Is it Over?

After 52 days on strike an agreement was reached between the union and the Boeing. Making this what could be the third longest strike in Boeing history (according to linked article) It could still be a week or two before I go back to work but it looks like things are wrapping up.

http://seattlepi.nwsource.com/business/385222_boeingstrike28.html


*hurries to get all the side projects I have started finished up* hehe

Hypotrochoidal fun

Just for fun I decided to make a simplified spirograph on the wire. The gears are 32 DP and have tooth ranges from 16 to 80 teeth. I have one or two more gears I am going to make for it but it is basically done. The gears run with the ring gear creating hypotrochoidal curves (or epitrochoidal if two externals are used). The tiny gear has one large hole because I wasn't sure what size to make them and I decided later to make the remaining holes smaller so the pen holds the gear better.

I may do something with the edges of the ring gear piece at some point also.

3/4 of a gear

Well I just got back from the shop. I got the first gear (20 tooth, 10 DP) burned out today. (There it is shown on the comparator) Going to make the second identical gear tomarrow. Then they need to have the bores done and the faces ground. Looks more like a gear anyways

Half a Gear

Well there is it. My one of my favorite machines at the college machine shop. Also the machine I made 'snoopy' on. It is a 5 axis Charmilles wire EDM. Electrical Discharge Machining has its advantages over other forms of machining because of its ability to cut just about anything that conducts electricity and of just about any shape and size that will physically fit in the machine. I thought of using this machine as a way to make gears for my evil bidding (aka all those weird gear related projects I like to do but never have the right equipment) a couple years ago and have done a couple (square gears, etc.) but haven't had a lot of time to just poke at it and see just how good of a gear you can make on this machine. I would like to determine what sort of gear quality I can get by EDM. So, I designed a simple planetary gear train to get things rolling.

I will be curious to see just how well the EDM does with the elemental parts of the gear teeth. Correct profile, lead, PD size, even things like finish. How well they run with each other which will depend on things like correct tooth spacing, runout, as well as everything listed above. I might not be able to check all these things but I will do what I can. I am almost more curious about the quality of the gears than anything else in this project.

I ran a test part through the wire and size held within about .0003. Not too bad. I can see it getting a lot worse though with something that has a lot of geometry (like the gears). One of the biggest things is the finish. Surface finish from this EDM isn't the greatest but We'll see what we end up with.

Tons of fun :)

Update: 11-5-08

I have cut a few gears on the EDM and they actually ended up really good! Nice profile, a tiny bit of lead error (taper), and decent dual flank composite variation results. Better than expected! yay!

Not a Gear

Here's something for *SOMEONE* who thinks my gear project was a boring idea :P

I made you a Snoopy :)

He's about 2.5" tall and made out of aluminum. I needed a practice job to get the hang of setting up the wire EDM so I burned out this little guy. I didn't draw it (it was a pre-loaded job) but it made me remember how to run the machine somewhat so it did it's job.

As for the gears; I got the files mostly done tonight. The first one should be ready to go tomorrow. I need to make the blank which shouldn't take too long but you never know. Finding the proper material in a college shop isn't always easy.

Back to School

well sorta..

It is day 31 of the Boeing strike and in a fit of boredom I went down to the local college machine shop and signed up for a special projects class so I can use their equipment. I will be going down in the mornings (and maybe evenings) to run their wire EDM to make GEARS! wee! mmmm.. Gears..

*cough* anyways.. so I am going to be making a planetary gear train that I designed (last night) just for the fun of it. I don't really have any other way to make the internal gear with any machine over there except wire EDM so I am just going to do the whole thing (minus the housing, etc.) on it. This will also be an experiment to determine what sort of quality you can get out of an EDM for gears. I am thinking profile is going to be the most iffy.. but maybe lead, runout, spacing errors too O_o We'll see..

I'll post pics :)

I figure now that I have signed up for something fun they will resolve the strike and I will be having to go back to work. That's how my luck goes.