Full Chisel Blog

August 6, 2009

Mariner’s Compasses

I was inspired by the brass Mariner’s Dividers offered by Lee Valley.  I decided to make a pair out of wood and I have a brass pair coming.  Why is it called a ‘pair’ as there is only one?

These are made of maple with a brass rivet at the axis.  It is a small piece of 1/8″ soft brass with a peened head on each end.  The wood at the pivot is slightly countersunk and I took great care with a small ball peen hammer to turn the head of the rivet after the two arms are assembled.

I cut it out with a coping/fret saw, using fine fret saw blades and ended up breaking a half a dozen blades in the process.  I am not sure what the problem was, I usually don’t break blades that often and this little project should have been easy.  The wood is not that thick and it was properly supported in the patternmaker’s vise.  I can’t blame the blades or the tools and there was no one around to blame, so I guess it was me?

The major advantage of this design is that it can be opened wider and closed narrower with one hand.  It is extremely easy to get just the right dimensions between the points.  I have started using compasses for all of my measuring transfers, so a couple of extras will be of great help.



  1. How are you finding the usability of that, Stephen? My only worry with that style of divider is that it might drift if it was set down. That is to say, in my mind it would be fine for transferring a measurement but not so fine for ‘holding’ a measurement for later. Of course, my mind could be wrong. 🙂 I’m fond of fey-pattern spring dividers.


    Comment by M.Mike — August 6, 2009 @ 11:46 am

  2. M.Mike,

    I haven’t had much chance to use the tool. I did give it a coat of St. John’s Oil and peened the rivet again, so it holds its position. I have a metal compasses that has a locking thumbscrew on an arc and that one doesn’t move. This one I think will be more handy for transferring measurements. I thought of using metal points but didn’t. I may make another ‘pair’ with iron points.


    Comment by Stephen Shepherd — August 6, 2009 @ 12:53 pm

  3. Hi Stephen,

    I’d be interested in hearing what you thought of the brass dividers after they arrive — that is, given the price and the presentation box, do they actually work?

    In the market for new dividers myself.


    Comment by Ken Pollard — August 6, 2009 @ 3:25 pm

  4. The price is, frankly, incredible. Solid brass. It would probably cost me half of the asking price just for the raw materials, and they cast it, machine it and polish it then put it in a presentation box. I cringe to think what the workers must be getting paid… but that wouldn’t stop me from buying a pair. 🙂


    Comment by M.Mike — August 7, 2009 @ 5:19 am

  5. Hi Mike,

    The conflict between price and product is my concern. I don’t know about these dividers — they may be fine –but I do regularly see newly made “violins” in my shop that are made with very low-cost labor, look ok in photos on the internet, but simply do not work, and never will.


    Comment by Ken Pollard — August 7, 2009 @ 9:31 am

  6. I don’t usually worry about quality when ordering from Lee Valley. If the object is a low-priced, low-quality item then they will say so in the catalogue, and if you didn’t catch that and bought it with grander notions they’ll take it back without trouble.


    Comment by M.Mike — August 7, 2009 @ 12:00 pm

  7. Thanks — that’s good to know.


    Comment by Ken Pollard — August 7, 2009 @ 1:12 pm

  8. Looks great! Thanks for the inspiration.

    Comment by Carl — August 8, 2009 @ 1:23 pm

  9. […] and at a decent price.  When I first saw these I of course made a pair out of wood.  I find the wooden version is handy to take measurements off the screen and for scaling.  The brass pair goes to the shop […]

    Pingback by Mariner’s Compasses « Full Chisel Blog — September 2, 2009 @ 7:12 am

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