Member postings for S.D.L.

Put your 3 jay back on.

Measure the shaft with your best micrometer.

Turn a bit of metal to the same diameter and put a 30 deg chamfer on end.

remove metal from chuck and put 4 jaw back on.

Use gauge just made to judge boring, the taper helps.

easier than internal measumrements.

Steve

Do as you suggest turn taper first then cut with BSPT die.

Steve

Get some universal channel 100 or 150 high as required weld up a frame, gusset top to bottom either side of fixings.

Bolt lathe to frame, lift and put machine mounts frame to floor for level ling.

frame probably ends up as two rectangles first one under head stock the 3 prices to side under tail stock

Steve

In a previous job I volunteered to part off some 316 stst M24 bolts that were too long. I was actually designing things but there was no one free to do it and I had a Factory Acceptance Test the next day and knew that the Resident Engineer coming would reject them for too many threads sticking through.

So onto the Colchester Master front Dickinson post add a Sandvick parting tool. Feeding by hand and Bang tip gone. see Mick and get another tip second bolt, bang another tip gone. Mick says lets see what your doing. digs out the rear tool post and fits on with sandvik tool moved to back and up side down. puts it at about 400rpm and cuts with power feed.

I did the rest of the bolts in less time than I did the fist two. Micks view always part under power feed.

Fast forward to nowadays got a Colchester student MkII in the workshop (Garage) so big by Myford standards. It came with original Dickinson T2 quick change post, using a Sandvik parting blade it parted Brass and aluminum under power fine EN was ok some of the time, stainless was always a disaster. I was looking for s rear toolpost but eventually I saw that the tool holders pulled out and twisted when there was a jam and fired back into place. I replaced this with a Chinese version of the Multifix type. I got the money back by putting the Dickinson and holders on e-bay and the Multifix that is half the size of the Dickinson will part 2" 316 StSt as if its butter sat on the front.

My take is many tool posts are not as rigid as we think and power feed is the key with a tool that rolls the chips or swarf so that it is narrower than the groove being cut.

Steve

We use both bootlace crimps and the RYB eyelets, fork and blade crimps at work on lamp circuits that run at 950V 4A and have a strike voltage up to 2KV. this arrangement passes both UL and CE low voltage directive via independent test house in UK, so that should give some idea. They do insist on the correct ratchet tools that have to do a pull test on a sample every year or 6 months depending on use.

As others have said soldering ends of wires going into clamp terminals is a no no now days however neat it looks.

Best connection is the spring clamps found on many terminals and increasing numbers of components, gets rid of the screws working loose during shipping.

Steve

Put a groove on each side with tool of choice ( offhand grinder, angle grinder dremmel etc) wrap in rag and put in vice with groove out of jaws, hit with big hammer. If doesn't break get bigger hammer.

Steve

It's not just the boiler being tested under the PSS2000 its a system test. Green book 1.2

Green Book clause. 3.13a states that system is "boiler shell including fittings and pipework"

Fittings are defined in 3.3 and include saftey valves and regulators etc.

In essence the whole system has to satisfy the inspector not just the boiler she'll, at the end of the day it's the inspectors nuts on the line.

Steve

For any class of fit the amount of clearance or interference increases with diameter so what may be sloppy on a small shaft would be proportionally tighter on a bigger shaft.

Steve.

Edited By JasonB on 28/12/2014 07:25:30

I have seen M10, 3/8 BSW, 3/8 UNC, M12 and 1/2 BSW, and I expect there was 1/2 UNC as well. I brought some threaded rod back from the U.S. for the UNC one.

Try some bolts or if very carful some Taps to try them.

A lot of auto locks have the size in very feint writing on the side, if tarnished try cleaning up wit a bit of WD40 and fine scotchbrite.

Steve

The martin Evans book that I took this from has good worked examples and certainly the tube thickness is what is in the Northern association guidelines. Note these design guidelines are separate from the testing book. This should not stifle developments but few boiler inspectors are going to have the experience to review FEA but this should not stop people adding blind bushes for fixings of door runners etc

Please spare a thought for your Boiler inspectors, many do a thankless job, at the end of the day its them that has to sign off and pass things. At our club for many years the boiler inspectors thought they were covered by the club insurance, It was only when I raised a question in writing during the review before the last code change that it was made clear that the club needed separate indemnity insurance for the boiler inspectors otherwise there assets are on the line. as you could imagine we took this out promptly. This insurance is shown on the southern fed form but historically the implications had not been understood.

Steve

Figures I used are shown below from my spreadsheet based on Martin Evans book which are the same as the Northern Association guidelines I mentioned earlier.The .9 join allowance is what I would allow, drawn tube is 1.

this gives .091" or 2.32mm

Steve

Barrel thichkness

Source

Model locomotive and marine boilers

By Martin Evans

ISBN 1 85761 138 1 P28

Where

P Plate thicnes in inches

D OD of Barrel in inches

Edited By S.D.L. on 24/10/2014 13:26:06

Hi Fizzy

The answer that I posted earlier was based on the Martin Evans formula. I have been rooting around in my workshop and found a guidance note titled.NORTHERN ASSOCIATION OF MODEL ENGINEERS BOILER INSPECTORS SEMINAR. Boiler Design Materials Calculations. In this they recoment that the Martin Evans formula of

P=( D*F*W.P)/(T.S.*R*C*T*2) be used

Now if I was a Boiler inspector at a club in the northern federation that is what I would use until the guidelines were changed.

On a different note, I have never used a strength of 1 on welded joint design even with coded welders hence my use of .9. When you were coded did the welds still have to be x rayed on butt welds and dye pen on fillets?

Steve

Using Martin Evans numbers I get minimum 0.082" wall allowing a .9 factor for the Tig butt weld.

Silver solder lap joint would be 0.8

Steve

Surely the reason for the tapered dowel is to give correct alignment???

Steve

That's why I posted asking if anyone can remember what magazine an article has been in. Several members at our club want to make some and although I have 1 clamp to copy I remember an article in one of the magazines but cant remember if it was in ME / MEW / EIM or one of the US magazines Home Shop Machinist or Machinest Workshop.

Steve

Does anyone remember an article in one of the model magazines about making clamps to this design.

Steve

There is a big discussion here

**LINK**

there might be another thread as well

Steve

The distinction is if they can do the calculation and analysis not if they have a Degree. I stopped my education at HNC as by then I was married and had a mortgage. I currently spend a fair amount of my time developing sizing tools for our equipment based on the results of validation reports. These reports are usually done by Engineers with masters or PhDs yet still I keep finding them full of errors.

The degree only proves that they are clever enough to pass the test not give them an automatic right to engineer staus. Having started off in a Drawing office where all the Designers were HNC / HND and doing all the design and stress calculations, whilst the Engineers sat in a separate office as project managers and couldn't organise a Pi$$ up in a brewery.

Steve

I Like the name model engineers workshop.

if there is so many motorbike and car fans that want garage articles why haven't they got there own magazine?

The magazine has been called Model Engineer for decades probably since the good old days whenever that was. I much prefer the term Scale Model when talking about a scaled model of a prototype. A model maker used to be one of the top trades in many companies. miniature suggests to me dolls houses etc and reminds me of steam fairs and the miniature parade with the explanation that whitworth threads live on as camera tripod mounts when it has been UNC for years.

it was natural when MEW was spun off from model engineering to call it Model engineers workshop to try and keep the original readers. Most of the famous old names, Thomas, Radford, Etc etc. We're making tools to improve there models.

Since the spin off others have come in, some such as the famous Sir John (I want my 2 quid back) have brought a whole new range on tools customised for home workshop use through Arc and others. So things evolve and change but I don't expect the publisher to play with the brand name, remember Royal Mails new name??

Steve

Correct torque is about 75ftlbs, which normally requires a holding fixture. The bearing nuts are better .

This force goes up for ER32.

Steve