Member postings for Ramon Wilson

Facing your centres off is your choice Doc but personally I'd just give some thought to the fact that if you need to in future - and you may - how you will hold the shaft with a fixed crank at each end and no centre.

I was very unfortunate to drop my Double Diagonal going up the stairs at Forncett. That bent the crank slightly enough that it could not be run. Once home and stripped down and held between centres again it was easily brought true. Not saying you might drop yours of course but there are a myriad of reasons you may want to hold it true again in the future

As Jason refers too use the smallest 1/8 dia centre drill and size the diameter of the countersunk hole by the depth of the drilling.

Sorry to hear you are finding grinding tools difficult. I can only say that practice makes perfect. If you find you get on better with Carbide then by all means use it but mastering grinding will give you another option when a suitable carbide tip isn't available. Just giving a tool edge a hone as Jason suggests is beneficial at times though not always the answer. I have a selection of slip stones however (see here) of varying section and grades to call on for that purpose. A fine grit square one and triangular section type are ideal, perhaps a round one too though not used that often.

Best - R

PS when centreing using a wobble bar as shown the bar should not rotate as the chuck is turned as a false reading can be had - it's the centre being clocked not the bar. I just hold it with my fingers as the chuck is rotated to prevent that or sometimes restrict it from rotating it by a toolmakers clamp if I need both hands.at the chuck end

Hello Martin,

As Thor says it may have been humidity but already in the material as you assembled it perhaps?. It certainly does seem strange as all other areas are free from rust so can only have come from the material and/or conditions on assembly I would have thought.

Like him I make all gaskets from thick copier paper (90-100gms) and soak it in (slideway) oil on assembly. Not always absolutely seal proof if running on steam of a decent pressure but perfectly fine for air.

That said I ran my first engine, a Twin Vic, at displays on steam for several years with such gasket material - pressure about 40 psi - without any issues save on the second outing. I had not lubricated the cylinders enough after running at the first display. Getting it out for the next the (gunmetal) pistons were solid, rust having formed in the bore either side of them. It required a complete strip down but fortunately the bores were not damaged. After that my clean down procedure after display was to run Steam Oil through on air until it came out of the exhaust. Never had the problem again and something I still do even though I only display on air these days.

Hope that's helpful

Regards Tug

Looks like you've mastered that then Doc

Doc,

I can't think of a single full size crankshaft with an axial pin to prevent the crank moving but there are the odd few that have a tight fitting axial key. As far as I'm aware all full size engines of the size you are replicating would have had the crank shrunk on so a key is unnecessary. Loctite 638 or similar replicates this with ease. The crankpin(s) is just Loctited but I make the last mil or so on the spigot a tight fit in the crank web hole

Apart from one, all the cranks I have made so far then have been Loctited and pinned but with a radial pin going in from the outer diameter of the crank through the shaft and just into the crank opposite. This gives the strongest shear but with only one face to disguise the pin on and a curved one at that - much easier to do that than a flat one if using the likely file and emery paper. The odd one was an attempt at shrinking on but it was well and truly stuck before reaching it's location - never attempted it again.

Crankpins are never pinned but I do make the last mil or so a tight fit as the crankpin reaches its location

That said the shaft and pins are both pinned on this latest one, mainly to assist in reinforcing the shaft as a whole, a 2.5mm pin if my memory serves right. Getting the pin to be invisible is a bit of an art if the crank is a finished item but easy enough if gone about the right way - that can be covered when you get to it. You can just get a hint of it on the upper surface on the right

There's nothing wrong with using the eccentric face as a wear surface just that the eccentric position is then committed.

Just realised I have to go out tonight, I need to get a grip - back later perhaps

R

Edited By Ramon Wilson on 25/08/2022 17:45:20

I suppose that depends on how the bearings are finished off - I don't see this as an issue as you can see the bearing face on the Corliss is just that circle on both sides so the bearing face area is the same either on crank or shaft.

The important thing is that there is clearance on one side or the other so it doesn't matter which side as long as the crankshaft is captive and not allowed to float. Trying to bring both faces on each bearing to a smooth running fit risks the possibility of a tight fit but then the bearing could be tweaked on the faces if so.

This really is a choice thing I guess but I prefer to use the inner faces to keep the shaft in place axially - after all if you don't have a second crank but a pedestal then that's all there is.

As you say Jason, all interesting thoughts throughout a build such as this especially from Doc's perspective

Regards - R

Yes I thought that was how the Warco tailstock was relieved, just like on a Colchester 2000 (and many others no doubt)

As you say though the live centre major diameter can be an issue at times. I have a very nice but larger diameter Jones and Shipman that's rarely used due to that situation so my 'turn to' one most of the time is one of those 'Skoda' centres (remember that constant advert in ME ?) bought years ago that still does the business but I recently purchased one of those small diameter ones from Arc - a real asset for sure as it's been well used since.

The only point that actually requires a step for location are the two faces between bearings and that for the crank webs. As you infer it's much better to be able to position the eccentrics from a lining up point of view so allowing that ability is much the better option

As an addition to the last post if you take a look at this image again you will see that where there is need for location - Crank web and bearing seats - the radius is reduced to virtually nothing and the mating parts lightly chamfered to accommodate any slight radius in the very corner - no undercuts required.

All other shoulders have a radius - why would there be a need to undercut such and besides it will probably lead to comments such as "What are those undercuts for ?" if you do - horses for course etc

Best - R

Edited By Ramon Wilson on 25/08/2022 11:32:33

I would agree to a degree with Jason here Doc as I didn't take on board that the steps were so shallow.

Even so there is no need to undercut unless something is going to sit firmly against the shoulder in question - money and choice are the keywords but an exposed undercut in a shaft for no practical reason is not going to look right - well not in my book

On the other hand if the shoulder is to locate something then yes an undercut would be needed if the step is minimal.

Though I have quite a few Dickson toolholders I don't have an extended version - just using a longer piece of HSS is enough if the occasion warrants it.

To my mind the tailstock clearance on the top slide is one area where Myford could have made a big improvement to the lathe had they chose to do so. Doesn't the Warco have that Jason?

Stunning work Carl and a superb model to be exceptionally proud of. Fantastic result

Puts the much smaller 1/32 'highly detailed' resin model seats well into perspective for sure

Tug

Doc,

I don't use the top slide for turning unless I'm turning a taper and certainly would not use it to turn parallel - just too much effort to get it set right only to lose it as soon as it needs moving. You can soon get bogged down in how to set the TS dead parallel which for this operation simply isn't required but, advice is what it is, you do the choosing.

I can't recall my ML7 but setting the topslide parallel interferes with the tailstock on the Super 7 when turning between centres giving restricted movement on the cross slide. My top slide is permanently set at 15 degrees for that very reason and only gets moved to change the angle if required

There really is no need to undercut the shaft, there's no justification for doing so besides it's not full size practice.

The tool you have ground is fine - you may just need to tweak it a bit to improve the cutting - part of the learning process in grinding tools by hand. Here's a short version of the one I posted previously roughing out the crankshaft for the Corliss engine - virtually the same as your shaft just larger

It was finished with the other, longer, tool shown previously. Note the radii - an undercut would be considered to reduce a crankshaft to a thinner diameter for absolutely no practical reason

If you have a dead stop then use it in this case. Carefully face a small length(s) of steel to the dimension(s) required and set the stop. With one hand on the hand wheel lift the self act lever a little before the stop is reached and finish off the last few thou by hand. A dead stop is not designed for running into under power! As Jason I have no DRO on the lathe - doing the above provides an accurate method by simple means.

As always though the advice is based bearing in mind on what kit you have and how I would tackle it as such. You do the choosing

Best R

Doc,

The edge faces of the tool need a reasonable back rake, the top rake is about 2-3 degrees, 5 at most, and there's no side rake on the top surface but you could put a little on if you are only cutting on the left hand side of the tool - mine has none so it cuts in both directions. Going right into a corner with all in contact puts a lot of cutting pressure on which quickly leads to chatter if the tool is not really sharp and the head stock a tad worn etc. Try coming up to the corner in several cuts inwards gradually creating the full form - that will improve things considerably. You do not need to undercut the shaft at all but set the leading edge of the cutter square to the shaft and let the tool create a radius.

If you haven't got a dead stop for the saddle then create one by clamping a piece of bar on the bed and coming up to it for depth. Make a simple gauge for the amount of movement required to set the stop bar position.

A method of stopping the saddle at a fixed position is a facility well worth having - once you have it you will quickly realise that. I use mine all the time using slip gauges to set the movement but as said a simple gauge can be quickly made.

Personally I would not machine the centres off in case you need to remount it between centres. EG to polish a tight spot.  Use the smallest centre drill and by all means face the ends to leave a small diameter cone if desired - once you remove them you've lost that ability to set it up again - your choice, but if you do face them off and you do require to remount it you will soon see exactly why I'm saying that.

Make the initial shaft to finished length plus a tiny amount for facing and use packing as you say to prevent the carrier from doing any damage.

Best - R

Edited By Ramon Wilson on 24/08/2022 23:54:11

Doc,

Though Nigel has it right with using wicks none of the small oilers on my engines have had any fitted so far. That said the oil boxes on the Marine Compound main bearings have been set up so with an inner tubing for the oil to wick into.

You can also get some practice in on shaping on the lathe as well as the mill as Jason suggests but you do have to have a means of division. I use a very fine knurl mounted in a simple push type holder. This is fine for brass and works well if the knurl is presented at a fine angle, cutting/forming on the rear edge, and moved along and back over the workpiece.

That second Knurl is surplus to requirements so if you would like to make a similar tool you are welcome to it. Send me a PM if so

Here are a few more oilers made using plastic tubing on the Double Diagonal engine which may give food for thought

These are quite old and have developed an oily patina but that disappears once full

Like Andy my very early attempts to make an oiler were using 'proper glass' in the form of sight tube glass, cutting it isn't so much the issue but doing it in very small lengths was and the breakage rate was high so that's when I looked for an alternative and began using the protectors off artists paint brushes. At first these were from my own but when I asked at the local art shop if they sold them they presented me with a box full of redundant ones and just said help yourself. Machining them from solid in acrylic is just as good but with tubes you don't have to polish the insides.

Hope that's of use - R

Edited By Ramon Wilson on 24/08/2022 12:23:14

Nice work as usual Jason but hard if not nigh on impossible to replicate in Docs much smaller scale especially the lower sight area if you want it to actually work. The flip over lifter would be too - good looking oiler though

I've tried to do this Paul but its not worth it at this scale as the dimensions are so small the oil does not move so it's a simple replication at best from a metering point of view.

Bernard, though real glass can be used it's fraught with difficulties in cutting accurately and cleanly piece to piece. Besides the constant breakage the pieces of broken glass become an issue too and the wall thickness makes for small volume. The clear plastic tube is so much better from all aspects on these oilers.

Jason, I doubt very much if the joint is properly glued the needle screw would have that much jacking force - it's only screwed down with the slightest of force between finger and thumb - never had it happen so far though a clumsy movement of my hand once knocked the glass and the top off one. If that happens clean the traces of super glue off as CA does not like sticking to itself that well.

Hi Doc, No I wouldn't say you are overthinking this but would agree with Nigel that as you have them they appear rather tall. However, when you look at images of engines or those in museums there is an absolute myriad of design of oilers to choose from so you can pretty much pick and choose.

Here are some pics from mine made for the Waller engine.

I don't 'turn' the 'glass' merely slide it on a piece of ali turned to suit as a mandrel and just part it off using a sharp pointed tool. This gives a tapered edge where the glue can form a seal. I use the thick super glue, the thin can create fogging in the glass (same as on a canopy)

The bottoms can be threaded but I turned a fine taper on these so no pressure is put on the glass in a turning movement when removing

Some of the other oilers made for secondary shafting etc

This is the main on the Waller pedestal bearing

And these are the very first made on my Twin Vic

That should give you some more ideas but as said you are on the right track, just cut the length down a bit.

Best - R

Hopper, the OP has a piece of that size, just wants to know how to work it.

As others have inferred "how long is a piece of string". As someone else who spent many years working tool steels of various grades it's unknown quantity makes for little use save a decent base plate or 'anvil' for use on the bench. I have such a lump - wouldn't even consider trying to cut anything off it to machine but it comes in handy at times as suggested.

As far as basic model engineering goes Silver Steel and Gauge Plate are all the home user needs when through hardening materials are required.

All the tool steels I have machined have been tough-er to do so, some more than others and consequently are difficult to machine compared to basic mild and low carbon steel. Other than carbide face mills that was all done using HSS cutters - at the time carbide end mills were some way off. Obviously cutters wear quicker so personally I only use tool steel when it is actually required for the job - mainly home made small cutters.

The result of heat treament of an unknown material is another matter of course.

Best - Tug

The eighteen cylinder radial engine made by Gerald Smith - a simply awesome example of machining skill and especially so when it was made on a treadle powered round bed Drummond.

I've only seen it the once and never had a camera but it's etched on my memory. Seen many fine examples of the art over the years including the superb models of Cherry Hill but none eclipses that for me though Peter Southworth's Agnes tandem compound stationary engine comes a very close second.

Tug

Edited By Ramon Wilson on 19/08/2022 11:04:53

Not a chicken joke but a true tale circa 1972 that brings that industrial safety legislation to mind

At the time I was working at our base onshore during a lull in diving activities. One morning a large lorry turns up with a considerable number of full bottles of 90/10 (90% helium) helium diving mix on it. Why they came I have no idea but was something to do with the US parent company as at that time all our diving was air based. We unloaded said bottles - slightly larger than the standard Oxygen bottle and laid them all out in the yard - must have 70 - 80 of them. Why they were loose no one knew as He02 bottles usually came in a steel cage referred to as a 'quad' usually containing '8' bottles. There they laid for several months.

One morning on another base working day the boss 'Bernie' comes out and says these bottles have got to be shipped back to the States - and they've all got to be emptied before they go!!!

I worked with another diver called 'Tony' and it could be said we did used to like a 'bit of a lark' so after the ubiquitous novelty of talking like Donald Duck was over we looked for something else. At the company next door they had one of those packaging air bag making bits of kit so we made a bag up some 10 ft long about a foot wide and filled it with the helium mix then a 20 ft long and then a 50 ft er - you know how these things go. The laughter got greater as this 50 ft sausage hovered about 5 or 6 feet above the deck (floor). At this point the guy in charge next door came to see what we are doing.

"I have some real big polythene pallet covers" you could staple together he suggested. No sooner said than done and we have this huge bag filled with helium straining at the leash sadly not enough to get any of us remotely airborne. Suddenly who ever has it lets it go and its off up gently but away with the breeze - across the river Yare to catch on someone's TV aerial and hang there being moved by the wind, the aerial bending in each direction in sympathy. Our boss Bernie fully supportive of our antics suddenly going pale and banning us from further stupidity.

The helium frittered into the atmosphere - an awful lot of moneys worth I guess - what a waste but we did have a good laugh from it

Happy days indeed

Tug

Hopper - I don't know about 'cunning', just something I came up with as the inserts are 14 BA and I didn't fancy tapping the cast iron using the only tap I had - again. I had previously done so on another engine and, as mentioned previously, used as DMB suggests, a larger size drill. Whilst that certainly eases the tapping pressure on such small sizes it raises another issue of the thread engagement being marginal at best in such small sizes. It worked well so will be used again on the Marine Compound.

Loctite used would have been basic 638 - as said the temperatures involved on steam had no effect - the engine shown was run on steam under 'working' conditions powering a model boat

As a sugar lover Hopper I can't say I've noticed the similarity - when you do get to taste it inadvertently it's a bloody horrible flavour that's difficult to get rid of. Incidentally I found a long time back that the best thing to 'kill' any Loctite residue is methylated spirits. Lots of other solvents will work to varying degrees also but as with the 'Domestos' slogan meth's 'kills it 99% dead'. No good as a mouth wash though.

As said Derek, I never did get round to making a pillar tool but a good friend did and another bought it when he passed on. One did, and the other now does, praise it's usefulness.

Tug

Edited By Ramon Wilson on 15/08/2022 14:40:40

Hi Jason,

Well I'm not saying anything is the best option (did I actually imply that?) but that as always, one has to bear in mind what kit someone has at their disposal. Whilst I have the means to reverse on both mills that I have both have to be switched at the control panel which unlike your button control makes things a bit fraught. Besides, on one, the Linley, the quill is not lever driven so it would mean trying to wind out at the same rate as the tap comes out. Fine if you are careful on the way in for a few initial threads but a most definite no no on retraction. If the tap was in some kind of sliding spindle of course that would be a different matter. On the other, Amadeal, mill the quill is just too heavy to feel small taps under say 2BA without a real degree of caution. Even then the same issue of control applies - lever on the right, control on the left

As you implied previously if DRO is available then that is a good and much better way to go too. In fact I've just done the flange holes in the Marine Compound in exactly that manner

As I approach my eighties however buying new kit, unless a required direct replacement, is not really viable as I intend to dispose of it all in a couple of years or so. Though I do use metric threads from time to time, moving over to metric threads as opposed to BA, though certainly less expensive, is not something I'm keen to do at this time in life. I have sufficient stocks of BA fasteners (still readily available of course).

I've been tapping holes for few years now - other than the Tapmatic devices which really are good despite my previous statement of rarely using mine - the best system I've ever used was a set of three large drilling pillars mounted above one big table, Meddings or possibly Pollard I think. They had a foot control to knock them into reverse which was instantaneous - wonderful bit of kit but it would require a bigger space that most have available.

I know things have moved on but I believe it's as important to show that you don't have to have modern kit to be able to do a job just as well as it is to show what's available now. Many now think of CNC pretty early on - as you know I left that behind twenty odd years ago but I've often had the comment ''Are the crankcases made by CNC'' on my diesels.

I began my model engineering as a complete amateur - zero knowledge but full of enthusiasm. In my mid thirties that quickly lead to a change of career and proper training before spending so many happy hours in a machine shop environment for the rest of my working days - like I said, quite a few tapped holes in that time - not always done on the right bit of kit

Best - R

PS just realised I haven't responded to others - have to go out right now, Sue is standing by the door, chomping at the bit - you know how it is   so will come back later.

Edited By Ramon Wilson on 15/08/2022 10:39:17

Whilst I cannot disagree with any of that thinking Jason, after all that's exactly why the castings I have have languished for so long I was attempting to show there are simple alternatives.

I have the means to power tap - TapMatic head - but rarely, if ever, bother to use it. I use my bench drill to power tap the initial threads as said and finish by hand. Most beginners will not have much else and (small) taps can be expensive items if you start breaking them. Power tapping in and out does require a means for the tap to move vertically within it's drive on coming out particularly on the smaller taps

I concur - control is all important - but that cylinder shown previously was a weighty beast compared to an 8 BA tap and it's floating as such on the mill table but as you can see it has a back stop in the angle plate and the magnet is used to keep it there on each repositioning. As always though - the constant worry of breaking the tap was ever present.

Taps are another matter - I still have (most) of the original (carbon) BA, ME32 &40 and brass taps bought from Tracy tools near 50 years ago and though most are still working well for most needs there are some that aren't.

Recent purchase to replace a worn 7BA in HSS was a bit of an eye opener for sure. I wonder what such a spiral flute type at that size would set you back let alone spiral point.

Best - R

Edited By Ramon Wilson on 15/08/2022 08:26:05