• We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Pair of compasses, to hold a pencil?

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

gregmcateer

Established Member
Joined
16 Jun 2011
Messages
2,922
Reaction score
213
Location
Stourbridge, W Midlands
You could use Jacob Rees Mogg with a pencil in his mouth and a spike up his jaxxy. He likes laying down on a bench and he's been put on the back burner, so won't be missed.
Sorry. Not helpful 😔
 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
17,794
Reaction score
703
Location
Derbyshire
Complicated and expensive solutions do seem to be the order of the day!
It's a well known amateur woodworking tendency. Head down, brain off, spend, spend!! Just think of all that sharpening b....x!
Surprised to see the Veritas daft solution was not the most expensive, but then it's only two pins and a pencil (£60!) you even have supply your own lath!
The Tooley Park offering is the most expensive, is challengingly complicated, and you still have to supply your own TWO laths - machined to precise dimensions.

If you can supply your own lath don't spend £76 just go for the lath with two holes solution. It solves the holding of the pencil problem - you hold it in your hand. o_O You can hold the pin too if you want, or pin it through to the board etc.
Maybe it'd help if I snapped a demonstration of this idea, with a few measured drawings and detailed arguments, recommendations on drill purchase options for the holes, how to measure between holes, safety hints (drawing pin hazards, pencil lead poisoning, etc).

The lath with two holes is also the easiest to operate by far.
 
Last edited:

Phil Russell

Established Member
Joined
17 Dec 2016
Messages
46
Reaction score
28
Location
Cambridge
Or look for 'blackboard' compass as used in schools. OK it is designed to take a stick of chalk but I am sure a pencil or whatever could be fitted.
Cheers, Phil
 

JoshD

Established Member
Joined
3 Dec 2020
Messages
88
Reaction score
90
Location
Norfolk
My contribution: Trammel/beam compass is definitely the way to go, because traditional ones just have too much play as you get to large sizes (a little bit of bend in one or both legs changes the distance). Very simple Trammel (two holes in a piece of wood):is fine as long as you don't need to fine tune the size of circle. If you do need to fine tune it it can become a real headache and you discover that your drill technique isn't as good as you thought it was (speaking for myself here): to get 0.5mm tolerance in diameter you need 0.25mm accuracy in hole spacing. Pillar drill helps. If you need to tune size more finely than that you're going to end up cutting quite a few and it will take time. The answer I reckon is a Vernier Trammel with fine tuning. I haven't got one but I'd like one .... Not for pencils though.

 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
17,794
Reaction score
703
Location
Derbyshire
... Trammel (two holes in a piece of wood):is fine as long as you don't need to fine tune the size of circle. If you do need to fine tune it it can become a real headache and you discover that your drill technique isn't as good as you thought it was (speaking for myself here): to get 0.5mm tolerance in diameter you need 0.25mm accuracy in hole spacing. Pillar drill helps. If you need to tune size more finely than that you're going to end up cutting quite a few and it will take time. .
If precision needed you just drill a cluster of holes and choose the best one. A cordless hand drill will do fine, 1mm twist bit etc. You don't have to adjust both holes - just the pin hole so 0.5mm adjustment needs 0.5mm.
This is woodwork anyway, the accuracy of a pencil lead isn't going to be much closer than 0.5mm.
 

JefL

New member
Joined
6 Apr 2017
Messages
4
Reaction score
7
Location
Bristol
Boy Scout solution - a piece of string with a loop tied at each end. Might take a bit of fiddling to get the length right but probably the most economical solution.

Jef
 

TheUnicorn

Established Member
Joined
21 Feb 2020
Messages
742
Reaction score
250
Location
South West
this seems very doable, you could knock up a prototype from this within minutes and at little expense

 

Wood&StuffLtd

Established Member
Joined
14 Feb 2021
Messages
28
Reaction score
11
Location
Poole Dorset
Unable to find one (some?) online.
I'm looking for a pair of compasses, up to say 16" radius, big version of the old brass school compasses?
Anyone know where I can find them please (UK ideally)
I use a trammel tool for drawing large radius circles. Just Google it to se a large variety of types including pensil holders.
 

TominDales

Established Member
Joined
21 Jan 2021
Messages
177
Reaction score
122
Location
Ripon
<grin/> Don't be so darned practical ;-)
If this is a one-off, I found Just4funs suggestion is quick cheap and practical. Its 15 minutes or less to make a trammel of that size. If you need to change the diameter a lot, then probably best to buy a quality trammel. Compass's get unwieldy at that size, although both quit hard to keep the point in place for both trammel and compass at longer diams. If just a few uses, its quicker and cheaper to make it. Home made work very well.
Another benefit of Trammels vs compass is its easyer to make an ellipses as well as circles, you just use the major and minor axis, whereas many more measurments with a compass. Here is one I was using recently, its a foot long, its actuallly a bit easyer to make longer ones accurately.

A tips on making, drill pilot hole for the nail, and from the bottom up (so that the exact radius is on the bottom, important to keep the hole perpendicular, or drill more than one hole!!. See phot the many nails is I ended up doing more and more diameter measurements, just lower the one needed and tap the others back, should really buy a proper one... The two end holes for pencil when doing an ellipse. Good luck
Home made trammel.jpg
 

Inspector

Nyuck, Nyuck, Nyuck!
Joined
18 Jun 2006
Messages
2,072
Reaction score
351
Location
Saskatoon, SK., Canada
:giggle: CNC router, gantry and bed large enough for any of the work you wish to do. Program in the circle or arc size and cut it or if you only want to mark it put a laser in the spindle and burn in the width of line desired. :giggle:

Gosh. You guys like to keep everything so simple. 🤓

Pete
 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
17,794
Reaction score
703
Location
Derbyshire
If this is a one-off, I found Just4funs suggestion is quick cheap and practical. Its 15 minutes or less to make a trammel of that size. If you need to change the diameter a lot, then probably best to buy a quality trammel. Compass's get unwieldy at that size, although both quit hard to keep the point in place for both trammel and compass at longer diams. If just a few uses, its quicker and cheaper to make it. Home made work very well.
Another benefit of Trammels vs compass is its easyer to make an ellipses as well as circles, you just use the major and minor axis, whereas many more measurments with a compass. Here is one I was using recently, its a foot long, its actuallly a bit easyer to make longer ones accurately.

A tips on making, drill pilot hole for the nail, and from the bottom up (so that the exact radius is on the bottom, important to keep the hole perpendicular, or drill more than one hole!!. See phot the many nails is I ended up doing more and more diameter measurements, just lower the one needed and tap the others back, should really buy a proper one... The two end holes for pencil when doing an ellipse. Good luckView attachment 104685
Yebbut what if you want to adjust it by, say, 0.1mm? :unsure:
n.b. to keep the point of the pencil in place it needs to be a slightly loose fit so that you control it with your hand. Mechanical pencils are handy with their little precise lead tubes easy to fit with a matching sized drill - though you need a countersink if the lath has too much depth.
 

pe2dave

Established Member
Joined
2 Oct 2007
Messages
791
Reaction score
201
Location
Peterborough, Cambs, UK
<grin/> You don't! Either get it right or 'build another'!!! It's one of those tools I'd "like", but seldom use - The home made trammel (with careful measuring) will suffice.
 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
17,794
Reaction score
703
Location
Derbyshire
<grin/> You don't! Either get it right or 'build another'!!! ......
Easier than that - you drill a cluster of holes near the pin hole until you get one as accurate as you want. They don't have to be in line.
 

Sideways

Established Member
Joined
26 Dec 2017
Messages
1,233
Reaction score
188
Location
United Kingdom
Veritas make a trammel / beam compass set in stainless steel that I rather like.
The best I ever used was made by a gent - since passed away - back in the days of his apprenticeship. Rectangular steel bar, closely fitted brass sliders and turned steel points. Lovely piece of work.
IMO a rectangular beam is better because nothing can twist but they are uncommon I think because it's harder to make a precisely fitting rectangular hole in the sliders than just drill an accurate hole for a round bar
 

toolsntat

Yep, I collect tools and tat
Joined
8 Dec 2007
Messages
1,885
Reaction score
210
Location
Leicestershire England
Did you know that if you use any trammel with a pencil (sharpened with a pencil sharpener) the diameter can be kept precise by mounting the pencil at the same angle as the sharpener.
As the pencil lead wears down the inside/outside edge of the line stays true.
Cheers Andy
 

TominDales

Established Member
Joined
21 Jan 2021
Messages
177
Reaction score
122
Location
Ripon
Easier than that - you drill a cluster of holes near the pin hole until you get one as accurate as you want. They don't have to be in line.
I agree - if you may be able to see in the photo I put up earlier, that there is is more than one nail width wise to get very small changes in diameter down to about 1mm. If you need realy fine, they buy an expensive metal one. Its so simple I suggest you give it a go and if it doesnt suit you then you can spend money. I only use the tammel one in a while so find making it work well. Much better an string, as the pencil wobble about on string. My son made one 8 foot long to mark up a scooter ramp and that worked fine.
 

Latest posts

Top