Screwcutting Simplified

Hi Blowlamp

I don't know when it will appear.

I have not been asked to publish anything in Workshop.

I have no control over the distribution of drawings for this item.

Not even sure how it works as I have not really followed it.

 

regards David

 

Hi DC1,

For a moderator, surely the answer to any dilemma is to look at the number of viewings of any thread to judge how popular it is, and popularity must the major consideration in any well run forum.

This thread has been, barring the sad closure of Myford, the most read thread for sometime (with over fifteen and a half thousand readings), which surely must signify its popularity. Now compare this number of viewings to any complaints, a bit one sided in this case, then think to yourself if any moderation is really necessary, except perhaps to maintain common civility.

 

The device that is being discussed here could be of benefit to a great many Model Engineers, and a few "proper" ones too. It does not matter a jot where it's details are published, or why that choice was made, being partisan does not help passing information to others. Some comfort can be gained for this site, though, in the fact that it was announced here first, with I believe every intention of full publication. It seems that this is now unlikely, but it does not stop any reader from making their own when the time comes, wherever the details are finally published.

chriStephens

Hi Chris

I have never been against this thread.

I don't like moderating a thread.

Members should be able to behave themselves and only post if they have something relevant to say.

If they don't like a thread, why don't they just ignore it?

Could it be because they like causing trouble?

regards David

 

regards David

 

Chris,

 

If you read all the posts on this thread you will see that on several occasions it has been stated that the construction article for the Super7 version of the reversing gear has been sent to the publisher. The original schedule suggested in print early next year but there have been indications from the publisher that it might be moved forward so there is some hope that it might be available late this year. I'm not in contact with the publisher, my information comes from Gray, so I don't have any more information on the schedule beyond what I've stated here.

 

Anthony

Anthony,

 

Excellent news. Engineering in Miniature (EiM) will be sponsoring the Alexandra Palace (Ally Pally) exhibition from 20th to 22nd January (2012).

 

EiM is normally published on the third Thursday of each month, which falls on the day before the exhibition opens. So Gray's S7 article should appear in the February 2012 edition on 19th January.

 

Those of us who do not intend taking out an annual subscription, but nonetheless wish to follow Gray's article(s), can obtain a four month trial subscription from the publishers for £12 including UK postage. Unfortunately, the publishers do not appear to be as forward looking as MyHobbyStore, so digital/online subscriptions are not yet available.

 

Edward

Hi All,

 

Off topic I know but information affecting this thread,

 

Lets hope Gray's health will hold out so that he can complete the details of the ML7 version, he has only just returned to work after a life threatening illness, one of many illnesses he has suffered with over the past 6 years.

 

Rob

I have been aware of this health problem since the very beginning of this thread but decided to stay quiet about it.

 

Perhaps the loud mouths who have tried to interfere with this thread will now hang their heads in shame, however as always, I doubt it.

 

K

 

KWIL.

 

You should perhaps send a personal message to each of the relevant parties explaining your position more fully.

 

This is to avoid any misunderstandings about your reasons for posting within the thread.

 

 

Martin.

While we're waititing on the Myford units, Gray has been busy on the dog clutch reverser for the C3 lathe. Pictures in my album.

 

Differences in construction call for different solutions. Because the spindle gear is hard against the end of the headstock and to minimize the end space taken up the dog clutch has been modified again, even more compact 'though still working on the original principles. The disengagement rod has been moved to the front because of dificulties in installing it at the rear of the lathe, some benefits, some drawbacks. Also, because of space limitations, the operating lever has been moved to the right end of this short lathe so the disengagement rod now also serves as the control rod from the control lever.

 

The C3 is quite a small lathe so it's interesting to see how certain space issues have been resolved.

 

Anthony

Hi all,

 

Just to bring to "Blowlamp's" attention following his posting a few days ago (shown below), that he has a members message which contains Gray's email address should he wish to contact him direct.

 

" Hi David.

 

Rob

Hi All,

 

I accompanied Gray to his friends house in Hampshire today, Gray was paying his friend a visit to fit a present, it was one of the screw cutting clutches that he had made in the course of the current article.

 

Fitting the unit took about 30minutes but a cut out in the change wheel cover took roughly an hour, due to setting up. Gray then set about showing his friend how easy it was to set and machined a 5/8" X 26 TPI thread 1" long, which was accomplished in under 10 minutes.

 

Believe this or not, this is the first time Gray has seen his design in action, yet alone had a chance to use it, I myself was extremely impressed with how the unit worked and how effortless the whole process was.

 

Rob

Hi Robin

Sent you a PM

Bob

Hi Bob,

 

Sorry for the delay, I have been busy in the workshop for the past few days, and have not logged on during that time, I have sent you a reply.

 

Rob

Tried to post a couple of photos from Gray this morning and tried again just now. Won't post and I get a message:

Sorry - the website has an error and the page you requested cannot be displayed at this time. Please try again later.

 

Hope maybe the moderator can sort it out.

 

In any case, Gray sent me photos of the main housing for the reversing gear on the Asian C3 lathe. Gorgeous work. I'll try again to post them this evening and again tomorrow morning if necessary.

 

Those of you who have access to the American mag Home Shop Machinist might want to look at Gray's article in the latest issue, September/October, page 26, which I received a few days ago. He has an article on fitting a micrometer dial to the carriage hand wheel on a Myford S7 to read out longitudinal position. This involves gearing to correct for the fact that one turn of the wheel is not one inch or 25 millimeters of traverse. Much more convenient to use than the leadscrew hand wheel at the right end of the lathe. He's figured out the gearing to correctly read out for either decimal inches or millimeters. I wish it had both installed but your choice, one or the other, aint bad.

 

Very nice drawings and photos. If you get a chance to look at this article it will give you some idea of the quality of his construction articles and workmanship and a preview of what his dog clutch article should be like. Everything that comes my way makes me more eager to see the see the dog clutch article in reality rather than talking about it.

 

Anthony

Anthony,

You can imbed pictures, you don't have to use the photo folder.

 

Thank you John. You are correct, of course, and at one point I actually noticed that this is an option, but until the first time you use the method it doesn't automatically occur to you. Sort of a Catch 22, dontcha know.

 

So, unfortunately, now that I've clicked on the "Insert Image" button it turns out that the options are to insert from your own ME Album on this web site, to which I haven't been able to post the photos, or from an outside URL. As I don't have a web site where the photos are parked it seems like Catch 22 strikes again.

 

The photo posted by John shows the main housing for the reversing gear in two halves. The right hand part is the back view of the part which attaches to the left end of the lathe and the left hand part is what you would see when the housing is installed on the lathe. All the action happens between these to halves. The other photo, for which I'll try to find a work around, shows the housing installed on the left end of the lathe.

 

Looking at the left side of John's photo, the large hole at the top is for the spindle gear. It's exposed like this only so that long material in the chuck can extend out the back end of the spindle and any attachments, such as draw bars can be mounted just as they would have been with the original setup.

 

The two holes directly below the large one are for mounting of the forward and reverse idler gears.

 

The single hole below the idlers is where the stud projects for the first driver of the change gears. Driving the stud are a pair of gears with the same tooth count as the spindle gear, each driven by its own idler, and selectable as to which drives the stud via a double-sided single-tooth dog clutch.

 

The hole directly to the right of the stud is where the selector fork mounts to shift the dog clutch towards the headstock for reverse feed, away from the headstock for forward feed, or half way between which selects neither gear.

 

Just above the last mentioned hole you can see a notch in the face of the housing. This is where the operating lever enters the housing to perform all the options mentioned and to disengage the clutch, either by automatic kick out or manually at the choice of the operator.

 

All the rest of the holes are for bolting the halves of the housing together and for mounting the housing to the lathe.

 

It's also worth noting that all the gears from the spindle to the stud are in constant mesh and turn whenever the spindle turns. this includes the forward and reverse gears, coaxial to the stud, which are part of the dog clutch system. The change gear mounted on the stud and all the gears below that point turn only when either forward or reverse feed is selected.

 

No concern about all the gears at the top in constant motion whenever the spindle is turning. Except when the leadscrew is being driven there is no load, they run freely.

 

Hope some of this has been helpful for anyone who might still be having dificulty understanding the mechanism and the method of operation.

 

Anthony

Hi Anthony & John,

 

I tried posting Gray's photo here but it did not work for me either, so I have added the second photo in "My Album".

 

Blowlamp, Gray said you may find this helpful with your own design for this lathe?

 

 

Rob

Well, this afternoon I was finally able to upload the second photo to my Album so it's displayed here. For some reason I still can't upload the photo thet John showed a couple of messages above.

 

In any case, this one shows the housing installed on the C3 lathe. Nothing in the housing in this shot but you can see how it surounds the spindle gear very closely while still leaving it open for drawbars or working stock to pass therough it. In fact, looking through the spindle you can see the shadow of hte chuck jaws at the other end.

 

As stated before, two holes below the spindle gear are the forward and reverse idlers, one hole directly below is the forward and reverse gears, the clutch, and the stud for mounting the first driver gear, to the right of the stud is the shaft carrying the clutch fork. Just above the clutch fork you can see the notch where thte operating lever enters the housing. If you download the photo and lighten it you will see that the dark spot just above the operating lever is a hex scew which mounts the housing to the lathe, just like the one at the top left corner of the housing.

 

You can see that this assembly is customized for theis application and is different than the one at the head of the thread or the gold photo in my Album which are both for the Super7. The units for the ML7, the big bore, the Boxford/South Bend, and the Maximat will all be unique while maintaining the general principle.

 

I'll try again on the other C3 photo later, just because it ought to be in my Album witth the other material.

 

Anthony