My latest CNC clock project

This is a clock I started working on recently to put my CNC through its paces.

The goal is to have a clock made 100% out of sold wood. This means some design considerations to make sure the gears hold up. The first was that the gears had to be at least .68" thick. I had to increase the diameter of the gears as well.

The finished clock will be about 75" tall with the actual gear mechanism and motor mounted in the top 1/3" of the clock. I wanted to build the whole thing on my 30" x 27" CNC so the clock is in three sections.

I have several videos but here is the latest’s. Notice that the plates are MDF. I did this to test before committing to solid wood.

http://www.youtube.com/watch?v=9cVKOQJgiuk


I will be making some changes when I do the final build, but this thing went together like a glove.


Attachment 237637Attachment 237638

These clocks you are making are sooo awesome!

Just completed the stand today (prototype stand).

http://www.youtube.com/watch?v=X4jdFYpuzjY


Attachment 237697

I have to ask this question--When you make the gears are you using a special oily/exotic type wood to lessen the wear on the gears over time, or is this not a problem. I find this type of work very fascinating!!! Keep 'em coming.

Bruce

@Bruce

You are supposed to use engineered products to make gears because of solid woods tendancy to chip on the edge grain of gears. On this project I increased the thickness of the gears to 3/4" in order to give the gears more beef.

As for actual gear wear, I dont think there will be much if any over time. First the gear designs are involute so that only a small portion of each tooth make contact. Also using brass rod for the arbors there is little or no load on the gears. Im sure if the clock is still running after a 100 years there may be a little wear.

If you use solid wood gears its more likly the teeth may chip over time. On a clock where I used 1/4" solid wood gears I had a few edge grain teeth chip off. On these I just used a little yellow glue and reattached. Have not had the problem with the thicker gears.

@Mick
If you are going to CNC the gears. Do a first light pass on the teeth at about .01 deep. This kind of scores the teeth and lets you be a little more agressive in you teeth cuts on your second pass. Try to do the arbor holes in two passes. IE cut them a little shy on the first pass then hit them again to get the hole sizes exact.

A note on the spacers. If you use solid wood on the spacers, hit the holes with a drill bit and a portable drill or drill press to slightly enlarge the holes or they will split when you add them to the arbors.

I just finished the prototype stand. It turned out so well that I decided to cut all the solid wood gears in MDF. I did this so that I would have two complete clocks. One 100% out of MDF and the other out of solid wood.

On the MDF clock I am using Generals milk paint and glaze to get the colors and effects. On the solid wood clock it will probably be generals dye and shelac. I will post some pics when I get some time.

Gentlemen,

Please keep your posts on topic and refrain from any commercial advertising, its not allowed in this forum.
Thanks,
Keith

I was not advertising. So someone metions they purchased my book and you kill thier post. Now you know why this forum is dead. and onlu gets a couple posts a week.

Thats it for me. No more.

Please delete my Sawmill Creek account. I would do it but I cant find the settings for it.

Michael,

I'm sorry that you feel the way you do but there is a solid reason why we do not allow anyone to advertise in our woodworking forums. In fact we don't even allow our banner advertisers to use our woodworking forums to promote their products. I own SawMill Creek and I never use it to promote my business. For the record there were several instances where one of your products was mentioned and you were not criticized for any violation of the rules here. I removed three posts, none of them was made by you and my intent was to save your thread rather than remove it from view.

Should I allow you or anyone else to use our forums for a commercial purpose I will have to allow the same for thousands of others. In a short period of time you would be hard pressed to find a woodworking discussion here and The Creek would die.

The following is an excerpt from our Terms of Service:

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