Sine Bar replacement

[David George 1Participant @davidgeorge1]

Just made a replacement Sine Bar to replace the one that I used to have. The original was a 2 inch X 1/2 inch size but the new one is 45 mm as I had a piece of 50 mm x 12 mm ground flat stock and that is the biggest I could make it. The original was borrowed a few years ago but in a vice it is so useful.

David George

[David George 1Participant @davidgeorge1]

[Thor 🇳🇴Participant @thor]

Looks good, I made a sine table to mount on the milling table.

Thor

[Chris Evans 6Participant @chrisevans6]

Looks very good, as you say very useful in a vice. I made a two and a half inch one some years ago. Also when I operated a wire eroder I made a three inch one from 8mm ground stock.

[Neil WyattModerator @neilwyatt]

That's very nice David. Would you be interested in writing it upo – with an explanation of how it's used? – I don't think MEW has covered sine bars for an age and a half.

(Confession, I don't have a sine bar and seeing this makes me want to make one).

Neil

[Chris TriceParticipant @christrice43267]

I bought my first one (a 100mm one) only six months ago after seeing a piece on them (I forget where) and suddenly discovering how very useful they are for setting angles precisely. As result, I bought a set of slip gauges to go with mine at the recent Warwick show. Combined with a test bar, I can now set my topside for turning tapers practically spot on first go.

[ZebethyalParticipant @zebethyal]

Tom Lipton has a good video on YouTube called What's My Sine? about making a quick and dirty sine bar that is probably accurate enough for most purposes made from a parallel and a couple of bearings.

He also shows an even simpler one made from a piece of wood and a couple of nails to prove a point about how accurate they can be even when made from such simple materials.

[Roderick JenkinsParticipant @roderickjenkins93242]

I was recently given a sine bar by my brother in law so I bought a set of slips off ebay. Easy to use on the surface plate or milling table but (directed at Chris) how does one go about using them to set the topslide – advice would be gratefully received.

Cheers,

Rod

[egaParticipant @ega]

Roderick Jenkins:

I invite you to look at my Smith-type taper gauge album.

[Howard LewisParticipant @howardlewis46836]

Roderick,

Being a bit of a hammer and chisel worker, I would try the following.

(You may need more than both hands!)

In view of the length of four way tool posts (if using QCTP You should be able to clamp in a holder) clamp a parallel in the Toolpost. Against this you then hold (or clamp?) the Sine bar (assuming a 5 inch, rather than Ten) and the slips. (Teaching Grandma to suck eggs, Don't forget to include the protective slips at each end of the pack).

With the top slide unclamped, press this set up against a fairly substantial parallel round bar (Silver Steel?) held in the chuck. When the Topslide etc has moved into good contact with the bar, clamp it in position.

You should then be ready to put away the Sine Bar, Slips, and parallel bar, ready to start work on a test piece to confirm that all is well before starting work on the actual workpiece.

H T H

Howard

[Philip RoweParticipant @philiprowe13116]

I made a sine table when I was an apprentice 50 + years ago, never have used it!

I was lucky that the first year of my apprenticeship saw me in a training environment where we did nothing (Apart from day release) making tools which we were allowed to keep on completion of said apprenticeship. The instructor thought that a sine bar was not so useful to me as an electrical apprentice and so specified the sine table instead. I still haven't worked out the logic in that. After it was completed I then had to make a case to keep it in which was machined out of black perspex and held together with cap head screws and lined with green baize! Totally over the top but it did teach me a lot which thankfully I have not forgotten.

I still have it somewhere, I must dig it out if only to let me reminisce about real training and I might even post a photo.

Phil

Why has predictive text never heard of sine or baize?

Edited By Philip Rowe on 22/11/2017 16:39:28

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