Member postings for Clive Hartland

The engine that powers Greyhound Buses and the M109 is a 2 stroke diesel and is double supercharged. It has a Rootes blower and an exhaust blower.

The space between the V cylinders is a Plenum chamber, the Rootes blower sits above it and the exhaust blower feeds the Rootes blower. The cylinder sleeves have a 360 deg. porting and I would assume the blowers just overpressure the cyl. to evacuate the exhaust?

The exhaust type is a parallel double tube with one end closed off and helps blow out exhaust gases. In fact my SAAB 95 had such a system in the exhaust, very efficient.

I can see supercharging before the fuel inlet as a method, that I am sure would work. I wonder what is the point as I have had McCoys and Doolings peaking at 20000 + rpm and these were single cyl.

We had an incident where an M109 engine, 'ran away' and to stop it a certain Snco bunged his combat jacket into the inlet to the superchager and it very kindly sucked it in and shredded it into fluff and bits of zipper. It barely coughed while doing! The Injectors where the pump type and on a rail and the linkage would jam and thats why it ran away.

I have had some work trickling in from the Bee Shop, customers wanting me to make my bespoke hives. All the hives come in flat pack form, roofs, shallow boxes and Brood chambers. All the joints are of the Comb type, glued and pinned (Hidden nailing) Also a hive stand to do, they are just screwed and nailed. I do sand them down and the end grain is given 1 coat of clear cuprinol.

Thursday, the bees were flying and some pollen coming in, I doubt if any nectar was taken though. Did a numpty the other day, went to sharpen a friends Jack plane blade, unscrewed the clamp screw and laid it on the bench still in the clamp plate. Sharpened the blade and went to reassemble it and the screw was nowhere to be found. I will make a new one, its 5/16 BSW and luckily I have a die.

Clive

No Michael, never a car salesman but I have chipped off a lot of paint and found some horrors underneath. Painting a model particularly a military model brings out its purpose, the camouflage and the earthy green gives it the right image and needs little imagination to see it in action.

I have made several military models, models of Thunderbird ground to air missiles, 1 I left natural Alu. the other I sprayed matt black and they had a totally different look and aspect.

I made a model of a field cannon and made the wooden parts dark and brass as natural, unfortunately it was stolen.

Another was a model of a ground to air photographic missile that was pre-programmed to fly out and return and then parachute down. This was for a presentation to a retiring Officer. He was very pleased with it.

familiarity with the item you are making allows a greater insight into what is achievable and how it should look.

Bobs model is a nice model and deserves a place to be admired not only as an example of gun used in the Great war but also in its uniqueness as a one off. I still say it needs a coat of paint.

Clive

As ever, where ever go or do things there are 'Eletists', I get this when I deal with people with the bees. Their bees always produce 100lbs of honey a year and they never swarm, When you get to the nitty gritty they mostly talk bees and not do.

As always a coat of paint will cover up most of the faults and give shape and shine and shadow to soften all the edges, revel in a job well done and sit and admire it.

Clive

Hello Ian, the screws on the Instruments would come in for service and repair and we would find that the slotted heads had split apart and you could see crystalline fracture. The factory changed the type of metal to what I know not, but after that we had no problems. Age I think may have something to do with it as well so age hardening possibly? They were CuNi in the parts list. I would think that they were machine cut on auto machines and bought in to spec. I still have some and they look more 'Brassy' than copper colour.

Now of course its all S/steel TORX or S/steel Skt head screws all torque set. We seldom see slotted screws anymore. Even grub screws are now steel.

Of interest a lot of the main bearings on the telescopes and standing axis are Alu. and have a ground finish. They are anodised and it has a polished surface. We are also getting Ceramic bearings now on the self pointing Theodolites as they orient themselves very quickly now.

Clive

Some years back we had a spate of screws that the heads would just snap off, it transpired that they were Nickel silver. Be aware that the screws you are making will have very little tensile strength and will need care that they do not take a lot of strain. They become very brittle. The way the materiel is formed will have a great bearing on this.

Clive

Yes Michael, they are the ones, i have said several times on here that if you live near a Cromwell outlet call in monthly and get the latest sales brochure. It is usually packed with bargains of all sorts. I have seen Milling cutters marked down form £25 to £5.00. It looks like end of line items as they give low stock figures for them.

Another thing, if you do buy them ask for them to be delivered to the outlet and save postage and the consequent hassle of delivery.

Clive

When I bought them from Cromwell they were on offer at about £25 for 6 cutters. They came in a nice cylindrical foam based container. Each cutter had a clear plastic sleeve on it to help withdraw it from the foam which was a good fit for the tool.

In use they cut well and leave a good finish on all the materiels I have used them on.

Clive

Yep, I have bought Swiss tech cutters as a set. Very nice and extremely sharp, take care as you withdraw them from the foam that they sit in. They are TC cutters. and I bought mine from Cromwell. I recommend them.

Clive

I think I have stirred up the Zinc fumes with my query, i'm going back to the bees!

I used a corrosive flux and a bit splashed on the back of my hand and the scar is still there.

Clive

Hello Ian, The galvanised metal does not reach down to the bottom of the lid/roof so has to be fixed by nailing. Also by handling the metal gets banged and gets a bit damaged as its dumped upside down on the ground as its also used as a support for the boxes as they are removed (Reverse stacking) Over many seasons of use they sometimes look as if they have been run over. The soldering helps keep the shape and integrity of the metal.

Clive

Hi Ian, I will answer your query about the roofs on the bee hives. A new Beehive is made from western red cedar for various reasons and the life is counted in say 3 decades though I have a couple that are at least 60 years old and still going strong. Now the roof is a square of Galvanised metal and it is folded to precisely fit over the wooden roof of the hive. As it is exposed to the weather for all this time I have made a habit of soldering the folded corners and soldering over the heads of the tacks used to keep the metal in place. This stops any penetration of water into the roof as bees do not like dampness or moisture in the hive. There is a ventilation aperture built into the roof.

When soldering the gas flame can get near the wood and scorch it so that why I need a longer replacement as over the years it has slowly burnt away from using corrosive fluxes. When making up hives I use 'Hidden' nailing as I have found that if nails are left exposed to Sun, rain and temperature change, they tend to work loose and look unsightly. I also use the gas torch for sterilizing the insides of hives as residues of wax and propolis can harbour disease and wax moth eggs or pupea.

I make up hives for sale as most beekeepers are not 'Handy' and sometimes make a mess of the assembly by putting the ' Bee space ' at the top of the box instead of the bottom. Basically lack of knowledge of what they are doing, they never read any books and just jump straight in.

Thank you for all the answers and I think I will look for a bit of copper rod, or whatever I can find and turn it down to size.

Please feel free to ask about bee things as I am happy to answer.

Clive

A general query regarding an attachment for my gas torch, this is a copper rod that is inclined into the gas flame for heating with enough protusion to safely solder with out scorching anything else.

Now the copper bit is getting too short to work safely, ( I use it to solder heads of nails in Beehive roofs. The nails hold the zinc coated metal onto the roof)

Am I right in thinking I need a pure copper bit, if so where can I get some. It is nominally 3/8" dia.

Clive

Edited By Clive Hartland on 21/11/2013 15:10:59

The information about Diamond wheels and HHS tooling, rough a tool out on a normal Carbide wheel on the bench grinder and the finishing on the diamond wheel taking as little off the HHS tool as possible.

The tool grinder is NOT a jobbing grinder and is only to sharpen tooling and not remove large amounts of the body of the tool. It is also used to make sure that the tool angles are correct.

When grinding tools a jig should be used to hold the tool in a fixed position, it is so easy doing it free hand to misjudge the angle and feed in and make a boo boo. I would not consider doing a milling cutter free hand and only do drills freehand if I have no other recourse.

A White Cup wheel and a flat rim diamond will in most cases suffice for precision grinding. The only other wheel to consider is a very thin diamond wheel for throating a milling cutter, that is if you can hold the cutter to do it. I find this very difficult to do on a Worden Grinder and would need to make more jigging or even make a new type of Grinder to suit. No doubt a Stent or a variation would be ideal and would look forward to buying a kit design if it were available.

Clive

I am sure that you need an 'Undercoat' plating for the gold to attach to. I cleaned up an old brass theodolite to the base metal and it was gold plated but it was first nickel plated.

If your clock plates are nicely grained then plating them will destroy that finish. Some years back I researched a varnish coating that was called 'Dragons Blood'. Don't laugh its true. Its the very nice gold coloured finish you see on old microscopes and other old scientific instruments. basically its a 'Hot' varnish method where the items are heated then quickly coated with the varnish which has a colourant in it, this being a red dye.

I was unable to locate a source and the composition seemed to be a trade secret. One I did find was called 'Frigilene' and could be brushed or sprayed on.

All the old instrument makers are long gone so all the trade secrets have gone with them and we are now left with the modern equivalents.

Clive

Regardless of choice of Height Vernier Chronos are offering a discount at the moment, why not use it?

No connection with Chronos apart from an occasional customer.

Clive

I am a bit surprised that users of the Myford handwheel have not learned that you set the handwheel to zero and then use the top slide to touch the tool to the work, no need of an adjustable rotatable scale at all.

I agree its nice to have an adjustable scale but at that cost I can live with my method.

Clive

You should ask for High tensile Studding, it is available from stockists. You should have no trouble with the threads stripping with it.

Clive

Michael, things have changed a bit over the years, as you say the lens is polished to a satisfactory quality and what they do now is fix it in the lens holder, and the brass or Alu with lens is then centered as a complete unit and the metal body machined to take out the eccentricity. It was a bit of a surprise to receive a new replacement lens and notice the glass was off to one side in its mount. They are centered using a Laser device and it takes only seconds to complete. The errors are usually very small.

We have used shellak and cellulose to fix circles in instruments but it is all the UV type glue now, they come centered and are put straight into the instrument and software takes up any errors in face to face errors in centricity. Prisms are held in position by grubscrews, then cemented and the grubscrews pressure released to stop pressure marks in the glass. Shellak is used to lock screws and plates so that they hold position.

Clive

Edited By Clive Hartland on 08/11/2013 07:37:55

Oliver, if your Swedish mates talk about ,' Glue' for gluing glass then possibly they are talking about optical cement that is cured by Ultra Violet light. Much like the dentist now uses UV to cure the tooth filling. What the UV does is accelerate the curing time. This cement is available from optical glass manufacturers, the name of a company I know is, 'Edmundson' who can supply all optical things.

As an aside the old optical cement (Balsam) was made from tree resin and refined until it was clear, this matched the lenses glued together and it was cured by heating.

This was superceded by a soft plastic glue that again was cured by heating but had a longer life and better adhesion to the glass.

This again has been superceded by the resin which is cured by UV. and is very strong and gives time to adjust the position of the glass parts and cures almost instantly. No heat being required.

I have had a further thought, perhaps they refer to the glue used to stick glass to glass on cars, like the blocks on car windows. The sliding type.

Clive

Edited By Clive Hartland on 07/11/2013 22:28:52