Author Topic: Colin Thorne's - Skeleton Timepiece (Read 33516 times)

raynerd · « **on:** November 08, 2009, 06:05:26 PM »

My birthday has arrived and I was finally "allowed" to open my cz120 engravers brass barstock that I have been waiting on and have a proper read through the plans for Colin Thorne's Skeleton Timepiece. This really has been a life long ambition and I`ve been tinkering with clocks on and off for the last 8 years so I hope to see it through however long it takes.

I`m also going to be keeping a blog here: http://clockbuilding.blogspot.com but to be honest, I post on here first and the blog posts come afterwards.

The research and efforts of the last month on wheel cutting is documented in this thread: http://madmodder.net/index.php?topic=2026.0

My aim is to continue with my efforts at wheel cutting whilest interupted efforts at other parts of the build to keep me enthused!

I recently got some punches, 20 x swiss needle files, Vertex dividing plates for the rotary table and currently on order a set of clockmakers tapered broaches. These are the only things that I can see me needing soon that I really needed to buy rather than make. I will need a depthing tool and jacots tool (or similar) which I am going to make myself over the next few months. I will eventually need a pivot file but these are £40 for one file and therefore I`ll get this later when I need it. I think I`ll manage most jobs with my standard shop tools and the few specialist tools I`ve bought.

A few pictures for you...

Here is my large set of Swiss and British made needle files -

This is my set of wheel blanks - cz120 of the required guages.

My collection of various arbors for wheel blank and wheel cutter holding.

The Frame
I`m having a break from wheel cutting for a few days and I`m going to put some time into the frame. I am roughly following the order that Colin says to put it together in, in his book "Clockmaking for the Model Engineer". : http://madmodder.net/index.php?topic=2125.msg22051#new

The frame will need to be cut out of 5mm engravers brass and both front and back need to be identical. Pivot holes in the frame will need to be drilled together when the time comes so it is essential that the plates can be aligned quickly and accurately when needed for drilling. This is done by using brass taper pins shown in the picture. A pin is driven into the front frame at the top and bottom, the front is then polished off so the pin is invisible from the front view and a small "stub" left on the back side. This stub corresponds to a hole on the back plate allowing easy and accurate aligning. The picture shows the universal taper pins and the brass plates. These thick plates where the most expensive part of the clock:

The plans I recieved are perfectly to scale so I did a photocopy, cut out a template and stuck it to one of the plates whilest clamping them together. I have seen this method used before and it is perfectly acceptable for the plates. The pallet is also roughed out in a similar way when the time comes. The plates were bolted together with M4 screws countersunk at the back side. I will then be roughing this out tomorrow on my brother-in-laws saw but I will be leaving on the little bolt tabs. I`ll cut these off right at the very end, clamp the plates together with the locating pins and finish the plates fully.

And that is where I am at right now. I`ll hammer home the taper pins next and then rough the shape out ....

Thanks for looking. Hopefully many more episodes to come!

Chris

dsquire · « **Reply #1 on:** November 08, 2009, 11:26:52 PM »

Craynerd

Well, lets start by wishing you a happy birthday. I shall also be keeping an eye on this thread as I am sure many other MadModders will also be watching. Good luck with your build.

Cheers

Don

andyf · « **Reply #2 on:** November 09, 2009, 02:50:09 AM »

Chris, a note of caution. Not all photocopiers are "dead on" as far as scale is concerned - my office Xerox was about 1% out. It might be worth checking the copies on any critical measurements such as from one hole centre to another.

Andy

raynerd · « **Reply #3 on:** November 09, 2009, 03:08:00 AM »

Done

it is just to get it roughly to shape. I`m not using it to mark any holes, I`ll mark it out once the shape is formed all from a centre line and the holes are drilled one at a time from a depthing tool. Once I`ve got the shape out, I can remove the template as the frame shape is not critical as long as it is square.

Powder Keg · « **Reply #4 on:** November 09, 2009, 11:22:50 AM »

I want to build a clock one day. I can't wait to see yours done

Stilldrillin · « **Reply #5 on:** November 09, 2009, 01:00:03 PM »

Good luck Chris!

David D

raynerd · « **Reply #6 on:** November 09, 2009, 06:26:48 PM »

... just spent 20 minutes writing this up then lost it hitting the refresh button!!

So here goes again.... perhaps shorted this time and more to the point!

After bolting the plates together yesterday I wanted to fit the locating pins so that the plates can be separated and realigned quickly and accurately. I was worried about doing this as the proceedure involved driving a taper pin through from the front face of the front plate and then polishing it out totally so that the plate/pin joint was invisible. I drilled a 1mm hole in three locations for the three pins:

My clockmakers broaches came today so I used this immediately tonight to cut a taper hole right through the front plate. A stub of 1mm was left on the top plate and using a stake the pin was hammered home. The pin was cut on the back plate to leave a 1mm stub. These are the pins in place:

The pins were hammered home from the front face so this now needed filing and then fine sanding to get a perfect finish so the pin was invisible. Hopefully this picture explains what I mean:

Perhaps I am getting over excited but I can`t believe that you can`t see a joint from the front plate yet I am left with three nice little stubs on the back side of the plate which locate perfectly with the back plate.

I then took the hole lot around to my brother-in-laws to cut the plates out with his band saw. This took about an hour to get them roughed out. I now need to file them and after an hour at this tonight, I have a feeling a good few hours are left on this job!! The clock in the picture is also the one I am attempting. Note that I have left in the bolts on little tabs which I`ll cut off when I have finished filing. To be honest, they are overkill and the locating pins with a small clamp would surfice but I`ll leave them for now and then cut the tabs off when I am nearer to finishing.

Thanks for looking...

Chris

dsquire · « **Reply #7 on:** November 09, 2009, 07:46:54 PM »

Craynerd

Nice start on the clock. I can tell that your excited. Before you are finished you will be an expert filer. Next thing we know you will be looking for a filing machine.

Whenever I do up a post I either do it in notepad and bring it in with a copy and paste or else select the entire post and do Control C for copy. Too many times just when you least expect it, it heads out to never never land, never to be seen again. With me now its just habit to do that with every post because I hate typing things twice.

Cheers

Don

Jere · « **Reply #8 on:** November 09, 2009, 10:38:41 PM »

Just wanted to say that it looks like an great start, I will definitely be following along.

Jere

Russel · « **Reply #9 on:** November 09, 2009, 10:41:59 PM »

Wow, very nice job! Someday I hope to make a clock, so I'm following your thread with great enthusiasm.

Files can do amazing things in skilled hands. People forget that sometimes.

Quote from: craynerd on November 09, 2009, 06:26:48 PM

... just spent 20 minutes writing this up then lost it hitting the refresh button!!

So here goes again.... perhaps shorted this time and more to the point!

I've done that more times than I care to remember. My solution is to write my longer posts out with a word processor and save frequently. When I am done writing the post, I copy and paste it into the reply dialog box.

Russ

raynerd · « **Reply #10 on:** November 10, 2009, 07:59:17 AM »

These should have been with last nights episode but I have only just got them my from my brother-in-laws camera. We had the plates pinned in the locating holes and also bolted together. As I said last night, I now have to file it all square and neat. Any tips for filing the curves, the little go I had I struggled a bit?

Darren · « **Reply #11 on:** November 10, 2009, 08:05:53 AM »

I would probably use some sort of flap wheel to remove the initial bulk from the curves.

raynerd · « **Reply #12 on:** November 10, 2009, 08:09:35 AM »

Hey Darren. I`ve never used one before but I think I have a couple in a draw in the shop, I`ll have to have a look what they are. Great idea and thanks for the suggestion.

Chris

raynerd · « **Reply #13 on:** November 10, 2009, 08:10:07 AM »

To be honest, there isn`t too much bulk there, it is just getting the finish right.

Darren · « **Reply #14 on:** November 10, 2009, 08:20:49 AM »

I'd still try a flap wheel, then finish by hand if necessary

kvom · « **Reply #15 on:** November 10, 2009, 09:38:03 AM »

Looks like an ambitious project. I will be following along.

sbwhart · « **Reply #16 on:** November 10, 2009, 12:24:41 PM »

Chris

Draw file method:- hold the file in both hands either side of the job keeping it as flat as posable move the file along the plate not across it, take you time, have good lighting, and a good clear line to work too.

Stew

raynerd · « **Reply #17 on:** November 10, 2009, 06:45:06 PM »

Darren since I read you post earlier in the day I did dig out my flap wheel but I only have 80 and 120 and even the 120 was being too aggresive or more like I couldn`t control it well enough. Thanks for the suggestion. I may possibly buy a very fine one for polishing at the end, this is the first time I have used one.

Stew - thanks!!!

Draw file method worked a treat, I did a bit of a google before hand and it really worked well. Infact, I used it for the flats as well as the curve. So another hour and I`ve now finished the two flat long sides and the large arcs at the bottom. I have a feeling I am going to have a few more nights on this if i want it to look accurate and neat.

Krown Kustoms · « **Reply #18 on:** November 11, 2009, 03:32:00 PM »

Great start,
I am still threatening to lay out a clock
but then I will know how much time I spend doing things the hard way.

-B-

Cliff · « **Reply #19 on:** November 11, 2009, 11:32:05 PM »

Hey Craynerd been following your post very close I have been interested in clocks since the late 60's I even ran a sales and repair business for about ten years till health problems caused me to have to close it. When I had to make something like what your doing I put the flap wheel in a small drill press so the piece I was working on was square with flap wheel and more ridged. Cliff.

raynerd · « **Reply #20 on:** November 12, 2009, 03:32:00 AM »

Cliff - many thanks for the idea regarding the drill press and flap wheel. I may give that a go although I seem to be getting quite a good finish with my needle files and time!

Please do keep following my posts and if you can give any other advice then I`d really appreciate it. I`m going to be making the pillars next and then back on to wheel cutting...

Chris

raynerd · « **Reply #21 on:** November 12, 2009, 02:27:55 PM »

Just wanting some advice with my wheel cutting - I`m trying to have the wheel blank concentric with the rotary table, would it be worth mounting the blank on the 2mt arbor in the middle of the rotary table and then trueing to final size with an end mill. That way I`ll know the wheel is true on the RT when mounted on the mill.

p.s just randomly sat eating my tea when I had that idea.....please, someone, is there a cure

Chris

Powder Keg · « **Reply #22 on:** November 12, 2009, 02:40:47 PM »

Chris,

You should be able to get it indicated in good enough with an indicator. It will save you machine time by doing everything you can on the lathe also.

Wes

Powder Keg · « **Reply #23 on:** November 12, 2009, 02:42:12 PM »

Forgot to mention. Looking good so far!!! You can get a lot done with a file can't you.

raynerd · « **Reply #24 on:** November 14, 2009, 03:43:00 AM »

Had a break from filing the frame and decided to do the pillars. I enjoyed this little bit of turning!

The bottom two need drilling and tapping in the centre section for the feet but I`ll do that later when I have finished the feet. The ends are tapped M3 and now I need to complete the washers.

Chris

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Author Topic: Colin Thorne's - Skeleton Timepiece (Read 33516 times)

Russel