Myford headstock dividing

[deverett]

In answering Lugnut’s plea for flywheel machining recently, I dug out a couple of pics which may have helped him, but one of them did not get posted for some reason. Looking at this picture and seeing something in the background prompted this write up.

The Myford S7 (and perhaps the later ML7) has a 60 tooth bullwheel for backgear engagement. This is ideal for use as a simple headstock dividing gadget to give up to 120 direct divisions. The gadget as shown will only fit the Myford S7, but the idea may be adapted for other lathes having a 60 tooth exposed bullwheel. The earlier ML7 has a 45 tooth bullwheel, which is not so convenient for dividing purposes.


This little gadget is mounted permanently in the headstock space into the hole conveniently put there by Mr Myford originally for the chuck guard. The only modification to the lathe is the coloured dimples that can be seen in Pic 1.

Division is rapid, simple and almost foolproof using the chart showing the dimple colours to match to the divisions required.

Parts required are very few and the device can be made in a day.

The device unmounted. The curved plate lies round the mandrel bearing preventing any movement. Just a single cap screw holds everything in place. There are 3 positions for the plunger - neutral, plunger between teeth and plunger straddling a tooth. A fairly strong spring in the plunger prevents it inadvertently hitting the bullwheel when not required and also when it is engaged, prevents any backlash.

Chart showing dimple layout and colours

Division chart

Unfortunately, I cannot take credit for the idea, it coming from 2 Model Engineer magazine articles separated by about 6 months of about late 80s vintage. When moving to Ireland, I disposed of my ME library so cannot be more precise, but a search of Colin Usher’ index will reveal the dates.

Dave
The Emerald Isle

 

[necchiom]

Hi Dave. I have the same S7 lathe (60 tooth) and I would like to develop the same device.
Do you know where to find more infos about plans/drawings and/or usage ?

Thanks.
Mose'

 

[deverett]

Mose

I have had a look through one of the ME index lists and the first issue that you need is Vol 154, Issue 3744, Page 38. The article is titled "Direct Indexing on a Myford Super 7 lathe" by C. W. Rose. I have not looked any further for the second article (detailing some mods to the original device - the small dimples among others), but I seem to remember it is by a different author.

Although I have GHT's Headstock Dividing attachement, I have never used it - I have only ever had the need for simple dividing and this gadget has covered all my requirements.

Hope this helps.

Dave
The Emerald Isle

 

[applescotty]

I looked through the index, and perhaps have found the second article. I don't have an ME collection, so I have no idea if it's the right one, but perhaps worth a look. Volume 154, Issue 3750, page 388, "A Dividing Miscellany" by David Paddington.

If that's not it, then never mind.

Scott

 

[necchiom]

Thank you to all of you.
Mosè

 

[deverett]

I looked through the index, and perhaps have found the second article. I don't have an ME collection, so I have no idea if it's the right one, but perhaps worth a look. Volume 154, Issue 3750, page 388, "A Dividing Miscellany" by David Paddington.

Or possibly Vol 162, Issue 3842, Page 152. Lathe Divider by D English

Dave
The Emerald Isle

 

[steamer]

Necchiom,

What kind of lathe do you have?

I did this with my Logan and it works a treat.

It gives me up to 24 divisions and I can clock a work piece in on a specific reference because the index pin has a sphereical end. The chuck is a 5C and has a home made adjust true feature built in.

Works great to make square and hex head model bolts and such.

Dave

 

[Maryak]

Possibly one of the articles you're looking for is "Headstock Dividing on the Myford series 7 Lathe"

Model Engineers Workshop issue 124 April 2007 page 34

Best Regards
Bob

 

[old-biker-uk]

Here is a similar arangement by one of our club members.
http://www.tauntonme.org.uk/oilyrag/feb08/dividing.html

or if you really want to do some serious dividing.........

Mark

 

[necchiom]

Hi folks, I have a Myford S7 lathe. I guess the device suggested by old-biker-uk would be one of the best solution: maybe this one is based on a G.H.Thomas project. Isn't it ?
But in the short term I would like just to develop the simpler but smart solution posted by steamdave so later on invest my (few) money on a more sophisticated Hemingway kit.

Talking about the Model Engineers Workshop, I have tried to find it on the net but at the moment nothing is available yet. Any further suggestions or scanned (PDF) copy of the articles ?

Regards and happy WE. Mose'

 

[Mainer]

Yes, that looks like the George Thomas dividing setup (actually, I think he said he got the design from somebody else). In any case, it's described, with plans, in his book, "Model Engineer's Workshop Handbook."

 

[steamer]

If you want some information on what I did, send me a PM or post here and we can talk. I used this set up last night to make some hex head bolts for my "Seadog" and it works great!

Dave

 

[applescotty]

steamdave and steamer,

I assume you then have some type of milling spindle in the toolpost or on the top slide to use? What is it?

Scott

 

[old-biker-uk]

Forgot to give credit to GHT for the dividing equipment. I built the full Versatile Dividing Attachment back in about 1982 from the Model Engineer articles (ME 146.293 (1980)).
The late Mr Thomas had the rare talent of being able to describe the construction of fairly complicated (for a novice) equipment, if you followed his instructions with reasonable care you ended up with some useful kit. At least I did...

I would certainly recommend his book and not just for the novice.
Mark

 

[steamer]

I have a Sherline head mounted on a verticle slide. It works but with the Aciera, I don't use the spindle for that so much. I will be converting the sherline head to a drilling spindle only. I also built a filing rest which gets used regularly with the indexer for making flats and hexes. THAT is useful. Mounts on the AXA toolpost and is controlled with a micrometer. I'll post a picture later.

Actually GHT spotting tool would do very well with bolt circles and a simple indexer. Mark them in the lathe and finish it in the drill press.


Dave

 

[deverett]

steamdave and steamer,

I assume you then have some type of milling spindle in the toolpost or on the top slide to use? What is it?

Scott

Scott

Like steamer, I have a filing rest, but mine mounts on the cross slide via the Tee slots. It is basically the Ian Bradley design, but slightly modified. As steamer said - a very useful piece of kit and much quicker to set up than the dividing head in the milling machine.

I do have a drilling spindle that mounts on the toolpost bolt. Just a large lump of steel machined all over with the ability to change the spindle end for end so that I can use it lengthways or crossways. The spindle has a 1mt taper and is powered by a motor a bit more powerful than a sewing machine motor. In truth, it is underpowered for serious drilling. Now that I have a milling machine, it is not used very much.

I can post a couple of pics if you are interested.

Dave
The Emerald Isle

 

[steamer]

Hi All,

I'll be posting progress on the "Seadog" at some point, I made a dozen #5-40 hex head screws last night using the filling rest and my indexer. I'll try to get a snap uploaded tonight depending on the situation when I walk in the door..........what does Mama want me to accomplish tonight! :big:

Dave.............from Massachusetts

PS I think the GHT spotting tool would be much more convienent for hole circles that are not super fussy. http://www.hemingwaykits.com/acatalog/Spotting_Tool.html

I built one of these for the ATlas and then sold it to get the Logan. I think I will build one to compliment the filing rest. Again it will drop right on my AXA. It really works well!


Dave

 

[Mainer]

Hey old-biker-uk: Nice job! I got part way into building that GHT dividing head, but regret to report I got sidetracked and never finished it. I can always claim I'm letting the castings "season" some more.... ;D

I did build another dividing head though, from a lathe headstock that's a duplicate of my lathe's headstock (South Bend 10K). It's handy because the spindle nose is the same, and the collets interchange. I can take a chuck off the lathe with work in it and move it to the dividing head.

The bullgear teeth on the 2nd headstock were whacked, so I turned them off and drilled it 24 holes for an indexing pin for direct indexing. I also fitted a 60:1 wormgear on the left-hand end of the spindle that takes dividing plates. Figuring out how to mount all that was a challenge. It just about fits. If I were to do it again I think I might use a 40:1 ratio to have a smaller-diameter gear to deal with.

The black handle in the middle is a split cotter spindle lock.

 

[Bernd]

Mainer,

Boy have just given me a nice present with that picture. My dad gave me what I believe to be a South Bend bench lathe. Many parts missing, tailstock, a support block under the bed in the rear and the lead screw to mention a few. I now know what I'll be doing with the head stock. My Bridgeport needs a dividing head. Many thanks for that pic.

Regards,
Bernd

 

[applescotty]

steamer and steamerdave,

I hadn't thought of using it with a filing rest. Have to add that to the list, too.

I appreciate any and all pics, but don't go to any trouble on account of me.


Scott