Member postings for Neil A

You could try the following if you have not already, you might be lucky.

https://www.colchesterspares.com

Neil

I'm afraid that getting steel of unknown specification can be a real time waster when it comes to using it. Like SOD, I do the same test of facing and turning to see if it is usable for what I want to produce.

I did come unstuck on this subject a few weeks ago when I came to make a new slitting saw arbour. I found a bit of bar in my scrap box, just over an inch in diameter and about five inches long, I had marked it up as EN3B. Set it up in the lathe, took the first cuts, lovely bright finish, swarf tight blue curls, (very hot on the hands). No, certainly not EN3B, It was part of a batch of short pieces of EN24Y used for cylinder head studs that I had acquired many years ago for a special job at home. I can turn it and drill it with care, but there was no way I was going to be able to tap a thread in it. I had just marked it with the wrong specification at some point.

Now I only buy material that I know what the specification is, saves a lot of frustration in the end, might cost more but usually worth it.

Neil

I note that you say that the bush should not rotate on the shaft, but as both the shaft and the housing appear to be hardened it would be possible to just have a fully floating bush with no interference fits involved. Provision would need to be made to feed oil from the outside to the inside of the bush.

Not knowing the details of the design I do not know if such a bush would be fully retained axially. Also it depends on the actual finish in the bore where the apparent indentations are.

If I remember correctly, EP oils have sulphur content which has an adverse on copper based bearings, this may make such bushes short lived, but this may be acceptable to you.

Neil

I also found the video interesting. In response to Martin Johnson's comment on the video, I note that the thesis referred to near the beginning was dated 2012/2013, so that particular piece of information had been available for ten years.

In my mind I would have thought that anyone seriously considering a project of this nature would have researched all available information on any material that was being proposed for use in the project. Perhaps I am expecting too much.

At work we would always refer to the "Anti-Reality Bucket" that people sometimes put over their head. Did someone find the biggest one in the world for this project?

Neil

If you machine the bore of an oilite bush the tool must be SHARP. Reaming smears the surface and closes up the porous structure.

Details of recommended cutting speeds and feeds can be obtained from the Oilite.com website.

All sounds an achievable fix for your motor.

Neil

I seem to remember that one of the problems of burning hydrogen directly in a conventional style internal combustion engine was keeping the temperatures in the cylinders less than about 1300 degrees celsius. Above this temperature the combustion starts to produce NOX. Someone may correct me on the temperature. So this is not as easy an option as it appears to be. This problem was encountered on the attempts to produce a Stirling Engine powered car. The hydrogen fuel cell does not seem have this particular problem.

As others have said, the real problem is producing the hydrogen in the first place. Then comes trying to store it without all those leaks. Solve those little issues and you might, only might, be on to a winner.

I'm not holding my breath and at my age petrol and diesel will probably see me out, but I watch the developments with interest.

Neil

I was really amazed when I read this post, in all my 40 years plus in engine design would I have even considered putting a flexible toothed belt inside the engine exposed to lubricating oil and high temperatures? I think not, even my colleagues would have choked at the suggestion.

It seems that someone in the design team has lost their way somewhat. Looking at the design of the belt run, it appears to be more suitable for a roller chain than a flexible toothed belt. Did someone decide to change the original design intent for something a few pounds cheaper?

Perhaps this is intentional built in obsolescence or they just don't care anymore.

Hi Bernard,

With your dimensions and Jason's photo I now understand what it is your are trying to produce.

I had not realised that the larger Warco and Amadeal lathes had that type of spindle nose configuration. I did not realise that the chucks were not direct fitting but needed a separate backplate. I was thinking of the smaller lathes style. I was completely wrong!

I think that Jason's advice of machining to a "feel' fit is good, although as you say pulling everything apart to check the fit is tedious. Do you have another backplate to machine a plug gauge for checking purposes?

Neil

Edited By Neil A on 05/05/2023 19:57:21

I have been following this thread with interest. I don't know the features of the Weiss 250 lathe, but the dimensions you quote do not tie up with the usual style of spindle nose found on the Warco and Amadeal lathes.

Is this a Camloc style spindle nose? If so, a look at lathes.co.uk spindle nose information might help.

Otherwise I am baffled!

Neil

Looking at the wiring diagram for the XMT-1115 board (110volts) on the little machine shop web site it seems that there should be either a bridging connection or an emergency stop switch between the K3 and K4 connections for the board to function.

https://littlemachineshop.com/images/gallery/drawings/4512-XMT-X1MicroMill.pdf

But I think that I would take Jason's advice and talk it through with the people at ARC before going any further.

Neil

I note that Tracey Tools sell Helicoil type thread insert kits in UNC sizes. Their prices exclude VAT and delivery, that might suit your needs.

Neil

Just looking through the posts again, I think that I would feel very uncomfortable about welding an alloy that I did not know the exact composition and heat treatment. Get it wrong and you could end up with cracks where you do not want them.

Someone may correct me, but I seem to remember that the highest stresses occur in the hub area around the fasteners of flywheels, I assume that a motor bike wheel would be similar.

Neil

When I was working I would specify a "Tappex" insert when a thread in an aluminium part needed reclaiming. These inserts could be used when a Helicoil insert had been stripped or otherwise damaged. The drilling size for them was close to the outside diameter of the Helicoil tap. The Tappex inserts were also self tapping so were simple to use.

The type that I favoured was the "H Type" either the standard insert or the thin wall version, the slotted end type could close up and nip the thread which I did not like. For aluminium I always specified the Austenitic Stainless Steel material as the expansion was close to that of the aluminium.

**LINK**

It will of course depend on what the hole is like when you manage to get the bits out and the remaining wall thickness. I hope that this is some help, the wheel is too expensive not to have a look at every option.

You can get a sample of the insert from the company, I used to have some in the draw at work when we were investigating them for use.

Neil

It's difficult to see from the photo, but it could possibly be a knuckle thread. This thread form has rounded crests and roots.

Neil

Just noticed that I have been beaten to it!

Edited By Neil A on 23/02/2023 16:32:29

Tufnol would be my first choice, my father used it years ago to replace the knob on a saucepan lid. They use Tufnol for some handles on steam valves.

Second choice would be one of the many hardwoods available now, the more dense the better, provided it's not exposed to direct flame.

Neil

I think this question of what material to use to make special bolts to hold balance weights on with should really be on its own thread.

The simple answer as to what is "high tensile steel" depends on what you are after. General purpose high tensile steel bolts as used in industry are in "S" condition or 8.8 grade steel which is approximately 50 ton/ square inch UTS material.

At work we would only design around a figure of 64% UTS when calculating torque loadings for these fasteners. Special fasteners, particularly for balance weights, were given much more attention with regard to material, machining method, thread forming and finally torque loading.

The more difficult question as far as I am concerned is how have these fasteners have been designed, I would certainly want more detail of the design and the proposed machining before I committed myself to a specific material.

I am sure others will be able to give you more guidance on this specific application.

Neil

I can fully agree with Samuel, don't dither about your choice too long, spend your time making parts not worrying about the different specifications of machine. Someone once said that any lathe is better than no lathe, I can't remember who said it now, but it's good advice.

I spent pretty much the whole of Covid lockdown dithering over getting another lathe, I ended up getting an Amadeal AMABL180 earlier this year, and choose what extras I wanted. I am happy with it, it does what I want. But I will say that I was not without a lathe during my faffing around, I had a small Flexispeed sitting under the bench to carry me through the period without a larger machine.

I also have a Seig SX2P from ArcEuro and I have found both companies easy to deal with.

The companies we buy from do not make the machines themselves, we rely on them to provide backup for the products they sell and they in their turn rely on their suppliers to provide a good quality product.

At the end of the day you have to choose a machine that does what you are expecting to make, that fits in the space you have available and suits the price you want to pay. Don't forget the extra tooling you will eventually need, you don't have to get it all at the same time, just buy as required otherwise you will end up with things that you will never use.

You will find that you will probably have to make some compromises over the specification of what you would like, but choose the features that you consider most important, we have all had that problem at some time. Good luck with your choice.

Neil

Tufnol is quite a resilient material, but as you say, 16 years of use without the outer sleeve should at least have shown some signs of wear or deformation. Perhaps there was one fitted originally and it has just completely disintegrated, we'll never know now.

At least it was caught and corrected before any real damage occurred.

Post-practice theory session? What ever could that be?

Neil

My thoughts are the same as SOD and John Doe 2, there should be a sleeve that was never fitted. Mistakes do happen, most engineers would regard bell hanging as a bit "agricultural" in nature, but this is a bit excessive!

You might like to check this website for a bit of information.

https://witneyandwoodstock.odg.org.uk/wordpress/wp-content/uploads/2021/09/tbc04_clapper_bush_wear.pdf

I think your Delrin is probably as good as should have been originally fitted to reduce the shock load. I think that if I was curious enough I would drop one of the other clappers just to see what that one looked like. You could of course contact the last firm that overhauled the bells and ask, what might be for them, an embarrassing question.

I think I would wait for the warmer weather before checking, it can get really cold up in the bell chamber and handling cold metal and laying under a bell frame that is too close to the floor is no fun what so ever, done it too many times.

Keep up the good work. To often for church members, it's up in the tower, it's out of sight and out of mind! Only the ringers know what goes on there.

Neil

P.S. Nigel you might find this website interesting.

https://dove.cccbr.org.uk

Edited By Neil A on 30/11/2022 12:25:19

The original Stuart Turner (Henley) drawings for the 10V and 10H gave 6 holes for the top cover and 4 for the bottom cover. The later drawings give 5 holes for both covers.

When I machined mine I did 5 holes on the top cover, but retained 4 holes for the bottom cover as my castings are very old and the two ribs on the standard go right up to the top flange. This would mean that two of the holes would be very close to these ribs, making the nuts awkward to fit. I did not want to machine these ribs away as I thought that it looked better with them, I am not intending to fit drain cocks on this model so the position of the holes was not an issue.

Neil