Member postings for Dinosaur Engineer

The use of serial taps significantly reduces the tapping torque. Also using the second serial tap as a finishing tap gives a nice tighter fit on a std fastener - useful for stud holes.

Easiest way of moving a lathe is to hire a tailift van. most tailifts have 1000 or 1500Kg capacity.

One of the biggest carriers of virus is the supermarket trolley . I've seen children with running noses sitting in trolleys , wiping their noses with their hands and then holding onto to the trolley handle. I myself had a severe flue like virus after a visit to the super market. It took me 3 weeks to recover. I hadn't left the house for a period of over a week prior to this. With the corona virus I now use bacterial wipes to clean the handles and wear surgical gloves. Maybe a bit OTT, but for an 80 year old with a reduced immune system prevention is better than catching the virus.

I had a damaged torx screw a few weeks ago on the underside tray of my VW golf. the correct size key was too small and the next std. size key was too big. My initial thought was to drill it out and fit a larger screw ., But I thought one idea was worth a try. I used a small ball pein hammer to spread the metal around the torx insert and then hammered the correct size key in. This worked a treat.

I used to work for a company that made cancer radiotheropy treatment M/Cs( Linear accelerators) they used tairly large pieces of tungsten in their focusing tungsten autocollimators. A work colleague had two pieces of metal about 300mm x 150mm x 80mm . One piece was aluminium alloy and the other pure tungsten.. He would throw the alum. piece in the air & catch it and then hide it in in his desk drawer . He would then bring out the tungsten piece and place it on his desk top without any body noticing the switch. Sometimes visitors who saw the al. piece throwing and then seeing the machined tungsten piece on his desk would idly try to lift it up. Their reaction was often hilarious. When the visitor was leaving. the trick would be repeated whilst the visitor could still seeing the throwing action - all good fun ! The tungsten piece was allbut impossible to pick up vertically from the top of the desk, it had to slid to overlap the disk edge to get a grip. The M/CS were tested in lead lined (Much cheaper than lead) shelters and left for a period for any small radation levels to dissipate. Happy days.

A chaser is very useful for rounding BSW crests . If measuring the O.D. or "try to fit" BSW threads with sharp crests at nominal O.D. the result will be very loose fitting threads. Better to have the recommended alternative flat crest than sharp crests.

Unless Loctite is now made in China , where would the Chinese get it from ?

The problem of removing dowels/pins from blind holes was solved many years ago by having a thread tapped in the end of the dowel/pin. This tapped hole was used with an extractor so that the body of the extractor bottomed out before the thread part when the extractor was turned thus causing the dowel/pin to be pulled out. Dowels and taper pins are commercially available with the tapped holes . I’m not sure about the extractors through hobby shop suppliers but am sure some large toolroom part suppliers will have them but it’s not difficult to make your own. The extractor is a piece of steel with a threaded end protruding at one end . the shank can round , hex or square. The hex shank is best as it can be used with a standard wrench.

The problem in plating copper as a base layer is that copper will adhere to" rusty" steel wheras nickel won't. Therefore its particulary important to make sure that the article to be plated is clean.

A piece of small round HSS is often used for large lead threads as the tool can be turned around to the helix angle.

I wonder how they tested the .landing gear & steam catapults without any aircraft ! Could they not have borrowed an F35. The vessel has been commissioned. Why couldn't they have tested the prop.. shafts for leaks before the propellors were fitted.

Surely the navy could have tested the prop.shaft seal in the dry dock. Car manufactures use a gas test to check for windscreen leaks .Maybe the leak could have been found after the vessel was 1st floated . The cost of changing the seal must be quite high. The size of the leak must be seen as significant or they wouldn't return to port. Maybe the leak could get worse ? It's just as well the aircraft manufacturers don't adopt the same test procedures i.e. check it doesn' leak when in sevice !

The relatively large clearance around the capscrew assumes the cap screw head can be at top tolerance size and if an accurate location is required dowels would be used. The aesthetics of the counter bore is not normally an engineering consideration.

Have used 3 flute carbide in the past - they produce straight holes to reamer limits.

An old remedy for mice & rats is slices of lemon . Apparently they don't like the smell and will keep clear of the odour.

I doubt if it's made from rubber. Rubber has largely been superceded by neoprene as rubber is now quite expensive..

ground flat stock is a more refined steel than silver steel. G.F.S. has the additions of elements such as vanadium which gives a tougher and less distorting ( during heat treatment) steel than silver steel . This allows gauges and other thin section hardened components to be made from GFS that couldn't be made from S.S.