Member postings for old mart

I would not recommend adding oil, that is one of the things that you want the air to be free of. Oiling rotary tools is a separate thing, downstream from the reciever. A shield between the compressor and the working area would direct the blast away from the operator if it was strong enough, but keeping the reciever in a separate area would be best, if possible.

Edited By old mart on 27/01/2021 16:10:19

We had thousands of reamers at work, mostly machine, but some hand ones, plus adjustable ones for emergencies. One of the NC operators mountain bike seatpost had corroded, an aluminium post in a steel frame, and we eventually got it out by cooling it with liquid nitrogen. Out of all the reamers we had, there was nothing except an adjustable one to remove the burrs and rust from the bike frame.

The are only useful if you have nothing else.

The only type of drill which will drill a hole to size without needing a reamer is solid carbide, and they cost more than a reamer.

Edited By old mart on 27/01/2021 15:59:34

Any flat surface will do and some little offcuts of 3mm hardboard as shims. Just find the high spot and press the drill down using one layer of shim at each end. Of course, it depends where the bend is located. If it is near the plain shank, you could hold the shank in the lathe and use the toolpost to push the bend using a soft pusher like a piece of wood. Great patience is needed and you will have to go just past the straight and come back to settle the metal down. If you can use the lathe, make a note of how far you moved the drill and also the ammount of bend still left in and you can reach the yield point without going too far past.

If I was using a long series drill, I would use shorter drills first to get the hole as deep as possible before finishing with the long one.

The Kunz Square Check 350 looks like a winner, but how much will it cost?

I don't know what it is there for, but the thread size is M37.6 X 3, which is smaller than the register diameter, 37.97mm.

 Now I see, with the larger picture, it is the diameter over wires. All is crystal clear to me now, I hope it is also clear to everyone else.

Edited By old mart on 26/01/2021 16:07:33

It's that dimension at the far right hand side that is causing the confusion with both drawings. The thread sizes are definitely smaller than the registers.

Edited By old mart on 26/01/2021 15:53:09

Maybe not as you say, but it could be checked at the desired top and bottom heights and adjusted to be true at those points. Thats what that granite square is there in the picture for.

As already mentioned, the spigot should be slightly less than the depth of the step, so the outside rear of the chuck contacts the backplate.

Edited By old mart on 26/01/2021 15:38:28

A quality height gauge would be straight enough, but will lack the fine adjustment for the squareness. I wonder if a base could be made incorporating the adjustment for a height gauge to mount on?

They had probably just carried out a final spring cut on a 15" gun barrel.

Lanolin is used on the Lockheed Hercules C130J propellor hubs. The hubs are sulphuric anodised, but not subsequently painted, but coated in lanolin. Paint might conceal underlying deterioration, and the lanolin gives protection for the hub under the cowling, but can be easily be washed off with solvents for close inspection.

Breva's post reminded me of this.

Edited By old mart on 25/01/2021 20:13:01

The height errors when taper turning have a lot to do with the relative diameters of the ends of the taper. If you were turning a taper of 45 degrees from 2" diameter to a point with the tool on centre, the result would be different if the taper was repeated with the tool below, or above the centreline. The error would get bigger as the point was approached. The model A is a high end toolmaking lathe and their recomendations have some meaning.

I have posted this part of the Smart & Brown model A manual before.

We still don't know the name of the shop the lamp came from.

A solvent based degreaser followed by oiled steel wool would be all I would use, no abrasives.

If a bruise shows on the thread as a shiny area, it is ok to dress it down locally with a little cheap half round diamond file, using the flat side. An ordinary file might not be hard enough if the spindle is heat treated. This 1 1/8" thread is plenty large enough to be unaffected by localised repairs.

The museum has regular mandatory reciever inspections and I have never been able to unscrew the plugs at either end for a visual check. The inspector does an ultrasonic thickness check of the lowest point where the corrosion is most likely. He told me that fortunately, explosions are rare and the usual cause of leaks is the partial failure along a weld.

Many of the compressors which don't get used much could have their working pressure reduced to give a bit more peace of mind. You probably don't need 150psi if most of the use is paint spraying, 50psi might be adequate.

Some of the wood lathe type chucks have changable top jaws which bolt on. If yours is this type, then you could make a set, or sets of custom jaws for it. Having a backplate ready to modify for it does make a difference.

Your local council re-cycling centre should take it, but check first when you can go, there may be restrictions during lockdown. My local centre allows odd and even car registration numbers on alternate days.