Xnaron Printable Magnetic u-joint option for Rostock Max

[Generic Default]

I'm going to do this upgrade when I get my board back in a few days.

The Ebay link is dead now, it looks like the seller stopped selling. I found some 3/8 x 3/16 and 3/8 x 3/8 magnets on amazon for a reasonable price, but I want to know what the holding force was for the magnets you guys got on Ebay. The amazon ones have a force of 6.4 lbs for 3/8 x 3/16 and 13.5 lbs for 3/8 x 3/8. Is that good enough for delta arms? Has anyone had a problem with the magnets breaking contact on high accelerations? I can design my own parts if I need to use different sized magnets, but it would probably be the most convenient to use magnets that are the same diameter as the arm rods.

[Broose]

My recollection is that the ebay ones were 10 lbs holding force, so the 3/8 by 3/8 should be fine.Could you post the amazon link to those?

I bought a digital pull scale and found that the pulling force of each of the rod ends with the ebay magnets on the balls before they disengage is about 2 lbs. The magnetic force of two magnets is proportional to the inverse square of the distance between them, so assuming the magnetic force between one magnet and a ferrous ball behaves similarly, the magnet needs to be as close to the ball as possible. I have not yet had mine fly apart due to acceleration, but I have not been pushing speed or accel to the outer limits. I think I have accel currently set to 800.

[lordbinky]

The ~10lbs force ones are N52 Neodymium which is what MHackney used and I thought the Link was for N52 as well.
http://forum.seemecnc.com/viewtopic.php ... =390#p8905

[xnaron]

Here is the new link for the magnets. The seller still sells but ebay doesn't allow magnets that can be swallowed. http://shop.revolutionmachines.com/3-8- ... 8-12pc.htm

[Eaglezsoar]

Here is the new link for the magnets. The seller still sells but ebay doesn't allow magnets that can be swallowed. http://shop.revolutionmachines.com/3-8- ... 8-12pc.htm

I can understand the policy but there are at least a hundred entries for the small magnets. There has to be more involved, but it is not that important. What is important is that you found the link to the magnets and I appreciate
you posting it here. Thanks!

[Generic Default]

Thanks for finding the original magnets! Here is the amazon link for similar ones;
http://www.amazon.com/Disc-Package-Eart ... 08&sr=1-91

The problem with those is that they come in a pack of 10, so I'd have to buy 2 sets for the magnetic arm upgrade. 2 sets would make the shipping free though, so the cost would probably be about the same as from the other website after shipping.

Does anybody here have a big enough budget to experiment with different sizes of magnets? There are some bulk magnet packs on amazon that have like 200 magnets per set, which might be an alternative for people who want to customize their delta printers. I also saw a pack of 50 ceramic magnets at Hobby Lobby a few days ago that only cost $7. If something like that works for the Rostock, we could save a lot of money and shipping time.

[lordbinky]

The ones you linked are N45, so they should be weaker than the N52. How that listing got 13lbs of hold while keeping a 1,000 less gauss is beyond me. Either they're over calculating or Revolution machines is selling themselves short.

Here's another site you can order magnets from, any amount of exactly of the same type Xnaron listed but they are still $3 more for 12 than Xnaron's pick before S&H.

http://www.kjmagnetics.com/proddetail.asp?prod=D66-N52

On the note of swallowing magnets, I don't know what triggered it to get so much attention recently. I had like 3 recall notices for various sets of bucky balls (tiny Neodymium magnets as a desk toy) I ordered. Everything with neodymium magnets has always had a warning and I know I've read a couple times where they explain WHY it's so dangerous when swallowed.

[Broose]

Here's another site you can order magnets from, any amount of exactly of the same type Xnaron listed but they are still $3 more for 12 than Xnaron's pick before S&H.

http://www.kjmagnetics.com/proddetail.asp?prod=D66-N52

Thanks for this link. Its pretty easy to chip these magnets and a source for just one or two is helpful

[doctorgonzo]

You know, I know it's my first post and all...but you can stack smaller magnets and achieve the same results as a single larger one. Just saying.

[Generic Default]

Have you tested it before? I was considering getting a larger pack (100 or 200) of the thinner disk magnets and stacking them up, maybe like 5 per ball socket or something. I don't know how that would affect the strength though.

We should also consider magnets rated for higher temperature and maybe just bigger magnets in general.
http://www.amazon.com/CMS-Magnetics%C2% ... ium+magnet

Those are rated for 28 lbs, which might allow us to use higher accelerations. We should also try to find neodymium balls instead of using chrome steel balls. I just ordered the ones from Revolution machines, so I'll try to do this upgrade and make my own customized effector next week when I get my rambo back.

[barnett]

you can stack smaller magnets

I think Jetpad is stacking thinner magnets.

[lordbinky]

Stacking magnets won't get you quite as good of strength as a solid one, but for this it could be unnoticeable. I still ran into the problem of the magnets not being sold in the right amount, so they would come in packs of 20, when I needed 24 to be equivalent.

[Broose]

One of the things I like most about the magnetic arms is the speed with which you can disasemble the platform with the hotend. I printed up a second platform and have the E3d set up for ABS and nylon, and the other head (makergear style, from the guy that makes the screw-in thermistor) for PLA. With the Dean's plugs, I can swap them out in hardly more time than it takes to swap the filament, then just change the Z-max length and PID and I'm back in business. With micro Dean's, it would be even faster.

[ApacheXMD]

With 4 pin micro deans, I have one connector for the heating resistor and thermistor, and then one additional connector for the PEEK fan and two pins for future expansion (lights probably).

[kbob]

I can swap them out in hardly more time than it takes to swap the filament, then just change the Z-max length and PID and I'm back in business.

With some careful shimming, you might be able to keep the same Z axis length with both heads.

[Eaglezsoar]

One of the things I like most about the magnetic arms is the speed with which you can disasemble the platform with the hotend. I printed up a second platform and have the E3d set up for ABS and nylon, and the other head (makergear style, from the guy that makes the screw-in thermistor) for PLA. With the Dean's plugs, I can swap them out in hardly more time than it takes to swap the filament, then just change the Z-max length and PID and I'm back in business. With micro Dean's, it would be even faster.

Dual Mag Platforms.jpg

Very nice picture!
Are those the original Xnaron effectors, they look different somehow.

[barnett]

Are those the original Xnaron effectors, they look different somehow.

Those effectors look familiar to me... actually nicer than the one I printed.

I have to agree my favorite thing about the magarms is how easy it is to take off them off.

[Broose]

Very nice picture!
Are those the original Xnaron effectors, they look different somehow.

Props to Barnett for the effectors and Xnaron for everything else
http://forum.seemecnc.com/viewtopic.php ... rms#p13340

[Eaglezsoar]

Props to Barnett for the effectors and Xnaron for everything else
http://forum.seemecnc.com/viewtopic.php ... rms#p13340[/quote]

Which slicer did you use to print the effectors? They look great! Are they ABS?

[Broose]

Which slicer did you use to print the effectors? They look great! Are they ABS?

I used Kisslicer and they are ABS. Of course, having the Xnaron mag arms helped with the print quality.

[Eaglezsoar]

Broose wrote:One of the things I like most about the magnetic arms is the speed with which you can disasemble the platform with the hotend. I printed up a second platform and have the E3d set up for ABS and nylon, and the other head (makergear style, from the guy that makes the screw-in thermistor) for PLA.

I noticed that the hotend you are using for the PLA has no slots in the Peek to aid in cooling, is that a problem for you?
I just went to his website and it does show there are no slots.
Is that a custom fan mount you have on the PLA head?

[Broose]

I noticed that the hotend you are using for the PLA has no slots in the Peek to aid in cooling, is that a problem for you?
I just went to his website and it does show there are no slots.
Is that a custom fan mount you have on the PLA head?

It seems to work fine for PLA with the fan. Yes, I made a little box to hold a 25mm fan next to the Peek.

FANHOLD.stl

(87.35 KiB) Downloaded 320 times

[Broose]

With 4 pin micro deans, I have one connector for the heating resistor and thermistor, and then one additional connector for the PEEK fan and two pins for future expansion (lights probably).

I think I'm going to go that way too and use the second micro deans for PEEK fan and work area fan(s). With Polygon's Repetier Firmware, he has separate outputs for the PEEK fan and work area fan(s). The PEEK fan comes on as soon as the hotend goes on, and the work area fans are controlled by G-code. Does anybody know if SeemeCNC's Repetier Max firmware works the same way?

[thenewguy]

Thanks for the files xnaron!

I'm having a lot of trouble with printing the ends. I got the balls from the source you suggested as well as the magnets a few months back.

I purchased a carbon fiber rod from a link posited on here and it is the correct size however I printed this thing about 20 different times with different settings and can not get the balls to fit perfectly along with the arms.

Either the arms will fit and the balls will have to much play in the socket or vise versa. I even tried drilling out the ends some and still having trouble.

I'm using kiss and have it tuned pretty well. Am I missing anything that I didn't think of? Do anyone remember what they used for settings?

Off hand I know I was close with using
Vase
Jitter at 360
Wipe and destring on
Nozzle and infill at .55
Loops at 10
Layers at .2

Any help would be awesome thanks...

[Broose]

What is the diameter of the carbon fiber rods? I bought enough for 2 sets from 2 different sources. one is .366 inch dia and the other is .376 inch dia. I couldn't get the larger diameter ones to fit and I ended up using the smaller diameter ones. Did the magnets fit all the way to the bottom OK? If so, you can chase the holes with a slightly larger drill bit most of the way down to fit your rods