I don't know how many of you have ever seen a lapping table. It's a big flat table with cutout grooves to let lapping compound and cut away material flow away. You normally put plates on it and move in a figure 8 motion to lap them flat. It is done by hand, and takes a LONG time and ALOT of muscle. what i am looking for is a cheap, purely mechanical way to move the plates around and not put any pressure on the plate itself so it actually laps flat. I was thinking of something with cams and push rods with bracket hold arms that came down and grabbed the sides of the plate to move it around.

What i am looking for it something a little simpler than all that it would take to make this way work. This way I have one motor and two output shafts, one that takes care of the x motion and the other that takes care of the y motion. What I am looking for is one output that would follow the figure 8 pattern and be very strong. If someone knows of a gearhead that runs this motion already that would be great. I highly doubt anything exists, and I bet I will probably have to do it the way I stated earlier, but I will listen to any suggestions or points in the right direction.

 

I was a fine arts major in college and did a lot of lithography. The exact same process was used to remove an etched image from the limestone tablets (extremely heavy) after a press run ws finished. Same motion and you would lapp one tablet with another used only for lapping. I would have given my right arm for such a device back then! If nothing else, please post pictures/diagrams of your solution. Good luck!


Modified by FastCougar at 6:51 PM 10/3/2006

 

You got me thinking ... so I started to research and ran into this website ... in case you need some inspiration/ideas on what types of mechanism could be involved:

http://www.cs.cmu.edu/~rapidpr....html

 

yea that site looks decent, i'll take a better look at it tomorrow. It's a really interesting idea because you have to take rotational motion and turn it into two directions of translational motion, and they have to be timed and synched to one another in a to/fro motion. I have a few pretty good idea now, hopefully that website will give me a really clear one.

 

any mech e thats taken linkages should be able to help you out...its what the class is all about...movement of machinery & linkages

 

i am a ME, in training of sorts. 3rd year at drexel. I know a few ways to do it already, but al involves two moving output arms. I was trying to think of a way to create one output arm, that way i can create one cage that grabs all four corners of the plate and i won't get rubbing on the edges of the plate from things moving back and forth.

Just looking for a simpler (aka cheaper) way to do it. It isn't even a needed thing, I just wanted to propose it to my boss as a profitable project.

 

i think i may have found something, but it is complicated as HELL.

http://www.freepatentsonline.com/4793573.html

 

After looking at the design i posted above again, I don't think that it would work. It actually traces out the 8 in 3D, and the point wouldn't kept normal to the lapping table surface, so I really wouldn't be able to grab the plates with it without it slipping off. Back to more ideas i guess.

 

http://www.turbofast.com.au/as....html

This talks about mirror grinding but I am going to put this idea to use on a set of rotary engine side plates. We normaly use a HUGE lapping machine on these types of items, as most machine shops can only handle small items.

 

One of the first places I worked after school was a shop that made printers (big).They had a speedfam lapping table that they used for the castings.The thing was hypnotic.I worked about ten feet from it and had to turn my back on it.Otherwise I would just stare at it (second shift).I just checked their site http://www.speedfam.com/en/index.html and it looks like they're into silicone chips now.There must be these things floating around at auctions.This thing took hours to remove any metal.

 

does anyone just have a diagram and a description of the figure 8 put out by these machines.