Squaring up MDF sheets

[Steve Maskery]

Track saw is the way to go and one does not have to be expensive. One comes up at Lidaldi from time to time at around the £79 mark.

I have a setting gauge for parallel cuts, it cost me less than a tenner to make and I can get repeatable accuracy time and again. There is an explanation of it on here somewhere, IIRC. It was the first thing I made for my Workshop Essentials series. Now, nearly ten years later, I still haven't found anything better.
For getting square I currently use a roofing square (£2 from a market stall, it is remarkably accurate), but sometimes I use my Square of Thales, it just needs a bit of refining to make it a bit more user-friendly.

 

[Estoril-5]

Cheers guys, well the first thing I need is a precision square as I don't have one.

Once I get that I'll make a T square and s framing square out of 18mm MDF

Sent from my Moto G (4) using Tapatalk

 

[Estoril-5]

I have a setting gauge for parallel cuts, it cost me less than a tenner to make and I can get repeatable accuracy time and again. There is an explanation of it on here somewhere, IIRC.

The search function on my phone isn't great, not sure if it's me or Tapatalk.

If you have a link that would be awesome.



Sent from my Moto G (4) using Tapatalk

 

[Steve Maskery]

Hmm, I can't find it either. I'm sure I did. I certainly posted a photo of me using it during my workshop build, so if you just want to have a quick flick through those 138 pages...
It's basically like a pencil gauge calibrated for my tracks. I reference off the back of the track and I get accuracy as good I'd get with a TS, as good as you can measure.

Here we are, found it:
post966884.html#p966884

 

[Estoril-5]

Thanks for all the replies guys, going to look at making my own t square using this 3 4 5 method (although I don't know how it works).

You remember Pythagoras's theorem from school?



5^2 = 3^2 + 4^2
5x5 = 3x3 + 4x4
25 = 9 + 16
25 = 25


Lets say we want to use ar larger triangle, we just scale both sides.

e.g scale by 2

2(5^2) = 2(3^2 + 4^2)
2(5x5) = 2(3x3 + 4x4)
2x5x5 = 2x3x3 + 2x4x4
50 = 18 + 32
50 = 50

or double the figures

10^2 = 6^2 + 8^2
10x10 = 6x6 + 8x8
100 = 36 + 64
100 = 100

I had a large piece of 12mm MDF at home and it looked reasonably square so I set out using the 345 method to see if it was.

Using my 300mm steel rule I marked out one line at 3 inches and the other at 4 inches. I marked the start and end points with a brawdal so the points were precise, lo and behold the third line was pretty much spot on 5 inches.

I'm going to cut that corner off and use it as a speed square.

I'll use that as a tool to create a try square and a t square.

Cheers for the help guys

Sent from my Moto G (4) using Tapatalk

 

[Jacob]

Alternative to a track saw is the home made saw-board (plus circ saw of course). Very simple, cheap, accurate and much more effective than you'd think. Google it.
Needs to be wide enough to allow the saw to pass the G clamps (if that's how you are fixing it).

 

[lurker]

I hate B&Q with a passion

But their sheet sawing is very good.
Last time I used them it was 3 free cuts & then 50 p per cut.

Get a say, 18mm sheet of MDF off their rack (Important! check it for edge damage)

Get the bloke to slice
1 X 8ft by 9"
1x 8ft by 5" .......this one needs to be the manufactured edge not the shop cut mark (none of the other cuts really matter).
Those will make your a circular saw guide.

A square of around 2ft
At home you can cut this diagonally and you should have 2 X squares (obvously you need to check them).

Cut the rest of the sheet to fit your car or a project.
Total cost; well under 20 quid.

 

[lurker]

Hmm, I can't find it either. I'm sure I did. I certainly posted a photo of me using it during my workshop build, so if you just want to have a quick flick through those 138 pages...
It's basically like a pencil gauge calibrated for my tracks. I reference off the back of the track and I get accuracy as good I'd get with a TS, as good as you can measure.

Here we are, found it:
post966884.html#p966884

Steve,
I have never seen this (post of yours) before, but I have a near identical one I made with a 1 metre wooden ruler.

Regarding your "rule of thales", I made one after you posted about it (about a year ago). TBH it wasnt until I had actually made one that "I got it".
Not only has it been a useful tool (rebuilding the old house) but its a great talking point and I have gained much Kudos demonstrating it to professional civil engineers 8) :lol:

 

[skipdiver]

I use a track saw as well. I will dimension sheets outside on trestles to more manageable sizes or sometimes just get the timber yard to cut them in half before they deliver. I then take them inside the workshop and get to work with the tracksaw on a bench with a 1/2 sheet of jablite on top. This lasts a while before i flip it over and use the other side. 1 sheet of jablite lasts for quite a while and is a fiver. If i have none to hand, then i use strategic battens. When cutting, i measure one side and set my guide rail to that using a big square that i know is accurate, having first checked that the end i am measuring from is also square. When i get to smaller pieces, i put those through my tablesaw, either ripping or with the cross cut function, whichever is appropriate.

 

[Shultzy]

If you want to cut large sheets down to more manageable sizes, invest in making one of these out of an 8x4 sheet of ply:

https://www.ukworkshop.co.uk/forums/sore-hoarses-mkii-now-with-added-plans-t44761.html

I cut down 36 8x4 sheets of MDF for my kitchen using this and a home made saw-board.

 

[Steve Maskery]

+1 for Aiden's saw table setup.
I've done it as is, but I shall probably remake it with shallower ribs, so I can get an extra inch or two in the legs for overall height. But it is an excellent, most excellent, setup.