Precision Engineers Square

[Oldneweng]

Today I was thinking about how to get my mill table square with the Y axis again after I finish fitting the DRO's. I decided that it would be best to buy a Precision Engineers Square.

All the ones I have found on the net have had double bevelled edges. As I want to run a DTI along the edge I don't think these are suitable. I have not been able to determine how much of a flat surface is left tho.

Any suggestions?

Dean

[KBs PensNmore]

Hi Dean, do you have a dial indicator? I made an L bracket that fitted on the back of the DI and used that in the collet to bring it all square. I found it more accurate to do than using a square. What type of mill do you have?
Regards
Kryn

[Stustoys]

Hi Dean,

Leave Precision out of your search.
I assume this is the sort of thing you are after
http://www.ebay.com.au/itm/Moore-Wright-Engineers-Square-225mm-9-Precision-Ground-Measuring-Face-400-09-/181757188090?pt=LH_DefaultDomain_15&hash=item2a519297fa

Stuart

[Oldneweng]

Hi Dean,

Leave Precision out of your search.
I assume this is the sort of thing you are after
http://www.ebay.com.au/itm/Moore-Wright-Engineers-Square-225mm-9-Precision-Ground-Measuring-Face-400-09-/181757188090?pt=LH_DefaultDomain_15&hash=item2a519297fa

Stuart

I was looking for something with a bit more beam/blade thickness. A single piece square.

349168

It may be that I have to use what you linked to. The problem is it is hard to tell how thick the blade is as I have to run the DTI along both external edges for best accuracy. I don't trust the slots to be accurate enough and I don't have any accurate way to locate to them. The single piece square above is flat which means I can sit it on the mill table or on equal height buttons for clamping at 3 points. I am only working on what my imagination has come up with so don't make any assumption I know what I am talking about. I am open to any suggestions, but if I recall correctly, there was a thread about doing this some time back and the best that came out of it was to use a square somewhat like I am doing it.

I found M & W squares like that at the same store using "Precision" in my search :D.


Kryn.

I am talking about a rotating table that needs to be re-set square to the Y axis after being moved re my thread http://www.woodworkforums.com/showthread.php?t=195371

349169

The scale behind the tied up cable is the angle the table is rotated from normal. In this case you are looking at the rear of the table.

Dean

[neksmerj]

I recently bought a small and medium size square from McJings.

I didn't test for accuracy but they appear to be decent quality, and reasonably priced in a nice plastic case.

I'd say a tad better than your plastic set square.

Ken

[KBs PensNmore]

Hi Dean,
Sorry, now I understand what you are trying to do. If you had a piece of bar 10-12 mm thick with 2 machined edges (parallel) that could be bolted to the table, square the bar using any square, check it both sides from the same face, to ensure that it is square to the front edge.
Just because a square is supposed to be, doesn't mean it is, so checking both sides corrects any discrepancies.:oo:
Once you have the table set correctly, is it possible to fit a dowel pin to correctly and easily locate each time?
Kryn, again:D

Hi Ken, I'd check the square to ensure that it's correct. Not trying to be smart, but do you know how to check it?

[pipeclay]

Can you use an inside mic off the machined surface on the coloum and the rear of the table.

[neksmerj]

KB, you're not being smart, I sometimes use the square as a hammer, just kiddin.

How do you test a square?

Ken

[Michael G]

How do you test a square?

With a better one -A ground cylindrical square is probably the best master for this. It is checked by measuring diameter top and bottom (that is, is it parallel?), and then on a surface plate measuring the offset of the top with respect to the bottom. If these offset measurements are equal then it is square to the surface. I vaguely recall there is a thread about it somewhere.

Michael

[.RC.]

How do you test a square?

Ken

https://www.youtube.com/watch?v=baqCWk4OmwU

[Oldneweng]

Hi Dean,
Sorry, now I understand what you are trying to do. If you had a piece of bar 10-12 mm thick with 2 machined edges (parallel) that could be bolted to the table, square the bar using any square, check it both sides from the same face, to ensure that it is square to the front edge.
Just because a square is supposed to be, doesn't mean it is, so checking both sides corrects any discrepancies.:oo:
Once you have the table set correctly, is it possible to fit a dowel pin to correctly and easily locate each time?
Kryn, again:D

Hi Ken, I'd check the square to ensure that it's correct. Not trying to be smart, but do you know how to check it?

The method I am thinking of is to use the square clamped to the mill table. Dial-in the side running parallel to the X axis adjusting until as close as possible, just like setting the vise parallel.

Using the DTI on the other side of the square, adjust the rotary position of the table until this is true to the Y axis.

If you are after perfection, flip the square over using the Y axis side as the pivot axis and repeat the process, but averaging any variations. If the square is precise there should not be any. OH, we have just checked the square for precision. :rolleyes:

This is the same way you check a normal (Woodworking) square, using the square to draw a 90deg line on a sheet of some type with a straight edge, flip and repeat to see if the lines are parallel.


http://d1r5wj36adg1sk.cloudfront.net/images/icons/icon1.png
Can you use an inside mic off the machined surface on the coloum and the rear of the table.





Pipeclay

The machined surfaces do not extend low enough.

349190

I have found a range of squares of the type I am looking for.

http://www.ebay.com.au/itm/KINEX-4034-15-300-x-200mm-Precision-Flat-Square-/311372059438?pt=LH_DefaultDomain_15&hash=item487f38932e

Unfortunately there is zero information besides "Product Name: KINEX 4034-15 300 x 200mm Precision Flat Square".

349191

How precise is anyones guess. Anyone know how thick the blade is on a Moore and Wright square?

Dean

[thorens]

The method I am thinking of is to use the square clamped to the mill table. Dial-in the side running parallel to the X axis adjusting until as close as possible, just like setting the vise parallel.

Using the DTI on the other side of the square, adjust the rotary position of the table until this is true to the Y axis.

If you are after perfection, flip the square over using the Y axis side as the pivot axis and repeat the process, but averaging any variations. If the square is precise there should not be any. OH, we have just checked the square for precision. :rolleyes:

This is the same way you check a normal (Woodworking) square, using the square to draw a 90deg line on a sheet of some type with a straight edge, flip and repeat to see if the lines are parallel.



Pipeclay

The machined surfaces do not extend low enough.

349190

I have found a range of squares of the type I am looking for.

http://www.ebay.com.au/itm/KINEX-4034-15-300-x-200mm-Precision-Flat-Square-/311372059438?pt=LH_DefaultDomain_15&hash=item487f38932e

Unfortunately there is zero information besides "Product Name: KINEX 4034-15 300 x 200mm Precision Flat Square".

349191

How precise is anyones guess. Anyone know how thick the blade is on a Moore and Wright square?

Dean

Hi Dean.
I have one M&W square still in box . i will check for you soon . it also available for sale too .
cheers'
Peter

[Stustoys]

Hi Dean,

The bigger they are the thicker they are, not a lot of help there I know :p I can measure a few tomorrow if you like. Though even the smallest I have you can run a DTI along.(I'll measure them tomorrow if you like)

I don't have one of the beveled flat ones. but if I recall correctly they are pretty thin.

I rest the square against the front of the table. You could clamp it to the table if you wish.(though as I dont have a swinging table I'm squaring work the the table).

Stuart

p.s. typed last night but still there this morning, I'll get out and get measuring shortly

[Stustoys]

Think I've misunderstood the question again.. but as I've already measured them anyway.
50mm square has a 1.5mm blade.
9" is 3mm
24" is 4.8mm

You can check a square without a master square if you have a flat plate.
Measure the blade for parallel. Put the short side on the plate against a straight edge, clamp a stop against the inside of the vertical blade near the bottom, zero a DTI on the inside of the vertical blade near the top, check zero by sliding the square away and back, check square by turning 180. Would be more accurate than using the X axis of my mill as its "less than wonderful", hopefully your mill would do better.

Stuart

[Oldneweng]

Hi Dean.
I have one M&W square still in box . i will check for you soon . it also available for sale too .
cheers'
Peter

Thanks Peter. I may be interested. Depends on the size.

Dean

[Oldneweng]

Think I've misunderstood the question again.. but as I've already measured them anyway.
50mm square has a 1.5mm blade.
9" is 3mm
24" is 4.8mm

You can check a square without a master square if you have a flat plate.
Measure the blade for parallel. Put the short side on the plate against a straight edge, clamp a stop against the inside of the vertical blade near the bottom, zero a DTI on the inside of the vertical blade near the top, check zero by sliding the square away and back, check square by turning 180. Would be more accurate than using the X axis of my mill as its "less than wonderful", hopefully your mill would do better.

Stuart

Thanks Stuart. 9" is around the size I would be interested in. 3mm is plenty to run a DTI against. I was not about to spend my money unless I knew what the thickness was beforehand.

I am not sure if my mill would do better, but the way I look at it is that there is no point in making it any better than the mill can do anyway. Being relatively new one would hope it would be reasonably accurate tho. :rolleyes:

Dean

[Stustoys]

Thanks Stuart. 9" is around the size I would be interested in. 3mm is plenty to run a DTI against. I was not about to spend my money unless I knew what the thickness was beforehand.
Just to be sure we are talking about the same thing. The 9" M&W I am talking about is the same as the one I linked to. While mine is much older I don't the thickness has changed much.

Stuart

[Ueee]

Does your column have a ground face Dean? You can set the table by putting a DI on it and clocking the front face of the column.
Cheers,
Ew

[thorens]

Thanks Peter. I may be interested. Depends on the size.

Dean

Hi Dean.
it have the long side 4mm thick and the base side is 21.50mm thick . i think it is 9" .
.
Peter

[Oldneweng]

Just to be sure we are talking about the same thing. The 9" M&W I am talking about is the same as the one I linked to. While mine is much older I don't the thickness has changed much.

Stuart

Yes. We are talking the same language., but considering Peter's post. :)

Dean

[Oldneweng]

Does your column have a ground face Dean? You can set the table by putting a DI on it and clocking the front face of the column.
Cheers,
Ew

The column ways are the only ground surfaces. The height they begin can be seen in the picture I posted. Where the way cover becomes unruly. It is the dovetail holding it above this. The column is about 190mm wide, giving a good distance between measurements, but this requires moving the table away from the column to get past the dovetails. The top surface of the dovetails is also ground. This gives a width of about 130mm for measurement.

A great idea Ewan. I will give it a go. Thanks.

Dean

[Oldneweng]

Hi Dean.
it have the long side 4mm thick and the base side is 21.50mm thick . i think it is 9" .
.
Peter

Thanks Peter. I am interested in it even after Ewans idea arose.

Dean

[thorens]

Thanks Peter. I am interested in it even after Ewans idea arose.

Dean

cool Dean.
PM me.
Peter

[cba_melbourne]

Dean, I think you are overthinking this. After all, this is only a low cost hobby-mill.

I did the basic tramming of my Sieg X3 using a low cost engineers square like this:
349321
The one I used was a cheap DIN875/1. It was 150mm long and that is plenty enough for this task.
Step 1: I put the DTI in the spindle, indicate on the 5mm wide vertical face of the square in x and y axes. Move the head up/down and tram/shim that columsn until the error is less than 1/100mm in 100mm travel.
Step 2: Move the quill up/down, tram the head to to the head carriage until you get that error too to within 1/100mm in 50mm travel. Note your Super X3 has a tilting head, so in x axis you need not tram the head but simply set the tilt, and make some sort of index mark so you find easily back if later on you need to tilt that head (or frill and ream for an easy to use locating taper pin).
Step 3: verify by taking a very very light cut with something like a very sharp (new, preferably uncoated) 20mm endmill (or a flycutter is even better). Move table bothe in x and y direction. The end mill marks on the surface finish MUST nicely overlap - else tramming is out, or there is slop somewhere. This test is very sensitive, probably more sensitive than if you spent $300 on a good precision square and DTI. If the cut marks are evenly wisible as circles, not as halfmoons, it means your mill is overall trammed to better than 0.01mm in 100mm. What more can you ask from an under $5000 mill??

If you do not have a suitable square..... make one!!! You have a lathe do you? Make a cylindrical square. These can be very accurate if you can align your lathe to cut parallel. It is made by finish turning a tube of about 50 to 100mm diameter and 150 to 200mm length, such as both ends measure identical diameter with a micrometer. Face one end in the same setup. Now you have a precision cylindrical square suitable to tram a mill. Of course you may need to adjust your lathe to make a cylinder 200mm long to 1/100mm parallelity, you do that by (un)twisting the bed, preferably with a jackscrew. If you can do that, you can tram your mill (if you feel not confident to align your lathe that accurately yet, then you do not need to worry yet about tramming your mill that accurately either, because I think the lathe comes first).

Good Luck, Chris

[Oldneweng]

Dean, I think you are overthinking this. After all, this is only a low cost hobby-mill.

I did the basic tramming of my Sieg X3 using a low cost engineers square like this:



Chris it seems you have not read the whole thread. I am not tramming my mill.

Dean

[.RC.]

I did the basic tramming of my Sieg X3 using a low cost engineers square like this:




It is a universal table mill... The table has been angled and now Dean wishes to bring the X and Y axis back square to one another again...

You put an indicator base on anything but the table, your square on the table, align the stock so it sits parallel the x axis ways, then move the indicator onto the blade of the square and adjust the table so the Y axis runs true within your limits to the blade stock...

[Machtool]

Chris it seems you have not read the whole thread. I am not tramming my mill.
And lets all hope you don't have to correct it with shims.