YouMagine

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Mark_Rehorst

about 6 years

I made a test print with the new worm drive installed in UMMD and I have to declare it a failure. There is a lot of Z ribbing at 2mm intervals- so there is some quality problem, most likely with the worm gear because it spins one full rev for every 2mm of Z motion. Photo here: https://4.bp.blogspot.com/-_WnQ6nhaZ60/WsmkTYmsJ4I/AAAAAAAAVT4/lJ-1Y7xupYAy1mQkcWOniAC0kroV-nFkwCLcBGAs/s1600/04080001.jpg The problem was hinted at in the second video linked in my previous post. When I moved Z in 1 mm intervals, every other step was good and the steps inbetween were off a bit. I'll be putting the Rino back into the machine today.

Patrick Szewczyk

about 6 years

Thank you very much for your efforts and your advice. I will move to a 500x500x695 build envelope to make things easier and keep some dimensions the same. Can't wait for the new post

Mark_Rehorst

about 6 years

I don't know where you'll find a 700x300 heater unless you pay to have one custom made. That's 2100 cm^2 and at 0.4W/cm^2 you're looking at almost 1 kW for the heater. You can use lower power, but it will take a while to heat up. The bed may sag a bit over a 700 mm span, so you might have to change the support and leveling structure or use a sensor and map the bed to compensate in the controller. It really depends on the print layer thickness you intend to use. If you want to print in 50 um layers over the entire bed surface you'll need to make changes. If you want to print in 0.5 mm layers you probably won't have to do anything. Otherwise, I don't see any issues. I've been working on a cheaper alternative to the Rino worm gear drive which cost about $140 via ebay, including shipping and the long, keyed 8mm shaft. The new design uses inexpensive worm gears from China and a NEMA-17 motor and costs about $40. I just installed it in UMMD and started testing two days ago. Video here: https://vimeo.com/263456441 and https://vimeo.com/263606489 I'll be publishing a blog post on the new design in a day or two. I switched to GT2 belt and pulleys which required a redesign of the belt clamps and the spacers that stand the pillow blocks off the plates at the bottom of the Z axis. I also redesigned the upper pulley plates with ridges that fits into the slots in the frame to prevent them from rotating. They now use a single bolt to hold them in position. The new worm drive uses 40:1 gears and 40 tooth drive pulleys which results in 1600 usteps/mm or 100 full steps/mm resolution, so full-step-multiple print layer thickness can be any multiple of 0.01 mm. The increased gear reduction will probably limit maximum speed to somewhere between 10 and 20 mm/sec, depending on the motor you use, but that's OK for the Z axis.

Patrick Szewczyk

about 6 years

Do you foresee any issues if I did this in 700x300x300? All the design features should still work just lengthen here and shorten there...

Leo_Aguiar

over 6 years

Hi Mark, thanks! Got it to work!

Mark_Rehorst

over 6 years

DesignSpark doesn't export to any other format, unless you want STL, OBJ, or a 2D DXF file, none of which seem very useful. DesignSpark is free. All you have to do is install it.

Leo_Aguiar

over 6 years

If anyone else has DesignSpark and could do the favor of exporting to a more common file format I think it would be greatly appreciated.

Leo_Aguiar

over 6 years

Hi, this printer looks awesome. I've read your blog and your attention to detail is amazing. The Z-axis design is fantastic. I'm planning on building my own printer and I'm convinced your design is the best. I just have one problem. Could you upload a file format other than rsdoc?

mifga

almost 7 years

having seen machines in this series at the Milwaukee Makerspace, I must say I am incredibly impressed by these!! so great!