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Member postings for Paul Kemp

Here is a list of all the postings Paul Kemp has made in our forums. Click on a thread name to jump to the thread.

Thread: Winson Pug 0-4-0
12/04/2021 00:36:56

Larry,

Are you saying the valve won't expose the whole port or that it doesn't expose the port at all? If the former as long as the port is uncovered about 50% and the port openings are almost equal at both ends of the stroke it should run. If the port is not being exposed at all then you have a problem. I did do some work on a Winson Pug but only after someone else got it running so didn't have any involvement with the valve gear. I did however have a Ruston Procter TE kit that was pretty awful in the valve events department, the crankshaft had flats milled on it to locate the eccentrics and they were way off! So I wouldn't automatically trust the dimples in the axles are in the right places! If you use masking tape to pencil marks on one of the drivers each side and mark against some reference point fixed or clamped to the frames the front and back dead centre of the piston you can then see when the valves are opening and closing relative to piston movement and make any required adjustments to eccentric position if they are wrong. It's pretty simple albeit a bit of a fiddle but takes a little bit of getting your head round what is actually happening versus what should happen!

Good luck,

Paul.

Thread: Lathe drive motor
11/04/2021 14:08:36

Mick,

In the interests of gaining knowledge it would be great to see some pictures of how it works if you end up taking it apart!

Paul.

Thread: Water Gauge seals
11/04/2021 14:05:09

I have used std O rings in the past without a problem. Chose a ring with the section just under the minor diameter of the nut thread so it slips over easilly and a neat / slight stretch fit over the glass. They do deform and go hard in use though and have to be changed whenever the glass is disturbed. Pauls comment re clearance in the bore of the nut where the glass passes through is very relevant, also don't make the glass too tight in the gauge frame bores for the same reason. I have tried the twisted PTFE tape method several times and never had any luck, my method must have been flawed! I also used some seals sliced as described by Chris from tube given to me by another club member and described as high temp silicon rubber, spectacular failure! As the boiler came into steam they just turned soggy and extruded out of the nut in a cloud of steam! So if you go that route be sure you know the tube material is the right spec. I have just bought some 9mm red line glass from LSM for the 6" with seals. Seals came as a length of clear tube, so I am hoping this is a better grade than I was given in the past!

Paul.

Thread: Lathe drive motor
11/04/2021 13:46:50

Not sure moving the position of the brushes would do it but maybe adding / subtracting brushes might? Say a dynamic way of changing a 2 pole motor to a 4 pole by engaging additional brushes? I know next to sod all about motors so this is purely off the wall speculation!

Paul.

Thread: Distorted ship's hull steel panels
11/04/2021 01:10:34

Simple question, complex answer. On most steel and aluminium hulls it is possible "to see her ribs". How apparent that is depends on many factors such as shell plate thickness, frame spacing, longitudinal spacing, whether a frame is a bulkhead with intercostal longitudinalls or if the bulkhead is "cut" round continuous longitudinals. Generally rivetted hulls are less affected than welded.

Structure of ships is governed by Class Rules, linked is an example from DNV for special service craft

http://rules.dnvgl.com/docs/pdf/gl/maritimerules/gl_i-6-1_e.pdf

Other flavours and types available. Worthy of mention that Naval vessels are not bound to be built to Class and afforded other exemptions from SOLAS and collision regulations. However the basic principles of Class standards for construction are usually considered!

Deformation of the shell plate is monitored at routine surveys through the vessel life and again there are limits on allowable deformation before replacement. Deformation of frames and stringers has less tolerance and a badly "tripped" frame or stringer usually has to be replaced immediately it is notified.

Bill is correct that mid ships L/4 is the critical area for longitudinal strength and frame and stringer spacing may be closer in this area.

Lightweight has not always been the order of the day in Naval ships, HMS Blake commissioned in 1961 sent for scrap in the early 80's had 10" armour plate around critical areas of the hull!

Paul.

Thread: Searching for old specific model steam engines
07/04/2021 23:14:34

Andrew,

No1 - I would say Maisie was a pretty common design for people to build "back in the day" and there must be quite a few of them around, ours was quite a small club back in the 70's and there were at least three Maisie's among our members back then! Given the one you seek would have needed a new boiler or at least a significant repair which is quite invasive I would think if it was done it would have been at least repainted and very likely to look significantly different now. So finding this one may be the most difficult.

No2 - I don't know what design that may have been but it sounds a little more obscure and if so give there are probably fewer of them around, that may be easier to track down than No1.

No3 - Back in the 70's 7 1/4" gauge was less popular than the smaller gauges and even today 7 1/4" is less popular than 5" - needs more space for a track, fewer clubs have tracks of that gauge, probably still true today. Something the size of a 7 1/4 Royal Scot is not an inconsiderable "lump" to move around. Out of the three this one may be the easiest to track down and given the size of the boiler it would have required would not be something that was built in the average back garden with a 2 pint paraffin blow-lamp! So as a starting point this one may be the one to concentrate on first. A general letter of explanation reproduced to all the organisation's with 7 1/4" tracks might generate a response, maybe also to the 7 1/4" Society? Something this size is less likely to have ended up stuffed and mounted on someone's desk, coffee table or bookshelf!

Good luck with your quest, certainly be interesting to hear how you get on. If you have any photo's of any of them that may help.

Best regards,

Paul.

Thread: Milling machines - western-made s/h recommendations up to 2k
07/04/2021 01:21:40

Agree with Nigel. I currently have a choice of mills, mate's Bridgeport with DRO, my Omnimill or a little Chester mini-mill (same as Arc small machine basically, I think they have it as the X1). My go to is the Omnimill, I don't think I would have got away quite so easilly cutting the gears for my half size TE on the Bridgeport, the horizontal spindle on the Omnimill made them easy. That said I did the crank splines on the Bridgeport as the longer table saved me making an extended sub table for the Omnimill and the DRO made life easier. Generally however I find the Omnimill more versatile like tonight where I milled a slot across the end of some round bar (handle for the reversing lever) clamping it to the table in vee blocks and using the ER chuck in the horizontal spindle then swapped to the vertical spindle to mill the corresponding register on the reversing lever with it clamped flat on the table. All done inside an hour. For me the VMC just wouldn't cut it. However it really depends what you are intending to do! If you are not bothered how long it takes and are prepared to be creative with set ups and take light cuts you can probably do all you need for a small TE or 5" loco on a lot smaller machine than the VMC. I did machine the entire water pump for the 6" engine on the X1 size mill and the myford 7, it was clearly really too big for the mill but with patience it is possible. When I was looking for a larger mill I did actually look seriously at the Warco turret mills but the Omnimill found me first and I am very glad it did. I won't be parting with it willingly any time soon!

Paul.

Thread: Searching for old specific model steam engines
05/04/2021 21:14:04

Sounds like the proverbial needle in a haystack! Do you have any details of them, maybe even photo's. Assuming they were built to commercially available plans of the day then you would need something tangible your grandfather did by making a modification that makes them recognisably different to any other of the same design or knowledge of him marking them in a specific place or maybe details of a boiler serial number from a test. Unless you can identify a trail from when they were moved on from the family ownership I think you have a mammoth task ahead but I wish you luck. There is a small chance if you have pictures, location and rough date when they were passed on you may get lucky. If you do I suggest you buy a lottery ticket!

All the best,

Paul.

Thread: Milling machines - western-made s/h recommendations up to 2k
05/04/2021 21:01:57

£2200 sounds a bit rich for me! Centec's are good machines I believe but I have never had one. I believe from what I have read they are improved by a riser block. My personal choice from the two is the one for £650 even if it needs a bit of work you won't go wrong if you have the skills. For £2200 you can have a new Warco I believe ready to rock with a year's warranty!

Paul.

05/04/2021 13:27:34

A non original hand wheel on the knee is a plus point. The original hand wheel for the knee was the same size as the others but that makes it very hard work raising and lowering the knee. Previous owners of mine fitted one about the twice the size and that was a real saviour when cutting the final drive gear of my half size traction engine! The bigger hand wheel made it much, much easier with over 70 teeth, there was a lot of handle winding! Nearly £1400 sounds optimistic in terms of price for a doggie one! I gave £800 for mine in 2017 I think it was, it's not pristine and has a few battle scars in the table but nothing drastic and a bit of wear but then it's almost as old as me! Still capable of turning out an accurate job though. HWM prices tend to be at the gold plated end of the scale so £1600 should get you a very nice one from a private sale.

Paul.

05/04/2021 12:30:57

Just be patient and wait till you find an Omnimill (home workshop had one recently for £1600). They are rare but they are about and no you can't have mine! Verical head can go up to 3000 rpm, can be positioned anywhere over the table plus you have the horizontal spindle. If you get the morse taper version tooling can be swapped between spindles. Some people have mentioned the vertical head could do with more support, I haven't found that an issue personally but there are ways to address if you do. Very versatile machine.

Paul.

Thread: Electric Traction Engine
21/03/2021 13:39:38

Ron,

Interesting idea. I am sure it could be achievable but it looks like it would be difficult to assemble. Loadings would be quite high so prone to wear. Personal thoughts is going through the side of the firebox with the gears hidden behind the gear guard would give the simplest and most robust / long lived solution.

Paul.

Thread: Boiler bush in Smokebox tubeplate not level!
21/03/2021 13:35:47

Sounds less likely that the bush has been soldered in out of square and more likely the thread in the bush was tapped out of square to the face. I think I would make a threaded guide that is a nice neat fit in the bush with a spigot say 1/2" long which can be used with a home made spot face tool (like a tap seat cutter) and then rotate slowly either by hand or cordless drill / flexi drive to face the bush square to the thread. I think I would be inclined to do it by hand rather than under power given the minimal amount to come off. Better to make it right in the first place than try and bodge it up with a wedged washer.

Paul.

Thread: Water Gauge tapered cock details
21/03/2021 01:09:00

Brian,

For the bores I started out reaming but when I realised the compression changes the bore on installation anyway I just drill it. Run at about 800rpm for say the 1/4" hole. I usually put a pilot in first I think I used 3/32 for the latest ones (not critical). Turn the outside with a HSS knife style tool around 4 degrees front and side clearance, minimal top rake (sideways if you get my drift), never fussed about the actual angles just grind to what looks right! Swarf comes off in coiled ribbons, just keep it away from the job as it will tangle if you give it chance. Surface finish is a dull polish but it's not that important as it tends to shave when you press it in anyway. I find it really easy to machine but watch the fumes. One tip, if you pressure test straight after assembly (air in water) you will get a few bubbles. If you boil it in water for 5 mins or so it will be tight. On the Ruston when doing a cold hydraulic you get a couple of drips of water but in steam it's as tight as a drum. I broke a glass on the Ruston with the shovel! It shut off completely and I carried on using the other glass to get back to base! Drill the passage for the steam / water after you have pressed it in.

Paul.

20/03/2021 23:04:29

Generally slow tapers (sub around 10 degrees) are considered locking tapers (Morse etc) so I am slightly surprised fizzy's at 2 - 3 degrees do not grab. I played around with taper plugs (yes I made reamers too) and yes I have one on the pump bypass of the 6" engine which is yet to be proven in service over time. In that application a small degree of leakage even when closed - internally is not a major issue but even having turned the plug and reamer at the same setting I had to lap it afterwards and fit an o ring at the gland nut to prevent external leakage under pressure. Comversely all the parallel plug valves with PTFE sleeves I have made so far (over a dozen) have been leak tight right from the off with no fiddling around. They are so easy to make I won't be changing any time soon. Also easy to repair in the future, just knock the sleeve out if ever needed, machine a new one and press in. I made the pair of sleeves for the 6" drain cocks in less than 10 minutes.

Paul.

20/03/2021 15:54:00

Hi,

Paul30013. There is some stuff on there from around 2012 for the ones I did for the Ruston and only a week ago for the 6" LS drain cocks.

Paul.

19/03/2021 23:27:45

I made my own and shortly to make another for my half size engine. Tapered plugs in bronze bodies I have never had much luck with, full size tend to have sleeve packings but they can still be tight to operate. I have made mine (2 sets for the Ruston SD 4" plus the drain cocks) with parallel stainless plugs running in a PTFE sleeve. No particular mystery to them I just make the OD of the sleeve 2 - 3 thou bigger than the bore in the body, the latest set of drain cocks have a nominal plug size of 1/4" and an OD of 11/32. I make a press dolly the OD of which is 5 thou under 1/4" to support and guide the PTFE sleeve and press in with the bench vice. Once pressed in obviously the bore of the sleeve reduces and I turn the plug to be a neat push fit. As PTFE has a high expansion rate if you make them too tight they are hard to turn when hot! The Ruston has 2 gauges and they have been in service for 9 years now and have so far never needed any attention and they close off dead tight with no leakage. If you are on TT you can see pictures there.

Paul.

Thread: Point radius 5" gauge
28/02/2021 19:31:58

I would say 20' would be the minimum for comfort, my ground level point is 10' (narrow gauge) which is fine for SWB 040 but an Eva May 060 that tried it stuck fast! Pay good attention to check rails too!

Paul.

Thread: Digital Callipers - again
26/02/2021 22:28:53

I bought from Allendale (I believe) at Ally Pally MEX probably in 2016 a 12" calliper on offer for about £50 as I didn't have anything of that size to assist with my half size TE build. It had very little use really only being used for machining ops on the larger bits like diff housing and brake drum etc. I bought in preparation for those parts so didn't get to really use it for about 6 months and before it was a year old I found when sliding closed to check zero it regularly started to jump. Initially it was only small amounts (less than 50 thou which almost caught me out!) but as time went on by inches! Tried cleaning, battery changes etc but nothing seemed to cure it. Any ideas what caused that? I can't follow up as its well out of warranty and it then befell an unfortunate incident where it was on the headstock of the lathe and the machine lamp drooped close to the case and melted a nice depression in it! Typically over the reading head! Opening the box it was very warm and the display had gone completely black! When it cooled down the display returned to normal so I thought I would try it, still functions but still jumps! Looking at it there appears to be play in the measuring head so the moving arm rocks slightly, not good for accuracy anyway but it appears when it rocks it jumps! I can't see any way of adjusting the play out so it's really only fit for the bin! Would be interested if anyone else has had similar experience though and the cause?

Conversely I have a ladle unit that must be 15 years old and is the go to instrument for anything not of high precision. I calibrated it with slip gauges in December out of interest and was quite please it is not more than half a thou out over its full range. It probably gets a new battery every 18 months. Great value for a cheap supermarket item!

Paul.

Thread: Push broaches for square holes
09/02/2021 17:53:04

You don't mention what machinery you have but consider looking for a slotting head for your mill if you have one. Will be way more than £100 for a broach but you will be future proof for any other sizes (and potentially shapes other than square going forward! It's a sad fact of life that time has to be expended either in making specialised tooling or setting up to use it - it's all part of the process

Paul

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