Author Topic: G. Thomas Versatile Dividing Head (Hemingway Kits)  (Read 10878 times)

Offline samc88

  • Full Member
  • ****
  • Posts: 276
G. Thomas Versatile Dividing Head (Hemingway Kits)
« on: October 04, 2022, 09:37:46 PM »
A nice tooling project on the bench now, been looking into one for ages and got some jobs coming up in the future where I would benefit from one. The George Thomas design looks like it should fit my needs perfectly, especially with the micro attachment as well which allows practically any division. Not sure when Ill actually start this as want to sort other things out first but anyway heres some pics of what comes in the box. My first job was to sort through everything and label up the material in the kit and compare to the material list. I find it much easier to find the correct material when sifting through the box this way. The kit also has excellent drawings, Im also going to be working from the book "workshop techniques by G Thomas" which has good build notes in there.

Offline Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7860
  • Portland, Oregon, USA
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #1 on: October 04, 2022, 10:36:22 PM »
That looks like a fun (and potentially useful) project!  :popcorn: :popcorn:

Kim

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #2 on: October 05, 2022, 01:53:16 AM »
Great project and very useful tool. You will enjoy building it. I built this tool 9 years ago. There are riser plates that you can get from Hemingway and a swivel base. My built is here.. https://www.modelenginemaker.com/index.php/topic,2031.msg31584.html#msg31584


There is also a micro attachment calculation sheet also used for the dividing head. https://www.modelenginemaker.com/index.php/topic,4965.msg94796.html#msg94796

Regards Don
« Last Edit: October 05, 2022, 01:57:16 AM by Don1966 »

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 556
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #3 on: October 05, 2022, 09:02:48 AM »
Very much agree with Don that the VDH is a great project and a most useful addition to tooling.  Have taken a look through Don's excellent build log, wh. I had not seen.  My own VDH was built before Don's, and am a bit ashamed to say it never got painted, I started to use it prematurely..! Also made the riser blocks and tailstock for mill use.  Though making the plates using the Micro attachment is an interesting exercise in itself, I must say that I have almost never needed anything but the head in its most basic configuration, the 24 holes on the main gear get one round the usual mundane requirements. But if you enjoy toolmaking anyway, it makes for satisfying work.  Unless there is a bit of clockmaking on the future projects list, which would exploit the more elaborate dividing very nicely ....    Dave

Offline Del_61

  • Full Member
  • ****
  • Posts: 27
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #4 on: October 06, 2022, 02:04:27 PM »
Hi, I agree its a very worthwhile addition to the workshop.

I built mine a few years ago including the riser plates. I also followed the "masters" instructions in his book "Dividing and Graduating" which is out of print but I understand is now incorporated into his book "workshop Techniques".

I made it exactly to his description including the parallel bore and split collets. It seems to work fine, I have seen others who have made the main spindle an internal MT2 instead. I cannot be bothered to make another main spindle with an MT2 !

Good luck with the project!

Regards

Derek

Offline Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 15293
  • Hampshire, england.
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #5 on: October 06, 2022, 08:48:24 PM »
They are very nice. I have made two: One lives in the main workshop and Sexy  :embarassed: has his own https://www.modelenginemaker.com/index.php/topic,2775.msg76875.html#msg76875

The old Myford MT2 collets are really nice fitted to the nose but you might want to consider making yourself an extra spindle with a 20mm bore so that you can fit a standard ER collet chuck if you don't have the full set of Myford collets  ;) .

Jo
Enjoyment is more important than achievement.

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 988
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #6 on: October 07, 2022, 05:39:09 PM »
What machine is “Sexy” ?

I don’t understand the lingo.

Andy
« Last Edit: October 07, 2022, 06:09:39 PM by Chipmaster »

Offline Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 15293
  • Hampshire, england.
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #7 on: October 07, 2022, 06:47:26 PM »
My Sixis 101 milling machine is named “Sexy” if you had ever used one you would know why  :embarassed:

Jo
Enjoyment is more important than achievement.

Offline samc88

  • Full Member
  • ****
  • Posts: 276
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #8 on: October 23, 2022, 09:40:15 PM »
Thanks all for the comments, Im glad to hear its a useful tool when done. First parts have been made this evening, namely the brass spindle clamp along with its steel spacer and the two steel cotters for clamping the overarm for the tailstock support. All simple turning jobs really, I need to get another die for the second cotter as the one I used for the first one left the threads not particularly pretty (although the nut does go on nicely with little slop, I think its just a bit dull). I'll hopefully get some more done this week with some machining pics (I forgot earlier). I have also been making a part to repair my friends chimney sweeping brush which has taken up some time this evening as well

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 121
    • My Homepage
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #9 on: October 24, 2022, 12:12:53 PM »
I built the device a few years ago.
I converted the drawings to the metric scale.
In total I made three spindles for it.
1. the spindle provided according to the drawing.
2. a spindle with ER 25 collet chuck.
3. a spindle with a mounting for a small jaw chuck.
« Last Edit: October 24, 2022, 12:20:48 PM by Bruno Mueller »
http://mueller-bruno.de/  http://www.bosch-combi.de/
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 556
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #10 on: October 25, 2022, 09:28:16 AM »
Interested to see your example of the dividing head, Bruno, and your other versatile components.  The accessory that I very frequently use, probably more so than the split collets made to GHT's schedule, is the insert mandrel that has a threaded spindle nose identical to the chuck mounting on my Myford lathe.  Very usually I will transfer the chuck, four jaw included, straight over to the dividing head, with no need to disturb the component being machined.  Dave

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #11 on: October 25, 2022, 05:34:22 PM »
The Chuck adapter you have is a plus for this dividing head Bruno. Using the threaded spindle the Chuck wants to unscrew doing certain procedures. With three securing screws and flats on the shaft on Bruno’s Chuck adapter and the Chuck back plate the Chuck is secure. I also have the threaded adapter for the Myford collet Chuck.… :ThumbsUp:


Don
« Last Edit: October 25, 2022, 05:39:10 PM by Don1966 »

Offline samc88

  • Full Member
  • ****
  • Posts: 276
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #12 on: December 07, 2022, 10:08:18 PM »
Finally making some progress on my Versatile Dividing Head. The clamping cotters are now done, next up is the tailstock I think, Im just working through the book. The Hemingway drawings are imperial but metric fasteners. Im using the threads given in the book (mainly as I have all the imperial taps needed, so the brass clamp pins are 2BA rather than M5).
I did square off one side of the tailstock to let me have a datum for marking out. Pretty pleased with the finish considering I used the full depth of the end mill for the 1" tall block. Was a little chattery but a couple of spring passes took care of that., came out better than I thought (this gets a rad put on it later anyway, I just took it as practice)

Offline Bruno Mueller

  • Full Member
  • ****
  • Posts: 121
    • My Homepage
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #13 on: December 09, 2022, 09:08:11 AM »
Yes, that was a good idea, also to adjust the threads. If you have the necessary tools anyway and take over the other dimensions 1:1.
For me, it was the other way round. I used the metric threads and converted the other dimensions to the metric scale. I have no way of measuring imperial dimensions properly.
However, I did not use the metric dimensions 1:1, but rounded the dimensions up or down. But always keep an eye on the dimensions of the castings.
I am at home on the European mainland and can't do much with the Imperial system of measurement.
http://mueller-bruno.de/  http://www.bosch-combi.de/
Whoever talks shit about me behind my back is in the best position to lick my ass. 
Greetings from the southwest of Germany.

Offline samc88

  • Full Member
  • ****
  • Posts: 276
Re: G. Thomas Versatile Dividing Head (Hemingway Kits)
« Reply #14 on: December 20, 2022, 10:10:49 PM »
More progress! The 3/8" holes for the tailstock clamps were drilled and reamed on the miller before boring the 5/8" hole to size. The brass clamps have to be in place for this as they intersect the bores so boring then scallops them. I did start to use my boring head on this as there was a lot of material to take out and I had never used it before. Im not convinced my machine is rigid enough for relatively deep bores but I could do with more practice with the boring head. Anyway I wasnt too convinced I would get the bore accurate enough with my limited experience so I moved  it to the mini lathe to finish off the bore which worked nicely and is a nice fit for the ground bar included. The other hole gets machined with the main body so will be left for now. Once the 5/8 bore was finished, the brass clamp was parted in two and a little faced off each side. Result is a really nice fit and nice clamping action, very pleased. The bar for the tailstock just needed facing and a light chamfer either end

Im still undecided on the approach for doing the main body on the 7x14 mini lathe. Whilst the lathe has the same centre height as the myfords the VDH is designed for, the mini lathe doesnt have a boring table to clamp it to. Ive a couple of ideas but in the mean time I thought Id tackle some of the simpler jobs.

Started off with the spindles for the tailstock clamps which were simply turned to length and threaded 2BA. Once those were done I turned my attention to the spindle locking bolt. This was going really well until it came to threading the end 1/4" UNC. The die I had was blunt as the proverbial blunt thing so that was no good. Aha I thought, I have change gears so Ill simply screw cut the thread. So off I went to little machine shop and the threading gear converter and turns out I need a 57tooth gear which I dont have (if only I had a dividing head!). So die on order and on to something else. Decided to work on the tailstock centre which is 1/2" silver steel (drill rod). This was just a simple job of turning a 60⁰ taper, pleased with finish I achieved here. I did it in the 3 jaw as measured the run out and it was only a thou, not bad for a Chinesium chuck. I did get fed up of tripping over myself so had some time yesterday for a tidy up, result being I want to spend more time in there, its good to make some progress at last
« Last Edit: December 21, 2022, 01:08:02 AM by samc88 »

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal