Wooden Gear Clock Build Log

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GrblGru
Posts: 228
Joined: Sat Nov 01, 2014 5:44 pm

Re: Wooden Gear Clock Build Log

Post by GrblGru » Sun Jun 07, 2015 8:24 am

Thanks alot for your explanation and of course the both files. Particularly the excel sheet is very interesting for me, because I am thinking about
the diametral pitch difference from wheel and pinion.
Also I could watch the Gcode file in my simulator. See the little 'bridges' to hold the middle pieces. Good work from Estlcam !

Finally, one great request to you. Please don't hurry. We all have time enough. Enjoy your hobby.
My workflow: Only a 2D-editor and GrblGru, that's it
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clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Sun Jun 07, 2015 2:22 pm

Don't get too concerned about the difference in pitch from the wheel and the pinion, it is definitely the 'exception' and not the rule. I maintained tooth width between the set so it works, but normally I would have both the wheel and pinion match in pitch. What this does is makes the pinion for the third wheel and the center wheel interchangeable. The difference between the two in size is very hard to tell , if at all, just by looking at them. Since I'm giving away these plans I wanted to make sure that if someone go the two mixed up it wouldn't 'kill' their clock project. Also, it's a set that I've built before so I knew it was a good combination.

Again, thank you so much for all of the assistance, it is so appreciated. I've had a lot of hobbies over the years but not of them have stuck like clocks. It's pretty much all I do, lol, if I'm not building one, I'm designing one. I have this design that I'm trying to copy based on a very old rolling ball clock, instead of hanging weights it has round weights that run through it to turn the mech...
Front.JPG
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Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Sun Jun 07, 2015 3:08 pm

Houston, we have a problem...

not any more, but we did... I could tell when I pulled the wheels and pinions off the CNC I was going to have issues, hence the reason I built the temporary frame to test drive the parts before I cut the expensive oak frame. I could tell by looking that it was going to bind and at that point I had one of three fixes, create clearance between the wheel and pinion, also called depthening, relocate arbor holes in the frame, or redesign the gear profiles. But first I had to put it together and see what we were up against.

One thing to keep in mind, this is the first time that I have ever used Inkscape to design it, love the program now but I still make a mistake from time to time. And, the first time that I have cut a clock with the SO2. I've made a couple of clock parts with it, but, not an entire clock. Not that these are excuses, just a learning process. When I see a paper clock plan to be cut with my scroll so I modify on the fly. If the gear profiles look like the bottom of the tooth, in between the 2 gear teeth, is too shallow I just cut to the outside of the line. I've built enough clocks to be able to look at a set of plans and usually see what I want to differently.

When I look at the design in Inkscape it looked really nice, but it's really hard to tell since my monitor isn't to scale. Also, I know that the endmill that I used didn't get all the way to the bottom of the profile, it looked pretty close in the gcode preview but not all of the way. However, moving forward I have purchased smaller endmills, some 3/32" bits from drillman and those will be the ticket!

However I wasn't defeated, I had all of those parts, made me a frame and so I have to put it together, and I did... then it stuck... then I fixed it... and if I had three hands I would post a video of me spinning the crap of those wheels, lol. Later today while I'm watching the NASCAR race I'll give you all a full recap of the process, what went wrong, and what I did to make it all work. In the mean time, I posted a few pics to my blog, they were too big to post here to see any detail, anyway, if interested, click the link below... it just a few parts shy of being a real clock... :D Catch up with you all later today! https://justclockit.wordpress.com/2015/ ... -together/
Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Mon Jun 08, 2015 6:49 am

It's time for the next installment of As The Clock Turns... :D

We'll pick up where we left off on Friday, a pile of parts. As I said in my post earlier today I knew there was going to be a problem with gear bind, but, to keep this build legit and to provide full disclosure of the project I went ahead put it together to see how bad it was. It would turn but it was stiff, way to stiff to operate with weight on it. Moving forward this shouldn't be a problem for you with CNC'ed gears like it was when I was hand cutting them with my scroll saw. You could cut a gear set with the scroll saw, assemble the clock, and turn it what you would think would be fairly easily yet when you add weight to the mech it would stop. Also, another culprit is the teeth of the gear bottoming out in the valley of it's corresponding pinion, which will stop it dead in it's tracks. I think the biggest factor in app generated gears is that the tolerances are a lot smaller. Wood guys add a little more clearance for wood movement which can make a world of difference.

To fix the bind issue I have a few choices, I could take all of the wheels and pinions to the scroll saw and cut all of the valleys deeper and sand the sides of each gear tooth (shudder). Or, I could redrill the arbor hole for the third wheel, backing it up and out from the escape wheel and the center wheel. I would pick the third wheel because of it's orientation in the frame, it sits between those two so I could redrill one arbor hole and potentially solve the problem. Or #3, which is the one that I chose, I focused on the 2 pinions, the one attached to the third wheel and the one on the escape wheel.


Since those 2 pinions only have 8 teeth apiece the required work was greatly reduced to achieve the desired effect. So, what I did was this, sanded down the tips of each tooth slightly and both sides of each tooth. I didn't have to modify the valleys on these pinions because I cut these last and actually cut them deeper already. Well, this fixed the problem and now she spins like a champ. Since then I have gone back into the design and I modified the gear designs. I am currently cutting the new profiles out and as soon as I can get you something that won't cause you fits I will upload the new cut files. Also, I am using a new endmill, a smaller one .0938 diameter, to cut the new gears, that way it will get all the way to the bottom of the profile.

TIP: here is a trick that I would use when I cut my gears with a scroll saw and it was the same thing I did to sand the tips on these pinions. I grab the appropriate size arbor for the gear I want to sand and take it and the gear to my vertical sander. I have a wood material rest that I made myself that I can move in and out relative to the sanding surface. I drill a corresponding hole for the arbor in this material rest, slide the arbor through the gear, and put the assembly in the newly drilled hole. Then I will push the gear towards the sanding surface to where it just touches and then spin the gear to gear a perfectly round, and slightly small gear.

Now, and interesting fact that I discovered when I went back into Inkscape to work on the gear profiles... When I selected the offending pinions I noticed that the size of each had changed, it was larger ever so slightly. Each of these pinion were suppose to be 1.15" in diameter, and they were at one point, but today they both were 1.159" and I don't know why. This is a similar issue that I came across earlier in this build. I don't know if I'm accidently transforming them in size as I move them around the work area or if it's something that happens when I go from metric to standard and saving files from svg to dxf... something I'm going to keep an eye on though...

So, back to our program. Assembling the clock once the parts are cut really goes fast, especially since I'm able to create fewer actual parts due to having the capability of milling some parts as a unit as opposed to individually as I had to with the scroll saw. For instance, the wind is made up of 6 parts, the click gear, a pulley back/center/front dividers, and 2 pulley drums. I was able to cut this in half as I cut the click gear and the back as 1 part, the center and a drum as 1, and the front and another drum as another. Doesn't sound like much but you can do that with other parts of the clock as well and it adds up. If I had cut the actual frame pieces, added the pendulum, and weight cords and shells, this would be a running clock right now.

Before you can assemble you have a little bit of manual labor that needs to be done. you have to cut your arbors, brass spacer tubes, and pinion/wheel connectors. Connectors are basically a wood dowel that has deen drilled and is glued between a wheel and a pinion to connect and support the assembly. Also, you will see that on the back side of each wheel there is a support and it does just as the name implies, it supports the wheel in front of it. These are especially useful when sitting up your wheel on an arbor or arbor tube as it helps to keep the wheel straight and parallel to the other wheels and pinions. You don't have this issue with pinions as they smaller in diameter and thicker in material.

Once you have all of your tubes and rods cut to length (I have an updated parts list with exact measurements that I will post later) you need to deburr each at the cut lines. You also need to inspect each arbor rod to make sure that there are no nicks, gouges, or other imperfections that cause us problems. Also, especially on the smaller arbor diameters, you need to make sure that your rod isn't bent. I do this by rolling it on a piece of glass, if it rolls flat without wobble it's good to go. I have a small set of hand files that I use to clean up the parts, especially the inisde edge of the tubes, you and get all kinds of undesirable objects there! And last but not least I polish all of the arbors. Friction is your enemy in wood gear clocks and every little thing adds up to either help you or hurt you. It's a real simple process for me, I will chuck one end of my arbor into my drill press and let is spin while holding some double 0 steel wool up against it. Flip it over and get the other end and you're done! Be sure and do not over tighten your chuck because it can leave impressions in the brass.

TIP: Be careful when polishing your arbors, do not use an abrasive of a material or substances that creates too much heat on the arbor because you do not want to reduce the diameter or warp the arbor from excessive heat.

Now that you have all of your arbors, tubes, and connectors made it's time to go down the check list to see if our wood parts are ready. By now you should have all of your wood pieces cut and sanded. However, there is something that we haven't really addressed yet and that is the use of set screws. The center arbor will need to have a flat spot, as indicated in the instructions that I will upload, filed into it for the center wheel support to be screwed to. that doesn't sound right but you know what I mean, hopefully, lol... For our set screws you will need to drill the appropriate parts in the designated places, as indicated in the parts file. Once you have done this we are ready to start assembly. I'm going to end part 1 and continue with part 2 in another message...
Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Mon Jun 08, 2015 7:47 am

halfnormal wrote:Thanks Rod for starting this thread. I actually purchased my S2 to make clocks and motion art. I am looking forward to learning the art of clock making.
somehow I overlooked your post earlier, glad to see another member interested in clocks on board! If you have any questions or just want to talk clocks, drop me a line either here or at rkueffer at teambighouse dot com. But be prepared, get me off line and talking... never shut me up...
Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

Georgei
Posts: 148
Joined: Mon Dec 22, 2014 11:22 pm
Location: UK

Re: Wooden Gear Clock Build Log

Post by Georgei » Mon Jun 08, 2015 8:34 am

Different clock but the method is the same.

From my experiments, for whatever is critical (i.e. Gears, bore holes etc.) the cutter with the best results (smoother surfaces) is a 1mm down-cut 2 flute spiral carbide.

I tried different diameter cutters but this was giving the best results.

Some photos of my progress.
IMG_7887.JPG
IMG_7887.JPG (258.6 KiB) Viewed 1589 times
IMG_7886.JPG
IMG_7886.JPG (184.32 KiB) Viewed 1589 times

bharbour
Posts: 413
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Re: Wooden Gear Clock Build Log

Post by bharbour » Mon Jun 08, 2015 3:03 pm

1mm...that's tiny. What are your speeds and depth of cut to keep that baby from breaking??

Tnx,
Georgei wrote:Different clock but the method is the same.

From my experiments, for whatever is critical (i.e. Gears, bore holes etc.) the cutter with the best results (smoother surfaces) is a 1mm down-cut 2 flute spiral carbide.

I tried different diameter cutters but this was giving the best results.

Some photos of my progress.
IMG_7887.JPG
IMG_7886.JPG
No longer have a Shapeoko, but use a machine of my own design...
https://www.youtube.com/watch?v=gFY4gC9TqD0
http://deltaguitarworks.tumblr.com

Georgei
Posts: 148
Joined: Mon Dec 22, 2014 11:22 pm
Location: UK

Re: Wooden Gear Clock Build Log

Post by Georgei » Mon Jun 08, 2015 3:16 pm

bharbour wrote:1mm...that's tiny. What are your speeds and depth of cut to keep that baby from breaking??

Yes they are tiny and snap very easy but give a fantastic finish - no need to sand my gears - they are perfect as they are.

I only use them to cut the critical parts that finishing is important - like the gear teeth, bore holes and levers. Everything else is been cut with a 2mm or 3mm cutter.

Usually for birch plywood I use 0.6mm cutting depth with 600mm/min feed rate at 16000 rpm.

For hardwoods I use 0.5mm cutting depth with 500mm/min feed rate at 16000 rpm.

clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Mon Jun 08, 2015 5:27 pm

I have to agree with you George, that was one of the bits that I recieved this weekend, used it last night to cut some modified pinions and it worked great. I will need to go back and check my settings but I think I was a little more agressive.

I've gotten pretty good at tool changes so that's not a problem for me anymore, but, I think I have come upon an issue. Every once in a while after a tool change I was encountering a loose bit after a tool change. I thought that it was me, and it may be, that I wasn't tightening the bit enough because I was too cautious trying not to move my router. But, now I think it may have been something else, after this happened again I pulled the collet and the nut to look at them and I noticed that real fine dust had accumulated in the slots in the collet as well as inside the nut. I think that this was enough to keep me from getting it tight enough because once I found that I started dropping both at each tool change and blowing them out and it hasn't happened since. Anyone experience something like this? Am I just nuts? :shock:
Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

clockit
Posts: 319
Joined: Sun Nov 16, 2014 11:05 pm
Location: California, MO

Re: Wooden Gear Clock Build Log

Post by clockit » Mon Jun 08, 2015 5:28 pm

And the more important thing... George, please post pics of your clock when you get it done, I can't wait to see it... :D
Shapeoko 2, Full Kit #7071, Makita RT0701C Router, 1000 x 1000 upgrade, Acme Z Axis w/Nema 17 Belt Drive

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