Member postings for ChrisLH

Very nice.

But I didn't get the point being demonstrated by engagement of the wooden wheels. I hope it's not obvious to everyone bar me !

Thanks chaps, made my day.

Chris LH

Lushingtons ? New one on me, I've no idea what they are. Google was no help (beer, and sheds only).

There are two pegs which fit the large ali drum. In normal mode. They are fitted axially from underneath and connect two rotating drums. In low speed mode they are removed and refitted radially connecting the outer drum to the static partn of the machine. Hopefully this addresses the problem and you are able to see what is wrong. A full explanation would require drawings and diagrams.

A query slightly off piste regarding granite surface plates. My daughter was very pleased with her black granite kitchen work surfaces. I was however rather taken aback on being told to be carefull not to get it wet. And true enought the result of leaving a blob of water on the surface overnight was a darkened patch in the morning. Two thoughts ocurred to me. One - Is the granite used for surface plates a special waterproof grade. Two - if it's not waterproof does water absorbtion result in dimensional changes. Any ideas

Manfred,

You have a PM

TC has a chapter in his "Model Engineer's Handbook" on the subject. He doesn't say he has measured steam conditions in a particular case. He does say however that "a normal boiler will provide steam at about 0.88 dryness fraction"

I copied John P's set up using my own design of dividing head and a smaller, vertical milling machine. It works very well. Photo in my Album. I know nothing about the electronics unit bought from Richard Bartlett some years ago except how to make use of it. Thank yoy John.

Myford 7 leadscrews are 8 tpi and 0.750 OD. If your leadscrew is the same OD a spare Myford tdi gear may suit ?

Jason,

I misguidedly thought that "epoxy putty" was how you would describe araldite, etc. in the US. Here's a link to the video I watched, you need training at an audio gym before watching as the vocal delivery is super fast.

https://www.youtube.com/watch?v=R3r0UZ7txzs (I haven't yet fathomed how to paste an automatic link)

The JBWeld product tested was "SteelStik". Is this the grade used by Ramon, yourself and other advocates ?

Edited By JasonB on 20/11/2022 12:15:36

And rear wheel drive Peugeot cars up until they went FWD, don't know how many start worms though.

Noel S,

Fly mechanism driven by a fast worm is common in music box clokwork where it's self starting. Less crude construction and finish though.

Curiously OD of the worm has a double taper - but in the wrong direction if you were hoping to maximise worm/wheel contact. So maybe they were trying to minimise the w/w contact so that pitch mismatch wouldn't stop the job ?

Gorilla 6.99 852

POR-15 32.28 556

Pratley 8.95 435

Loctite 7.98 434

EP-400 11.99 347

A+B 18.13 271

Noted that Loctite, a reputable brans did badly and you don't necessarily get high quality for high prices

Relative price Relative shear strength

KBS Numetal 22.95 1615

JB Weld 4.98 1264

Hercules 18.16 1247

Oatey 6.94 1016

PC7 12.70 954

Quicksteel 6.35 938.

I watched a video some months ago on this subject. The guy did tests on various "epoxy putties" but it was US based so may apply to some brands not available here. Here is a summary but bear in mind that the test conditions probabaly would not satisfy stringent standards.

Table follows in second post.

SOD,

Did you mean "speed" of gravity. ? My contact with same was always in terms of "acceleration due to ....". I've never even wondered about its speed ! Perhaps it comes into astronomy and is not important for my main interest, mechanical engineering.

Just pick a nit to death, are not all pendulums "compound" since we can not pack mass into a point suspended on a weightless rod as demanded by the definition of a simple pendulum ? Just asking.

For those who are not quite "on the ball", "tuppence short of a shilling".

Never seen one of these.

Genuine curiosity and ignorance, what are the features that make it a jig borer rather than a vertical miller ?

Hello Julius,

I've just mugged up on posting photos so just for fun I'll complete the exercise. Top picture shows the raising arrangement in its normal state. The top disc with tommy bar holes is the "nut" The thinner disc below it is the "key". In the bottom photo the "nut" has been wound up the collum to give an end view of the Myford type key which engages the coarse screwthread. The "key" which engages the vertical keyway (which is just visible on the RH Side) is just a thick plate profiled with a tab projecting inwards from the bore. The "key" is normally prevented from rotating by a short dowel into the casting below. The dowel can be removed should the need arise to rotate the collumn.