Member postings for Ramon Wilson

John

I have tried three times to answer your specific questions on the best epoxy and their qualities. I have no bloody interest in your VAT issues

No I'm not being uncivilised but I am being straight - it's the last help you get from this direction

Tug

Over many years I have mainly used epoxy in aeromodelling and making sailing models - occasionally but quite rarely in model engineering where I prefer JB Weld.

At one time there was an extremely good epoxy made by Isopon called SuperEpoxy. 20min or so set time and extremely strong but slightly flexible. I used this successfully without a single failure over several years but virtually overnight it became unavailable so I switched to other brands finally settling on Zap as it's near but not quite equal (in my eyes) to it. Apart from true standard Araldite most epoxies from cheap to expensive proved either brittle or rubbery.

If I could buy true Isopon Super epoxy again it would be a no brainer but in the meantime Zap for me is acceptable - until I've tried the Bob Smith Industries version that is.

I'm afraid I have no experience on VAT so cannot comment on that matter

Tug

Yes - Zap 30 min has around 25-30 mins work time depending on the ambient temperature. It my workshop - usually around 65C it will begin to gel after about 20mins. Once that begins there is little time left to work with.

I find a good hour has to pass before handling it with safety but that of course depends on what the workpiece actually is.

Tug

John (Smith) I was not aware Bob Smith Industries glues were available in the UK. Their CA glues are well recommended in USA so would 'assume' (not always a good idea!) that their epoxy would be of a similar quality.

I'll certainly be ordering some epoxy and CA to try out and compare with the Zap

I usually search eBay mainly to see the variation in price of items - amazing sometimes the considerable differences in cost of some products - never had an issue with archived purchases either but each to his own

Thanks for that link

Tug

I have used Zap epoxies for several years now. About the best available at the moment in reasonable small volumes but there are others.

An eBay search should get you a rapid supplier - I bought my last from 'Als Hobbies.

5, 15 and 30 min all available in 2oz and 4oz sizes

Tug

Whilst I don't want to go into specific details I would just like to comment on the superb after sales service I have just received from Warco.

A total appreciation of the situation on their part and a very speedy response - can't thank them enough.

Should go without saying but no, no connection, just a truly satisfied and very happy customer

Thanks indeed

Edited By Ramon Wilson on 13/01/2022 18:34:46

John, I have no idea but a little tale, perhaps of interest.

Martin Shaw, his son worked in our drawing office but his interest was model railways. When his father passed he inherited a couple of his models - a lovely Allchin and a Merryweather steam fire engine. Martin would loan them out for exhibit at our ME Day at the Forncett museum so they graced my workshop on several occasions

Many years ago a local ME friend said he would like to introduce me to a 'Frank Waterton' who was very keen on I/C engines - I was well into making a Bentley BR2 at that time and Frank had expressed a desire to see the parts.

A visit was arranged and we set off to Woodbridge in Suffolk. From his accent Frank was obviously from 'Northern' parts. At an early stage in the conversation he said to my friend "I really miss my friend Ernie" and began to tell of their ME exploits. By the look on his face he was not too pleased when I asked if he meant an Ernie Shaw. When I explained that I worked with his son his demeanour changed instantly and he got quite excited calling his wife in to explain. Apparently they had lost touch after Ernie had passed.

Frank then asked did I know about the trams that Ernie had made - a very detailed account followed my shake of the head. Apparently, I believe before the war, the subject of making individual motors to power a trams wheels had been raised in ME. Ernie claimed that he felt it could and (I'm sure I have this right) none other than Edgar Westbury said that he didn't think it could. Some correspondence reverberated through the pages of ME I was told and Ernie not only made the motors but they did indeed work.

Obviously when I returned to work the following week I sought Martin out and explained all this. "How come you didn't take an interest in model engineering yourself" I asked - " I always felt my father was too good to follow in his footsteps so I focussed on model railways" was the reply.

The next day Martin came into the machine shop bearing something wrapped in rag. "Would you like these" he said "They belonged to my father". It was indeed the very winding tool he had made for the project. Simple, one could almost say rustic, in approach but the perfection of machining is obvious. I've treasured it ever since but would happily hand it on to someone who had direct interest in it - as said it is a little piece of ME history and may mean something to others. The other item was a boring head to fit the Myford nose piece - again basic to look at but works to perfection

The winder

Some years later Martin, who also had a passion for trams decided to have a go himself Here he is asking me about something on a drawing at a Forncett open day.

Sometime after he retired Martin moved to Blackpool where we continued our correspondence over many years before two years back it suddenly stopped. Well into his eighties by then I can only assume the worst.

I hope that's been of interest - one of a couple of anecdotal tales coined over my years with model making.

Regards - Tug

Edited By Ramon Wilson on 12/01/2022 19:28:33

Superb workmanship and excellent documentation - thanks for sharing it

Tug

Very nice model making and fine workmanship all round John - trams certainly make lovely subjects with variety of skills required

Are you familiar with the name 'Ernie Shaw' a Manchester area model engineer ?

He apparently built a model tram with working home made individual electric motors after being challenged (in Model Engineer though I have no idea when) by a well known and prominent model engineer of the time that it couldn't be done.

I was given, by his son Martin whom I worked with, the coil winder he made to wind the armatures I believe - I would be more than happy to pass it on to you should you want a little bit of model tram history.

PM me if you would like it

Tug

I haven't seen the article in question but as someone who has provided drawings in the past to ME for articles I'd like to offer my thoughts.

I certainly don't think you are being pedantic but on the other hand I feel you may not be giving matters due consideration. Yes there has been some appalling drawing standards for model engineer drawings over the years some of which have been offered by those who you would expect to know better but many by those who have no background in the art of technical drawing but are eager to share their project with others.

I have no formal training in drawing as such and know my own drawings will some time show both projections and, despite a dedicated mind to ensuring there are no omissions and mistakes, both occur and are always noticed after publication.

I have worked with many styles of drawing both at work and at home but the drawings that show many parts on one sheet are how it was done off a drawing board - easy to forget that with todays CAD and the much better way of a sheet per part if preferred. As long as the information is clear and defined (and correct!) how it is displayed should be irrelevant.

If I have a criticism it is that of differing datums on a drawing - something frequently done on ME drawings and very frustrating for the newcomer who is unaware until something doesn't line up after working to them. Anthony Mount's McOnie design has a classic example of this but I'm not knocking AM - his Waller engine drawings are just the opposite and were a pleasure to work to.

This subject is another that comes up from time to time - the issue is without question, many drawings do have many faults but to expect professional quality from mainly amateur offerings is a point to be taken well into consideration.

Long gone are the days of the editorial office too and in this day of minimal staffing levels it is unlikely there is anyone capable or available to check and modify or indeed rectify mistakes to perfection level - desirable as that may be.

Standards are without doubt not the same - I am currently working to drawings first published in Model Engineer mag in 1923. Beautifully annotated in fractions I have found just one error in the drawings published over several issues.

It does, I'm afraid, comedown to that old cliche, measure twice and cut once - double check everything

Regards - Tug

Edited By Ramon Wilson on 09/01/2022 14:11:24

Looks like (not is) a Sparey 5cc - I'd say the brass serves no purpose unless its a jury rigged compression screw?

Tug

Most finished projects but finally making this after setting out to do so some twenty seven years earlier was very satisfying

Yep, like I said t'is a ripe ol' chestnut.

As said Nigel, I have text books which explain this in detail but seven differing books on stationary steam engines with many many images don't support that it was a practice that was consistently used - little visual evidence of the 'correct' practice in any of the images in these volumes all by George Watkins

Stationary Steam Engines of GB Vol 1, 2 and 3

The Textile Mill Engine Vol 1 and 2

The Steam Engine in Industry Vol 1 and 2

As also said, for me the technical aspects are one thing, the model making aspects are another - BA bolts, nuts, even with the smaller head are not usually of true scale appearance compared to those in these images for instance.
Yep, it's a right ol' chestnut is this one

Tug

I've just read this thread for the first time having seen the subject discussed ad infinitum in the past.

Having delved deep into it in the past I understand (I'd like to think) the logic of the thin nut first but - purely from a model engineering perspective and as a maker of stationary engines I'd say I'm firmly in the camp of thin nut last purely from an aesthetic point of view.

Whilst making the Corliss engine I perused may images in the volumes on stationary engines I have but could find little evidence of the former but many of the latter.

That said however I still found the need to put thin nut first because of potential 'you have the lock nuts wrong' kind of comment.

To me this still looks 'wrong'. The one thing that surprised me given the amount of technical evidence to be found to confirm the principle it was the real lack of practical evidence in the many images perused. I don't think I found, for instance, a single engine with lock nuts on the foundation bolts - just heavier thicker nuts set on what appear to be just plain plate washers.

This is one of those discussions (second only to the metric versus imperial topic surely) that brings forth good argument from both camps but for me it comes down to what looks right on the model just built. 

Keep smiling - Tug

Edited By Ramon Wilson on 05/01/2022 22:00:51

Hi Steve - yes most definitely. Nearly all the laps I have made (quite a few now) have used copper as the wrapper but the principle is the same. I've not tried cyano as such but would think a gel type cyano best as only the leading edge of the wrapper should be fixed. Make sure the leading edge to the motion is the fixed edge - otherwise it tries to unwrap it i.e. the motion wants to be away from the fixed edge. The wrapper slowly looses its concentricity in it's thickness but the outside remains perfectly circular. I'd just use a 2mm grubscrew as the expander.

This type of lap expansion works extremely well and I have used them for many projects - not my idea but one that came from Len Mason in his building the Mastiff series in ME if I recall correctly

With regard to the wet and dry method make the paper width wider than the length of the bore but no more than twice the length of the liner as the more that's outside on axial movement the more it can loosen and expand and begin to lead to bell mouthing as it compresses going back in - yes axial movement should be used otherwise you will create rings but not excessively so compared to the radial movement - WD 40 will be a fine alternative to paraffin - I always have the latter on hand because of the diesels.

As you have a couple of spare practice first as you suggest - I'm sure you'll soon see how little action is required to achieve the surface smoothness you are after.

Regards - Tug

Edited By Ramon Wilson on 03/01/2022 21:01:09

Steve,

Any form of lapping/polishing is going to remove metal by it's very nature. By doing it as suggested is nothing more than a form of lapping anyway but the metal removal is absolutely minimal. It's not going to remove deep tool marks of course but as you have made them to such limits I'm assuming those are minimal any way.

As always there are lots of ways of skinning cats but the size of the rolled wet and dry method is controlled by the length of paper used - you can fine tune it to quite small limits to the right kind of fit. It itself it's flexible, even on a hard-ish mandrel, so acts more like a floating hone and so will follow the bore rather than be rigid like a lap - this also helps if bell mouthing is a concern. It certainly wont affect the roundness the amount you need to polish nor induce a taper unless you dwell in one spot.

How ever you do it good luck - you have an impressive project there.

Tug

Edited By Ramon Wilson on 03/01/2022 13:33:00

The OP states that the builder has made go/no go gauges to size the bores to a consistency of within 0.01mm - .0004 ins. To take such care is indication that the builder requires them to remain so.

Whilst the simplicity of wrapping of wet and dry around a mandrel may seem rather low tech and Heath Robinson and perhaps out of keeping with the work done so far it is suggested simply because it works - to the degree of the minimal metal removal required to polish the surface without increasing the size to any extent - not much point in working to 'four tenths' if you are going to increase it to six - or more.

From the image the liners appear to be brass - not something that stands up to lapping well from a metal wear perspective - though very efficient, brass piston laps wear rapidly on CI pistons for instance.

Tug

Steve - you do very nice work

My thanks to Jason for pointing you in my direction but....

You say you have sized the bores to .01mm and really only want to smooth them. My thinking in that case is that a lapping approach per se would possibly be too effective and may oversize the bores slightly.

Personally I would approach it using fine wet and dry paper with paraffin and a drop of oil as a lubricant. I would use, say a 1/4" or 6mm dia ali rod with a neat slot cut down into the end to take a slip of wet and dry paper cut to the width you want and long enough once wrapped around the rod to just fit in the bore with ease, not too loose but not tight either.

You should be able to polish the brass by hand but if not just use a light power source at low revs - always turn the way the paper is wrapped other wise it will tighten in the bore - if you do that with power you could quickly take it over size. I would think a minimum grit of 800 to begin with, certainly no coarser, going up to 1200 if desired

The above is based on how I would approach the job based on treating bronze bearings that are tight.

Hope that's of use to you

Tug

I wouldn't use lapping paste other than to lap the bearing bores independent of the shaft bearing areas to size if required. If a crank isn't turning freely with the bearings fitted up tight albeit possibly on the tight side all lapping paste will do is wear the high spots off the bearing and shaft.

'Bedding in' should not be considered a means to cure misalignment issues

Much better to find any discrepancies and deal with any alignment issues first before bedding in. For instance if a bearing is a good running fit on it's shaft position when free but upon being tightened down has a marked tightening effect on the shaft - search for and cure that issue first until satisfied taking each bearing in turn. The shaft may be tight in the bearings but that tightness should be uniform throughout it's rotation - no tight spots in one, or more areas. It should not be so tight as to require force to drive it to 'run it in'.

Just about to do this with my marine engine build and will only use paraffin and oil to lubricate as the shaft is brought to a running fit

Tug