Welcome to the SeeMeCNC Community

A big thank you to John and Steve (SeeMeCNC) Johann (Who I think everyone knows), Zack (Inventables) I am having more fun with my printer than I ever thought.

Jealous.... That machine looks great.

that looks so much easier to assemble probably a bit easier to calibrate since everything is probably more sqaure.

JOHN! YOU MUST KIT THIS. RIGHT NOW!

g.

Brilliant and innovative use of magnetic ball joints. Nice polish and fit and finish on everything.

I like the use of aluminium in particular.

Thanks for the nice comments Guys. Setup and calibration was really easy with every part CNC machined it was just putting in numbers and setting the up limit switches. The magnetic ball joints is the thing I am most proud of! I had never seen it done on a printer? I did get the idea from the ATX show I go to every year in Anaheim CA the same concept is used on some very EXPENSIVE delta robots. I tried sourcing the mag-ball joint and did find some made in China however they were way too expensive. So I decided to make them myself. It was actually very easy and I personally think nothing could come close as far as precision. Another thing I really liked is using Makerslides. My reason for this choosing Makerslides was also they are very precise and have great adjustability with preload. You can see the magnet ball joints in action here: http://youtu.be/hHdPz895r8g

*drools*

g.

That shows that the base can be much thinner without the PC power supply.

Would you please leaborate on the magnets and the setup. Are the balls the magnets or are the magnets in the rod ends. What is the shape of the interfacing between the two.

You should be really proud of the use of the magnetic setup, brialliant!

Sure thing Flateric, I will show you some pics I think you will see. The balls are the magnets. JB weld to Adhesive glues the mags to aluminum.

Impressive.

What is the friction like on the magnetic ball joints? Are you concerned with high speed moves?

The magnetic ball ride on a Teflon bearing pad. With 2-3 pounds of force there is almost no measurable friction. Something that I think is important to pay attention to is the positioning of the balls when JB welding them to the aluminum sockets so that they are located naturally north or south on the poles. You can feel the difference it in the way of counter force if they are not in alignment. When you watch it in action you can see that they move so little I am thinking they will last for years. Then the bearing replacement is nothing more than a small Teflon disk I punch out of this material I purchased from McMaster Carr: 76025A333 Its enough for material for 10 lifetimes! I believe there is nothing that will come close to giving the precision the magnet joints can provide for so little money?

Thanks for the great information. From my searches it looks like the magnetic ball joints are about $10US each times 12 would be $120. Is that about right or did you find another lower cost source?

regards,
Michael

Glad to help Buddy! I made mine with these: http://www.fridgedoor.com/maspd03.html These are very special!! Super mags. And some of these from McMaster Carr: 91259A546 I just used a 1/2" ball endmill to machine the socket in them. Post link of the ones you found and let me take a look?

It's interesting that they're cheaper there than here: http://www.rare-earth-magnets.com/c-12- ... gnets.aspx

g.

I like that - home made ball joints! I most certainly am setup to do that.

I was looking at:
http://www.frenergy.com.au/categories/M ... ll-Joints/ (Australian so shipping is high)
http://www.tmcmagnetics.com/ball_joint_assembly.html
http://www.wpiinc.com/index.php/500871.html
http://www.magnetics-china.com/magnetic ... oints.html

I found similar prices to mhackney but couldn't find a US distributer.

I like the Teflon bushing. Pretty simple solution to friction. Any issues with the Teflon being cut from a flat sheet then placed in the cup of the socket?

Out of curiosity is there a reason why the ball is magnetic versus the "socket"? You mentioned a polarity influence on the joint. If the ball was steel and the socket was magnetic there would be less influence to polarity but not sure how to accomplish that with off the shelf parts like you have.

Another source for magnets- kjmagnetics. They seem reasonably priced and lots of options. Not sure of minimum orders or shipping costs. I do have a couple of samples from them sitting on my desk at work.

Wow, that thing looks amazing. Do you have plans to kit that and sell it?

Great find on the other source for mags! You know I could very easily make up kits but that’s not really what I want to do. I am a builder and have a huge list of things/ machines I want to design and build within my lifetime and it is going to fast!! I am sure you could do the same type of thing with mags at the sockets I just didn’t even consider thinking it would be much harder to do. Here is something I think is truly awesome and doable with mags. I just took this pic with my cell phone. I will call this Guy Mr. Yoda at 50 micron. The really cool thing is this is from a machine that has a build volume of 6 times the Replicator 2 and platten of 14”. If everything go's OK I will post a pic of him completed. About 11 hours…. Yikes.

Sorry forgot to answer your question about how the Teflon disks staying in place. It works great with nothing more that the adhesive that comes on the material. Should you ever need to replace them it is simple to pop them off.
Werner

I have and am actually investigating making a higher end aluminum kit with some other bells and whistles. The challenge really is "price" and what will the market support. The costs of raw material and machining of aluminum are much higher than laser cut melamine. Then factor in motion control and bearings (whether ball or other) for the delta arms, etc and the costs add up. I am building an aluminum frame delta myself and with electronics and everything all-up I'll have about $600 into it plus lots of labor. In order to make something commercially viable you "should" factor in $100/hr labor costs and a 50% markup or so. Obviously companies selling millions of something can work on very narrow margins but niche products like this require more margins to do it right and provide the support and documentation to make it as turn key as possible. I've been doing this for several years in my EclecticAngler.com business so I have a pretty good idea of what it's all about.

I see the roll of filament and the extruder up on top, can that be mod'ed with the standard Roshock max? I think that is a much cleaner look and would really go for that.

Has anyone else done that?

Yes it can be done, a hole even exists to do it. I don't know of anyone who has done it on a MAX though.

Like Mhackney said I am sure it could? That is the reason I designed mine that way, I just wanted it clean and out of the way. I thought it might be more of a pain to change out color but it is not a problem. Thats also the reason for mounting the filament feeder where it is so it would be easy to monitor and do change outs. I will make a facia to wrap around it someday. Mr Yoda is looking good so far we are past the chin.

Looks like he has a hair on his chiny chin chin! Looking good so far!