Member postings for Neil A

Just found a link to the Metal Improvements Applications green book.

**LINK**

Interesting reading if nothing else.

Neil

Shot peening aluminium alloys is used in the aero industry. The "shot" I saw being used at Metal Improvement Derby factory for peen forming wing panels was about 6mm diameter and projected with very little force, almost just dropping, to produce the curvature required.

I think shot peening in the home workshop would require a lot of effort to achieve good results, not impossible, just time consuming.

I think that you will find designs for peening guns and flap wheel shot projectors on the internet which could be made at home. The biggest problem as I see it is controlling the intensity of the the shot impact consistently.

MIL-S-13165C gives quite a bit of information on the process and measuring the intensity, but is more commercially based. The Metal Improvements website has some down loads which may help you.

The shot used in the peening process is not just steel, but can be glass or ceramic beads. I'm not sure were you would source the media, but you will need quite a lot of it. After the shot has been used it goes through a system that removes any broken or deformed shot, which would damage the work if used again, as well as sorting by shot size.

Shot peening is a messy process, years ago I attended the opening of Metal Improvements new factory at Newbury, I was told that this would be the only time that the floor would be free from shot! Do consider that the shot will go everywhere.

I hope this helps a little.

Neil

I don't know if this is any help, but Rapid Electronics sell a T5 wedge-based lamp 6 volt 1 watt (order code 57-6819) and a 6 volt 0.5 watt ( order code 57-6804).

The dimensions are close to what you quote. Have a look and see what you think.

Neil

I have a Sieg SX2P mill and the largest cutter I use is a 50mm dia. face mill that has 4 APKT 1604 inserts. I don't use the full diameter of the cutter, a maximum for 30mm, usually a lot less with a modest depth of cut. I do keep a check on the temperature of the motor for my own peace of mind, but it has never got beyond the warm stage.

Sandvik Coromant in their Training Handbook recommend a 2/3rds rule for cutter engagement.

**LINK**

It's a slow download but informative.

As regards machining stainless steel, depending on the grade of stainless, the inserts should machine it without a problem. I have used my cutter on an unknown grade of stainless and I did not have a problem.

As the others have said, don't overload the machine and you should be OK.

Neil

This looks like a fixture for cross drilling round bar. The items in the second picture are interchangeable drill bushes that fit in the cross bar at the rear of the fixture. There should be a screw in the tapped hole that engages with the cutout on the head of the bush to stop it coming out when the drill is withdrawn. A handy fixture.

Neil

I don't think that there was a particular convention for which way round the rods were fitted, although manufacturers would have their own preference. It is probably more to do with how much clearance there was inside the crankcase for the big end bolts. This would have been fixed in the design stage.

I can't remember ever swapping the rods around when a reverse-rotation engine was built, that would have caused confusion when you have a standard rotation engine sitting beside it in a boat. The only thing I remember is checking the timing of the oil feeds to the bearings and up the rods to make sure they worked both ways.

Reverse-rotation engines are a bit special as it is normally easier to install a reverse reduction gearbox, keeps both engines the same on a boat.

Neil

I've just looked at the design in book 38, I don't believe there is anything wrong with the design. What could be confusing is the fact that the 14mm hole in the front bearing, item 64, is sleeved down to 8mm diameter by the tooth rest support clamp ring, item 75. This ring prevents the clamp screw marking the tooth rest support spindle which is only 8mm diameter.

Hope this helps.

Neil

I would second the sliding fit and use Loctite 641 bearing fit or its equivalent.

A 0.001" interference on a 3/8" diameter is very high, we used to reckon on 0.001" per inch of diameter as a good interference fit.

Heating one part and cooling the other works well on parts that have a reasonable mass, but small components will equalise their temperature too quickly and you may not get them together before they grab.

With a small diameter bush like this, probably with a thin wall thickness, nearly all the interference will end up reducing the bore. With the Loctite method the bush can be finished to size before fitting.

How much clearance? Check the data sheet for what you have. Loctite guide gives 0.001 to 0.003 clearance as optimum.

Neil

Edited By Neil A on 06/03/2019 21:58:06

Edited By Neil A on 06/03/2019 22:08:35

I've had the same problem with the foam liners for large Custom Cases. It seemed to lose resilience and turned into a sticky mass over about 30 years of use. I also found that the residue did leave some slight unsightly corrosion on the metal surfaces which took some time to clean off.

I have replaced them with a similar foam from the manufacturer as I thought I was just unlucky with the way the cases were stored, but now see that I shall have to keep a close eye on the condition of the foam in future.

Thank you for the timely warning to check all my micrometers and other instruments that have foam in the cases.

Neil

My own preference would be for option 1. It is what I am used to.

When I produced CAD drawings at work, like Duncan, I used various coloured lines on a black screen, but they were always printed out with black ink on white paper. Also the outlines were drawn 0.7mm with the other lines and dimensions at 0.5mm. Of course, this was on A0, A1 and A2 sized sheets, you would probably need to make a scaled adjustment when working on A3 or A4.

As regards to using colour on the printed drawing, personally, I find that some colours are not that easy to read. Julius de Waal produces some very nice drawings, he uses rendered pictures, isometric views with some colour, in addition to conventional 2D views, to illustrate his models. Drawings like his I have no problem with, I quite like his style, although he does put more parts on each sheet than I would.

At the end of the day it is all about clearly defining what is intended to be made and hoping that you have not been ambiguous on some feature or missed out some dimensions. It can be difficult to check your own work. It is all too easy to know what you meant to be made, but have you actually shown it?

Neil

Just to clarify my thinking

If the spindle is truly vertical then rotating the column on its horizontal flange will not effect the vertical axis of the spindle, only its position in the X and Y axis above the table. Hopefully the horizontal faces of the column and base are parallel to the top of the table otherwise there will be some effect, albeit small. Rotation is limited by the clearance in the setscrew holes.

Sorry to cause confusion, should have stuck to saying "no dowels".

The SX2P just has the four M8 fasteners holding the column to the base, no dowels.

If you think about it a small angular movement between the column and base has no effect on the vertical axis of the spindle.

I'm afraid I've not able to identify your castings from an internet search, but as has been stated, they seem to be from a horizontal engine.

Could you give the nominal dimensions of the cylinder, approximate bore and length, this might help in the identification. Also, perhaps, a list of the cast on part numbers might again give a clue to the supplier.

Of course, there is the possibility that they are not all from the same model, just to confuse things.

I hope that someone can identify them for you, they seem to be good clean castings, just waiting to be machined.

Neil

You might find what you need at "Rapid Electronics", they have a fair selection.

Just search for E10 MES lamps.

Neil

Edited By Neil A on 06/09/2018 11:04:33

I think John is right about there being just a simple knurled nut clamping the setting dial to the worm wheel.

It has been a long time since I saw one of these clock mechanisms with the cover off, but it does jog my memory of watching someone reset the time when the clocks changed from GMT to BST. They had no special tools and it was done in a matter of minutes.

Neil

Looking at the drive, I suspect that there should be some sort of spring friction drive between the worm wheel and the hand setting dial. A view on the other side of the hand setting dial may show some signs of this.

This would allow the hands to be moved in relation to worm wheel.

I am sure that others on this forum will have a better idea of the details of these types of drives than I do.

Neil

Just had a thought, usually the springs are in the form of a dished washer giving just enough friction to drive the hands, but still allow the parts to be moved in relation to each other.

Edited By Neil A on 19/08/2018 12:21:22

If the thread was 36 TPI rather than 38 TPI it would make more sense. It can be difficult sometimes checking the thread form on small diameter fine threads. It can be quite awkward to get a thread pitch gauge into the right position.

The taps Tracey Tools have are not very expensive in carbon steel, I would certainly get a plug tap just to try if I were in your position, you might be surprised.

Neil

The only reference I can find for 3/16" x 38TPI is in my old 11th Edition Machinery's Handbook for "American Standard Thread Forms". 3/32" x 48TPI also appears in that table.

Whether anyone currently produces threading equipment for this size I have no idea. I'm sorry this information is not very helpful.

Perhaps the original builder had taps and dies for this size from where they worked.

It looks as if your easiest option is to plug and tap in a size that you have, although it is disappointing not to be able to replicate the original builders parts.

I don't know if you are game for making carbon steel taps and dies, perhaps someone can give you some tips on how to go about it.

It is nice to be able to bring an old model back to life, very satisfying. It looks good.

Neil

Edited By Neil A on 09/08/2018 15:03:45

Have I missed something here?

The only two people in this discussion who have actually attempted to answer the original question of whether there was a metric version of the engine are Jason B and Jim Nic.

Everyone else seems to have hopped on the old hobbyhorse of imperial verses metric, which is not the answer we are after.

If there was a metric version already produced, I am sure that Ian McVickers would not wish to "re-invent the wheel", but just save himself a little extra work. It is just a fact of life that older drawings were produced in the dimensioning system of the day.

In reality the imperial and metric systems are no better or worse than each other, just different. They both produce working models. You just have to be careful if you choose to mix them on the same part.

Neil

Edited By Neil A on 08/08/2018 23:58:15

Edited By Neil A on 08/08/2018 23:59:25

I have been following this post just to see where it leads. I think that we have all at sometime experienced "dyslexic fingers" while typing or have been "helped" by spellcheck to put in the wrong word.

It is always nice if the grammar and spelling are correct, but none of us are perfect, so there are bound to be little errors here and there. It only really matters if the errors alter the complete sense of the statement made.

At this stage, I am reminded of the following passage from "Through the Looking Glass":

"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean—neither more nor less."
"The question is," said Alice, "whether you can make words mean so many different things."
"The question is," said Humpty Dumpty, "which is to be master—that's all."

Neil