Author Topic: Beam Compass we called them Trammels  (Read 2472 times)

Offline sbwhart

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Beam Compass we called them Trammels
« on: November 22, 2017, 07:34:58 PM »
Over the week end I made a Beam Compass or as we use to call them Trammels but I thing Beam Compass is a better description as the man said it does was it says on the tin.

Your probably wondering why I needed one of these old fashion drawing/marking out instruments in the modern days of cad. The reason is quite simple I need to draw large arcs in order to model the valve gear on the loco I'm building and my little lap top was just too small to be able to see what was happening so it was a mater of good old pen a paper to the rescue.





Stew
A little bit of clearance never got in the way

Online crueby

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Re: Beam Compass we called them Trammels
« Reply #1 on: November 22, 2017, 07:52:18 PM »
That looks great - I really like the fine adjustment on the one leg of it, have not seen that style before. Those come in handy on woodworking projects too. How did you make the hex holes in the uprights to take the crossbar? Also, does the adjustable leg have a lead holder or something on the top, or is that the handle to hold it while it pivots? Very slick design.


Offline mklotz

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Re: Beam Compass we called them Trammels
« Reply #2 on: November 22, 2017, 08:06:45 PM »
Elmer Verburg's take on the classic beam compass has an interesting feature.



It has a conventional pivot fitted with a fine adjustment just like the expensive ones. What makes it special is Elmer's take on the pencil holder. This is a miniature V-block with an integral clamp. As such it will accept, naturally, pencils and pens. But, in addition, it will accept center punches (for laying out holes for chain drilling, etc.) and X-Acto knives for cutting out gaskets. The plans cover a connector and another bar to extend the range of the compass. I made these too but forgot to include them in the picture. With them the compass can scribe a 24" radius.
Regards, Marv
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Offline sbwhart

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Re: Beam Compass we called them Trammels
« Reply #3 on: November 22, 2017, 08:29:56 PM »
How did you make the hex holes in the uprights to take the crossbar? Also, does the adjustable leg have a lead holder or something on the top, or is that the handle to hold it while it pivots? Very slick design.

Hi Cruby

To answer your ?

Its just a 9mm hole to take the 5/16" Hex

No lead holder its just a handle

The pencil/holder should take other attachments as required I just drew it up to do what I wanted it to do.

Stew
A little bit of clearance never got in the way

Online crueby

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Re: Beam Compass we called them Trammels
« Reply #4 on: November 22, 2017, 08:36:18 PM »
How did you make the hex holes in the uprights to take the crossbar? Also, does the adjustable leg have a lead holder or something on the top, or is that the handle to hold it while it pivots? Very slick design.

Hi Cruby

To answer your ?

Its just a 9mm hole to take the 5/16" Hex

No lead holder its just a handle

The pencil/holder should take other attachments as required I just drew it up to do what I wanted it to do.

Stew
Ah, now I get it - the bottom of the knurled nut will act on the flat to keep the points lined up. Slick.

Another tool to add to the to-make list!

Offline Pete49

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Re: Beam Compass we called them Trammels
« Reply #5 on: November 23, 2017, 01:41:26 AM »
nice bit of kit Stew. Still on my to do list :facepalm:
Pete
I used to have a friend.....but the rope broke and he ran away :(....Good news everybody I have another friend...I used chain this time :)

Offline sbwhart

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Re: Beam Compass we called them Trammels
« Reply #6 on: November 23, 2017, 07:27:49 AM »
Thanks for your interest Guys.

I've attached the drawing.

Stew
A little bit of clearance never got in the way

Offline ShopShoe

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Re: Beam Compass we called them Trammels
« Reply #7 on: November 23, 2017, 01:20:59 PM »
Marv,

As soon as I saw your post above, I googled to find your writeup of this. I have to say I liked what was there:

http://www.homemadetools.net/forum/tools-elmer-verburg-27353#post36907

I hope it is OK to put up this link here.

--ShopShoe

Offline mklotz

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Re: Beam Compass we called them Trammels
« Reply #8 on: November 23, 2017, 03:26:23 PM »
Marv,

As soon as I saw your post above, I googled to find your writeup of this. I have to say I liked what was there:

http://www.homemadetools.net/forum/tools-elmer-verburg-27353#post36907

Thanks for the kind words.  I've been documenting most of the tools I've built over there.  When I'm gone my heirs will find a bunch of curious objects whose function they can't guess so I wanted to construct a record for them.

For a complete picture of what I've published there, go here...

http://www.homemadetools.net/builder/mklotz
Regards, Marv
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