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By Trevanion
#1331359
I'm in the market for a decent quality layout compass that will actually draw perfect circles rather than spirals #-o Most of my work can be done with a pair of trammel points but sometimes they're a bit clumsy for anything under 12" or so, and I've only ever seemed to have found rubbish schoolboy compasses that move as soon as you start looking at them.

Anyone got any suggestions of anything worth looking at?
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By Jacob
#1331369
Trevanion wrote:I'm in the market for a decent quality layout compass that will actually draw perfect circles rather than spirals #-o Most of my work can be done with a pair of trammel points but sometimes they're a bit clumsy for anything under 12" or so, and I've only ever seemed to have found rubbish schoolboy compasses that move as soon as you start looking at them.

Anyone got any suggestions of anything worth looking at?
Anything bigger than a normal pair of compasses I'd use a lath with a hole for the pencil and another for a pin. It actually works better than trammel heads and compass extension devices, because it lies flat on the board.
Also there are large engineers dividers available in many sizes, which will scratch a line.
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By Trevanion
#1331375
Jacob wrote:Anything bigger than a normal pair of compasses I'd use a lath with a hole for the pencil and another for a pin. It actually works better than trammel heads and compass extension devices, because it lies flat on the board.


Been there, done that, pantsed about for ages trying to get the diameter set correctly with the pin every time I would use one before I gave up on the rigmarole and bought a pair of Eclipse no 33s.

Image

I think they're better than traditional trammel points (or at least the ones I've seen, they may have copied someone else's ideas no doubt) because of the eccentric tip pins which when you turn them gives you a large range of adjustment to fine-tune the measurement. You can, of course, adjust them to be as low to the workpiece as you like but I like to have them an inch or so above.
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By toolsntat
#1331379
Good quality beam compass.
Like a trammel but with much more finesse.
Cheers Andy
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By Trevanion
#1331389
toolsntat wrote:Good quality beam compass.
Like a trammel but with much more finesse.


God damn it, Andy. Now you've made me want to make a small beam compass.

Weekend project perhaps? :wink:
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By Jacob
#1331391
I still think a lath is easier. Tape measure radius 2 marks with a pin, for the pencil and the pin itself , drill holes to fit pin and pencil. Could be 1mm hole for a clutch pencil, or ditto but countersunk enough for an ordinary lead pencil. Can't see a problem, accurate to fraction of a mm, I've done it often.
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By Trevanion
#1331393
Jacob wrote:I still think a lath is easier. Tape measure radius 2 marks with a pin, for the pencil and the pin itself , drill holes to fit pin and pencil. Could be 1mm hole for a clutch pencil, or ditto but countersunk enough for an ordinary lead pencil. Can't see a problem, accurate to fraction of a mm, I've done it often.


If it works for you Jacob, that's great. I've never gotten along with it. In the time it would take me to pants about drilling holes in a bit of batten and try to get it accurate enough to mark with I would've done 3 separate sized diameters to dead accuracy. The heads have probably paid for themselves with the time saved messing about.
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By toolsntat
#1331396
Damn n blast :evil:
Just remembered I was fiddling with absolutely just what you needed on Friday.
My mate was putting some bits into the sale and yes a very fancy pair of adjustable beam compass heads was one of those :shock:
Ah well :roll:
There out there :wink:
Cheers Andy
Last edited by toolsntat on 21 Jan 2020, 09:12, edited 1 time in total.
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By Jacob
#1331422
Trevanion wrote:
Jacob wrote:I still think a lath is easier. Tape measure radius 2 marks with a pin, for the pencil and the pin itself , drill holes to fit pin and pencil. Could be 1mm hole for a clutch pencil, or ditto but countersunk enough for an ordinary lead pencil. Can't see a problem, accurate to fraction of a mm, I've done it often.


If it works for you Jacob, that's great. I've never gotten along with it. In the time it would take me to pants about drilling holes in a bit of batten and try to get it accurate enough to mark with I would've done 3 separate sized diameters to dead accuracy. The heads have probably paid for themselves with the time saved messing about.
Er - not sure what you are doing messing about but getting it accurate quickly is no problem: drill say 1mm hole in batten, tape measure to next one, mark with scribe point and drill it 1mm. I've got a cordless drill and boxes of bits always handy. It's easier than adjusting trammel heads and easier in use. You need a good scrap pile source of handy battens but could always plane up a few for future use. Say 4mm x 25mm
Maybe it's pricking out the hole first which makes it accurate - the drill bit goes straight in, spot on.
By novocaine
#1331424
Jacob, stop, he hasn't asked how to do it, he's asked for something specific. Leave him to it please.

anyways, seems like an almost perfect time to buy a bit of vintage. :) (mmmm pretty)

https://www.ebay.co.uk/itm/Vintage-Drau ... Swk09eILk9

the 6" with it's extension will get you out to 10" comfortably. for everything else there's your trammel.
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By Jacob
#1331426
novocaine wrote:Jacob, stop, he hasn't asked how to do it, he's asked for something specific. Leave him to it please.

anyways, seems like an almost perfect time to buy a bit of vintage. :) (mmmm pretty)

https://www.ebay.co.uk/itm/Vintage-Drau ... Swk09eILk9

the 6" with it's extension will get you out to 10" comfortably. for everything else there's your trammel.
I know I know :lol: but I've got drawers full of drawing board kit like the above, including beautifully made compasses with extension bars for radii up to 300mm or so, but it simply doesn't translate into a woodwork working environment.
I used a lath with holes for the drawing up and all the way through the process of making a set of round headed windows with curved glazing bars. Kept it hanging up and used it again and again. It's my go-to method, even for a one off.
OK don't worry I'll stop repeating myself!
PS drawing board kit became redundant in shedloads, with the advent of CAD. It's still around and can be bought for peanuts or less. I was given a plan chest full of it via freecycle. Drawing boards /draughting machines similar but have disappeared faster as they take up more space
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By Droogs
#1331447
Get yourself one of these.

https://www.fabory.com/en_GB/west-sqr-l ... Arelevance

pricey but will outlast you and the apprentice's apprentice
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By Jacob
#1331467
Droogs wrote:Get yourself one of these.

https://www.fabory.com/en_GB/west-sqr-l ... Arelevance

pricey but will outlast you and the apprentice's apprentice
Plenty of cheap ones about https://www.amazon.co.uk/OOOUSE-Profess ... 07YD5YVMM/

but they don't work so well as it's too easy to break the lead of the pencil. Bin there dunnit. Worth trying though as you can use the scribe point instead.
By worn thumbs
#1331475
I find that different sizes call for different solutions.I used the nail through a long batten and a hole for the pencil technique when I had an 8 metre radius to draw (needed another pair of hands for that). Trammels I find good for slightly smaller curves ,down to say 450mm and from there down to very small I use my home made solution below.
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By Droogs
#1331476
The main specification about it was that it is a heavy duty bit of kit and will be nice and secure even with the ham-fisted. Is all metal construction including the locking nut unlike your plastic example Jacob. That is the "point" of the OP's post - the thing has to be secure to create an accurate circle, not that he keeps breaking his pencil nib