Member postings for Paul Kemp

Spot on old chap, it doesn’t matter what you do there will always be someone on here with a reason why you shouldn’t or can’t do what you have done. Best plan is to risk assess and satisfy yourself the hazard is acceptable for you and carry on regardless

Paul.

Your assumption is correct. If you put your finger over the end of the boiler clack pipe then all the pump output should return to the tender without developing any pressure on your finger. A by-pass is “normally” an open and shut valve of some kind, ie flow in and flow out, not a three way diverter with one in and two outs.

Paul.

Try firebox doors, reckon you might have a little more luck!

Paul.

Never built a Stuart so can’t comment on the bearings. On the crank pin it would be good practice to have a small fillet radius where the pin meets the webs. Really depends on the lathe and the tool size it can accommodate and how much you need to machine off. You could use a narrow parting tool and rough out by plunging in and then take the last few thou by traversing the parting tool. Or you could use a vee tool to rough out the centre and then a left hand and right hand tool to rough the sides, finishing with a parting tool as previous. If you have a long overhang to get in and a small section tool limited by the tool post you can give the end of the tool a little more support by making a “pin” that will rest under the tool onto the cross slide so it has support closer to the tip. Plenty of options what you do ultimately depends on your kit and available tooling.

Paul.

I predict a riot…..or at least another lockdown

Paul.

Couple it up to the flame licker and put NDIY back in his box

Paul.

Derek,

Its about 45 years since I annealed brass for forming so memory is a bit sketchy but I am pretty sure you don’t want to heat it to red heat to anneal (due to the zinc). I have a vague memory of swiping the surface with soap and heating till the soap goes brown / black and letting it cool naturally to anneal. Brass if I remember right tends to work harden quickly (much quicker than plain copper) so regular annealing as soon as it starts to resist is the name of the game. The “extra” material needs to flow somewhere and if the metal has hardened that won’t happen easily or well.

Paul.

When I picked up the L6 I went with a crew of four with all of the above, plus two sheets of 8 x 4 x 3/4” ply split into two lengthwise to make a roadway across the grass plus a haltrac type hoist to hold it back as the grass was down hill! It was quite a difficult move as it had to be turned 90 degrees, pulled out through a standard door, turned again, moved across the grass and over a drain into a narrow passage between the houses, out into the road, lifted on the engine crane and the trailer backed underneath. I was very fortunate in having an experienced machine mover on the crew! All went very smoothly really but it took us about 3hrs in total to get it on the trailer.

Did a similar exercise collecting my omnimill but we winched that onto the trailer and was most fortunate we had a forklift the other end to lift it off! I will need to move both machines again in the future! With care and good planning everything is possible.

Paul.

I have a Harrison L6, it came complete with inverter, faceplate, catch plate, 2 x 4 jaw and 2 x 3 jaw chucks, fixed and travelling steadies, burnerd multi fix collet chuck and full set of collets, Dixon tool post, with about 6 holders, loads of tooling plus the Harrison boring table and the conversion gear for metric threads. I gave £1800 for it in 2020. It’s never been in industry only model engineer owned so in perfect condition. If that helps?

Paul.

John,

Getting the sprinting right on a loco is a complex affair! On a full size engine the weight carried by each wheel would be weighed (scales set in track and loco traversed over them). For a model, if the axle boxes are set down hard on the horn keeps by the springs, they are too stiff. The ideal is when the loco sits on the track the axle boxes are just floating in the horns (ie not jammed hard against the keeps). Ideally if you get a depression in the track the wheel should be able to follow it. Easy way to check if you are in the ball park is to put your hand on the boiler and rock the engine side to side (gently) you should get some movement without any of the wheels lifting clear of the track. Similarly pushing down on the front buffer beam or the cab footplate you should be able to get a little movement again without any wheels leaving the track. That would be a good rough starting point. Your situation is further complicated by the leading bogie and trailing truck. Not sure if the MW Brit has side control springs on the leading bogie? That can be in influence on the bogie following a curve or crossing a point. Springing is a really complex subject! Good luck! Be interested to hear how you get on.

best regards,

Paul.

Ramon,

If you are interested here is an example of a bush to broach a parallel keyway on coupling for a taper shaft (a lot steeper taper than a taper key). It’s all the same idea though!

https://www.youtube.com/watch?v=H9ZYAdnXzqs

Paul.

Firstly as others have said, backlash in feed so retract tool before reversing - number one rule!

Second how did you set your 60 degree tool in the tool post so it was accurately aligned to the job? Fish tail gauge or guess work? Any screwcutting tool needs to be properly set at 90 degrees (axis of the centre of tool) to the job. Looks like you had your 60 degrees biased 40/20?

Paul.

SOD,

I think your water analogy is probably a good simplification of the grid system. Think of it maybe as a water grid on the same connectivity nationally as the electric grid. For your pot and for simplification imagine a reservoir into which all the suppliers pour their contribution to demand and consumers taking what they need from the pipes.

You cannot guarantee that any consumer will necessarily receive the contribution of a particular supplier, that is why the market is set as it is, suppliers get paid for the contribution they make to your pool of energy by the wholesale utility buyer / seller and consumers pay the retail local utility provider for the energy they use who in turn have contracts with the wholesaler for the energy they sell. There are profit margins applied at each transaction.

As alluded by other posts there are times when there simply is not enough “renewable” energy being generated to meet the supply agreements of all those claiming to supply only 100% renewable energy. So the claims being made by these suppliers are simply not true on an instantaneous basis so we can apply a bit of smoke and mirror magic here to keep the lights on that over an average of time suppliers are only selling renewable energy they purchase, the fact they may purchase more renewable energy than they are selling when the wind blows and the sun shines allows the somewhat false claim to be substantiated. The excess is not stored it’s shared by load balancing. That’s my take on it anyway. Certainly where I live right close to a wind farm there is no guarantee that green wigglies from the windmills are going into my lathe 24/7 with no brown ones being excluded!

Paul.

John,

100 out of 100 for perseverance with a Modelworks kit, especially the Brit, lad in our club had one and I never saw it actually make a full lap of the track! I had a Winson traction engine (fore runner of model works) that three before me had tried to complete and failed and like you by the time I had it running I also had a box of original useless parts that had been replaced with new!

On your question trying to use 7mm bar I am afraid you are pushing the laws of physics and the properties of metals, it’s not going to happen and especially not safely. I would respectfully suggest you abandon that plan and look at an alternative of a decent bit of heavy bar perhaps with locators to stop sideways movement that you can thread through between / behind drivers that will bear directly on the frames. Having once seen two fellows trying to lift a 5” tender engine that was in steam from a bench onto a track and them dropping it with the consequential damage I would suggest any lifting operation for re railing that cannot be completed by lifting gently on the front buffers needs careful consideration and if the track where you run causes such frequent derailments that you need to make these preparations then the PWay dept have been neglecting their duty

Paul.

As an aside and not relevant to this conversation as Doc doesn’t have a shaper I believe I have also made a replacement clapper box for my hand shaper with a guide arbor that allows setting of a hole for a keyway of whatever size I desire to grind the tool to either parallel or at any angle I wish! That is a similar approach to Jason’s method of packing the work piece - you can do that with a single point tool but not with a broach. I don’t think in any of my posts I have suggested a parallel bush and tilting the wheel to use a broach and I don’t think Jason did either?

Paul.

Ramon,

it is simple. Flywheel remains flat and perpendicular as any conventional operation ie parallel in all directions to the plane of the press ram. The way you get the taper in the keyway which is not on the sides of the keyway, these are parallel in all circumstances, the taper, as mentioned is only on the head of the keyway. To get that taper which as Jason points out is very small anyway either 1:96 imperial or 1:100 metric when you cut the slot in the guide bush to carry the broach you pack the dividing method (rotary table, plain dividing head etc) or if you are lucky enough to have a universal dividing head you can tilt it. If the total length of your bush is say an inch and we are working to the metric standard you need 10 thou of inclination across the length of the bush. Mill your slot in the normal way. Place your bush in the hole large end up preferably and broach. The taper in the base of the bush slot is what guides the cut of the broach and automatically you will have the required taper in your keyway. Use your shims behind the broach in the normal way to get the required depth. The very small angle of the broach to vertical caused by the guide will not cause the broach any distress at all.

I am afraid I am not CAD literate but I am sure Jason in the blink of an eye can produce a sketch that illustrates if this text is not clear.

Machine your key to the same angle on its TOP face and as long as you drive it in from the right side you will get a uniform contact over the length of the key and no tilting force to wobble ur wheel. If you drive it in too hard it won’t be coming out in a hurry!

Paul.

Fred,

I don’t post here very often but have been following this from the start. It’s a great account of a fantastic ‘journey’ (how I hate that phrase but it fits here). The result must surely be well deserving of a gold medal if you were ever to enter it in the exhibition competition. Fantastic job sir, well done.

Paul.

Now, you’re talking, you could even go the extra mile and taper the bottom of the bush slot for a “proper” tapered key

I cut the spline keys in my half size traction engine gears (granted cast iron and nice and soft) with a bench mounted arbor press, no idea of its number or capacity, it is fairly hefty, a good 2 man lift to get it on the bench when it was placed there but it did the job just fine. From memory the keys were 5/16” and I made the bush as you describe with 2 slots, one for the broach and the second for a key to index it (8 splines).

Paul.

Nigel, I have absolutely zero concerns about our club compliance with the quoted regs. We use an 8” gauge that is checked or calibrated against a master gauge at least every two years by a commercial organisation which issues a cert and a calibration certificate so it is a traceable and auditable process. Prior to this it was checked against a dead weight tester owned by a member of a neighbouring club along with gauges from other local clubs. Again a record of the test was provided for our files. So no shortcuts taken. My understanding was the OP required a method of checking his own model gauges for his own use, there was no mention of issuing his own certification for boiler safety?

My point on the 3/4” gauge was you are testing it against a 2% standard but it is incapable of being guaranteed to be much closer to 10% accuracy itself throughout its range. Model gauges are at best indicators.

Paul.

Nigel, in pedantic terms what you say is correct but in practical terms are you not stretching the point a little, certainly considering the ‘guidance’ as quoted by Duncan from the code? Do you think the national standards laboratory would even consider calibrating a 3/4” dia 0 - 150 psi gauge to even 2% when the width of the needle would equal that? If the proposed deadweight tester is checked against a calibrated gauge every 2 years then the spirit and intent of the rules will be met.