Vernijigger

[billmac]

I thought you might be interested in this unusual old tool. It is a Vernijigger from the early 1950s and was used as a way of locating drilled holes reasonably accurately where the cost of a full drill jig or a milling machine could not be justified. The makers claim that it could be used to locate holes within about .001" but I'm a little dubious about that claim.

The X and Y arms have vernier scales and fine adjustments rather like a big vernier caliper. The tool holder can take either a spring loaded centre punch or normal drill bushing of which there are a selection in the box.

The science museum in London has one of these and you can view it here:

Verni Jigger Variable drilling jig with Vernier se | Science Museum Group Collection

Their tool is a little more complete than mine - it appears to have a clamping plate which mine lacks. It also has an instruction book.

If anyone has used one of these for real work I would be interested to hear about it.

The mill engine museum where I work had this tool in their tool store for very many years without ever using it. It was offered (twice) at auction but did not receive any bids so I decided that I would buy it. I am not usually a collector of tools that I have no practical use for, but this was an exception. It is beautifully made and I just couldn't let it go.

The photos show the tool after a bit of light cleanup. The cabinet has not aged well and I have had to do some repairs. Not surprising given the significant weight of the tool.

Of course with modern DROs there is no real application for a tool like this, but it might have been handy for some jobs in the 50s and 60s.

 

[jhruska]

Very Nice.
To determine hole center to center distance, bolt circle diameters, and other features so that a part can be reproduced when there is no print.
That's how I would use it.
John

 

[L Vanice]

Very Nice.
To determine hole center to center distance, bolt circle diameters, and other features so that a part can be reproduced when there is no print.
That's how I would use it.
John

Or maybe think of as a poor man's means of getting by without a Moore jig borer. It could stand in for a simple drilling jig for use on a drill press when you are not making enough identical parts to justify making a drill jig. Having a print would not prevent one from using it.

Larry

 

[Asquith]

Bill,

Many thanks for showing us this.

I'd never heard of a Vernijigger, but have now found some information, thanks to the invaluable Grace's Guide.

It was featured in The Engineer, 28 August 1942, p.177, from which this screenshot is taken. The device was made by R. K. Dundas Ltd of The Airport, Portsmouth (not the safest place to be in 1942!).

The optional extras included a sighting device with magnifier, cross-hairs, and illumination, for inspection purposes.

Link to article (small payment required):-

https://www.gracesguide.co.uk/Special:MemberUsers?file=b/b0/Er19420828.pdf

Link to Grace's Guide page for R. K. Dundas:-

R. K. Dundas - Graces Guide

 

[TedinNorfolk]

At the Institution I worked at there is an indexing table with permanent 3j chuck-just like the Marlco. But this one had a sliding arm with vernier. Vernier read 0 when the pilot bush at c/l of head. V useful for putting pitch circles in flanges etc. It probably still lives on the Meddings gang drill!

 

[billmac]

Or maybe think of as a poor man's means of getting by without a Moore jig borer. It could stand in for a simple drilling jig for use on a drill press when you are not making enough identical parts to justify making a drill jig. Having a print would not prevent one from using it.
Larry

Yes- I think this is exactly what the makers had in mind. Whether it was successful in sales terms I don't know for sure, but I doubt it. I have never seen another which may point to it being an interesting idea but not a commercial success.

 

[billmac]

View attachment 258142
I'd never heard of a Vernijigger, but have now found some information, thanks to the invaluable Grace's Guide.

It was featured in The Engineer, 28 August 1942, p.177, from which this screenshot is taken. The device was made by R. K. Dundas Ltd of The Airport, Portsmouth (not the safest place to be in 1942!).

The optional extras included a sighting device with magnifier, cross-hairs, and illumination, for inspection purposes.

Thanks for that. I should have thought of Grace's Guide. I knew about Dundas from the Science Museum photo and notes. Laying out holes for riveted aircraft parts is a possible application that would have been extremely topical in that area in the mid 1940s.