Possible new ideas for Model Engineers’ Workshop

[Anonymous]

Posted by Michael Green 2 on 15/09/2016 13:02:37:

My biggest concern with model engineering is actually CNC – so much can be done with a CNC lathe or mill (or even 3D printer) that a lot of the jigs, fixtures and special tools that used to be made for doing 'interesting work' are discontinued or have been forgotten.

I take it you've never actually used a CNC machine tool? I make as much, or more, jigging for my CNC mill as I do for the manual mills. And jigging for the CNC mill requires more thinking ahead than that for manual milling. If you accidentally have a clamp in the way with a manual mill you can stop and do something about. The same is true of a CNC mill, except you only find out after the crash.

Regarding hands on gear cutting, why teach something that almost nobody is going to use, at least commercially? A couple of years ago at a show I talked to a young man who worked for Mercedes high performance transmission group, ie, motor racing and Mercedes AMG. I started quizzing him about the details of gear design, and he said "oh we don't deal with that, we let the gear supplier sort it out".

Having said the above I am about to submit a short article to MEW that highlights a pre-CNC industrial technique.

Andrew

[Michael Green 2Participant @michaelgreen2]

Not sure what using a CNC machine tool has to do with vanishing tools and techniques but for the record in my day job I have programmed robots and PLCs, installed/ maintained CNC machinery and direct those that do program them. Enough of that.

The point that I was trying to make is that when you have a CNC machine, it's easy to tell it that you want a particular profile or radius in a location and the machine will do what it is told. However, for example how do you cut an interrupted R600 radius on a (small to medium) manual machine? – it must be able to be done as it has been done before.

Most hobby machinists have basic manual machines – a lot of the time a CNC machine is generally a build project in itself. Only a few have professional or semi-professional type machines with tool change and integrated 4th/ 5th axis and all the bells and whistles that I see in the workplace. A lot of the old techniques that commercially are redundant because of CNC are still relevant to a hobby machinist because they have not got that technology on tap.

I despair of some of the engineering trainees we get because some don't even know what a drill press is. There seems to be a view that you draw something up, send it out to a subbie and it comes back perfect. No thought about whether the design is good, easily/ cheaply made or even necessary. I don't have thousands of dollars/ pounds to get a specialist to make up change gears for my machines so I had to learn how to cut them myself. Magazines like MEW and HSM (Home Shop Machinist – a US publication) are probably one of the few current reliable sources for documenting 'old' techniques.

It is getting so weird that a few years back I was in the situation where I was doing things on my manual machines at home because the fitters at work did not have the skills/ equipment to do it there and CNC equipped subcontractors would have charged an arm and a leg for 15 minutes work. (It's weird because I am not trade trained and work mainly in an office – I just seem to be the person who solves the problems)

So at the risk of repeating myself, I would like to see some short articles talking about techniques and equipment that were used before CNC or are a non-CNC alternative that may have application in a home workshop.

Michael

[I.M. OUTAHEREParticipant @i-m-outahere]

Oddly enough in a post about setting up a vee slot to align with a saw slot there was a mention of Hicky (icky) balls and as I'm not a toolmaker i know nothing of them so some explanation would be nice , it could also be an article on toolmakers buttons and how to use them .

CNC v Manual – i usually stay out of that argument as I don't own any CNC equipment, that being said i think both should have a regular monthly place in MEW and i think Neil has got the balance pretty much right .

I kind of like the cartoon like muddles and the stubb mandrel piece so maybe you could add a did you know or on this day in history section with interesting facts or useful formulae .

[Author]

Posts