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+-- Thread: Ulmia Square Adjustment (/showthread.php?tid=7069193)
Ulmia Square Adjustment - HomerLee - 08-05-2015
I have an Ulmia Precision Try Square like this:
http://www.amazon.com/Ulmia-Precision-Tr...lmia+Try+Square
No, I didn't pay $260; $20 at a garage sale. Anyway, it is not so precision. It is off about .024" over the length of the blade. I know a common carpenter's square can be adjusted with a punch at the inner or outer corner. This square has two small screws in the brass surface on the handle on either side of the blade. Anyone know what they are for? No other screws anywhere. I had assumed the blade is riveted and there is no adjustment. I had also assumed a precision square would be just that. There is no sign the square has been abused.
.024" seems too much for a square that supposedly sells for $260.
Thanks
Re: Ulmia Square Adjustment - mignal - 08-06-2015
Ulmia claim much greater precision than that. 0.04 mm's over the length, which is more like engineering accuracy.
If you don't get an answer here you could try emailing them. They have an email contact address on their website.
Re: Ulmia Square Adjustment - Bill_Houghton - 08-06-2015
I concur: get in touch. According to their website, their U.S. contact is Peck Tool. On some of my try squares of less impressive brand, I've adjusted square by holding the stock (handle part) in one hand and whapping the end of the beam (rule part) on the bench, at the high corner. Shouldn't work, but it does.
If the screws aren't for adjustment, and the warranty has run its course, I'd go for filing instead. File, test, file, test, repeat until done.
Re: Ulmia Square Adjustment - OldBaleine - 08-07-2015
I've had the 25cm model of that square for at least thirty years. I am sure that I didn't pay more than a tenth of the price your seller hopes to get for his.
Each of the brass edges of the stock has a milled dovetail keyway into which the milled dovetail edge of the rosewood stock fits. Each brass edge strip is slotted at the top to enable the blade to pass through it.
There are four small brass screws at the top of the stock; one on each side of the blade, two on each brass edge. These screws have nothing to do with blade adjustment. They are wood screws, placed there to fix the brass edge to the stock.
At the top of the stock, where the brass edge piece was slotted in order to accommodate the blade, the side-to-side "clamping effect" of the dovetail keyway is compromised, and the screws were inserted into the stock to securely attach the edges of the brass strip on either side of the slot.
The blade is riveted to the stock. I trued mine with a small diamond hone and my reference square, although you could as easily use the "deviation from a scored line" method.
My square was made in Germany, decades ago, in a climate very different from my own. I suspect that the deviation from perfection occurred soon after manufacture. The rosewood stock is fairly stable, but it is not unresponsive to changes in moisture content and fluctuations in humidity.
I recommend that you make the necessary adjustments to get it as close to perfect as you require. Mine has proved to be very reliable over the years.
Re: Ulmia Square Adjustment - HomerLee - 04-09-2016
My bad. I meant to post sooner, but I discovered the Ulmia is not out of square at all. The common method of checking a square by making a mark along the long side while the short side is aligned with the "straight" edge of a board (such as plywood), then flipping the square over and making another mark which should align with the first mark can yield a false result if the straight edge is not perfect. Rather than just flipping the square and marking another line, I used a Pinnacle precision straight edge, flipped the sguare over and placed the short end in the exact same place on the precision straight edge that it had been, then made the second mark along the long edge. This resulted in two parallel marks, the distance between them equal to the length of the short end (handle) of the Ulmia square. The result was two lines that measured perfectly parallel, showing the square to be dead on 90 degrees.
When you think about it the tiniest bit of a foreign object or imperfection in the "straight edge" used will cause the apparent error to double when the square is simply flipped.