Colin Thorne's - Skeleton Timepiece

[spuddevans]

That's looking good there Chris, keep up the good work


Tim

[raynerd]

Hi Guys, digging up and old one...I`m determined to get well into this before starting any more projects. I`ve remade, for the thrid time, the wheel cutter and this one looks good and sharp. Both my other attempts have had leaning teeth and the only conclusion is that the cutter is not EXACTLY at the centre height of the wheel.

My setup as shown earlier in this thread, is my rotary table mounted upright on the mill. The centre height of the rotary table will be the centre height of the wheel and therefore I need to ensure the cutter is aligned like to this absolute RT/Wheel centre....
The rotary table takes a 2mt and I have a centre that would fit. I could put in the centre and eyeball the cutter to the centre point. Would that be good enough or can anyone think of a more accurate method? - this sort of thing is my downfall.

Chris 

[Stilldrillin]

Chris,

I can only repeat what I said, at the top of the page........ 

David D

[raynerd]

Hey David! I`m really sorry ... I have to admit it has been a long time, about 4 months since picking this one up last. I posted my question elsewhere and thought I may get some good replies here also so I never re-read, not even the last few posts. Appologies, and yes I do remember the reply now however never had another go so never used it. Will attempt it for sure.
Thanks
Chris

[raynerd]

Although I`ve not actually posted on here, I`ve not been ignoring this project, no I`ve just been continually failing at trying to cut a wheel!! My last three attempts at wheel cutting have been a steep learning curve. Not centering the cutter, not tightening the wheel, cutter not sharp enough...   Stew on here, offered to lend me a hand and so I visited his workshop last week and managed to make a multi-tooth cutter and cut a wheel. I`ve been meaning to do this sooner but only just got around to getting all the pics off my camera.  

The method we used I first read from an article by David Creed on making a multi-tooth cutter and also on Deans excellent Website: http://www.deansphotographica.com/machining/projects/multipoint/multipoint.html

We have basically followed the instructions and ideas on there but here are the mandatory pictures!

This first one in my opinion was the most impressive. When calculating the tooth arc, we had to make a tool to profile the cutter to represent this arc. I had read that the easiest way of doing this would be to grind the end of a suitably sized drill bit as I have done and shown in an earlier log. Stew came up with an excellent idea of using a magnified projection of the tool to determine the correct size and profile. As you can see from the photo, Stew set up a torch, magnifying glass with the tool in between. This allowed us to project the profile onto some CAD drawings of the correct circle diameters. It worked very well and it was surprising how accurate this allowed us to be.  


This shows the profiling tool ground to size and shape..... as you can see, it was in use at the time of the photo and hence all the swarf!


Here are all the arbors and jigs made by Stew.....and taken home by me.... THANKS I owe you one!


Another picture of the jig for drilling the 4 holes in the wheel blank....


Cutting the profile of each cutter side...


Cutting away the spare material of the cutter on the other jig...


The cutter straight off the mill...finally made!


And time to harden...cherry red and then straight in a bucket of cold water:


The cutter mounted on the arbor and starting to cut the wheel. The wheel was mounted on my CNC divider which seemed to work quite nicely.


And the final wheel cut!


Thanks again Stew!

Chris

[Bernd]

Hey Chris,

Glad your getting it straighted out.

Now as far as that last picture of the gear. Is it the way you took the pic or are those teeth curved to the right a very slight bit?

Bernd

[sbwhart]

I was thinking that Bernd but having actually seen the wheel I think it must be an optical allusion 

Stew

[Dean W]

 

Almost every clock wheel I've made looks funny in pictures!  It's a strange illusion, but if you see the wheels
in real life, they're correct.  Odd what a camera lens does to closely spaced teeth.  I think it's caused by a
bit of barrel distortion in the lens, especially in point and shoot digicams.

Glad you got a good 'un, Chris!  The cutter jigs by Creed and J. Malcolm Wild are handy kit for us clock dabblers.

Dean

[NickG]

Well done guys, looks good. 

Nick

[raynerd]

Cheers guys, it was an excellent day! Certainly an early start but got a lot done!

Chris

[Bernd]

Almost every clock wheel I've made looks funny in pictures!  It's a strange illusion, but if you see the wheels
in real life, they're correct.  Odd what a camera lens does to closely spaced teeth.  I think it's caused by a
bit of barrel distortion in the lens, especially in point and shoot digicams.

Dean

Thanks Dean. I thought I was going to have to have my eye balls adjusted.    (So those were real deer that jumped out in front of the car  )