Winner A Dividing Head By Wayne

[wayne.inspain]

Thank you LucknowKen, You are correct, lot of work but enjoyable.
Today I had a go at the indexing plunger, and I think it might work!!

The barrel is 16mm reduced to 8mm to go through the arm then threaded m8 then reduced to 6mm to loose the rest of the thread. inside is bored 12mm,
then 10mm flat bottomed to take the spring, I used an 10mm end mill to flatten the bottom of the hole then drilled 4mm the rest of the way through.
The plunger was 8mm printer rod reduced one side to 4mm and 6mm the other, leaving a collar of 8mm in the middle for the spring to bear on The cap is 16mm with a 12mm shoulder then a 6mm hole drilled through. The spring goes between the collar on the plunger and the cap. If any of that makes any sense to any one can they please explain it to me!!

And it goes together like this, I haven't pressed the cap all the way in because I might not get it out and I haven't finished it yet. Still got to make a knob to make for the end, I have left the plunger end a bit long for adjustment. When this is functional I will make a brass nut for the plunger body

 

[wayne.inspain]

The knob for the end started from the same 25mm piece of brass. I wanted it to be knurled but I haven't got a knurler, I thought of making one but I don't have the wheels. I stripped down a couple of cigarette lighters for the striker wheels, they might have done, but the finish would be very fine. So I would have to cut them by hand. I made this lash up on the end of the lathe with my 100 tooth change wheel.

I have seen other people make these sort of things on the net but they always seem to be a bit more elegant than mine, but it worked ok..

I used the 60 degree threading tool I ground earlier, and made 100 small cuts, and then when round again just for luck.

I threaded the end of the plunger and that is how it assembles.

The cap needs pushing home but I will leave that until later. I am pleased with this, the action is just about right and it feels nice to use. The spring is out of
an old printer, but don't ask me what model I have taken loads apart. Next I will make the knob for the indexing arm which requires me cutting an internal thread, I have been putting it off, I want the knob to have a blind hole, I know it is going to end in tears I will have to think of some thing.

 

[Mark_f]

I can't wait to this when finished. What are your plans for the face plate ? Mount a chuck on it?

I threaded my spindle for a chuck to go on and made the inside to accept 3C collets. I can also use a center and drive plate.

 

[wayne.inspain]

Hi Mark the holes in the spindle fit the 4 jaw chuck I have so I will mount this and then cut a new worm wheel and worm, then make a new main spindle
using the new worm wheel which can have a much larger center bore, Most of the tooling I have is m3 taper so I will bore that through the spindle, my chuck
bolt on the lathe so I will use that method on the spindle end. The face plate I have started will fit this also.

 

[wayne.inspain]

I have just been experimenting with a piece of broom handle in the lathe with a pen in the tool holder tracing the line the cutter would take to cut a 1mm
thread with a 3mm lead screw and it seems the where ever I engage the half nuts the pen in in the same line. This would mean I can cut a 1mm thread and engage the half nuts anywhere on the lead screw and still cut the thread. This is probably true for any thread pitch multiple of 3mm. Could some one tell me
if this is correct before I trash a perfectly good piece of brass.

 

[wayne.inspain]

This is the solution I decided on.

The design is not mine, there is one on this forum by James and several variations on the net. Apiece of aluminium tube on the left, (an old arrow) a rod to go inside,( the float arm from a toilet cistern, a couple of springs and some off cuts. I need to make a locking collar for the for the toilet arm, no I mean the telescopic sear push rod. The push rod moves the sear and the half nut leaver is pulled round and disengages the half nuts. I have done some test runs with a clock on the saddle and repeat-ability is about o.2mm. I will make the locking collar then start the nut for the indexing arm.

 

[wayne.inspain]

With a collar fitted I did a test run and got set up for the threading of the blind hole. I did not think this was going to work, I could see the tool I had just
ground from a broken drill being broken once again as it ploughs in to the bottom of the blind hole, but it didn't, it work perfectly, once going I didn't
even need to stop the lathe between cuts. The hole was 14mm deep and I cut a 12mm long thread with out a run off.

Same procedure as the previous knob and then there was 2 knobs !

Next job division plates!

 

[wayne.inspain]

The release mechanism for threading I just fitted to my lathe I would recommend it, it works great, not just for threading but for the power feed
too. There is some one on this forum called James that has made a video of the operation, it is worth a look. It also appears that if the pitch of the thread you
want to cut in a multiple of the pitch of your lead screw you can dis-engage the half nuts and re-engage them any where you like and still cut the same thread.

 

[wayne.inspain]

what explains bugger bugger bugger bugger better that bugger bugger bugger, I made the division plate with the wrong hole pcd. bugger !!!!! I took a piece of 100mm by 6mm black flat cut it round with the grinder the lathed it true , bored a 20mm hole through the middle, then on to the mill and then spent 15 minutes butchering it with the wrong pcd. After re-drilling it got what I wanted....6 more holes gives 1 degree of travel of the work piece. Getting near to finishing now!! I am not bitter!!!!

Don't any body ask me what the extra 4 holes are for.!! Bugger.

 

[Randall Marx]

Hey Wayne, what are those extra four holes for in your index plate? (JUST KIDDING!!!!!!!) Been there and done that. :banghead: