Square for checking tool setup.

[ryan.s]

What type of squares do you guys use when checking the setup/alignment of your tools. I've been using speed squares and framing squares but to get really accurate readings and better ease of use I'm thinking a machinist square is more appropriate? Are most brands of machinist squares pretty true or do I need to get an expensive one. Are the HF ones any good?

http://www.harborfreight.com/cpi/cta...emnumber=39047

Thanks!

[LJR]

I have a set of plastic drafting triangles in the shop which I use for setup. They're cheap, accurate, and come in quite a range of sizes. And if I drop one on the floor I don't panic.

[Pappy]

Same here. I keep a 45, a 30/60, and an adjustable triangle in the shop.

[kwgeorge]

My personal preference is to have 1 high quality engineering square that everything else is referenced against. Never has the need for such become more obvious than awhile back when I decided to take a look at a Craftsmen $25 tri-square I had bought. Seems the cheap aluminum was not machined properly and it was not at 90 degrees to the ruler. I have since salvaged the ruler and threw the rest away.

I am not saying that cheaper tools are necessarily a bad thing but when it comes to a measuring device you should be confident that it is accurate so that you obtain the predicted results. So buy a good square and use it to check others and when tuning a tool.

My .02

[markmt]

I ave these squares and have checked the accuracy on a granite slab at work (aerospace industry). They are within 0.010" tolerance. I was pleased nd shocked. They are worth the money. You can teke them to a machne shop and have them checked and toleranced.

Good Luck
Mark Taylor

[Tom Miller]

I've been very happy with these:



They're from Lee Valley; you can see them here.

Regards,
Tom

[scorrpio]

I managed to snag a good deal on a Starrett combination square on ebay, but I also have a http://www.grizzly.com/products/G9787 from Grizzly, and it is a very well-made set. All three heads are hardened cast iron, ruler is hardened steel, etched, so it the scale on protractor. Zero flex anywhere, and square head is dead square. All-metal construction, there are no plastic parts.

Overall, I'd stay away from plastic and cheap aluminum. Those plasting drafting triangles might be fine, but I prefer to put faith into brass, hardened steel and cast iron. A good mark of quality is etched, rather than stamped, markings.

[LinuxRandal]

A machinist friend of mine said for woodworking, he'd recommend one of the cheaper sets from Enco. Should be well within woodworking tolerances.

[woodsmoke]

I use different sized drafting triangle. Cheap,accurate,can be modified easily if needed, and like tape measures I can have several laying around so I don't have to worry about where I left it last time (always one hangin round somwhere).

[scorrpio]

A machinist friend of mine said for woodworking, he'd recommend one of the cheaper sets from Enco. Should be well within woodworking tolerances.

Gross misconception. Joinery that's not dead square will come out crooked. It does not matter much if ALL rails in your panel doors are 1/32" short - but if their ends are not square, your doors will look horrible.

[BobSch]

I've never had any luck with drafting squares. Try a set of Machinist's Squares Griz has them for less than $17 http://www.grizzly.com/products/H2993

If you want to check Whatever you're using, try this:



Put your triangle on a straight edge in position (1) and mark the bottom (A) and top (B) then flip it over, put the bottom on the A mark and the difference at B is TWICE the error (If any).

[JimD]

I will also vote for drafting triangles. Besides being as accurate as any of the other alternatives and being cheaper, they are also somewhat soft so they will not damage a carbide blade if not used quite correctly. I do not use the drafting triangles for layout, I would prefer something else for that but for tool setup, I think they are ideal. My normal layout tool, for the few times I put lines on something, is either a steel ruler or a conbination square (checked for accuracy and known to be accurate). For long measurements I use a tape measure (again, one I checked so I know it is at least roughly accurate).

While I agree that things go together much better when built square I would also add that the concept of square includes the concept of straight. Few pieces of wood are exactly straight - and if they are they may not be with a humidity change. We should make things as straight and square as possible but also realize wood is not steel and that is a good thing.

Jim

[LinuxRandal]

Gross misconception. Joinery that's not dead square will come out crooked. It does not matter much if ALL rails in your panel doors are 1/32" short - but if their ends are not square, your doors will look horrible.

$40 for a set that the tolerances were .0008", if that's not square enough, what are you working with?

[scorrpio]

.0008 is good, and $40 is not exactly a 'cheap' set when compared to some $10 set out there. I did not look up Enco sets, I was simply referring to the statement that 'woodworking does not need to be so precise'.

Wood might warp a bit out of straight and square over time, but at the moment of glue-up, you really want it to be straight and square. Just like wood itself, wood glues allow for some flex, so a small amount of warp is fine after proper bond is established. But for that, original assembly must be very precise.