to propane back in the 60's, by the time the Brigade had found a rowing boat to reach it there was nothing left higher than 4" above the water line..

Thread: Need chart for a Excel Rotary table.
05/04/2018 19:08:36

Plenty of accurate charts are available via google.

Charts are for plates though, they give you the number of holes and which row etc.

Thread: Rotary Table
02/04/2018 16:57:40

Dividing head

better for gear cutting and cutting splined shafts.

will give you angles assuming your machine is big enough.

Rotary table

Best used flat so good for drilling circle plates

some will mill curves if the gear and worm are up to it and some will strip the threads.

OK for any dividing that does not need a tailstock suport

Thread: Milling curves
29/03/2018 19:00:35

A heavy duty rotary table would be better something with decent size teeth on the worm and wheel.

Thread: Oldsmobile electric steam carriage (latest edition of ME)
28/03/2018 20:56:51
Posted by SillyOldDuffer on 28/03/2018 17:13:25:

Are we having our legs pulled gently for April Fools' Day? In addition to the 'Electric Steam Carriage' the front cover also promotes 'A Wooden Traction Engine' and 'Perpetual Motion' - it's all a little suspicious!

smiley

I still remember the B&W film of Italians getting in the spaghetti harvest shown by the BBC midlands news.

Thread: Clever invention
27/03/2018 20:44:26

Always worth reading the Screwfix reviews someone will have found a drawback, in this case a larger drill than normal is required,

Thread: Tangs not on centres
25/03/2018 17:44:46

The tangs are used to drift out the taper via the slot cut in a drill press. Tailstocks do not have the slot and therefore the tang is deleted

Thread: Un workable steel
25/03/2018 17:40:38

Posted by Jim Nic on 25/03/2018 12:10:52:

I came on a piece of 3" dia steel bar of unknown composition a while back and kept it as a "come in handy". When I found a use for it and tried to machine it I could cut it only with carbide tip tool and then only if I ran it at a very low speed and with a small cut. Even then my lathe was working hard but I kept going because the steel was "too good to chuck away".

The result was that after an hour or so continuous working I had overheated and burnt out my lathe motor.

An expensive lesson! I now only have material that I have bought and know it's composition.

Jim

This raises a somewhat off topic issue of motor ratings.

The motor plate will have the hp or Kw output on it and right next door it should have the rating as CONT or INT.

CONT gives you continuous output at that power output all day. INT gives you intermittent power output for something like an hour or less. Then it needs a cool down period like a welder does and so must be run lightly loaded for a while.

Some machines with electric speed controllers will blow the electronics instead when you stray outside the duty cycle. Trouble is it's difficult to tell how hard we are driving our motors.

Same result though. Ouch, my wallet hurts.

Dave.

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