What's new
What's new

Unusual Matrix length bars/ setting rods.

sable

Titanium
Joined
Feb 7, 2013
Location
midlands,UK
Apologies if this should be in the antiques section but.

Has anyone seen anything like these before.

I bought them off Ebay as length bars ,I guess I should have looked at the pics a bit better as I was expecting the normal ones that are 7/8" diameter and have a hole tapped in the end ,these are 5/8" diameter and the ends are plain like micrometer setting rods.

I wonder if there was some means like a collet available to join them together or if these are just heavy duty mike setting rods, they are only workshop grade by the way.
IMG_0518.jpgIMG_0520.jpg
 
Could have been intended to simply be laid in a vee or tray on, or adjacent to, the machine's table. Jig bore / milling machine trick common before DRO era. 'Workshop grade' might mean that despite the several lengths, the set might not even be truly general-purpose - could have been custom made for a particular manufacturing plant and process.

Arranging a tray is easy enough, but you'd need to find an affordable way to get them calibrated at least once if you expect to trust them.

Bill
You may well be right as the box has HBM roughly engraved on the outside.

I will calibrate them with my mikes.:D
 
These could have been used in the all-mechanical precursor to the DRO. Machines that needed better positioning than the micrometer dial on the crank would provide could be equipped with troughs along each axis. Precision length rods were laid in the trough and a dial indicator was used for less-than-shortest-rod. Long lengths were made up from multiple rods laid end-to-end, like gage blocks.

Having said that, most length rod systems looked a bit different. They generally had enlarged collars near both ends so the rod didn't lie directly in the trough. And many (most?) had radiused ends so that end-to-end contact was less likely to be affected by chips, dust, etc. So mike setting standards may be correct.
 
Sheesh! Photomagraphs. Looked to be about double or triple that. Seem more like shop-floor "risk-these, keep the good ones in the toolroom".

Yes ,It can be tricky to judge size from a picture ,when I bought them it never occurred to me they were so skinny.
 








 
Back
Top