Member postings for BW

Where do I find this please ?

See first photo in this article. Not the same tool, but a similar idea, and much easier to understand.

http://www.haythornthwaite.com/133%20Spherical%20Turning.pdf

Am curious.

Anybody ever seen one of these things in the flesh ?

http://www.ebay.com.au/itm/6-In-1-Multi-Metal-Mini-Wood-Lathe-Motorized-Jig-saw-Grinder-Driller-Milling-Set/322027988900

What materials can they realistically cut ?

I've got a vague memory of seeing a photo of a dremel type diamond disc stuck onto a computer drive and then used to sharpen things.

Bill

In the latest new there is a description of a tool post by Richard Smith, page 35.

If the tool post is pivoted by using a spanner on the flats at the base of the thread then what is the purpose of the big handle that fits in the hole at the top of the post ?

At the moment am struggling to understand the purpose of this handle.

Bill

Yes ! Good idea.

I'd be interested in a DVD

Bill

Neil,

Ironically, I usually get a superb finish using that tool, even on cruddy "black bar". I know it as a "vertical shear tool" or a "shear tool" - well documented here http://www.gadgetbuilder.com/VerticalShearBit.html

It removes cuttings as fine as steel wool - quite amazing - it was my first ever succesful tool grind.

To date I have been completely unable to get a good finish with the standard round end HSS tool bit.

I usually get a good finish if I turn a knife tool around to almost rub - as mentioned by Sparey and Westbury in their books - I can also get a good finish if I turn a tangential tool around by 90 degrees to turn it into a shear tool, or put a big radius on the cutting corner, but a conventional round grind HSS bit - never worked for me.

......... and thanks very much to everyone for all the replies on the skiving.

This is called gear skiving and I think it is amazing ............ https://www.youtube.com/watch?v=XUDkQQJ8Uyw there are various other videos on youtube.

Bill

I saw a post a while back on this forum about end mill type gear cutters.

A bit like a corner rounding end mill cutter only it cuts the profiles between the teeth.

Thought it was a stunning idea and am aware that somebody in USA has a patent on it .

I reckon people must have tried diy versions but have found very few references in google - I did find on google a mention of a video by John Stevenson - is that the same chap that posts on this forum ?

Am puzzled that I havent seen much about this in forums, blogs and old books - is it something that would impress a newbie like me but more experienced people instantly see various traps ?

Bill

I get the impression that not many people use this technique - only a couple of videos on youtube and not much in forums and blogs.

It seems like a terrific idea to me ........ why is it not popular ?

Bill

What books should I be reading to be able to understand material strengths & properties and be able to intuitively know things like this in a few years time ?

Bill

Thanks for replies.

Corrected link

http://www.model-engineer.co.uk/editorial/page.asp?p=1278 look through the index and see the photo labelled page 80

Hopper, I've looked at the photos again and your comments make sense to me. Will now read the article again and with this new understanding the photos and the drawings will make more sense.

Will try to better understand the two pivot points as well.

Thanks again.

Bill

Has anybody made the ball turner described by David Fenner in the 25 year anniversary special edition ?

I've read the article a couple of times now and I don't "get it", I don't understand what the piece attached to the back of the cutter is for and why its connected to the other arm that comes out of the back of the main block.

Its a repeat of the article in volume 127 July 2007

Photo on this page its the article that starts on page 80.

model-engineer.co.UK/editorial/page.asp?p=1278#

Hello ........ Am wondering what books / websites / threads / back issues of magazines I should be reading to get a better understanding of what I can and cannot use mild steel for and when I should start considering other materials ...........

For example - I've made a copy of my lathe nose - 1.5" diameter x 8tpi out of mild steel, what should I be reading to find out whether or not I could use that in a diy wood lathe - am guessing that things like that should be hardened high carbon steel ? Similarly have made a couple of morse tapers in mild steel - they seem to work okay but I think the bought ones I've got are all hardened steel.

Would a "light use" hobbyist, like me, be able to get away with using mild steel for some things whereas in an industrial situation things like these would always be made of stronger harder materials ?

What logic do others apply when deciding what materials to use to make a part ?

Bill

Found this

WWW.cncintheworkshop.com - website for the current CNC articles in mew

Didn't realise that the website gives access to all articles from issue 203 onwards

I'd like to better understand what cnc machines are and what they do, I've ordered all of the available books in the Victorian public library system.

Is there a Sparey or a Harold Hall equivalent who writes introductory books for cnc machines and 3d printers ?

Any mugs guides or good introductory forum threads or web pages you can recommend ?

Am wary of buying a book that might turn out to be a dry as dust library of computer codes.

Regards

Bill

OK,

Please ignore previous post.

Found a heap of 1/5" timing wheels up to 72 teeth here http://www.globalindustrial.com/g/motors/timing-belts/aluminum-timing-belt-pulleys/XL-1-5-pitch

So as per Michael G's post can see how to run a hybrid sysem with a 21 drives XX joined onto a standard change wheel.

Thankyou Michael - good idea - have bought a 21 tooth for $5.47

Bill

I've been pondering this 21 tooth pulley and the following photo posted by John S.

I found this link for different belt lengths - https://sdp-si.com/eStore/..%5Css%5CPDF%5C15501003.pdf - and I note one can buy the belt by the metre and make your own custom belt lengths, cannot find many different sized big wheels (found a few up to 36 teeth nothing bigger) to stick at the other end of the belt from the 21 tooth - have concluded that it would be a pain to make them. What should I search for please ? Are these standard items I would know more about if I was conversant with cnc machines and 3d printers ?

Bill

From Issue 204 : These should be cut by thread milling, using the leadscrew to turn the mandrel with the lathe switched off. To dothis a toolpost milling spindle and a leadscrew handwheel such as that described by Alastair Sinclair (Model Engineer’s Workshop, issue 91, July 2003) will be needed.

Am curious ......... what would the milling cutter look like in the thread milling process described above ? Would it be a very skinny vee shaped end mill ? or a chunky slitting saw with a vee shaped cutting profile ?

Hey Les,

That issue has been bugging me too, Windows Vista, I think its similar to Windows 7.

Do you have to copy an entire directory or just a few files ?

If you do this sort of thing with any program do you have to somehow tell the computer to look in the new directory or does it simply just find the files wherever they are ?

I dont know much about computers

Bill

OK,

I contacted the Lathegears author.

Download for PC available here

9dt553xj8vnwzyf/LGV1.2.exe?dl=0 >**LINK**

Why I think its so good ............

You can set a maximum error ie 0.3% and it will only calculate combinations inside that tolerance

You can include all gearbox ratios as well as all change gears

You can specify certain gears must stay in certain positions.

If no combination exists it will calculate the number of teeth required on the missing gear

Will calculate both metric and imperial threads for both metric and imperial lathes

Will output all results to a file on PC and you can then copy and paste or print or do further calcs in excel.

Bill