7' triangular frame - accurate transfer of marking out

[flintandsteel]

This is a bit of an issue but I'm coping - even if it is very slow at the moment.
Ok, the hypotenuse is marked out at 10mm intervals. The issue once I reach the usable limits of my engineer's square is how to keep on marking out up the diagonals. Yes I can do it with a good straight edge and square combination but it is very laborious.
Ideally what I'd really like is some kind of parallel action arrangement like on a wall mounted sheet cutter.
Any other suggestions ........ or anyone know where I might find a scrap sheet cutter?
Are sheet cutter better known as something else? as I've not found one yet.

 

[oakmitre]

I cannot work out what you are trying to make - do you have an example - on google images or similar ?

For marking out 7 feet, I wonder if a till roll printer would be able to produce a piece of paper with increments that you could carefully align and punch.

 

[NazNomad]

...the hypotenuse is marked out at 10mm intervals.
how to keep on marking out up the diagonals

I can't get my head around how you've got a triangle with diagonal lines in it, what are you making?

 

[flintandsteel]

Hi
It's a Triangular loom.
Take the hypotenuse as the base line. The lines marked on the hypotenuse have to be transferred through to "exactly" the same position on the diagonal other 2 sides thus intersecting a drawn line and thus marking the location of pins set at precise positions around the entire frame. As the measure on the sides becomes 14.1mm it's impossible to achieve such precision any other way excepting having a CNC jig made or adapting a parallel action to do it with ease.
Just looking to speed up the process as today it took over 2 hours to do this job as there were about 230 lines / marks to transfer.
Following that additional lines are then drawn mid way between the diagonal side lines. So basically a *!* big triangle with about 700 steel pins around the edges.

 

[oakmitre]

So the gaps between pins on the sides are larger than the base line. I wonder if a piece of paper tape aligned with a plumb bob would do it.
There is an extension for inkscape called scale generator. That combined with a till roll printer, you can print your own scales.

Or make a large T-square using mdf and check it for square using an 8" mdf board, putting the T-square on the short end,then flip it to the other end and draw a line to see if they meet.

 

[RossJarvis]

I think I'd lay it out and somehow mark out a square to encompass the whole triangle, mark out the 10mm gaps at top and bottom and use a 7' straight edge between these and mark where the straight edge intersects the hypotenuse....If that makes any sense.

 

[Eric The Viking]

I think I'd lay it out and somehow mark out a square to encompass the whole triangle, mark out the 10mm gaps at top and bottom and use a 7' straight edge between these and mark where the straight edge intersects the hypotenuse....If that makes any sense.

It certainly does to me!

Are these things made commercially? If so they must have a way to do it efficiently.

Assuming all your looms are the same size, how about one life-size pattern of ply with drill/punch holes, made from Ross's suggestion above. The one thing you can usually speed up the most by batch production is setting out.

Otherwise can you make one big square and stretch something like fishing line between pins, then use that to get the positions you need on the triangle?

Still struggling to get my head around your description, BTW - a drawing or photo would really help!

 

[Myfordman]

Set dividers ** to 14.14mm and mark along a straight line on each of the triangle sides.

** ideally spring bows locked to dimension.

 

[t8hants]

Have you got a scientific calculator, if so use that.
Take the distance you want to divide by the number of pins you want that will give you a number, i.e. the distance between each pin.
Then punch that number in (Example 12, then punch = ANS)
the screen should now show ANS now punch +12
Every time you now punch = the answer will increase by 12, so you get 12, 24, 36, etc.
I have used this method for making exactly space railings for years.

 

[Jacob]

Can't quite visualize what you are doing but it sounds like you need dividers. They are cleverer than they look, very accurate and quick once you've got the knack.
For a long length of small divisions you might divide and mark out multiples, say 10x your 14.1mm = 141mm, then divide these each into ten.
They are called dividers because that is their principle use; dividing lines accurately into smaller divisions.
It's a bit of a lost art but not difficult to get to grips with.

PS and much quicker than any of the methods above.

 

[NazNomad]

I think I'm missing the point. Shouldn't the loom have the same number of pins on each side, irrespective of the size of the loom and the distance between the pegs?

I can't imagine how you'd weave on a tri-loom without the same number of pins on each side?

 

[bugbear]

This is a bit of an issue but I'm coping - even if it is very slow at the moment.
Ok, the hypotenuse is marked out at 10mm intervals. The issue once I reach the usable limits of my engineer's square is how to keep on marking out up the diagonals. Yes I can do it with a good straight edge and square combination but it is very laborious.
Ideally what I'd really like is some kind of parallel action arrangement like on a wall mounted sheet cutter.
Any other suggestions ........ or anyone know where I might find a scrap sheet cutter?
Are sheet cutter better known as something else? as I've not found one yet.

Actually, I'd suggest "good straight edge and square combination" won't work, since the reference face of the square is unlikely to be long enough over such long distances.

The following suggestion only applies if you're making enough of these for the overhead to be worth it, and the lengths of all 3 sides are accurately cut and joined such that the desired interval on the two short sides are consistent within your desired accuracy.

Your essential problem is one of arithmetic - I'm assuming that you find marking the long side easy, by simply using multiples of 10 on a metric tape.

So simply make a 14.1421 interval ruler. When making this, cumulative errors are your enemy, so make a table (table 1, either using a calculator, a spreadsheet, or anything else convenient) of all the distances you need, then mark them all from a common origin, using a trustworthy measure (e.g. engineers rule, ruler from a good combination square).

Make your custom rule according to the life span it needs to have - either cardboard, hardboard, MDF, steel, your marks can vary from pencil mark to drilled holes.

Now, make another table (table 2) of absolute offsets, the interval being the total length of your new rule. You will mark the start of each rule's worth of points according to this table, using a trusted tape.

Marking out is now trivial - take your tape, mark the intervals from table 2, pick up your custom rule, and mark all your sub-intervals from each interval mark.

Done.

BugBear

 

[Rob Platt]

translates as 9/16"
if i`m understanding the question properly which is easy to mark out
all the best
rob

 

[Jacob]

........
Your essential problem is one of arithmetic - ....

Or to be precise; division. That's why "dividers" are the tool for the job.
You might need several sizes if you are doing a long length into many small divisions.

 

[Jacob]

........
Your essential problem is one of arithmetic - ....

Or to be precise; division. That's why "dividers" are the tool for the job.
You might need several sizes if you are doing a long length into many small divisions.

Actually it's more geometry than arithmetic. Division by geometry.

 

[deema]

Make yourself a T square, I would suggest a bit of ply with the T screwed and glued.