Your opinion. Building body for i3v 12in out of aluminum rails and v slots.

I have had my second 3d printer for about 2 weeks. An i3v Prusa 12in from Makerfarm. I noticed that it can't seem to get the quality finishes on the surface of my prints as compared to my Replicator 2.

I wonder, can I get prints to that quality from just tweaks? All I have been doing is tweaking for the past 2 weeks.

Are the quality of prints based on the fact that the body is made of wood?

I found this website http://openbuildspartstore.com/, and I think it looks easy to make a metal body with these parts, and with the parts that come with the i3v kit. And maybe even extend some of the axis for a larger build volume. Especially the z axis.

Would body made of aluminum extrusion rails get the quality close to my Makerbot Replicator? Would the motors be powerful enough to extend the x and y axis?

I don't doubt you'll get quality prints using v-slot, depending on the engineering tolerances of the parts you buy. That being said, you can get good quality out of a wood-framed printer, but it does take a lot of tweaking (as you discovered). I think one of the main issues is dealing with flex in the frame or axes.

Odd things like the placement of filament can cause quality issues. Each time the extruder pulls on the filament, the filament pulls on the extruder (equal and opposite reaction). If your extruder isn't rock sold, it will move and will cause irregular banding issues on your print. This particular problem can be overcome by simply running the filament through a bowden tube, one end of which is allowed to contact the top end of the extruder and the other fixed to either a strong point on the frame or even somewhere on the table the printer sits on. The force will no longer act on the extruder and you'll get a definite improvement in quality.

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Originally Posted by sapient24

Would body made of aluminum extrusion rails get the quality close to my Makerbot Replicator?

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Yes, but only after tweaking. The Makerbot has been subject to a great deal of design and tweaking effort. To get good results you'll need to be prepared to put in some effort beyond bolting extrusion together.

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Originally Posted by sapient24

Would the motors be powerful enough to extend the x and y axis?

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It depends on how much you'll be extending by. You might want to consider upgrading to NEMA 23s.

Thanks for your reply 3dkarma. I'm going to do it once I establish some confidence with my new machine. I've seen people pop out really good looking prints with Makerfarms Prusa with little to no mods. So I got some learning to do..

The question on migrating from the wood frame on MakerFarm i3v printers comes up periodically in the reprap and MakerFarm subforums here. IIRC, there have been a few who have committed to go off and swap out the frame, but I don't recall anyone coming back with results.

Where do you think the wood is creating a problem for you? Prior to my purchase of a MakerFarm i3v, I concluded the way MakerFarm is already using v-slot aluminum rails should minimize concerns with the wood frame. The v-slot rails will already be providing a lot of rigidity that something like a wood frame rod & linear bearing i3 printer won't have. The angled frame sides that widen at the bottom provide a very rigid support for the vertical v-rails. Short of migrating to a full cube frame structure, I don't recall anyone offering a good, strut based replacement for the support provided by those sidewalls. You'd likely be wanting to keep a plate type of sidewall.

During the build, I studied my 8-inch printer and observed the following areas where I felt there was a possibility of concern -

• Single thickness plates at the front and rear of the Y-axis could be subject to flex. I solved this on my printer through making them thicker by adding wood reinforcements
• The z-axis motor brackets can flex a bit; I currently haven't done anything about this possible concern
• The x-motor mount can flex. I haven't used it, but attempts are underway in the MakerFarm subforum to develop a printed replacement with reinforcements that should minimize flex. See X-Motor Mount One Piece Print Idea.

Unless there's something I've missed, I'm not sure migrating to an all-metal frame would do much. Like 3DKarma suggests, you'd want to do that only as part of a system of other tweaks, including things like providing better belt attachment points for the x-carriage and y-bed. Make sure you're familiar with the mods thread in the MakerFarm subforum and the i3v tweaks available on Thingiverse if you haven't looked there.

Finally, I wouldn't be surprised if some of the print differences you see are driven by differences between Marlin firmware and Replicator firmware.