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View Full Version : Has Anyone Made a Beam Trammel Set?



Pherdie
04-25-2015, 03:21 PM
I'm kicking around ideas for my next project and thought a beam trammel w/ accessories might be a handy and fun project. I've searched this site, did some 'Googleing'​ and examined Starret's offerings (C251 series). Starret's systems apparently offer spring loading in the trammel bodies as to allow greater precision for body/beam movement when loosening the bodies for adjusting separation on the beam, something that logically appealed to me.

I did find information on construction of a set in Metalworking, book2, by Dick Torgerson. Unfortunately, both Torgerson's design and Starret's don't seemingly support a marking device. Possibly both could with a special adapter.

In search of further ideas I reach out here, especially for accessory ideas that would enhance the value of the tool. For example, a conical point for the pivot end to center on holes?

Pictures are worth much more than words, so if you could post pictures of your interpretations and ideas, it would be much appreciated.

Thanks in advance.

boslab
04-25-2015, 03:23 PM
You can get a reasonable beam compass as used in drawing offices of yesteryear, I have a small one, handy thing for sheet metal work
Mark

mklotz
04-25-2015, 04:04 PM
Elmer Verburg showed a design for a beam compass in his book Elmer's Engines. Not shown in the picture is an extension beam and the linkage used to attach it to the basic beam.

http://i81.photobucket.com/albums/j234/mklotz/tools/compass.jpg (http://s81.photobucket.com/user/mklotz/media/tools/compass.jpg.html)

The pencil holder will accommodate markers as well as X-Acto knives for gasket cutting and prick/center punches for laying out chain drilling etc.

I built it according to his design but if I did it again I would use a compound screw arrangement for the fine adjustment.

Pherdie
04-25-2015, 06:28 PM
Very nice job, Marv!

That's exactly the type of stuff I'm searching for.

Thanks!!

EddyCurr
04-25-2015, 07:13 PM
I've searched this site, did some 'Googleing'​ and examined
Starret's offerings (C251 series). Starret's systems apparently offer
spring loading in the trammel bodies as to allow greater precision for
body/beam movement when loosening the bodies for adjusting
separation on the beam, something that logically appealed to me.I own a Starrett C251 varient. It has the same 18" maximum
dividing range as the current C251C, but includes accessories
not shown with the C251C on the Starrett site. If images of
this set's components might be helpful, I can oblige.


In search of further ideas I reach out here, especially for accessory
ideas that would enhance the value of the tool. For example, a conical
point for the pivot end to center on holes?I also own trammel sets that came from a custom glass shop.
Some of these have a trammel fitted with a suction-cup in lieu
of a point. Is that a feature of interest?

.

dalee100
04-25-2015, 10:47 PM
Hi,

Made one many, many moons ago when I was learning to be a machinist in school. Might even have some prints around here some where.

Dalee

Spin Doctor
04-26-2015, 11:31 AM
I have a really nice one my grand father made in the 20s or 30s. Multiple points including probes for use as an internal or external measuring device. Uses a 1/4 x 1/2 bar. IMO better than a round bar.

RWO
04-26-2015, 02:12 PM
Guy Lautard's The Machinist's Third Bedside Reader has plans for a collet style pencil lead holder for a beam trammel.

RWO

metalmagpie
04-26-2015, 02:30 PM
Whatever design you come up with, it should be able to mark on metal and have a fine-adjust feature. My current solution is a pair of Starrett 50As with a Verithin silver pencil cut off, rounded to size and held in the pencil holder. I am interested in the radius markers that hold various soapstone holders too. Here is a link to the latter:
http://www.axistradeinc.com/storefront/Radius-Markers-R-221

Here is a link to General's US-made Starrett 50A knockoffs:
http://www.generaltools.com/520--Precision-Adjustable-Trammels_p_256.html

Also google on "beam compass". I found something the other day that is said to hold a sharpie. Under $10, too:
http://www.amazon.com/Dasco-1405-Beam-Compass-12/dp/B000GARYYY

metalmagpie

wierdscience
04-26-2015, 10:06 PM
I've made a couple over the years,never anything fancy,just utilitarian.Easiest recipe I have found for one is using full radius edge aluminum flat bar for the beam-
https://www.onlinemetals.com/merchant.cfm?pid=18150&step=4&showunits=inches&id=1282&top_cat=0

That makes producing the female holes in the point bodies very easy to make.For marking I have used everything from carbon steel to carbide scribes,but the best I have found was a cheap 1/4 carat diamond wheel dresser.It will scribe anything and never gets dull.

oldtiffie
04-26-2015, 11:09 PM
https://www.google.com.au/search?q=Beam+Trammel&biw=1536&bih=706&tbm=isch&tbo=u&source=univ&sa=X&ei=Fqg9VZTTD-PAmQXNzoGwDA&ved=0CBwQsAQ

https://www.google.com.au/?gws_rd=ssl#q=Beam+Trammel+

A good/fair pair of digital calipers - with the "jaws" ground to a point - make a quite good and serviceable pair of beam trammels.

J Tiers
04-26-2015, 11:36 PM
I HAVE a beam trammel set, it came in a toolbox, I sure didn't buy it intentionally. I have yet to use it or need it in any way, and do not expect to in future. I don't know why I have not binned it, or whaled it off in an excess tool sale.

Don't give anyone the idea.... we'll see that project in the same issue with buggy whip braiding.....

Rosco-P
04-27-2015, 07:58 AM
Be willing to bet, you'd find a trammel build article written by Geometer or (the real) Tubal Cain in an old issue of ME or MEW.