Member postings for Matt D

Hacksaw a bit off and burn the chips with a gas torch? Then do the same with a bit of known bronze or brass and compare the colour of the flames? My school days are long gone but I seem to remember something in Chemistry lessons about this.

At work we use the led belts or strips for various things. Maplin code N91NA are 12 volt ones but I expect that they are available in different voltages and from RS etc. Not expensive but they would need protection. Could you make and mount a suitable holder?

12.9 hex bolts do exist; I seem to remember that my Ducati Desmo single has very long ones through the cylinder head/barrel but as they are doubtless specials for these engines this won't help! Could one use softer bolts with a hard stepped block set into the end to reduce the mushrooming? Should be possible in M10.

In response to Peter's original post I seem to remember that when I bought a shop made indexable tipped boring bar with an 8mm shank diameter I was advised by the manufacturer to expect to be able to bore about two and a half times the minimum boring diameter deep before I should expect vibration trouble. I expect that the material being bored, the speed and the condition of the lathe would change this. Locking up whatever slides are not being used might help too.

38mm deep could be about right for an 8mm shanked boring bar mounted in a tool post.

Perhaps slightly off topic but for my 21st (late 1970's) I was given a 180 amp arc welder with a carbon arc torch. Still have it somewhere and seem to remember that brazing with it was easy. Very like an electric flame with no gas to worry about.

I don't know if it was the best stuff but we used to put Stockholm tar on an elevator belt used for lifting bales in the 70's, it was probably pine oil. More recently on drive belts we used a spray tin of "Belt Dressing" which contained Rosin. I probably shouldn't mention it but on my Edgar 5 lathe I had a flat belt, the joint of which clicked and annoyed me so I replaced it with a cheap 40mm synchronous belt with the teeth facing out (bliss). To do this you will need some form of belt adjustment unless you are very lucky but the web is full of adverts for cheap toothed belts with quite a range of lengths. Unless such modern things offend it might be worth a look.

Matt.

If I understand it the loads are applied by the halyard and the furling line and that both furling devices can move on their mounts therefore the loads experienced by the bearings are mostly in line loads. Yes, the furling line will apply a side load but it can't be great can it? A well sealed thrust bearing at the top of the sail and annular contact at the bottom? I expect that the sail loading can be pretty high so both bearings will need to carry quite high static loads without coming to harm. Sea water in bearings and grease on sails are both bad and lots of plastics absorb water don't they? Salt can be abrasive so what ever is used (except perhaps for naval bonze) it needs to be sealed well.

The dowel and locking screw can be seen in photo 121 on page 185.