Working on a Lazy Susan

[Burkhardt]

I prepared a plate for a rather large Lazy Susam (22" diameter) and tried to make sure it will not warp or cup because I will cut the ball bearing channel (for marbles) directly into the plate. So I designed a jigsaw puzzle pattern that allows for circumferential grain orientation. While in the first place intended to be functional, I find it came out quite pretty and I wanted to share the idea. The whole thing was cut with an 1/8" bit from 7" wide Cherry and Poplar boards. It took about 2 hours at 80ipm for all the slices but that is about as fast as the small bit will go without too much deflection. If somebody is interested I would be happy to share the Vcarve file. It is not yet finished (just sanding sealer) and I suspect it may look better when done.

https://lh4.googleusercontent.com/-lr9l3ax2Fqo/UnMrpQ-Q6cI/AAAAAAAAETw/nhXlT-qXyhY/w833-h862-no/DSC01960.JPG

[myxpykalix]

G,
I LOVE IT! The fit looks like it was perfect and you did a great job. Before you go and carve a groove in it you might want to take a look at this:
http://www.vxb.com/page/bearings/PROD/LazySusan/Kit8883

I bought one of these for a 3D scanning stand i made where i could spin an object 360 degrees and had markings for every few degrees. It is very fluid and spins quite nicely and has screw holes for attaching to the top and bottom.

This way you won't "lose your marbles" (although many of us have been accused of that already!):eek:

[butch]

That is great. Took a little time?

[dana_swift]

I made myself a lazy susan like that from MDF, mine was square and exactly the shape of my card table (surprise surprise :) ).

I used the "marbles" approach with great success. It made the thing disassemble and store easily. I just keep the "marbles" in a pouch with the two identical lazy Susan halves.

Three tricks to make it work really well:

1) Make two bearing races (I used 3 as my LS was 36", however two would probably work well for your 22") that way the center is as well supported as the edges. Make the outer race about 2/3 the radius, and the inner one at 1/3 the radius.

2) make a flat pocket approximately 0.050" deep from just outside the outer bearing race completely across the bearing area. This contains the marbles when you first put them on the surface before you have distributed them around. It really helps keep any rolling balls from going past the bearing race, onto the floor and, then to someplace you cant reach.

3) If you use a 1/2" ball nose to cut the bearing races, then use 1/2" or 0.450 ball bearings instead of marbles, I tried marbles, but they are not made to the same diameter even though they look that way. Take a micrometer/caliper to them. Cut the depth of the bearing races so you have about a 0.1 gap between the top and bottom plate. So.. if you are using 1/2" ball bearings the 1/2" ball nose cut depth from the original surface will be 0.200". The cut depth below the pocket will be 0.150". Ball bearings made this thing work much better than marbles. They can be bought in almost any size you want on Amazon.

Get the bearings first. That determines the depths you need to cut.

Beyond that you have done magnificent woodwork! Your pieces look like a perfect mate!

Another suggestion, is make a temporary LS with MDF just to try your geometry before cutting into that beautiful wood! Be sure the bearings are not trying to climb out of the races. Fix the prototype.. not the article :)

Keep us posted!

D

[dana_swift]

Addendum:

An engineer friend of mine who designs ball bearing systems suggested I should have used a V bit to cut the bearing races instead of a ball nose. The V bit provides two points of contact with the bearings on each side instead of one. I have not tried that, but his point was good.

Thought I would pass it along-

D

[Burkhardt]

Thanks All for the advice!

Actually, I did some prototyping already in Birch plywood, see below and some other experiments with ball bearings. The marbles can not get lost easily because I cut the ball channels with a ball end/plunge bit, not a ballnose cutter. Different companies make them, not expensive, but magnate is the only supplier who offers one with a 1/4" shank which is important. With this bit I only need to plug the entry/exit opening.

I would normally prefer regular bearing balls because of the mentioned better accuracy. However, I am planning to make the ball channel visible and want to use red glass marbles for the looks. I found some on Amazon tht are reasonable cheap and accurate. Only disadvantage is they are 14mm diameter while my ball end cutters are 1/2" (too small) and 5/8" (too big). I will need to use the smaller one and run several paths with offset.

I hope nobody is going to ask why I am doing this.....maybe Jack Jarvis' is right and I lost my marbles already.

http://ecx.images-amazon.com/images/I/31QF5YPdxCL._SL500_AA300_.jpg

https://lh4.googleusercontent.com/-ghFz46rul5A/UleHkP8GTJI/AAAAAAAAETo/AmzfA6oU5pk/w962-h811-no/DSC01951.JPG

https://lh5.googleusercontent.com/--Gj06X22cLc/UI4SCBvrBLI/AAAAAAAADm8/bgYQa1DHx6g/w1024-h768-no/DSC01170.JPG

https://lh4.googleusercontent.com/-MyfUSBs6Nfg/UFaXOAVOEnI/AAAAAAAADks/Bvmq9lqFVNw/w1024-h452-no/DSC01148.JPG

[Ajcoholic]

That is extremely neat!

I have shared a lot of files, and I appreciate your willingness to share with others also! I'd gladly give that a try if nothing more than just because it is a great looking tray/shelf!

Andrew

acoholic@ntl.sympatico.ca

[myxpykalix]

G,
You might want to try your local "Dollar Store". I've seen bags of regular marbles for a buck there. Also they have the the clear ones in the section as table decorations. I've also seen some "Steelies" there. I don't know it they are the size you want but it might save some money and hassle just to go down there instead of ordering from amazon:eek:

[mark_stief]

O.K. you said don't ask but Why:rolleyes:

[Burkhardt]

O.K. you said don't ask but Why:rolleyes:

The simple answer is I am a nerd and like pushing the envelope of what is possible with such a machine.

The more complicated one is probably that I am a frustrated engineer stuck in a well paying management job that does not allow me to use my best skills. I may go into the sign business when I retire. Just something practical with my hands.

Now, where is that shrink when I need one? I know there are bigger problems in the world...

[Burkhardt]

That is extremely neat!

I have shared a lot of files, and I appreciate your willingness to share with others also! I'd gladly give that a try if nothing more than just because it is a great looking tray/shelf!

Andrew

acoholic@ntl.sympatico.ca

Andrew, I had a few requests by PM and tried to send it out by email but the files are just too big. Instead I posted that on Dropbox. You can download it here:

Outer Slices (https://dl.dropboxusercontent.com/u/29562014/LAZYSUSANSLICEOUT.crv)
and

Inner Slices (https://dl.dropboxusercontent.com/u/29562014/LAZYSUSANSLICEIn.crv)

Both Vcarve files contain a shallow surface cut that I do with a down-spiral bit and a through-cut with tabs that I do with an upcut bit. In this specific application the surface cut is probably not required because gluing together will not be perfect and it needs to be skimmed anyway.

I would suggest trying the fit with a pair of slices. I did not add any allowance and on my machine the bit deflection for conventional milling direction will give just enough clearance for a good glue gap. Your Mileage Will Vary....

[steve fedor]

Very clever. I found this, might be helpful for the bearing race. You have inspired my interest for some cool xmas gifts.

http://woodgears.ca/reader/walters/thrust_bearing.html

[scottp55]

Love to see stuff like this. Thank you.:)

[Burkhardt]

Very clever. I found this, might be helpful for the bearing race. You have inspired my interest for some cool xmas gifts.

http://woodgears.ca/reader/walters/thrust_bearing.html


I love that web site, lots of wild ideas. Even more admirable as most of these gadgets are made by hand or with simple power tools.

I the meantime I finished that thing. Looks nice to me, although my wife noticed the open bearing race may make it a bit unpractical due to food scraps falling in. Oh well.

Video clip in motion (http://youtu.be/g7pYSzSEiGo)

https://lh6.googleusercontent.com/-I5QN7bsm0ig/UnU-o1sVAEI/AAAAAAAAEUE/_ahJdXBqVo0/w1024-h600-no/DSC01967.JPG

[chiloquinruss]

Thanks for posting. I have added them to my 'round-to-it' folder! :D Russ

[myxpykalix]

ooh...watching that spin.."i be hyp-mo-tized!":eek:

I hope you learned a valuable lesson here....always pass your design ideas past the the boss so she can tell you where you are wrong first!:rolleyes:

I think it looks great, you did a good job of fitting things together really well:D

[steve fedor]

Here's an inexpensive solution to keeping it clean and I think you can put it in the dish washer. Try clear door bumpers from Big Box to keep it in place.

http://www.pier1.com/20%22-Round-Glass-Table-Top/2260459,default,pd.html#q=glass-top&start=6

[Bob Eustace]

This truly is a fantastic example of what CNC is all about.