Member postings for Dennis WA

Joe you wrote:

The only modelling club worth 'something' is the Centurion Society Of Model Engineers - located at 193 Kwikkie Cres, Zwartkop, Centurion, Pretoria direction - google for contact info - the members may have a better idea of sources on interest. No modelling club in JHB

For the record the Rand Society of Model Engineers (founded 1934) is still operating in Florida Park, 15 kilometers West of the Johannesburg City Centre. It is open to the general public on every Sunday. There are 1200 metres of multigauge track (3,5", 5' and 7,25" ).   Like our colleagues in Centurion, the members are the best guide to suppliers and sources of services, such as specialist foundries.

Dennis (a member of RSME)

Edited By Dennis WA on 03/06/2022 14:09:25

Edited By Dennis WA on 03/06/2022 14:09:50

Thank you all for taking the time to provide insightful feedback.

It is clear that on a S7 the rigidity of the cutting tool mounting is critical. Then the selection of the appropriate insert. Then the selection of d.o.c., feed rate etc.

In the past looking for good finish on my S7, I have followed the suggestions made. I found that it often does not work first time around in producing a good finish. So tweaking is required.

Note that I have never tried to use a minimum d.o.c.. I found the comments on small d.o.c. interesting.

Dennis

A fellow club member who has a Myford S7 wants know what is the minimum depth of cut he can use to get an excellent finish when using inserts on steel.

He was aware of tables published, but I have not seen them. Can anyone enlighten us?

Dennis

Pocketmags copy available! Thanks to Beth for keeping her promise.

See also the 2017 thread by Andrew Tinsley

https://www.model-engineer.co.uk/forums/postings.asp?th=129638

Thanks Dave. Tubal Cain covered the build in 1975 (ME Vol 141) which became the book.

I now have a bound copy of Vol 141. It seems there were no other posts highlighting errors or construction tips.

Dennis

I am about to start building a 9H. The complete set of castings etc came from a deceased estate and includes the pump and governor, plus drawings.

Searching Bill Phillips and Chris Orchard's ME index and this site has not turned up any construction notes or observations.

Are there any that I have missed?

Thanks

Dennis

DC31k writes above: There is another thread on here mentioning an article on Schlesinger limits by a South African guy which can no longer be found (I believe it was somewhat turned into an article for MEW). If this were also located again, it would be good to host it.

The article is : "No limits: George Schlesinger" by Alan Bester.

MEW No 246. Autumn 2016

Richard

I used a piece of coated steel approximately 150x80x1.6 mm that was to hand.

Dennis

Duplicate post removed

Edited By Dennis WA on 08/04/2020 22:36:40

Richard,

I am sure you have thought about this, but do not get paint on any surface of the gap bed that sits on, or is adjacent to, the main lathe bed. To preserve the accuracy of the machine when reinstalling the gap bed it must be clean and go in the exact same position.

My Student stands on a concrete floor with some shim under one corner to get it firm and level. I have no problems with accuracy of the finished product.

If you want to raise your student you could use heavy steel channel across each end. My Myford Super 7 ( which is on a factory steel cabinet with tray) is raised like this. I also have no problems with its accuracy.

I have a high precision level which helped to ensure the lathe beds were not twisted. I machined test bars to confirm the lathes cut the same dimension near the chuck and at the end of the bars near the tailstock.

Good to see you are able to use the Student.

Dennis

Howard The grub screw provides an adjustable stop for the gear quadrant that meshes with the pinion on the shaft carrying the pointer.

Conclusion: There is no provision for zeroing the pointer with the dial.

I opened the movement after removing the bezel using a sharp blade. It needed a clean and I reset the pointer to rest at +20 and it now goes round to -25 without difficulty. More than enough range for me to check the deflection of crankshaft webs, which indicates a shaft running out of true.

Problem solved!

Dennis

Thanks Howard

Slacking the grub screw was the first thing I tried. No effect. I could not unscrew it from the body either.

I will try and see if the bezel is seized on the body preventing rotation.

Dennis

Bazyle

Thanks for the comments. I have watch and clock tools and repair experience. I cannot get the bezel off without resorting to force, which is not an option!

Dennis

Thanks Ady

My problem is that I cannot rotate the dial. How does one do this so as to set the pointer where you want it?

There is a screw in the body, but I have not been able to work out what it does.

Dennis

Richard...Phil has done a great job in helping you, including emphasing the safety aspects.

I agree with Dave that you have sorted it out as you have progressed and are learning as you go.

I have a 1964 Student Mk 1.5 and have followed the thread with great interest. At no stage could I add anything to what you had got from other folk.

Congratulations on your progress - enjoy using the Student and good luck with your studies.

Dennis

Is it possible to turn the dial so that the reading covers the positive and negative movement equally? The picture below shows what I want. The picture with the yellow arrows shows what I have : an anti-clockwise movement from rest position at -18 to full deflection at -5.

Thanks

Dennis

Edited By Dennis WA on 08/04/2020 10:36:01

Andrew

I am really pleased that you are going to take a short break and then rejoin us!

All the best

Dennis

Sadly your withdrawal harms the benefit that most of us derive from this forum. It only benefits those who believe they can ignore good manners when expressing their opinion. 

Edited By Dennis WA on 18/07/2019 15:32:42

Edited By Dennis WA on 18/07/2019 15:33:53

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