Forgotten engineering techniques

[colin hawesParticipant @colinhawes85982]

Hardened flat parts that have bent slightly during hardening can be straightened by pening on the concave surface. Colin

[colin hawesParticipant @colinhawes85982]

Reamers that cut slightly undersize can sometimes be made to cut bigger by rubbing a very hard tool along the flutes. With a little luck this will raise a microscopic burr. Colin

[stewart woodParticipant @stewartwood82335]

I remember a machine that was used for threading nuts many years ago ,that had a tap with a long plain shank which was bent at 90 deg. The nuts where threaded one at a time and traveled up the tap and off the back end to drop threaded in to a box .Did the nuts go round or was the tap revolving ? can anyone remember how it worked . Stewart

[Anonymous]

Posted by stewart wood on 23/01/2015 19:14:38:

I remember a machine that was used for threading nuts many years ago ,that had a tap with a long plain shank which was bent at 90 deg. The nuts where threaded one at a time and traveled up the tap and off the back end to drop threaded in to a box .Did the nuts go round or was the tap revolving ? can anyone remember how it worked . Stewart

This has been discussed before; I think the concensus was pairs of moving fingers?

**LINK**

Andrew

[Chris Pattison 1Participant @chrispattison1]

Bill Hancocks:

Send a copy of that book to the USA. They clearly have not read it yet.

[Sam StonesParticipant @samstones42903]

Stewart et al,

I couldn’t find a clear explanation via the link(s). However, as it was explained to me years ago, nut blanks were driven along the tap being threaded simultaneously. The tap was held stationary in the following manner.

The outside of the nuts was guided along a tube whose end was curved through 90° to match the curved end of the tap.

To start with, there has to be a number of finished nuts along and around the bend of the tap and the tube to stop the tap from turning.

Obviously, there had to be a simple way of passing (or otherwise) inserting the tap into the tube.

Perhaps the tube was slotted?

[Nigel McBurney 1Participant @nigelmcburney1]

Toolmakers buttons, The principle of these butons can be used obtain accurate meshing for a train of gears, I used it to bore the hornplates of a 1.5 in Allchin hornplates for the third shaft gear, the crank and second shaft horn block and bearings were mounted on the hornplate, the axle bearing hole was bored to location by marking out,to get achieve a good mesh for the third shaft , the pair of gears (2nd to third shaft and 3rd to final drive )were mounted on a "button" and the button position adjusted until the two pairs of gears were meshing correctly, the gears were then removed and the hornplates set up as a pair and the button clocked up to be co axial with the machine spindle ,and the bearing holes bored to size.

Soft centres , i have a soft shaft with a circular steel disc bored to accept the shaft, the shaft is welded to the centre of the shaft, the shaft can then be mounted in the 3 jaw chuck, the shaft can then have a centre turned on it and the steel disc can then be used as a catch plate,suitable holes being drilled in the disc for a stud to drive the carrier,the centre has to be skimmed every time it is used, this gives a very accurate soft centre and for a quick job saves removing the chuck and mounting up hard centres and catch plate. Lathes used to be supplied with a soft centre in addition to the usual hard ones,and nowadays they do not appear to be available.

[john carruthersParticipant @johncarruthers46255]

back to the tallow….
we used it as a flux when soldering up leaded lights, just scratched the joints and wiped them with tallow.

I also had the great fortune to work alongside an old guy Maurice 'Mo', who did his time as a 'mill and engine wright'. He took a lot of knowledge to the grave.

After spending a couple of days trying to get a recalcitrant long belt to stay on they called for Mo. He had us shut the doors and windows, spin up the drive pulley, then squirted it with an oil can.
"see where that oil went boy? that's where your other pulley should be."

[robjon44Participant @robjon44]

Hi guys, I have a soft centre that I made in the sixties, piece of five eights bar welded into a piece of three quarter by quarter flat, turn long end to provide previously mentioned shoulder, 2 or 3 tapped holes in one arm to accommodate bolts or driving pegs. At the time I was confronted with a particularly vexatious job, a long slender shaft with many diameters which became like a banana & no centre lathe in the place, I therefore rough machined it from both ends against a revolving centre with a finishing allowance, then almost instantly convert a 3DB capstan into a centre lathe to finish all over running perfectly true & straight, it is still in my box of useful things 45 years later, the only modification I can think of is if that if you used it a lot then drill & tap the pointy end & screw a bolt into it & turn the point on that. How I miss those days, an extra £2 a week on the basic rate for being a skilled turner, unlimited piecework, I could earn 8 times as much money as in my home town, no wonder we said "my needs are simple, a glass of water, a crust of bread & a new 750 Norton every year".

[Jesse Hancock 1Participant @jessehancock1]

Larry, hope you're still reading this thread.

They use the method which you describe to bend large diameter tubing into arcs as well. While working on the New dock at Avonmouth we tried to bend pipes using this method. We failed since we just couldn't control either the heat or the cooling process.

Just google large diameter pipe bending and be prepared to have your neurons flip.

What works in one direction also works in the other to take out a bend heat the bend and then cool it until it becomes straight.

Edited By Jesse Hancock 1 on 04/04/2015 09:11:47

[Chris Pattison 1Participant @chrispattison1]

I used to work in a company who made exhaust systems. We used a simple press arrangement to get the bends. It distorted the pipe somewhat, but as there was no aesthetic requirements, there was no concern.

What did impress me was when I visited a factory where they were bending very large diameter pipes – about 2m diameter, with a wall thickness of about 50mm. The method used was a large induction coil around the pipe which heated up a narrow circumferential band of the pipe. The pipe was mounted in a clamp arrangement and then progressively pulled over an arc to achieve the desired angle of bend. As the bend was achieved, the heated portion progressively moved along the length of the bend.

[Gordon WParticipant @gordonw]

Years ago I worked on night shift, on a miller, next to me was a pipe bender. This thing was only fired up a few times, it put beautiful bends in large dia. tube ( maybe up to 12" dia. ) and thick walled. It would drive me mad 'cause of the noise. I was told it fired steel balls thru' the bore during bending, hence the noise. Sadly I never looked into how it actually worked. Anybody who's done piece-work on nightshift will understand. I've never met anyone since who believes me.

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