A cheap surface plate and home-made scriber stand

Описание: A scriber stand is made on an engineers lathe from brass bar. An 8mm thick recycled glass plate is used as a cheap substitute for a surface plate. These are used for marking out and layout of engineering projects. There is no commentary, so you can listen to the music, or mute.

A user has asked how flat the surface of the glass is. I cannot give a very precise answer because it is likely that every piece of glass is a bit different and varies with manufacturing methods. But for a lot of hobby work we may not need such a high degree of precision. The bottom line is that the surface can be checked as I demonstrated roughly using a dial indicator in a more scientific fashion than my quick demo.

An important factor is the support under the glass. If it is not on a reasonably flat surface it can sag. The piece I use had been the base of a kitchen appliance and had several plastic feet on the bottom. One of them was missing and that made it sag a bit in that area and you can actually see that in the video. To minimize this effect get the thickest glass you can. This came from our recycling shop called the Seagull Center.

Another use for thick plate glass is as a substitute for surface grinding. Simply lay a sheet of wet and dry emery paper on the glass and then rub the object in circles over the emery paper using light oil or water etc. I used this method to take 8 thousandths of an inch off the 100mm diameter big end bearing cap for our Tangyes stationary steam engine. It only took 30 minutes and worked perfectly. As a teenager I ground the flat head of my 1935 Austin 7 car using this method and did the big-end bearings the same way. By constantly moving to different areas of the glass it tends to even out any irregularities in the glass.

INDEX TO THE VIDEO:

00:20 Disassembling and reassembling the scriber to show its parts
02:00 Using the scriber stand on a glass plate
03:00 Checking the surface of the glass with a dial indicator
03:40 Using an end mill in a drill press
04:20 Lathe work
05:30 Using a reamer
06:15 Final demonstration after adding a brass locking ring and knob for ease of use
07:15 Measuring the thickness of the glass plate
07:30 THE END