Member postings for Sam Stones

These animated projects really fascinate me.

Therefore, (as Devil's advocate), does the back EMF work 'for' or 'against' the solenoid motor's performance?

Or, does it produce lots of radio interference and burnt out contacts?

Just curious.

Regards,

Sam

Would adding a diode across the coils/contacts have any benefit?

Thanks Nick.

We could form a mutual admiration society, all welcome?

Sam

It's reassuring to know that if I accidentally swallow my chewing gum, it won't solidify.

Sam

Hats off, Nick.

A great profile and what a wealth of information on your website.

I wonder if other members will be spurred on to open up their own profiles.

Regards,

Sam

Nick wrote ...

Absolutely! Just click "settings" at the top of this page and fill in your credentials.

It took a bit for me to find it but it's there.

Then, why not click on 'My Profile' to add the stuff you hide under your bushel?

Edited By Sam Stones on 05/11/2018 23:11:38

Although many Forum members don't like the idea, including a few details in your profile might help too Michael.

Regards,

Sam

Post (i.e. later than) homunculus

Hi James J 1,

I'm going to send you a PM within the next 24 hours.

regards,

Sam

I have to admit Mick, I’ve only ever taken the time to examine the Myford I owned.

Even the machines in the toolroom (except for the ball screws on the Cincinnati) missed out.

Apologies to Robin for my digression.

Neil,

As I recall, those gear covers were die-cast.

Swinging on the hinges when the cover was open invited problems.

Regards to all,

Sam

Expected top in Melbourne, a comfortable 26 degrees.

... Posted By Mick B1

... Well, I'd've thought that was the right way to do it - accurate, strong and wear-resistant.

Yes Mick!

Another plus for Myford.

‘You'll See It When You Believe It’ - Wayne W. Dyer.

Regards,

Sam

Edited By Sam Stones on 21/10/2018 19:33:46

Simple knurling is a less obvious use for thread chasers.

Allowing for the helix angle, grip the chaser sideways in the tool post. As here.

Rotate the work in 60° steps, each time shaving grooves across/along the workpiece.

If you don’t have a chaser, you can make one up using half of a screw thread as here.

The piece (half of a screw) could be glued in place or brazed. In this instance, a steel screw suitable hardened would last longer, but brazing would interfere with the degree of hardening.

In this photograph is one I prepared earlier - about twenty five years earlier.

Knurling the brass knob by the above method took only a couple of minutes. The red and the black knobs were commercial mouldings intended to be pressed onto Alan screw heads.

Regards,

Sam

I was quite surprised to note, when I added a Myford (Norton) gear box and new leadscrew to my ML7, that the leadscrew was thread rolled. That was in about '65.

Sam

A lack of fillet radii - cannot be over stressed.

Okay, I am playing with words here but in the light of the above remark …

The radius is more theory than practice …

and with due respect to Hopper (assuming we are referring to thread root and not thread crest), in the many years while I was ‘doing’ technical service, the vast number of moulded products that failed in service, failed through lack of adequate fillet radiusing. This included a wide variety of threaded components, e.g. caps, closures, water filter canisters, and on through a wide assortment of moulded parts, big and small.

The source of the problem was often tool design or mould-making oversight, i.e. sharp edges left on the external corners of mould cores and profiles.

For further reading - Google ‘Fillet radii’ and a myriad of examples will appear.

My apologies if I’ve covered this somewhere else.

Regards,

Sam 

BTW – when I bought my (now long gone) ML7, it came with a box of thread chasers, mostly with tangs for hand chasing.

That's a fascinating video of pen making, especially the method of closing the lathe collet.   

Edited By Sam Stones on 20/10/2018 00:19:38

Although largely intuitive to many of us, it is worth mentioning in this context (and for lathe work in general), that the stiffness (resistance to bending) of a round bar, projecting from a chuck (cantilever style) is nonlinear in relation to both its length and its diameter.

Although more complex when considering for example a fluted drill, the stiffness of a round bar relates to the cube of the length and the fourth power of the diameter.

Put simply …

Halving the length (overhang) increases the bending resistance by eight times.

Halving the diameter decreases the bending resistance by sixteen.

I'm pleased to know Roger, that your drilling project was a success.

Regards,

Sam

The three-cornered scraper in my original set of three M&W scrapers tended to be a bit clumsy for small holes.

My real standby, especially for deburring tiny holes, was to modify the tip of a three-cornered needle file; i.e grind off the teeth and bring each flat down to a shallow (pyramid) point. A breeze to sharpen too!

Unlike the results from a standard 60 degree centre drill however, deburring threaded holes this way can leave a less-than-true (none symmetrical) result.

Sam

Another gem of yours Michael! That's just how I imagined.

Where do you find them?

Sam

A great link too Tim. Thank you.

May be a bit late in the day Roger but ...

I'd use the tool post instead of the tail stock chuck, while shaping a HSS tool bit with very acute ‘clearance’ angles. Alternatively, grind off half a (scrap) drill and fit that into the tool post.

I've never used a graver, but that could produce the necessary conical concavity.

Sam

“What’s this?” said our primary school teacher holding up a reddish orange piece of fruit. It was back in the mid-forties when food in Britain was still rationed and lacking variety.

Being a smart seven year old, I knew the answer immediately.

“It’s a tamaydah!” I called out with confidence, having heard of them either on the radio or via a black and white film (movie) featuring Bob Hope and Lou Costello.

It was actually a pomegranate not an American tomato.

I’d go for hard ‘G’ as in ‘gib me cookies’.

Sam

Despite having lived in Melbourne since 1972, and it may be hard to believe, but this was my very first visit to see an MSMEE exhibition.

However, I was not a complete stranger to the group. Back in the 70's, when I began building the John Stevens’ skeleton clock, I had taken the opportunity to attend a couple of their meetings. They were well worth the experience.

For this particular occasion, I chose to go on Sunday in time for the 10 am opening. It was also one of those Goldilocks mornings, which Melbourne can turn on.

Overall, there was clear evidence and according to the President’s welcoming note …

As the icons of the 19^th and 20^th century such as steam and internal combustion engines fade into history, new technologies take their place such as electromotive vehicles, 3 dimensional printing, alternative fuels and energy sources, LED lighting and ever increasing levels of automation and computerised control …

If you skip through my photo album however, you can see there is little doubt about the skill, patience, and imagination from young and not so young devotees.

The album comprises single frame SnapShots from a small number of video files. My apologies for those images with camera shake. I elected to support the camera on a monopod, rather than luging around my much heavier tripod. The monopod happens to be much lighter, is easier and quicker to adjust for height but, in this instance, didn’t fully alleviate the jerk’s jerks.

My thanks to John McNamara (just peeping over the shoulder's of two visitors), for bringing this event to my/our attention.

Regards to all,

Sam

MSMEE link …

**LINK**

Thanks John.

I'll look out for you. Probably Sunday.

Regards,

Sam