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Member postings for John Ockleshaw 1

Here is a list of all the postings John Ockleshaw 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: bending small bore copper pipe
11/11/2017 02:41:44

Hello Sam,

For copper tube a pipe centerline radius of two pipe diameters is fairly easily achieved. With smaller radii you need internal support and are likely to have tearing in the outside of the bend.

Martin's table illustrates the requirements.

If you Google this link you will find a mine of information http://www.pines-eng.com/pdfs/H&HBendGuide.pdf

Regards, John

Thread: Change gears
26/10/2017 07:09:42

metric threads.jpg

This may be more easily read Kevin

26/10/2017 06:38:26

Hello Kevin, Here are the gears for metric pitches. They will suit you if your lead-screw is 8 TPI.

Regards, John

Thread: LMS 2F Experiences
22/09/2017 02:30:42

Hello Bryan,

I tried to build the original boiler, none of the inner firebox plates were flanged, as it cooled during silver soldering the butt joints opened up.

Subsequently I built a gas fired boiler with the same outside dimensions, which is very successful.

I filled the side tanks with steel ballast to give it more adhesion.

The four wheel riding car is made from four lengths of steel tube which act as a gas tank, it carries a water tank as well as the driver.

The loco drives and hauls well.

Regards, John

Thread: Micro Burner
26/08/2017 09:36:03

Hello Michael,
Attached is a photo of my small torch set-up. The needle is just cut off square. The dark mark in the small delivery hose is just a joiner. The nozzle of the large torch just pokes into the compressors inlet without any sealing. The piece of wire attached to the gas valve is an indicator so you can open the valve to the same position every time. Acetylene is supplied at 15 psi through a regulator. The compressor still works OK after 15 years but it has not been overworked.
I don't think the set up would work with propane, its flame speed is so low the flame would not hold on to the needle.

Hello Jason,

I did not put the hypodermic needle onto the large torch's hand piece because the handpiece and its hose are cumbersome for the job. I used the compressor so as not to interfere with the big torch's mixing of the air and acetylene - I may well be romancing in a fools paradise.

Regards, John

25/08/2017 08:10:27

Hello Michael,

I direct the output of a air/acetlyene torch into the inlet of an aquarium air pump then couple the pumps discharge to a hand piece carrying a hypodermic needle, with plastic hose. By adjusting the air/acetylene torch's output you can get a stable flame on the hypodermic that will not burn off when you wave it around. If you like I will take a photograph of the set up.

I use it for silver soldering chain links made from 0.005 " diameter bronze wire under a microscope, amoung other things.

Regards, John

Thread: Machining Tungsten
13/08/2017 03:32:09

Andrew,

May I suggest you spark erode the hole after turning your sphere, Fit the supporting shaft then spark erode a taper pin hole through the assembly. I have not spark eroded tungsten but I have an Xray target a will experiment on it if you like.

Regards, John

Thread: Machining in exchange for beer
05/07/2017 03:05:29

Hello Sam, If you can get access to a spark eroder drill your workpiece to the a/f"s size then sink the hexagon in a few minutes.

Regards John

Thread: Trepanning a deep hole in en24t
16/03/2017 06:41:17

To John Stevenson,

At my place the spark erosion would cost a few KWHr's of electricity. Almost priceless.

John

16/03/2017 00:50:28

Hello Windy,

Can you get access to a sink type spark eroder ?. Use a piece of copper tube for the electrode.

Regards, John

Thread: Hofmann dividing head manual
14/03/2017 07:52:59

Hello Sandy, I have a Hofmann UTH dividing head, the operating instructions and the tables for indirect, differential and spiral milling. The set of change gears is as listed by Vintagengineer above.

If you would like me to copy this information then send me your email address as a PM.

Regards, John

Thread: Name plates
29/12/2016 06:04:20

Hello John,

Photo engravers often required deep etches especially for embossing plates used by bookbinders working with leather.

Eric Chambers in his book Camera and Process Work, still available, describes the process well,

Briefly - you require a hard "paint roller" say 1/2" diameter beverage tube on a metal core, wide enough to span the smallest dimension of your name plate.

A piece of plate glass with a very thin coating of letterpress ink on it.

Roll your paint roller in several directions on the glass until it also has a very thin uniform coating of ink.

Some bitumen dust similar to what is used in lazer printers, a tray for it and a very soft brush.

A hot plate, to fuse the bitumen dust.

Then after the first etch of your nameplate, say 0.003" deep, wash and dry the plate with hot air. Roll the plate with letterpress ink, sprinkle it with bitumen powder, gently brush the powder in four directions against the sides of the etching, brush off any loose powder. Put the nameplate on the hot plate and fuse the bitumen. Return the plate to the etching bath and go another 0.005" deep. Roll-up again, powder, fuse and etch, repeating until you have your reguired depth.

The flanks of the lettering and lines will have a smooth outward curve without under cutting.

Regards John

Thread: Any ideas how to undo these screws?
13/11/2016 00:31:24

Hello Ian,

If you have access to a spark eroder, big enough to get the tripod head submerged as it is shown in your photograph then make a electrode with a conical point the same size as the countersunk head and a very short cylindrical tit to enter the hexagon hole. Crank the end so it looks like an Allen key. Grip this in the eroders chuck.

Lock the quill in the vertical position, turn the power on, feed the electrode into each screw with the tables feed screw. Back off if you get a short, then resume.

There should be enough of the original hexagon remaining to undo the shanks with the tripod separated.

Thread: drilling balls
10/10/2016 03:28:57

Use your sink type spark eroder, especially easy if it has digital readout on the table

John

Thread: Forming round heads on small steel rivets.
31/07/2016 10:19:51

Hello Ken, I use D bits to form the cavities. Machine the taper on and hand file the radius on the second punch's D bit. For the third one hand file that as well if you do not have a ball turning tool.

One other thing - machine say a 5 deg. chamfer on the face of the punch leaving say a 0.020" land around the opening. This will save marking your workpiece if the punch is not perfectly plumb.

Best wishes, John

31/07/2016 03:35:29

Hello Ken, I think it was the late W.J.Hughes who recommended using three hollow punches to form rivet heads.

The sketch shows their proportions. They limit random buckling of the shank and offset heads.rivet head.jpg

Thread: Thread pitches on small parts.
12/06/2016 06:48:14

Hello Dave,

If you have , an old fashioned, slide projector mount your threaded plunger in the plane where the slide normally goes and you can have a wide range of magnifications.

You can check the magnification by first using a drill shank, which is easily measured accurately, as the object.

Regards John

Thread: metric on imperial
09/06/2016 03:10:31

Hello Kevin,

This table may be of interest to you.

a Hercus model A lathe is identical to your Boxford model A.

Regards Johnmetric threads.jpg

Thread: "Depth clock" query
01/02/2016 00:42:35

Hello Michael,

If you have access to a surface grinder, with coolant, you can cut your lump of granite ( from a kitchen bench top maker or headstone maker ) with a cheap diamond saw sold for the lapidary people. To square it up use ordinary silicon carbide grinding wheels say 37C30MB or 37C36KV, they cut quickly and give a good finish. You can chamfer the corners as well.

Regards, John

Thread: Polishing castings
09/01/2016 01:42:15

Hello Engine Builder,

With respect, may I disagree with you regarding polishing castings of engine components.

James Simpson & Co's pumping engines had the Corliss valve wrist plates machined and left bright as were the LP steam cylinders back covers and the edges of the flanges of the Corliss valve bonnets just to name a few examples.

In my opinion they helped to make their engines elegant.

Regards, John

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