By donating you support this blog and my wishlist

Sunday, February 14, 2010

Measuring and layout tools

The accuracy of your work is only as good as your ability to measure accurately. Thus it is important that you have the proper tools for measuring and marking your workpieces. However, even the most accurate measurement tools are worthless unless you know how to use them properly and know their limits and accuracy.

Here I'll show you the tools that I have bought till this day and give some details about them. Most of the tools have been bought from eBay (mostly from China) as new and miscellaneous items I have bought from a local tool supplier and some items I have got for free. I won't dive in to how to use these tools in this article, but plan on writing more detailed articles of specific tools later.

Because I'm sure I get to hear these "chinese imports are no good" and whatever, I will say this: They are far good enough for the home shop machinist and model engineer and are as accurate as stated. They might not last in 24/7 use like brand names, but how often does a home enthusiast do work around the clock?

And yeah, I tested one micrometer (the 0 - 25 mm model, made in Israel) for measuring accuracy over its travel with grade 1 gage block set (Jo blocks) in increments of 0.01 mm for the heck of it: Repeats flawlessly.

Left side of the picture shows three micrometers in their cases. The smallest at the bottom of the picture can measure from 0 - 25 mm (4.40 EUR), the one above that measures from 25 - 50 mm (20.80 EUR) and the biggest from 50 - 75 mm (11 EUR). The two bigger ones also include measuring standards that are used to check that the micrometer reads correctly. All the micrometers were bought from eBay.

In the bottom just to the right of the smallest micrometer is a dial test indicator in its case with two dovetail adapters. This is used mainly for dialing in, for example, a milling vise. The scale deflects 40 - 0 - 40 in 0.01 mm steps, thus the overall scale is only 0.80 mm wide. Bought from eBay, 26.55 EUR.

Above the dial test indicator is a big permanent marker that is very good for writing on metal and when scriping lines. With it is an automatic center punch and a carbide tipped scriper. 

In the middle of the picture is one Mitutoyo brand dial indicator with a 10 mm travel and 0.01 mm graduation. This is a very versatile measuring device for use in a mill and a lathe and in measuring differences on a surface plate, just to name a few examples. This was bought from a local tool supplier, 36 EUR.

To the right of the dial indicator is an edge finder. The tool has a 10.00 mm shank and the very end is 4.00 mm in diameter. This is used in the mill to find the edge of the workpiece. Bought from eBay, 2.95 EUR.

To the right of the edge finder is an electronic height setter. This lights up a red LED when the mills tool touches the top of it, indicating that the tool is exactly 50.00 mm above the workpiece. However, this tool has been damaged and the exact height of it is now 49.74 mm and thus I got it free from my school as the other route would have been the melting furnace.

The long silvery color bar in the top right is accurately ground test bar that I got from a friend of mine. It has a diameter of 17.97 mm and is very rigid, thus making it a very nice test bar for checking for example lathe headstock alignment.

The two stacked blocks are 25 - 50 - 75 blocks (known as 1 - 2 - 3 block in imperial units) which are identical. The dimensions are very acurate and these can be used for measuring or for setups in the mill as they have screw holes all over them. Bought from eBay, 14.60 EUR.

Just left of the 25 - 50 - 75 blocks is an angle setting fixture. It has a 10 minute accuracy and is a very versatile on the mill. It can be adjusted over a 90 degree scale. Bought from eBay, 23 EUR.

In the middle at the top of picture is a metric set of transfer punches from 1 mm up to 13 mm in 0.5 mm steps. These are used when duplicating for example drilled holes locations from an existing part to a workpiece. Bought from eBay, 9.55 EUR.

In the top right corner is a small magnetic base that can hold a dial indictor or dial test indicator and has a one locking knob. Bought from eBay, 14.10 EUR

Under the magnetic base is two calipers, one is with a 1/20 mm Vernier scale and the other is digital (12.90 USD, I mainly use the digital as it is quick to read and there is some tricks that can be done with it, like comparisons.

Under the calipers are a set of small tools: 1 - 7 mm radius (both inside and outside) gage (4.95 EUR), metric and imperial thread gages, slip gage (2.69 EUR, Biltema) and a fishtail gage ( to adjust and make threading tool bits for the lathe.

Under the small tools are a cheap protractor (3.99 EUR, Biltema) and an adjustable scribe (5.99 EUR, Biltema) to be used in layout and setting lathe compound angle. Next to these is a tape measure (nearest hardware store, about 5 EUR) for bigger measurements where accuracy is not so important.

1 comment:

  1. This is a very good article. Accurate measurements are vital in our industry, especially when working with small diameters. These tools are wonderful and should be part of every machinists tool kit. When selling metric steel, our customers need measurements to be exact, so we check each and every item with carefully controlled micrometers to ensure accuracy.