Author Topic: How to make Gib Headed Keys,the most easiest way?  (Read 3116 times)

Online Dan Rowe

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #15 on: January 04, 2018, 04:14:38 PM »

I understand however, the in the US the standard is a 1/96 tapper, but just because other dimensions are in inches that does not make it the "the Imperial" standard.
In the US tapers are usually given in inches per foot not as a ratio. 1:96 is 1/8" per foot.

The common taper for US taper pins is 1/4" per foot or 1:48. The metric taper pin is 1:50.

The taper attachment on my South Bend lathe has degrees on one end and inches per foot on the other. I suspect it is the same for a Boxford lathe also.

Dan
ShaylocoDan

Offline Johno

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #16 on: January 04, 2018, 04:56:10 PM »
Dan,

UK Imperial tapper pins are also 1/48 with the metric ones being 1/50. So it would appear whilst US/UK, & Can/Aus/Nz/etc. tapper pins are interchangeable, gib-head (& plain tapper keys) keys are not. It would interesting to understand to what extent other common components may not be that interchangeable as first assumed?
How many times has some one used metric tapper pin reamer, that was at hand, just to find out that the US/UK tapper pin always proved to be a poor fit. Or vis-versa ?

ian

Online Dan Rowe

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #17 on: January 04, 2018, 06:02:56 PM »
Ian,
BS 46 might have the taper as 1:100 now but I just looked in "Machine Drawing and Design" by William Ripper the Dean of Applied Science University of Sheffield 1914. Page 51 lists the taper of a key from 1 in 64 to 1 in 96.

It looks like you should check when working on historic equipment.

The taper pin issue was always a problem on the ships I was on. Some of the equipment used metric pins and anything from the US had imperial pins and it is not easy by looking to know which was which.

Dan
ShaylocoDan

Offline Johno

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #18 on: January 04, 2018, 07:19:45 PM »
Dan,

BS 46 an very early 1950's standard, so it must be assumed before that it was down to the "Works Engineer" to devise the standard such items were built to. You can imagine the rivalry between the different manufacturers when claiming that "their system" was better than others.

So, you are right of course to be wary when working on very old equipment and trying to determine what standards they may have be built to. I would suggest that there was no standard given that it was not until the 1840's that Sir Joseph Whitworth developed the first standard for screw threads and went on to develop the first screw cutting lathe in order to make standard nuts & bolts. Up until that time screwed components were made by individuals and no two would match another persons. Standards for other components would also not of have existed.

I recall as an apprentice I had the opportunity to do a little work on the a full size replica of a steam locomotive. It was a replica of "Locomotion No 1" built in 1825 to mark it's 150 year anniversary. Locomotion No 1 was built to haul the Worlds first Steam Public Railway : The Stockton- Darlington in 1825. On the original, the bearings were fastened to the con-rods by a system of yolks, keeper plates & wedges, no two assemblies were the same & certainly not interchangeable. When replicating the parts we used tools and equipment that simply did not exist 150 years ago & ours just looked to "engineered" to convey the period. So, for the first time as apprentices, we were asked to make rough looking parts!

Offline Bobsmodels

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #19 on: January 04, 2018, 07:38:12 PM »
Hi

I posted this awhile back and it may look like overkill, but once you spend about a half hour to make the master for which ever system you use it is easy to get repeated results.  Easy to set up the for a
new sleeve and to make keys.  You do not have to set up angles every time. 

Bob

Offline Xldevil

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Re: How to make Gib Headed Keys,the most easiest way?
« Reply #20 on: January 05, 2018, 05:38:04 AM »
Talking overkill,this is a very nice tool.

<a href="http://www.youtube.com/watch?v=pwcw5lCskyE" target="_blank">http://www.youtube.com/watch?v=pwcw5lCskyE</a>

http://www.repco-tech.co.uk/keyway-cutting-tool/


Made an inquiry,but I guess the price is far beyond my budget.
« Last Edit: January 05, 2018, 05:41:08 AM by Xldevil »