By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Perko7

Here is a list of all the postings Perko7 has made in our forums. Click on a thread name to jump to the thread.

Thread: Ambiguous words
23/04/2022 12:00:33

shot, meaning either:

- completely knackered

- numerous small projectiles in a casing for use in a rifle

- being struck by such small projectiles, or larger individual projectiles, having been impelled from a rifle or other firearm

- the injection of a small quantity of medicinal fluid into ones anatomy

- the measurement of a small quantity of alcoholic spirits

Thread: Gasless MIG welding
15/04/2022 06:03:55

I've joined quite a lot of thin steel assemblies over the last few years, mostly SHS with wall thickness around 1.2mm but also some sheet down to 0.8mm using a plain inverter MMA welder and 2mm rods. Like others have said, the trick is plenty of current and short 'stitching' beads all linked together. Too much time spent in the one spot will certainly blow a hole, but these are repairable. Sometimes i stick the bare end of another rod into the hole and weld over it, other times a spare scrap of metal from the waste bin, even ordinary nails are useful for this. Like other skills it takes time and practice to reach any level of proficiency, and a touch with the angle grinder afterwards hides most mistakes.

Thread: Blobs on drawings
12/04/2022 13:37:03

I was taught to use arrows when I first started manual drafting in the 70's but after a few years in the engineering drawing office the change was made to use a slash as it saved time and was easier when nesting small dimensions. Then in the 90's we went to CAD and it all changed again. Been retired for a few years know but still use the slash on hand drawings and the arrows on CAD drawings.

Thread: Mankind occupies a strange place in the ecosystem !
30/03/2022 12:07:15

Intriguing to think that people who may balk at the use of natural dye extracted from dead bugs could be happy to use synthetic dye extracted from living genetically modified microbes. I know which one I would prefer.

Thread: Chuck & backplate problem
30/03/2022 11:55:21

I assume the photo shows the back of the backplate with the threaded boss that screws onto the spindle, and that the other face has a raised section that lines up with the recess in the back of the chuck. This is the register which provides the correct alignment for the chuck.

Old school method would be to lay a sheet of paper over the back of the chuck and rub over with a charcoal stick or chalk stick or something similar. This will highlight the locations of the mounting holes and the recess for the register. Now lay the piece of paper over the backplate, line up the register recess, and centre pop through the paper for the 3 mounting holes.

A modern alternative would be to lay the chuck backside down on the photocopier and take a copy of the back face, then go to step 2 above.

The bolts are only there to hold the chuck on and stop it spinning, it's the register that provides the precise alignment, so a little inaccuracy in the position of the holes is not a major problem and they can be made oversize if needed.

Thread: Loco lettering
09/03/2022 13:23:52

Thanks for the ideas.

This was mostly a case of making do with what was at hand at the time as an experiment. Pre-coloured vinyl would certainly be easier but if the colour density is too high it might be difficult to trace the letter outlines unless I update my light table (currently a convenient window facing sunlight) to something with stronger light. I do have a friend (the same one who did the builders plate) whose wife has a vinyl cutting machine for doing letters and other shapes for scrap-booking but hesitate to ask too many favours.

09/03/2022 12:18:05

Hi all, been experimenting a bit with letters and numbers for my 5in gauge model of a Qld Railways DL class loco. Eventually settled on the following process:

- generate full size drawing in CAD and print out

- trace onto white self-adhesive vinyl covering for folders/books etc (generic name in Australia is 'Contact' , may be called other things elsewhere)

- cut around outline using sharp hobby knife

- paint whole area of sheet with appropriate colour enamel (may need 2 coats)

- separate individual letters, peel off backing and place in position.

I'm not sure how durable they will be, but the Contact covering I have used seems fairly robust as a book covering for school books etc so should be ok for a lightly-handled loco. To be on the safe side I sprayed the completed lettering with a coat of clear gloss.

TIme will tell how successful this approach will be, but it was certainly easier than trying to hand-paint and cheaper than many other alternatives such as computer-generated vinyl letters, waterslide transfers etc.

Also of note is the builders plate, engraved from brass plate by a friend using a small CNC mill.



Thread: Financial surnames
06/03/2022 07:52:14

Don't know if you had them in the UK but in Australia we also had the Threepence, Florin and Crown. The Threepence (or Thrippenny) was of course 3 pence, the Florin was 2 shillings (24 pence) and the Crown was 5 shillings. I always though the Florin sounded French.

Thread: Oops
01/03/2022 12:52:30

Well after more than 24 hours the end result is:

Plywood 1, Bakers Soldering Fluid 0.

Concrete floor and rubber mat unharmed. Bits of steel on the bench were washed and now show only light surface rust most likely from residual moisture after washing. Affected tools which were washed and oiled show no after-effects.

Some of the ingrained dirt/rust/metal filings on the bench changed colour but the timber itself appears unharmed. It might have helped that over the last few days we have been experiencing the greatest rainfall ever recorded, with over 80% of our annual rainfall being recorded in a 3-day period causing widespread flooding. Humidity has been in the 90%+ range during this time too.

Regardless, next time I'll be more careful and remember not to leave opened bottles of anything where they can be knocked over.

28/02/2022 12:06:47

Thanks all for the speedy responses.

I already found a MSDS online MichaelG but thanks for the one you provided.

After mopping up the spill I waited a while to see what reaction if any resulted. Seems like the accumulated oil/dust/rust/dirt ingrained in the benchtop simply neutralised the relatively mild acid properties of the flux as no apparent ill effects an hour later. Likewise the concrete floor appeared unharmed as well as the rubber floor mat. Did notice a 'soapy' feel on the skin of my fingers which came in contact with it when mopping up, but that soon disappeared after washing my hands again.

The only tools that came in contact was a pair of side cutters which I washed and then sprayed with light oil.

Assorted bits of metal lying on the bench which were also splashed with flux were washed and left to dry.

Interestingly, I use an old artists flat painbrush about 6mm wide to apply the flux. It never gets washed and after several years the only damage is some slight corrosion of the aluminium ferrule. The timber handle and the bristles seem to have survived fairly well, although the bristles have suffered from applying flux to surfaces already heated by the soldering iron/blowtorch..

I'll see what everything looks like in the morning. Expecting some light surface corrosion on the steel bits but that won't be a problem.

28/02/2022 06:16:02

Knocked over a bottle of Bakers Soldering Fluid on my workbench, mopped up with paper towels and washed any equipment or materials it touched but wondering what else I should do. Workbench surface is plywood with clear polyurethane finish but pretty battle scarred. Some spilt onto concrete floor and rubber matting as well. Any suggestions?

Thread: What are the yellow fittings please
30/01/2022 12:33:13

I think the key term is resistance. There still needs to be some movement available to allow the track to adjust to temperature variations. If the outer ends of the sleepers were rigidly restrained then the straight track leading into the curve could buckle at high temperatures. In the days of short rail sections with bolted fishplates there was enough movement in each joint to adjust to temperature variations, but with continuously welded rail that is not possible.

Thread: Access to the underside of heavy engines?
30/01/2022 12:26:08

My engine weighs about 50kg, but I can't roll it onto it's side as the side steps are fairly delicate and would be bent in and foul the motion, so I usually tip it onto one end. It needs some stabilising supports but at least I can see and get to all the bits while standing. Previously I would lay some rails between the fixed workbench and a mobile bench of a similar height and roll the loco onto the rails. Meant I had to sit on a low stool to get to the underside and was a bit hard on the back and neck muscles as well as usually needing temporary additional lighting.

Thread: 3.5 inch wheel form tool..?
29/01/2022 11:48:00

+1 to Duncan's reply. I used a round-nose tool of the correct radius fed up the 3 degree angle until the diameter at the root of the flange was correct, then fed down the 20 degree angle until a smooth transition was obtained. The radius C was achieved using files and a template to check progress. It was slow and somewhat tedious but enjoyable at the same time. I only had 8 to do, each one took maybe an hour after the castings had already been turned roughly to size. Was my first attempt so someone more experienced could no doubt do it faster.

Thread: How to keep Paint Fresh?
29/01/2022 11:39:06

I often decant into clear plastic milk or juice containers (after they've been washed of course smiley.) If you can find one or two of the right size so there is minimal air gap, and then store upside down. Bonus is you can see the colour of the paint without opening the lid. Downside is that you have to pour into another container to get a brush into it.

Thread: Catastrophic Failure of Pressure Vessels
14/01/2022 11:30:23

Further to Paul Lousick's post, I was involved at one time on the construction of valve stations on a high pressure (5000 psi) gas line across outback Australia. A pinhole leak from a flange gasket would cut your arm off if you walked too close. Safety procedures in that field are understandably rigorous.

Thread: Shims
31/12/2021 08:58:58

Model hobby stores usually carry stocks of brass sheet in various thicknesses from about 5 thou or 10 thou up. I also use the metal packing strips along with broken bandsaw and hacksaw blades and the tear-off foil from various food packaging.

Thread: G’day from Queensland Australia
20/12/2021 11:35:19

Hi Ray, what part of Qld are you in? I'm in Ipswich. There's a few other ex-pats and natural Aussies involved in this forum too so expect the usual light-hearted banter at times, particularly around Ashes test time (we won't mention the second test in Adelaide which finished today!)

There are a couple of other people on this forum also interested in the 1831 and a mate of mine in Ipswich is building a Wallaby too but just out of interest in the engine itself, not to go in a loco.

I'm building a 5-inch gauge petrol-powered Qld Railways DL loco (some photos in my album) which is nearly complete but has had some reliability issues during testing so is currently having a heart transplant.

Hope you find what you need for your 1831.

Geoff P.

Thread: How are your clubs responding to Coronavirus
13/12/2021 04:16:41

Here in sunny Queensland Australia we have been able to operate our public running days for the last couple of months following relaxations in the requirements for masks and social distancing on the proviso that people check in using a Govt-supplied app on their phone.

Since then the Govt has stipulated some significant restrictions on attendance at gatherings for people who have not had 2 doses of an approved vaccine, but has placed the policing of these to the organisers involved, which includes entertainment venues, clubs, social organisations and sporting groups!

So, we are now required to request evidence from our visitors on their vaccination status, and decline entry to those not meeting the requirement. frown Not sure how we are going to manage that with 4 entry gates onto the property! We usually only have just enough members to man all the required positions on our normal running days.

On the positive side, Queensland has today relaxed it's border restrictions so visitors from other States can now legally enter provided they are vaccinated and have proof of a negative Covid test within the last 72 hours. With vaccination rates exceeding 80% in most States it seems like movement throughout Australia might be a bit easier this Christmas.

Thread: Stephensons valve gear
28/11/2021 23:14:29

Many thanks for the prompt replies, all clear to me now. Will follow up the resources mentioned as well.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Rapid RC
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest