Re: VIDEO POSTED! Details about the BerryBot3D
April 04, 2013 05:47PM
nophead Wrote:
-------------------------------------------------------
> even one magnet plus a steel ball would pull
> towards the pole so probably has no benefit.

I think that difference is that two magnets will pull pole towards pole, while magnet and steel will pull pole toward center of the mass. Thus kinematics of two arrangements will be different, with joint 90 deg bent you will get contact area at magnet pole - steel equator vs magnet 45 deg lat. - magnet 45 deg lat.
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 01:37AM
Great comments Guys! And thanks for the compliments!! Kudos to you Viktor for playing with the idea! I figured someone surely had to have played with the idea. The two magnets simply won’t work with regards to the precision we are looking for. Although there is no question the mags would be very attracted and have pounds of force to spare the problem lies in that point of contact, it would very to a great extent. I am thinking that’s why Viktor did not pursue it? Like Viktor said the contamination and wear at the joint would also be huge.
Happy building!
Werner
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 03:46AM
hey BerryBot3D , can you post a video of your printer doing a calibration cube such as one here:[www.thingiverse.com]. i think your design is awesome. from what i gather there is concern of accuracy of shapes. i don't think there is, and a video would help! thanks!
Berry,

What is the purpose of the Teflon sleeve in the barrel?

Awesome work!

Jeff...
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 01:57PM
Contamination is easy to fix with a flexible cover over it, but why would there be any wear? Don't the two balls roll without slipping, so there is no relative motion between their surfaces?


[www.hydraraptor.blogspot.com]
VDX
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 03:19PM
... yes, the magnet balls rotate without wear and whn not overpowered or skewed, with an astonishing precision!

I didn't continue with the idea not because it won't be accurate, but because i have other projects on my desk, that are better fitting to my needs winking smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 05:50PM
Hi Nophead, I think you really need to play with a few mags to see why it wont work the way you are thinking. My Son could not figure out why I would not let him play with my mags. The thing is that the good quality magnets are multi plated chrome. The layer just beneath the chrome is copper a fairly soft material. Even when I was playing with them being as careful as possible not to let them snap-connect to each other there were times it seemed unavoidable just because they are that powerful. That snapping can create tiny flats on the balls. Not a huge problem but it will also micro fracture the chrome making them much more susceptible to pealing and making them unusable. Even without the snapping issue you would have to keep in mind that we are talking about 6 lb. of force on a minute area of contact. It’s a recipe that would never work! Now you put the mag in a caged socket with somewhere amount 2 1/5 lb. and an area 1000s greater riding on a cushion of Teflon that also acts as a wiper to keep any contaminates out "I think it will last forever periodically swapping in new pads".
I hope this helps Buddy?
Werner
Werner
Re: VIDEO POSTED! Details about the BerryBot3D
April 05, 2013 07:00PM
Yes I see your point. The contact area between two spheres is theoretically zero so the pressure is infinite. Is that why Viktor gave his prototype away?


[www.hydraraptor.blogspot.com]
Re: VIDEO POSTED! Details about the BerryBot3D
April 06, 2013 03:14AM
Hi Jalessi, My decision to use Teflon as a liner in my hot end barrel was twofold. 1. To minimize the amount of friction as the filament passes through and 2. Aid as an insulator for those long runs using hot bed temps.
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 04:24PM
This video is for jamesdanielv asking if the Delta printer can hold shape??

[youtu.be]

BerryBot3D - I just started playing with KISSlicer (Keep It Simple Slicer) this is a great slicing program. I was having a lot of weird problem slicing some large models but the KISSlicer did exactly what I wanted beautifully! A Buddy from the Reprap forum had some concerns about Delta printer being able to keep good registration and shape and asked if I would do a video so he could see for himself. It just so happened that I wanted to do some playing around with support structure and KISSlicer so this is what you get!
Thanks for watching.
Werner

Edited 1 time(s). Last edit at 04/07/2013 04:29PM by BerryBot3D.
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 06:10PM
Hi Werner,
Wow! That's a superb surface finish and dimensional accuracy! Very impressive!
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 06:31PM
Werner,
That really is an impressive job! When you see the struggles that others have had getting good parts, you make it look effortless. I'm still wiring my own machine, and was going to leave printing until later, but you've encouraged me to finish that up right away.
Thanks!

Gary H. Lucas
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 06:49PM
thanks Werner. looks great. it shows that delta bots if properly constructed work great! your design seems like it should be a golden standard!
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 07:08PM
I was pretty sold before...now I'm wondering if cartesian bots have a future.


- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]
Re: VIDEO POSTED! Details about the BerryBot3D
April 07, 2013 08:19PM
it all depends on if your closet space is it wide and rectangular, or is it tall and narrow smiling smiley

delta is just another choice in our arsenal. delta is perfect for tall statues.
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 07:11PM
I watched the Yoda video and your hotend video. Totally impressive! As someone building my own custom cartesian reprap machine, I know what it is like trying to build the prototype *and* the finished product all in one build...and getting the finished product to look that polished. Actually, I am 95% complete and was running out of gas when I saw the videos...gave me the boost I needed to actually finish.

One small question/comment: I love the magnetic ball rod couplers. Did I understand from the video that they are "received" by ball end milled pockets in the rod ends? If so, I wondered if you considered conical pockets rather than what I would assume to be spherical pockets? My first impression would be that conical pockets would be better than spherical in terms of determining the spatial position.

Again, beautiful.
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 09:30PM
Hi Mars, Yes they are spherical. The balls are exact diameter to the ball end mill. Now the beautiful thing is that once the Teflon pad is installed, the socket naturally puts a concentrated load toward the outer circumference of the socket. This achieves two things perfect caging of the magnetic ball and a better seal from contaminates for maximum precision and ultra-low friction. If there were any wear it would give a build in compensation to a small extent. The more I observe the pads with hundreds of hours on them now I am thinking it will be thousands of hours before I will need to think about replacing the pads. Keep in mind replacing all the pads is only a five minute job to complete.
I hope this helps Buddy!
Werner
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 10:19PM
"This video is for jamesdanielv asking if the Delta printer can hold shape?? "

This smal little Cube ist not a problem for a Delta, and your Print printed in the Center

Make a bigger Cube 100mm x 100mm x10mm or bigger and then see the Problem !
A Delta Prints only smal Objects in the Center of the Bed correctly.
When prints larger Objekts or/and print NOT in the Center see the Problem

Prints from a Delta have a better look, and have when prints larger Objects many Geometric mistakes
A Delta its better for Skulpture Objects an not for technical Objects

Prints from a XY Printer have a good Geometric and a not so good look
A xy Printer it better for technical Objects an not for Skulpture Objects


Your Printer ist a very good Work thumbs up

Hardwarekiller

Edited 2 time(s). Last edit at 04/08/2013 10:33PM by Hardwarekiller.
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 11:05PM
delta style cnc machines have been used for years with great success. for 3d printing its going to be just as accurate as any other method.
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 11:11PM
I am satisfied that people will like this delta setup. The lines printed are straight enough as well as the layering. Try getting a larger than 100mm part not to warp first, and then tell me about straight lines with it. sheesh!

40mm or 50mm part is well within reason for the video demo, and it was impressive!

good job berrybot!

Edited 1 time(s). Last edit at 04/08/2013 11:12PM by jamesdanielv.
Re: VIDEO POSTED! Details about the BerryBot3D
April 08, 2013 11:22PM
I've printed parts well over 100mm square on a delta and the lines are all very straight and as dimensionally accurate as any of my other printers.
Re: VIDEO POSTED! Details about the BerryBot3D
April 09, 2013 07:43AM
Hi Werner,
How did you calibrate the BerryBot? To get such good accuracy don't all the frame members, rod lengths, etc need to be just as precise, or is there some way of calibrating for the inevitable slight inaccuracies?


[www.hydraraptor.blogspot.com]
Re: VIDEO POSTED! Details about the BerryBot3D
April 10, 2013 01:13PM
Hi Nophead, I didn’t do any calibration. I did have very precise numbers to plug into Marlin that I generated from the cad drawings I used to machine parts. I also verified the numbers I got from cad on the actual machine often not being able to get same results off by as much as .3mm but went with numbers from cad anyway. I think as a builders/designers we are always asking ourselves how good is good enough. In the case of building my machine I did the very best my equipment/ machines and I could do. I also believe that everything stems from a precise base. I spent a lot of time designing what I thought would provide the precision and structure needed to create very accurate parts (see image). I have now printed parts 13.5” long off of center that are within a couple 10th of a millimeter. I am happy to say for a fact it is doable! In the image attached I am making a part that part is 13.5” long, very accurate and perfectly straight. I am finding one of the biggest factors “at least for me”, in reference to accuracy is in the settings in Repetier or Kisslicer style/material. I have seen as much as .2mm just playing with these settings. I am very happy with the results I am getting, its actually better than expected or will ever need.
I hope this helps Buddy!
Werner

Edited 2 time(s). Last edit at 04/10/2013 03:12PM by BerryBot3D.
Attachments:
open | download - SW Base Explode_1024x687.jpg (183.5 KB)
open | download - 100_1024x703.jpg (610.6 KB)
open | download - DSC_0021_1024x680.JPG (564.9 KB)
open | download - Open Cube_1024x729.jpg (370.1 KB)
open | download - DSC_0019_510x768.JPG (370.7 KB)
Re: VIDEO POSTED! Details about the BerryBot3D
April 10, 2013 02:46PM
akhlut Wrote:
-------------------------------------------------------
> I was pretty sold before...now I'm wondering if
> cartesian bots have a future.


I have 2 cartesian bots based on the Mendel design and a RostockMax printer, I've got a lot of time on all of them.
There are a lot of things to like about the Rostock.
The obvious disadvantage of the Rostock design is the packaging, it's very tall.
It is also significantly harder to level the bed and get a good print out of, once it's done it's done, but people really struggle with it.
Another issue is that the quality of the Universal joints really matter if they are overly tight you get what looks like backlash in the print, if they have slop you get the same thing. The magnetic joints look very promising.
The last issue is the quality of the delta support in firmware, it's adequate, but there are still issues.

I don't think Cartesian bots are going anywhere but the delta bots have a place, I'm currently building an Ultimaker style machine and I have an HBot I'm working on off and on.

Edited 1 time(s). Last edit at 04/10/2013 02:49PM by Polygonhell.
Re: VIDEO POSTED! Details about the BerryBot3D
April 10, 2013 11:56PM
Hi Berry,

Great printer that you designed! Was viewing your video and was wondering where you purchased the geared stepper motor used in your extruder? What gear ratio is the gear head?

Thanks.

Jim
Re: VIDEO POSTED! Details about the BerryBot3D
April 11, 2013 02:53AM
i plan on using your magnetic ball idea for my micro deltabot. they look fantastic.
Re: VIDEO POSTED! Details about the BerryBot3D
April 11, 2013 10:26PM
Hi Jim, Thanks, I get the gear stepper you see used in the BerryBot3D at:
[www.stepperonline.com]
I challenge anyone to get this kind of quality gear stepper for a better price!
I have ordered many from this company and they have always delivered as promised. If you would like some info on how I get the shaft from 8mm to 5mm just let me know and I can put something together for you. I just got some more, please see photos for data sheet and package info.
Happy Building Buddy!
Werner

Edited 1 time(s). Last edit at 04/11/2013 10:38PM by BerryBot3D.
Attachments:
open | download - 2013-04-11 19.11.14_432x768.jpg (252.9 KB)
open | download - 2013-04-11 19.12.07_1024x577.jpg (131.8 KB)
open | download - 2013-04-11 19.11.34_1024x577.jpg (141.4 KB)
open | download - 17HS19-1684S-PG5.pdf (384 KB)
Re: VIDEO POSTED! Details about the BerryBot3D
April 11, 2013 10:30PM
Hi Aduy, Glad to hear you are going to give it a go! I know you will find it to very easy and works awesome!
Good luck Buddy!
Werner

Edited 2 time(s). Last edit at 04/11/2013 10:39PM by BerryBot3D.
Re: VIDEO POSTED! Details about the BerryBot3D
April 12, 2013 12:10AM
Berry, thanks for the stepper info. How did you make the stepper shaft to 5mm? I do have a metal lathe but not sure if that would help any. Thanks.
Re: VIDEO POSTED! Details about the BerryBot3D
April 12, 2013 09:10PM
Hi Jim, There are probably many ways you could turn the diameter of the stepper motor shaft but here is how I do it. Since you have a lathe this will be easy! Chuck the stepper in your lathe. Keep in mind you will never want to turn on the lathe!! Get yourself a standalone stepper driver controller off ebay. [www.ebay.com] This one of my favorite things and a very handy thing to have in you tool box for testing out steppers, only about 11 bucks. Attach a rotary tool with grinding wheel to the tool post. You can rig up just about anything from small belt sander to die grinder I even used to use a ¼” air drill. Get your stepper rotating a few hundred rpm and start grinding the shaft down very slowly! I like to have the filament drive wheel in hand to check as I go for a snug fit. The finer grit wheel you have the better. A mini belt sander if you have one works very well. Take your time to get a good setup for this operation you will find it great for all types of projects. I have used everything from bungee cord to wood clamps to get tools mounted securely to my tool post. I now have a very nice mounting adapter for a die grinder that I machined out of aluminum. One other thing, be sure to put a towel down over all the ways on your lathe as not to get any grinding grit on them!!
Hope this helps Buddy!
Werner

Edited 1 time(s). Last edit at 04/12/2013 09:27PM by BerryBot3D.
Attachments:
open | download - 2013-04-12 18.04.06_1024x577.jpg (403.8 KB)
open | download - 2013-04-12 17.36.42_1024x577.jpg (572.9 KB)
open | download - 2013-04-12 17.36.55_1024x577.jpg (504.1 KB)
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