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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: Safety of phone chargers
22/04/2019 15:13:44

If you think phones are a charging capacity issue - just wait until electric cars come down in price and up in battery capacity to become really popular. No way gen capacity in cities will be able to catch up with the demand.

Thread: Imperial Tube
22/04/2019 04:38:19

JB and Paul - no idea what clue you mean. All I see under title is "All topics / Latest posts"

I see OP responded with OD and ID and length after your posts. I take it he's in UK somewhere.

21/04/2019 20:09:58

ID? OD? Length? material? some hints would help. Also what country / region are you in?

Thread: Where's my Dykem blue gone - there's no need to read this
20/04/2019 01:28:47

What shop? laugh

Thread: Presumably this is done using CNC... but even so its impressive
20/04/2019 01:26:10

It is microns and it is CNC. Lots of shops in China can do that level of matching particularly in moulds. However it is time consuming and expensive and of very little practical use except for very small parts.

One thing that mouldmakers do in China that has been a continuous annoyance to me in industry for many many years is the use of 4 locators between inserts, at the corners, as the test piece in the video shows. To restrict all the degrees of freedom of the inserts, only two locators, at diagonal corners, and a flat area on the parting line are needed. To make 2 totally unnecessary close fitted locators at the other two corners is a waste of money and in many cases leads to confusion and errors at final fit up and bluing-in of the mould. Several times I have seen a toolmaker miss his bearings and grind off the wrong locator causing a loose fitting mould insert, and unless it could be welded, could result in a $20,000 to $50,000 insert being scrapped. I gave up arguing with mouldmakers in China about this around 25 years ago. It is just a tradesman's bad habit that probably started very early on in the development of the trade in China. As great as some of these guys are, they keep doing the 4 locator thing over and over again despite frequent fit cockups and despite about 100,000 Western toolmaking / tool design guys like me asking them for 35 years PLEASE don't do it! I may as well talk to the wall.

When I first started programming CNC wire edm machines for mouldmaking I got a panicky call from a toolmaker in our company shop "the four insert sets we just cut don't fit the blocks. Your programs must have been rubbish". I went down ASAP, heart in mouth of course. Sure enough, they didn't fit. I did notice that he had blued them as we usually did when machining them conventionally. Bystanders were coming around for a look at the disaster. As a last hope of the off chance I'd get lucky, I said "can we try cleaning off the blue?" We did, and the inserts fit, dropping in by gravity with a light suction sound. Everybody on the toolmaking team was quite shocked. I resumed breathing, because I still had a job.

You may say oh there was a speck of dust the cleaning cleared out, or a tiny chip, but this was the same case on ALL FOUR sets of inserts and blocks...... I'm not blowing my own horn, but my programs were proved right. But just as important, if not more important, the wire edm operator was damn good and very careful about all parameters, and the guys at Japax that built that old wire edm machine in the early 1980's really knew their stuff.

With this team and that machine, that sort of ultra close fits in our tools became our shop standard - 30 odd years ago in Toronto Canada.

Thread: Hard to please OAPs
17/04/2019 14:13:10
Posted by V8Eng on 17/04/2019 13:53:58:

life is for living so stop moaning and live it as best you can, it’s not a rehearsal you know.

Well said! wise words to keep in mind in life.

Thread: 5 inch 0-4-0 Shunter
17/04/2019 14:11:11

Looks great Ron! Good luck with the first running. Be sure to have a bystander take some video when you are whizzing by.

Thread: Removing a grub screw
16/04/2019 22:00:15

You don't have to be left handed, but it helps! smiley

Just joking, hope you don't mind my pulling yer leg!

Seriously, LH drills will often loosen and back out stuck or broken screws without any other brutish attention. When I bought my few, about 5 sizes in total, they only cost about $8.00 total from an industrial tool supplier . They did not cost any more than normal twist drills at that time. I kept them in a plastic container separate from other drills and marked LH. Over the years they have simplified the removal of LOTS of difficult stuck fasteners with no damage to the items they were in, so in my opinion, well worth having, and good value for money too.

16/04/2019 20:59:56

Mick - LH drills are very handy for repairs on the port shafts and engines of twin screw ships and boats.

Also very handy for steering gear repairs on cars and trucks in Canada and USA. (LHD)

Thread: Printing small parts for car restoration
16/04/2019 00:20:18

Bear in mind that if you 3D print ABS by the FDM process it usually ends up about 70% as strong as injection moulded ABS parts even if made really well with great inter-layer bonding.

If you buy a higher end printer you could print in polycarbonate with various reinforcing fillers including carbon fibre - these parts are very durable- but the print machine and materials cost far more than ABS.

If you are doing functional repairs that pass casual inspection you could use 3D printed parts. If you are restoring toward a competition, 3D printing will likely not cut the mustard.

Stereolithography can make beautifully detailed accurate parts but the resin used is too brittle for say door handles. Might be OK for an interior vent or button cover but if someone belts it or touches it on a cold day it will likely break.

Underhood parts for prototyping are made every day in high heat nylon by SLS process, including intake manifolds and coolant system parts. They can not be finished to a gloss polish though, and are usually sand-like finish in off white colour. Very useful for development/ racing / prototyping but again not going to pass inspection at a concours d' elegance.

Thread: Missing Strip Spring Needed
13/04/2019 01:38:01

If making the spring in 1080 and austempering, do not overbend - make to pattern. Do not scratch or mark the surfaces of the stock.

Austempering according to the pros that do it every day for industry:

**LINK**

12/04/2019 16:16:18

AISI 1080 steel strip, austemper after forming. Varnish after heat treat for corrosion protection.

Thread: French Mystery Tool
12/04/2019 13:55:19
Posted by Georgineer on 12/04/2019 11:33:43:

It's a grostling iron.

George

It may be, but the snibs are different than the irons on the ACME grostling machine common in the USA. 

Edited By Jeff Dayman on 12/04/2019 13:56:55

12/04/2019 08:56:48

Martin you are thinking newer style tire machines - I'm thinking ones from 1930's - they were very different and there were many styles and gimmicks.

Thread: Problem with penetrating oil can
12/04/2019 08:54:38

I used to buy War Dept 39+1 stuff in 2 or 4 quart cans and used a squeeze trigger bottle to apply it. This was less expensive than aerosol cans and avoided their nozzle / tube issues as you describe. Last few years have changed to "non solid handheld hex head fastener removal tool" initials L W brand penetrating oil which does a better job on rusty old junk and does not leave a nasty residue as the other does. Also their nozzle works!

Thread: What Did You Do Today 2019
11/04/2019 22:27:29
Posted by Bill Phinn on 08/04/2019 22:33:33:
Posted by Jim Young 2 on 31/03/2019 17:58:10:

Re brittle strimmer cord, I moaned at my local mower repair place about the short life of coils of strimmer cord. They recommended storing in an ice cream tub in water. Seems to help but of course it soon dries out when left on the strimmer.

"Jim, I've been using Stihl strimmer line for the last 38 years, and never had a problem with it even when used with my relatively powerful Stihl KM130 brush cutter. I've never had to keep it moist or resort to any other method to reduce brittleness, because it really isn't brittle unless I make the mistake of trying to cut excessively tough material with it such as thick brambles, which, as the manufacturer advises, I would normally use a (Stihl) metal blade to cut.

Just make sure you buy the right diameter line for whatever cutting head you're using. I use 2.4mm cord (orange coloured) but you may need a thinner one. Your manual should say."

Water may make a difference to brittleness if the cord is made of nylon. Not sure about UK and Europe but most trimmer cord here is not nylon, it is HDPE or LDPE outer with HDPE inner. Water will make no difference to PE (polyethylene) of any kind. Sun exposure may damage any plastic trimmer cord.

Best trimmer cord I have used is the 4-ribbed style shown in fig 5 page 2 in the patent at the link below. I have a big spool of it made or orange HDPE like Stihl line but I see it has been superceded in stores locally by simpler square or hexagonal extruded line.

**LINK**

Edited By Jeff Dayman on 11/04/2019 22:28:21

Thread: French Mystery Tool
11/04/2019 22:12:58

It may be for a tire machine, to spread old-style narrow tires or maybe guide them onto rims. I remember vaguely an attachment shaped like this on my grandfather's old tire machine which dated from the 1930's.

Or, could be some sort of guide to ease electrical cable or soft pipe into channels of some kind.

Thread: A close shave or why safety glasses are a must
09/04/2019 21:56:51

All good points about glasses, shields and other PPE. Can't be too careful especially with eyes.

But when I first saw Stew's picture with the embedded cutter, I thought "why the heck is Stew Dremeling the shop ceiling?" face 1

Thread: LED light array
08/04/2019 20:05:21

Hi Clive, Three observations about the clear LED cover that got the burnt spots - a) I think the manufacturer used polystyrene rather than polycarbonate for the shield, and it probably is not very flame retardant, maybe rated UL94 HB at best , where it should be UL94 V0 or 5VA rated material b) they placed the LED's far too close to the clear shield c) They may have been driving the LED's with way too much current. 10-15 mA is lots for LED's, usually.

If you cut away the burnt clear material over the LED's it will be an improvement on the flame retardency of the enclosure!

Chinese LED fixture makers get away with a lot. The better ones are fine, but there are some time bombs out there.

A UL or European agency approval sticker is a good thing to look for when buying an LED fixture but there are lots of fake stickers around, even ones with convincing hologram graphics that look real. If spending considerable money, I'd recommend calling the UL or Euro agency hot line and ask if the file number on the UL or agency sticker matches the product ID and serial number on the LED products. If they don't match, don't buy them. I've found some unsafe fakes that were on UL's black list by this method, on sale openly at a large hardware chain store here in Canada.

Thread: Just desserts
07/04/2019 14:59:20

This thread has nothing to do with model engineering or workshop activities. Suggest you post these sorts of unrelated things elsewhere.

Moderators please?

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