How to make a near perfect square - Video

[Stone Message]

Hi Everyone

I friend of mine asked me to make him a large square for some layout work he was doing. As I am a bit of a "squareness" fanatic I had to make sure that it was near perfect.

The technique of making the square is simple enough but the accuracy comes from a simple cut done on my tracksaw cutting station that I created with my Parf Guide System. The result is accurate to 4 mm over 10 m and it was made from workshop scraps.

Here is the video:


Peter

 

[tony_sheehan]

Fantastic,  look forward to viewing this a little later this evening

 

[Stone Message]

Once I realised how square it is possible to make these things I decided to keep the one shown in the video and I have made a new one for my friend. This time I have used a butt joint rather than a mitre for the interface between the two long sides which made assembly much easier.

I took the original over to another (seriously professional) friend and invited him and his new apprentice to check it out for square. They used their 12" engineer's square and agreed that it was spot on.

Peter

 

[PreferrablyWood]

Thanks Peter..

I'll have to a least get an Engineers Square like yours, anything bigger I now know it's possible to fabricate my own..

 

[Stone Message]

Thanks Peter..

I'll have to a least get an Engineers Square like yours, anything bigger I now know it's possible to fabricate my own..

Excellent. I see that you have the Parf Dogs but I will be happier when you have the Parf Guide System in your strap line !

Cheers.

Peter
(modified to spell my name correctly !!!)

 

[PreferrablyWood]

Thanks Peter..

I'll have to a least get an Engineers Square like yours, anything bigger I now know it's possible to fabricate my own..

Excellent. I see that you have the Parf Dogs but I will be happier when you have the Parf Guide System in your strap line !

Cheers.

Petre

They will be added, brilliant system!

 

[bobfog]

That's impressive!

Even some of the more expensive boutique brands only achieve 10mm over 10 metre on metal 8"'squares.

 

[Svar]

That's impressive!

Even some of the more expensive boutique brands only achieve 10mm over 10 metre on metal 8"'squares.

Are you sure? 10mm over 10m (1:1000) is pretty poor even for a general purpose framing square. Woodpacker guarantees their squares to at least 1:10000. Same with Incra or Starrett.

 

[bobfog]

Maths isn't my strongest point but the Veritas precision metric square advertises it's as accurate as an engineers square at 0.025mm over 25mm. So by my
Calculations that would be 10mm over 1000cm.

Am I wrong?

 

[mouppe]

That's impressive!

Even some of the more expensive boutique brands only achieve 10mm over 10 metre on metal 8"'squares.

Are you sure? 10mm over 10m (1:1000) is pretty poor even for a general purpose framing square. Woodpacker guarantees their squares to at least 1:10000. Same with Incra or Starrett.

Woodpecker's states this about their 1281 square: "Our manufacturing process insures the 1281 Square is accurate to within one thousandth of an inch or less along the full length of the tool." That's 1/12,000.

My Veritas 36" straight edge is 15/360,000. (From the Lee Valley website: These Canadian-made precision steel straightedges are ground flat over the entire length on both edges, the 12" and 24" lengths to within 0.0010" and the 36" length to within 0.0015".)

 

[Svar]

Maths isn't my strongest point but the Veritas precision metric square advertises it's as accurate as an engineers square at 0.025mm over 25mm. So by my
Calculations that would be 10mm over 1000cm.

Am I wrong?

You are correct, but I'm surprised Veritas would make such a statement.

 

[Stone Message]

I Have the Veritas 24" straight edge and it is amazingly useful - everything from checking the fence line of my Kapex to seeing if I can still use my hand plane properly.

Peter

 

[Kev]

It's been ages since I did anything like this .. last time was well before MFT's and Dominos .. back then the trick was to make two squares and progressively tune them against each other and a straight edge.

The reality these days is that with the cutting and connection tools available, various fastening systems etc .. you can make some very interesting alignment tools from aluminium too.

Peter's dead right in the versatility of making, for all intents and purposes, disposable perfect squares.

Thank's Peter, once again you're causing old neurone to fire again [smile]

On a slightly different topic Peter, I hold you fully responsible for a recent mega purchase I made with Incra [mad] [embarassed] [big grin]

Kev.

 

[Stone Message]

It's been ages since I did anything like this .. last time was well before MFT's and Dominos .. back then the trick was to make two squares and progressively tune them against each other and a straight edge.

The reality these days is that with the cutting and connection tools available, various fastening systems etc .. you can make some very interesting alignment tools from aluminium too.

Peter's dead right in the versatility of making, for all intents and purposes, disposable perfect squares.

Thank's Peter, once again you're causing old neurone to fire again [smile]

On a slightly different topic Peter, I hold you fully responsible for a recent mega purchase I made with Incra [mad] [embarassed] [big grin]

Kev.

Oops - sorry. Apologise to Mrs Kev and tell her that I forced you to do it !

Peter

 

[Kev]

Oops - sorry. Apologise to Mrs Kev and tell her that I forced you to do it !
fessed
Peter

Unfortunately, in an act of self preservation [member=11196]Peter Parfitt[/member] , I've confessed to your involvement ... my wife's access to government, defence and satellite systems through her involvement with educational sales means she can probably retaliate with an aggressive em spam attack - be safe [eek]

I'm really looking forward to the Incra kit ...  [big grin]

Kev.

 

[geoffshep]

Obviously this is (or can be) a disposable item, as you have said.  But it would be interesting to know what happens to it over time, given the stability of the MDF.

 

[Stone Message]

Obviously this is (or can be) a disposable item, as you have said.  But it would be interesting to know what happens to it over time, given the stability of the MDF.

I think that you are right - it might stay good for a very long time. The real plus is that it can be replaced very quickly using scrap MDF and a handful of dominos, biscuits or even screws.

I might make a smaller one out of plywood and see how that turns out - I know it will be square.

Peter

 

[Michael Kellough]

It's cool that you can make a good square that way but in the age of cheap smooth panels I wouldn't try to make one out of sticks.

Just get a piece of MDF and cut it square. If you want a triangle cut it in half and then you have two. If it's too heavy cut holes in the center. If there was tension in the panel and it moved after the secondary cuts then just re-cut.

With Peter's Parf Guide system it should be a piece of cake. (I have one on order)

If you don't have the Parf Guide but do have an MFT download Rick's Kapex manual which has an interactive 4 cut calculator so you can fine tune your MFT to cut extremely square.

 

[eddomak]

Firstly, thanks Peter for your video - I saw it before seeing this thread. Well explained and brilliantly presented as always. I am guessing your method works on a standard MFT.

... Just get a piece of MDF and cut it square. If you want a triangle cut it in half and then you have two. If it's too heavy cut holes in the center. If there was tension in the panel and it moved after the secondary cuts then just re-cut.

Secondly, just when I was about to go and try this out, along comes this even simpler idea. Especially in a situation for a "disposable" square, I am guessing it would be faster to cut a triangle on the MFT and hack the insides out with a jigsaw if I needed something lighter and/or somewhere to hold.

Thirdly, I guess it could be easy to adapt either the square or the triangle to form some cheap/easy corner clamps.

 

[Stone Message]

Firstly, thanks Peter for your video - I saw it before seeing this thread. Well explained and brilliantly presented as always. I am guessing your method works on a standard MFT.

... Just get a piece of MDF and cut it square. If you want a triangle cut it in half and then you have two. If it's too heavy cut holes in the center. If there was tension in the panel and it moved after the secondary cuts then just re-cut.

Secondly, just when I was about to go and try this out, along comes this even simpler idea. Especially in a situation for a "disposable" square, I am guessing it would be faster to cut a triangle on the MFT and hack the insides out with a jigsaw if I needed something lighter and/or somewhere to hold.

Thirdly, I guess it could be easy to adapt either the square or the triangle to form some cheap/easy corner clamps.

Yes, cutting a square and then making two triangles is a great idea. However, for the size that my friend wanted the piece of MDF would have been too heavy. My gluing will last for ever (dominos used as well) and so my lighter version is always an option. I certainly think that the square/triangle idea is brilliant for smaller squares.

I am sure corner clamps and many other ideas will be created by users of the Parf Guide System as people realise that  they can exploit its accuracy in so many ways.

Peter