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

Member postings for Jeff Dayman

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

Thread: Coping with voltage spikes
16/08/2020 17:25:40

Just some out of the box thinking -

Maybe decouple the LED's power source from the car entirely. A pound shop book reading LED lamp with a switch and small battery could be deconstructed and the components arranged near the gauge to be read. The wires and bits could be camouflaged behind panels etc. to keep original appearances. This way you would have a trouble free light for use at night to read your gauge, with its' own power supply - no fancy circuit or phD in electronics required.

Forgive me if this approach is too basic or crude, but I could probably adapt the pound shop book lamp in less time than it took to write this. A cheap LED penlight type flashlight would likely work too.

Offered purely as food for thought.

Thread: Silver soldering a Minnie traction engine boiler
15/08/2020 18:18:57

Paul - I agree with your points. Before any mods to any proven existing boiler design a detailed analysis is needed, with design and stress calculations. Any proposed mods should be reviewed with the local boiler tester for safety. Hunches and gut feelings are not enough to risk design mods when public safety could be compromised.

Len Mason in the Minnie book said to test the finished boiler to 120 psi and hold it there for some time. In a previous sentence he said model boilers should be tested to twice working pressure, so I infer he intended working pressure to be 60 psi. Looking at the small area of the throat plate, its' flanged sides, the fact that the top butts against the boiler tube to support it against forces induced by pressure, and that the throat plate has 6 stays, even at 120 psi the stress on the plate and stays is very low. If the joint is silver soldered competently I would not expect any trouble.

Answering an earlier comment re number of Minnie boiler failures, I have never heard of one or read of one failing, for the 40 year period of my model engineering interest. Many have been successfully made and run. I would be interested to hear if there are any failures and how they failed.

Thread: How good is a good faceplate?
15/08/2020 01:26:23

take it off , put it back on, and re-clock it,  3 times. I'll bet it is a little different every time, at the 20 micron-ish scale.

and it does not matter at all, for most ME work.

If you skim it enough times, the whole face plate will disappear. smiley

Make some parts, have some fun. Life's to short to be chasing rainbows.

Edited By Jeff Dayman on 15/08/2020 01:26:55

Thread: epoxy resin preventing from sticking.
14/08/2020 23:58:48

Silicone may interfere wit the curing of the epoxy. Paraffin wax (solid at room temperature) as used for candles and home canning can be used as a "mould release" coating, and will not interfere with the epoxy cure, or bleed out of the hinge later!

If you melt some wax in a tin over a pan of hot water and dip / air cool the hinge twice you will get a thin but complete coating. Good luck with it!

Thread: Colchester Student Mk1 Won't Start
11/08/2020 22:09:10

Knowing the wire diameter would be useful to someone making a new spring.

Thread: Anyone recognise this?
10/08/2020 15:16:25

One suggestion I would make for the red mill would be to route all electrical cables with some good cable clips every few inches along the top motor mount / pulley enclosure plate, to the back of the machine. Otherwise at some point you will get one or both cables tangled in work, around the spindle, a broken belt, etc.

You probably already know this but endmills mounted in drill chucks as seen on the pics can work loose and jam. If you don't have some already you would be wise to get some collets for whatever taper sockets are fitted in your spindles. If they are R-8, so much the better compared to Morse taper or others. Twist drills in drill chucks are fine, endmills need proper collets for safe accurate ops.

When the spindle is running be sure and keep hands hair and clothing well away from the handwheel at the top, it is a major hazard when turning.

Looks to be a very handy machine.

Thread: Vickers Bl 8 inch Howitzer cannon of 1917
10/08/2020 12:01:20

Looks and works great Mal! well done.

Thread: Silver soldering a Minnie traction engine boiler
09/08/2020 19:52:44

Bob Worsley- as others have mentioned Minnie's boiler is a proven design which many people have built and steamed with success.

A flanged joint is more usual practice for the throat plate joint in many boilers but this does NOT mean a butt joint will not be acceptable for Minnie in combination with the substantial side flanges of the throat sheet, the firebox stays, and material thickness / joint design/ physical dimensions of plates that were used by Mr Mason and all since.

What IS unacceptable is changing or editing any published and proven boiler design with offhand suggestions like your statement "easy enough now, to curve a piece of 90 degree copper to solder over the top, inside or out". If you did such unproven mods to a boiler you may unwittingly change the stress distribution in the system and CAUSE an unforeseen failure.

Such suggestions for changes to proven boiler designs like Minnie's need to be accompanied by calculations, tests, and several competed boilers steamed successfully, or public safety is at risk.

Thread: Taking a pair of wire cutters to a standard baseball cap
04/08/2020 00:41:32

Hi Duncan, I was not aware of the meaning of maga in Nigerian slang. But I would not suggest mentioning this fact to someone with the extra word "Krav" in front of "Maga" on their cap. If you do, you may find your limbs rearranged by the cap wearer and will have to drink coffee up your nose through a straw for about 6 weeks.


03/08/2020 22:01:48

Paul - is it only 10% reduction? I'm sure it is even higher if worn backwards but at an angle, the closer to 45 degrees it gets , IQ seems to fall off rapidly. Probably related to antenna symmetry..... worth investigating, I think.

Sam - I'm sure there is such irrefutable evidence, but we will never know, it is probably stored even deeper in America's most secure vaults than the Coke formula and the Kentucky Fried Chicken recipe. Completely bubba-proof. I wish someone would adjust the gain on the chip embedded in the president's hairpiece retainer tape to tune that guy in a bit.

03/08/2020 20:30:59

It's a serious offense in many parts of the world to remove that button, as it is a little known CIA / NSA tracking device and microphone to help them monitor and control the world's population. It's not a lightning conductor as many people in Iowa USA believe. 

It is no accident that many people in China refuse to wear baseball caps intended for markets outside China.

But if it is bumping your head , by all means remove it. Buying a pickup truck with higher doors would save you getting out the cutters and risking spontaneous uncommanded hat disassembly.

Probably be wise to line the hat with aluminum foil though, to prevent the "missing button tracking rays" from CIA / NSA satellites reaching your brain.

Edited By Jeff Dayman on 03/08/2020 20:32:36

Thread: Cleaning emergency !
03/08/2020 04:02:33

I'd be looking for some smaller tires and make some artistic and clever crop circle-like patterns in it. If you can't fix it - feature it!

(or get new rug)

Thread: New Lathe - poor suface finish on my results
31/07/2020 13:44:40

Bolts are made for strength, with tough steel, which does not turn well sometimes. The heads are hot or cold forged on, and in smaller sizes the threads are rolled on, not screwcut, again for strength. If you want easy cutting steel with a nice finish find some free machining grade steel, like 12L14 or 1144SP. You will not likely find this type of steel at the local hardware store. Don't be tempted to buy rebar for machining projects either, although it can be cheap - it again is made tough for a specific purpose, not for machining.

Thread: Silver soldering a Minnie traction engine boiler
24/07/2020 22:27:57

Your soldering on the small boiler looks good Mark. Smart to get some practice with that, and now you have a nice boiler for powering small model engines. That extra solder can be removed, it is not a big deal. Much better to have a bit extra than not enough. Good luck with the Minnie boiler! Clean things up often while soldering, don't skimp on adding flux if things are not flowing as you want.

Thread: Bulbs Electric Life of
24/07/2020 22:23:12

+1 on using an LED, of course you should probably look in Digikey or other electronics supply places to get one with high reliability and longest possible life. I have seen the better ones listed in such places as 50,000 hour , or 5.7 years continuous operation guaranteed life. Only a dollar or two more than the cheapies. Using a cheapie would definitely be a transgression in this application.

Anyway as to brightness there is no reason you could not use a dark plastic filter sheet or two over/around the LED to block some of the emitted light to dim it, while letting it run at design rated current for best life. In this case it may be needed to hide one's light under a (semi transparent) bushel. (sorry)

Any ex phone charger wall wart power supply would work for powering it, if output V and I were what the LED required. Just food for thought.

Thread: Can anyone tell me what this might be?
24/07/2020 18:27:25

It may have started out life as a pneumatic upper clamp for a tire hot-patch machine from the 1930's. We had one with a similar head in my grandfather's garage. The machine was like a drill press with a fixed lower anvil like the table of the drill press and your bit sliding up and down the column to enable fitting it over various size tires and tubes. hot patch was a tin of flammable stuff placed on the patch over the leak, and lit with a match. After it had burned the clamp was pressurized and clamped the heated patch to the heated tire or tube to bond it. The machine and the hot patch method had fallen out of use by the 1960's I think and the press didn't fit most modern tires by that time. Cold patches and cold core plugs for patching tires were very good very fast and commonly in use by the mid 1960's when I started hanging out at the garage as a kid, and most tires on cars were tubeless by then in North America. I do remember my grandfather using the old press and hot patch kits a few times on old car tires and still remember the smell of the huge cloud of smoke the tin of hot patch stuff made- a cross between burnt rubber and fireworks.

Thread: Using Counterbores
22/07/2020 12:00:18

It's a reverse side spotface tool I think. We had a similar version for finishing some spotfaces from opposite side, on valve castings in a firm I worked at years ago. We did them from the opposite side because the cating was sitting on a datum for other ops, and we wanted the spotfaces to be sized relative to that datum also. Picking up the datum after breaking the first setup would have been difficult.

Thread: Lockdown Reading - Nevil Shute Rediscovered
05/07/2020 16:34:23

"No Highway" and "Most Secret" are also very good, by Mr. Shute. I have my Dad's collection of most of his works and I also like them very much.

Good stories, well written, without the Hollywood style dirt and embellishment.

Thread: Cutting brass with saw questions
02/07/2020 19:39:21

This is the third or fourth time the OP asks for advice then gets rude and shirty with polite long time contributors to the forum. Moderators, zap this joker, please.

Bob, sorry you experienced the rudeness, recommend the "ignore member" button. I did, some time ago. I only saw this exchange today as I checked a few threads without logging in. After I logged in, the OP was no longer a burr in my saddle blanket.

Thread: micro switch
01/07/2020 15:56:25

Hi Ian, If possible, I would recommend changing to a modern enclosed microswitch. I have used Omron's D2F series in many projects with great success. About 1 UK pound retail, probably 50 p or less each from an Omron distributor in UK. Many styles of lever and terminals available, several operating forces and volt / amp combinations up to 5A at 250 VAC. These are good units with small size high performance and quality at a good price. No connection to Omron except as a very satisfied user. (if you still use a computer mouse chances are it has two D2F's in it, or a cheap knockoff of one - billions of them in service worldwide)


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
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