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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: M4 x 0.75mm pitch CSk machine screws
22/08/2019 22:12:28

Are the threads in castings, bar, sheetmetal? (not familiar at all with Cozette blowers)

How deep / how many threads are there in the material?

What is the material the threads are in?

How many screws / holes are there?

Thread: Part built Allchin 1.5 inch
22/08/2019 22:08:12

Derek you have another PM.

Thread: M4 x 0.75mm pitch CSk machine screws
22/08/2019 21:08:38

Some idea of the application would help responders offer some remedial ideas.

If they are for panels in sheetmetal work, and only a few threads, there may be ways to use more available fasteners.

.75 mm pitch ( .0295" pitch) is very close to 34 tpi (.0294" )) . If you have a lathe than can cut 34 tpi you could make your own screws.

34 tpi (.0294" pitch) is close to 32 tpi (.0312" pitch) , only .0017" difference in 32 to 34 pitch, and 4.0 dia is .157". A stock #8-32 machine screw is .164 dia x 32 tpi. If not too many engaged threads are involved you could probably overtap the holes (if tapped) #8-32 and use #8-32 screws which are widely available in many materials, lengths, and head styles.

You could probably overtap the holes (if tapped) M4 x 0.7 and use M4 std screws, again if not too much thread engagement is needed. M4 are also available in lots of materials lengths and head styles.

If you can find some 3BA screws you could probably use them although their pitch is nominally 0.73mm not 0.75 so if there are a lot of engaged threads the screws might jam.

If you ever need to replace the screws in future years you might be glad you used #8-32 or M4 x 0.7 - BA screws are less and less available, it seems.

Edited By Jeff Dayman on 22/08/2019 21:09:18

Edited By Jeff Dayman on 22/08/2019 21:09:36

Edited By Jeff Dayman on 22/08/2019 21:11:54

Thread: Part built Allchin 1.5 inch
22/08/2019 20:07:28

Derek you have a PM just FYI.

Thread: Torx head variant or faulty batch?
21/08/2019 18:21:24
Posted by JasonB on 21/08/2019 15:23:34:
Posted by Clive Hartland on 21/08/2019 15:18:57:

My answer was to put a screwdriver against and wipe it out.

That's not the model engineers way of doing things Clive, you know you should have spent the next three years contemplating making an EDM machine to modify your existing toolssmile p

Edited By JasonB on 21/08/2019 15:24:07

Jason you say that like there's something wrong with doing it that way..... smiley

(I actually built an EDM, for this sort of thing and many other jobs, I guess that makes me a fastener-abusing viking heathen. Congrats to Clive with the screwdriver action against the dimple! You're welcome to share the fastener viking designation with me! Now where's my cutting torch and big hammer.......)

21/08/2019 14:35:03


How is a hex better under any circumstance than a Torx?

I would like to understand your problems with Torx.

From my armchair.


A hex socket fastener, if filled with rust and road grit in areas where salt is used on roads in winter, can often be opened/cleared with a small cape chisel quickly. Torx sockets are very hard to clear of rust and grit because of the tiny recesses at the lobes, and they must be cleared out to get a drive tool into the socket at correct depth. To add to this difficulty, for a while car designers were placing a lot of Torx head screws in recesses on the parts they fastened. This made it impossible to get a pair of vise grips / mole wrench over the head to remove them, or clear the sockets, or chisel the heads off. Torx socket screws under cars in areas with salted roads in winter turned many jobs which would normally be 10 minutes into many hours of work just to remove fasteners. This does no one any good, and customers resent having to pay for the hours.

In my opinion all fasteners used in exposed areas of cars trucks and machinery should be external tool drives only, ie hex bolt heads preferably, or external spline/multipoint heads, and be kept proud of mating surfaces for tool /cleanup access. this has not apparently been on the minds of car truck and machinery makers for a very long time.

I have seen Torx fasteners in industry for years and many firms I have worked for were lobbied hard by the manufacturer to force designers to use only Torx screws. They sold the firms on these things by promising low costs and longer assembly tool life. None of these savings actually came true, and in several cases with outdoor exposure as mentioned, resulting in impossible repairs, large dollar warranty claims caused serious losses.

The only people who ever benefitted from Torx fasteners were the manufacturers of them, in my opinion. There are several fastener drive systems far cheaper and just as good or better than Torx, but they are not marketed aggressively as Torx are. Just is just my opinion, but one based on many years exposure to Torx fasteners in industry using, specifying, and dealing with the outcomes of using them.

21/08/2019 02:02:23

The right side one looks like "the recess formerly known as Torx" laugh

Could be bad or worn tooling, could be a China oddity, could be a new and better

I'd be a whole lot happier with them if they looked like the left one or better yet were a straight hex socket.

I hate trying to deal with rusty Torx sockets on cars and other machines. Just my $0.02 worth. Ready and waiting to be slammed as usual by the armchair experts.

Thread: Water pump dimensions
20/08/2019 20:46:24


Thread: What coating/grease for long term tool storage
20/08/2019 20:44:47

White lithium spray grease is excellent if applied heavily at keeping rust at bay long term. However it is REALLY difficult to remove after 5 or 10 years. Just cleaned up some small engine bits I had storage with this stuff on them for 18 years, thought I was going to have to call the RCAF for an airstrike to get it off. Eventually laquer thinners shifted it.

Thread: Water pump dimensions
20/08/2019 20:39:09

Jason did you mean 1/2" stroke from a 1/4" offset eccentric? I think 1/2" stroke would work for the shown pump body, but not 1" stroke.

Thread: Hex Silver Steel/Tool Steel ??
20/08/2019 17:07:21

You can buy hex steel stock in many different sizes in North America in 1045 or 4140 steels. I'd be surprised if you can not get similar items in UK.

Thread: Part built Allchin 1.5 inch
20/08/2019 04:23:38

Hi Derek, you can also make your own shim washers. One way is to get some small sheets of copper in various thicknesses. Figure out your OD and ID needed. Drill the ID's in the sheet about 1.5 x the OD apart. Cut squares with the ID centred in them with tin snips. Snip the corners to make octagons then snip the corners again to make them roughly round, a bit bigger than the needed OD. Mount all these blanks on a bolt that fits the ID, and use washers and nuts to tighten the stack of blanks. Make the bolt long enough to hold all the blanks and leave a good bit of the thread for chucking in the lathe. Chuck the bolt and stack of blanks in the lathe and turn the OD of the whole stack and the end washers. Dismantle after turning and there's a drawer full of shim washers (and a sad looking set of end washers plus a bolt with iffy chucked threads - no extra charge for the last bit).

PS you can also punch the ID's if you have a hand punch or gasket punch if you'd rather not drill the copper sheets

Edited By Jeff Dayman on 20/08/2019 04:25:10

Thread: My Faircut Lathe
19/08/2019 04:06:05

duplicate post, sorry

Edited By Jeff Dayman on 19/08/2019 04:06:54

19/08/2019 04:06:04

Idea for heavy motor raising -

1. obtain box of beers and a big pack of good sausages for BBQ (get the good buns and mustard too)

2. invite rugby playing friends by for BBQ

3. apply beers and sausages

4. mention that you had some tennis playing friends by two week ago and they couldn't even lift a little motor we've got in the shop.....

Thread: 1935 Austin Seven Ruby ARQ
19/08/2019 03:57:51

I too had to spend some time in the throne room a while back in relation to leg surgery (achilles tendon) and meds afterward.

It would have been a lot easier to take if I'd had an orb and sceptre , like some other throne users....

Hope this gives you a chuckle Geoff - get well soon.

Thread: My Faircut Lathe
18/08/2019 21:29:43

First thoughts re motor placement -

1. cut a hole in the bench for the belt run, mount motor under bench. Make sheetmetal swarf/hand guard around belt. Belt would need to be lengthened to reach motor under bench.

2. Pivoting around the jackshaft, swing motor/frame/jackshaft up to a pre-made sturdy wood frame mounted to wall and roof under the rafters, little bit higher and to the right of the blue bike helmet.

Good luck. Glad you made some chips already!

Thread: Motorcycle General Discussion
17/08/2019 14:50:47

Ah, the old Flex-O-Matic rear brake rod, and WFO pipes! Lovely. The pipes are an effective early warning system to nearby drivers as JA said. Revolting paint job. Oh the follies of youth..... and no ashtray in sight

Pound / dollar store oil in the crankcase to save money, likely....

Edited By Jeff Dayman on 17/08/2019 14:51:47

Thread: Part built Allchin 1.5 inch
16/08/2019 20:23:41

Hi Derek, if you plan to operate the tractor in public at a club, who is the boiler inspector at the club? I'd talk to that inspector before doing anything with the screws, or worrying too much about it.

If you are using the tractor only at home and it has passed a hydraulic test, I don't think you have much to worry about. The only remaining concern MIGHT be loss of zinc in the brass screws over time if they are under the water line in the boiler. However this could take years to cause any issue and in many cases never happens - it depends a lot on your local water. If your house faucets don't have punky brass / de-zinc issues your boiler probably won't either.

Just food for thought.

Thread: Stuart Turner #1
16/08/2019 20:14:51

That's looking great John! Well done! I like the colour scheme as well.

Thread: Arkwright Scholarship
16/08/2019 02:26:24

Centre punch to start with? (w hardened / ground tip)

Gasket hammer (small ballpein hammer) with welded-on head?

Cold chisel? (w hardened / ground tip)

Screw plate? (the old kind, with lots of threaded holes, but maybe metric ones these days - very handy for cleaning up threads / thread sizing / shortening screws for all manner of projects)

Small vise? (milling ops, screw cutting, tapping, basic fitting - and usable for life if made well)

Keats style V blocks for lathe use? (welded up from angle iron, drilled etc.)

Finger plate w various clamps? Cheap as chips, million styles, handy for many ops. Could do some welded bits for it too.

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