Member postings for Dave Smith 14

Mario

Go for the job level you have the experience and competence for. I interviewed and employed many non UK Engineers over the course of my career. They were judged on whether they were suitable for the job nothing else.

Dave

Does not surprise me at all. These schools tend to have first class facilities in all subjects and use them. Not every public school pupil will go on to be a legalised bank robber in the City. How many will go on to blue collar jobs, very very few, but what it does do is give all of them a start in understanding how things are made, which a fair percentage will need to know for future careers. Engineering is not dead in this country it just works differently to how some people remember or think it should.

Dave

Kevin

Good luck with your hydraulic. For those of us about to or actually building a boiler anything you have learnt along the way that would be useful to share?

Dave

Howard

Not done it but I have made my tender body from mild steel to my own laser cut patterns. Having worked professionally with sheet stainless I see no real issues. You will want annealed stainless if you are intending to bend it. Remember it works hardens as you bend so you only get one shot at it. Drilling is not an issue providing you lubricate and keep the pressure on while doing it. Soldering needs the flux that CUP sell, but I have had no issues with it. Best thing is to try some test pieces or a small part of the tender. first.

Dave

Peter

Look at this boiler pages on this website

**LINK**

Steve was a complete novice when he started and has built his own boiler which has at first attempt got its shell certificate. Loco is not complete so has not steamed. His build sequence is very detailed.

Dave

And in cans

And in cans

MORE 4, 6 part series.

On record as we ate going on holiday!

Dave

Google is correct, the yellow paste is called Duralac. Used extensively in Aerospace.

Steam engines for sale disappeared a couple of years ago. Nearest equivalent I have found is: Classified Steam

Regards

Dave

Stuart

I have a Warco WM250V lathe and WM16 mill. For the price they are very good machines and providing you don't flog them are capable of work as good as anything. DRO's help tremendously on both the lathe and mill. They don't make it any more accurate just a dam sight easier to get you to where you want to be, which helps you achieve accuracy.

Dave

Like Peter I have an old Henry permanently plugged in between the mill and lathe. Mill gets hoovered between ops or cuts depending on the swarf thrown up. Lathe gets cleaned as and when required, probably after each job. The workshop when I get fed up with it looking a mess.

Dave

SOD

The cloud based F360 will not be significantly different if at all. For non linear analysis you need specific software. The majority of industry including Aerospace uses linear analysis for the bulk of its work. I was involved in thin sheet structures and we only used non linear analysis where the effect of birdstrike was required and we were using much lower reserve factors than many industries typically 15% margins on proof stress, ie providing our reserve factor was above 1.15 we were happy. If fatigue was the issue then the reserve factors goes up because your stress limits come down. IMO providing you keep the stress well within the proof stress and fatigue limits then a linear analysis is quite adequate. If you work on a reserve of > 4 you are unlikely to get a problem. By the way I did an FEA on a steel Highlander boiler a couple of years ago for a guy on this forum. Interesting exercise. With a steel boiler the stressing is easy, with plenty of material properties data, the main issue is getting it built and inspected properly.

Dave

Keith

I agree in principle with your comments but you do not want any undercutting of the solder in the joint as this creates a nasty stress concentration which could result in a long term fatigue failure as the joints in a boiler are never in pure shear and always have some element of peel in them which will try to cleave the joint open. So a 'small' fillet is going to be preferable and I know our club boiler inspectors will insist on it. Just my opinion from experience of vacumn brazing aerospace parts.

Dave

Barrie

Fabulous but bonkers!

Dave

Iwata Neo. Good entry level dual action airbrush. Works quite happily with enamels, cellulose and acrylics. If you going to spray say 3.5" gauge and up then as Nick says a mini spray gun is a better bet. Best to have both.

Dave

Planet rock for me, for a commercial station /i reckon as good as the Beeb.

Dave

The other thing is they lighter, you remove mass from the point where you do not not want it. Buckling comes down to stiffness again for a given load which is controlled by the cross section as you say. In my racing days we did as much as we could to take the mass out of the pistons and the little end of conrods.

Dave

My two pennies. It is not about stress but stiffness. This what a lot of engineers miss, it may be adequately strong but deflections is sometime the overriding consideration. The rod is strong enough we know that from the smaller little end, but the crank end needs to be a larger to ensure the crank or whatever it is attached to does not flex unduly. Particularly where the attachment points are cantilevered.

Dave

Great result, but please keep your fingers away from the moving parts even a small machine will take a finger off.