Here is a list of all the postings norm norton has made in our forums. Click on a thread name to jump to the thread.
|Thread: protecting from rust|
Just to add a thought to the desiccant vs. refrigerant discussion - I had a desiccant unit in my workshop for two years and it worked well; the background few hundred watts of heat seems to help. Then it all gummed up with stuff contaminating the silica gel and the removal of water stopped. I sent the unit off and they replaced the silica gel cartridge and all worked again, for two years, then guess what… My workshop is pretty clean but the silica gel cartridge is too a good filter.
So that went in the bin and I have had a refrigerant unit working now for fours years and it is just as effective. I note the relative humidity every now and again and measure the condensate coming from the pipe that I have pushed through a wall to the outside. When the workshop temperature drops to 5degC then water removal virtually ceases but, and this is the important bit, the outside air at 0deg is carrying much less moisture and if your workshop heats during the day the dehumidifier will keep the relative humidity low, ready for the next cold night.
At 55% Rh I never see rusting, even on freshly cut metal left out for a week, and a dry workshop atmosphere is much more pleasant on a cold morning.
|Thread: Water guages|
I bought a few sizes (EBay - medical/food supply) and cut thin o-rings. The problem is that the silicon tube wall is around 1.5mm thick and would not go into the fitting. I successfully made it work by stretching a smaller bore, but it was a fiddle. Much easier are the 1mm thick o-rings from Reeves, and they are only about 30p. I used two at each end with a touch of silicon grease. I also agree with the PTFE tape and Foliac (steam seal) solution.
|Thread: Do aliens make this stuff?|
I know it is fun to get excited about hazards, but as engineers (or hobbyists) we shouldn't replace science with sensation. Rik probably has a magnesium alloy and these have been extensively used in high performance engines and aircraft, where weight is a premium, without undue hazard for many years.
Magnesium powder is a very different hazard from solid magnesium alloy. When magnesium is combusting it will react with oxygen, CO2, water and even nitrogen, which is why only a dry sand will extinguish it.
A thin piece shaved off an alloy can be ignited in a hot flame because you have taken it beyond its melting point, but it is difficult to ignite a solid lump because even if one corner is molten the larger portion will take the heat from any combustion. It can be cut with machine tools but grinding is not sensible as the fine dust is the fire hazard. Welding and casting are for experts, but I think it is TIG welded with a normal argon gas shield.
Lots of materials go bang if you make them fine enough or hot enough.
|Thread: Rotary Laser centre finder|
Chris: Nice job, well done. I agree that fitting it around the spindle collar has benefits. I find that my R8 toolholder mounted one is not too inconvenient to swap and will carry on like that. The main problem is that you need a shallow angle (I use 9 deg) which means the spindle has to be lifted well away from the job. You then find out how much horizontal error you have in your supposedly vertical mill column!
Regarding the diffraction of the beam, you just need to ensure it is still a reasonable spot of around 1- 2mm at 200mm. When this hits the vertical work face you are simply looking at whether this 'wide red paint brush line' is sort of horizontal or not.
Billy: Your last posting said a lot of good things and clearly this was all looked at two years ago. Your comment to have an adjustment for the displacement of the laser from the centre line is sensible as this can overcome having to move it too far from the workpiece. You are right that it is more sensitive at lower workpiece diameters. On my mill it works well on small 3/8" diameter objects (buttons ?) that stick up as little as 3/16" from a workpiece (providing the surface is not freshly machined and shiny). Your comments about the lathe made me realise the usefulness of a laser rotating in the lathe headstock to align the tailstock - thank you!
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