Is my MFT or Squares out of square?

[Charlie Hill]

I was cutting some oak on my MFT earlier using Parf Dogs and the guide rail. The cut was just off my pencil mark which I had made with a old engineers square, 150 mm. So I got out my digital angle measurement thingy 200mm and the cut read at 89.9.

So I checked the Parf Dogs and they were 89.9, tried a couple of different locations with same results. I can't use the digital gauge to measure the engineers square as both being thin they keep slipping off each other.

I tried marking a line with the square then flipping it over and marking again, but could not see any difference ( my eyesight isn't brilliant unfortunately so might not have seen the discrepancy).

So I am now wondering which, if any, of the 3 items are square?

How can I check this please?

I could buy another high quality square, but would need to wait for delivery, but would like to get on with my current project.

 

[Birdhunter]

I just checked one of my 2 MFTs with my Woodpecker's framing square and 4 Qwas dogs. Its long leg is about 25" (63.5cm) and the short leg is about 12.5" (31.75cm). I also measured the MFT and the framing square using an electronic angle measuring tool.

At every place I tested on the MFT, the framing square was perfectly nestled against the Qwas dogs. No slop at all. I've checked the Woodpecker's framing square and it appears to be absolutely square. It is a massive tool!

I measured the framing square with the angle measuring tool. Some of the time, I got 90 degrees and some times 89.9 degrees. I was careful to zero the angle measuring tool.

I used the angle measuring tool to measure the MFT using 4 Qwas dogs. Of course, the angle measuring tool only spans a couple of dogs on each leg. Again, some of the times I got 90 degrees and some times 89.9 degrees.

I think the Woodpecker's square is true. I think the MFT holes are true. I think the electronic angle measuring tool is accurate to 0.1 degrees.

The Woodpecker's framing squares again available. I'd recommend getting one. I have 3 sizes and use them all.

 

[Stone Message]

Hi Charlie

It helps accuracy with the Parf Dogs to secure them with knobs from underneath as they then seat on the surface of the MFT3 and do not lean.

Your engineer's square should be spot on because the standards that govern engineer's squares (certainly in the UK) are much tighter than woodworking tool specs. But to be sure use your setup to cut what you think should be a rectangle. Then check the diagonals - they should be identical. If they are then you have a perfect set of right angles and you can check your square.

There is a slim chance that the holes on the MFT3 are either a smidgeon out of square or slightly larger than they should be thus allowing some lateral movement of the dogs.

One note of caution to every woodworker...

I had always assumed that my father's old woodworking squares were spot on but I discovered, when doing some fine adjustments to my Kapex, that they were not. So, I went and bought a brand new 12" square and guess what - it was a mile out. I then went back to the shop and tried every square that they had and none were right. I then went to Woodworkers' Workshop and got a 12" engineer's square which is absolutely spot on.

In a woodworking store you can see if there is a problem with their squares by trying them against each other. The Incra Guaranteed Square I have is also spot on.

Peter

 

[Charlie Hill]

I just checked one of my 2 MFTs with my Woodpecker's framing square and 4 Qwas dogs. Its long leg is about 25" (63.5cm) and the short leg is about 12.5" (31.75cm). I also measured the MFT and the framing square using an electronic angle measuring tool.

At every place I tested on the MFT, the framing square was perfectly nestled against the Qwas dogs. No slop at all. I've checked the Woodpecker's framing square and it appears to be absolutely square. It is a massive tool!

I measured the framing square with the angle measuring tool. Some of the time, I got 90 degrees and some times 89.9 degrees. I was careful to zero the angle measuring tool.

I used the angle measuring tool to measure the MFT using 4 Qwas dogs. Of course, the angle measuring tool only spans a couple of dogs on each leg. Again, some of the times I got 90 degrees and some times 89.9 degrees.

I think the Woodpecker's square is true. I think the MFT holes are true. I think the electronic angle measuring tool is accurate to 0.1 degrees.

The Woodpecker's framing squares again available. I'd recommend getting one. I have 3 sizes and use them all.

 

[Charlie Hill]

I just checked one of my 2 MFTs with my Woodpecker's framing square and 4 Qwas dogs. Its long leg is about 25" (63.5cm) and the short leg is about 12.5" (31.75cm). I also measured the MFT and the framing square using an electronic angle measuring tool.

At every place I tested on the MFT, the framing square was perfectly nestled against the Qwas dogs. No slop at all. I've checked the Woodpecker's framing square and it appears to be absolutely square. It is a massive tool!

I measured the framing square with the angle measuring tool. Some of the time, I got 90 degrees and some times 89.9 degrees. I was careful to zero the angle measuring tool.

I used the angle measuring tool to measure the MFT using 4 Qwas dogs. Of course, the angle measuring tool only spans a couple of dogs on each leg. Again, some of the times I got 90 degrees and some times 89.9 degrees.

I think the Woodpecker's square is true. I think the MFT holes are true. I think the electronic angle measuring tool is accurate to 0.1 degrees.

The Woodpecker's framing squares again available. I'd recommend getting one. I have 3 sizes and use them all.

Thanks Birdhunter, so that might explain my digital measurement readings. Now to establish if it's the MFT or engineers square that is out I will do the tests Peter has suggested.

 

[Charlie Hill]

Hi Charlie

It helps accuracy with the Parf Dogs to secure them with knobs from underneath as they then seat on the surface of the MFT3 and do not lean.

Your engineer's square should be spot on because the standards that govern engineer's squares (certainly in the UK) are much tighter than woodworking tool specs. But to be sure use your setup to cut what you think should be a rectangle. Then check the diagonals - they should be identical. If they are then you have a perfect set of right angles and you can check your square.

There is a slim chance that the holes on the MFT3 are either a smidgeon out of square or slightly larger than they should be thus allowing some lateral movement of the dogs.

One note of caution to every woodworker...

I had always assumed that my father's old woodworking squares were spot on but I discovered, when doing some fine adjustments to my Kapex, that they were not. So, I went and bought a brand new 12" square and guess what - it was a mile out. I then went back to the shop and tried every square that they had and none were right. I then went to Woodworkers' Workshop and got a 12" engineer's square which is absolutely spot on.

In a woodworking store you can see if there is a problem with their squares by trying them against each other. The Incra Guaranteed Square I have is also spot on.

Peter

Thanks Peter. Birdhunter has queried the accuracy levels of the digital tool! I will try your suggestions.

By the way was this the square you bought http://woodworkersworkshop.co.uk/epages/eshop814530.sf/en_GB/?ObjectPath=/Shops/eshop814530/Products/FISSQUA300 Almost half the price of the Woodpeckers equivalent, from what you say there is no need to spend the extra money. Just in case I discover the square is inaccurate!

 

[Stoli]

How can I check this please?

You can check your MFT with the "5 cut method".  Rick's Kapex supplemental manual has the details (and he rightly notes that you really only need 4 cuts, as long as you have a straight side).

The basic method is to put a straight side against your fence and make a cut.  Now rotate that newly cut side around so it is now against your fence and cut again.  Repeat until you are about ready to cut the first side again, and make sure that when you perform this cut there is a measurably sized offcut (~1" or 25mm or so, exact value not really important).  Then measure the width of the top and bottom of the offcut.  The difference between these measurements, divided by 4 times the length of the last side, is a measure of the error.  You will likely not be dead on, there will almost always be some difference.  You will have to decide what your acceptable tolerance is.

 

[Stone Message]

Thanks Peter. Birdhunter has queried the accuracy levels of the digital tool! I will try your suggestions.

By the way was this the square you bought http://woodworkersworkshop.co.uk/epages/eshop814530.sf/en_GB/?ObjectPath=/Shops/eshop814530/Products/FISSQUA300 Almost half the price of the Woodpeckers equivalent, from what you say there is no need to spend the extra money. Just in case I discover the square is inaccurate!

Yes, that is the one that I have and it is spot on. You do need to realise that it is quite heavy but I do not find that a problem.

Peter