Adventures in 3D Printing Part 1: The Search for the Ideal Printer Farm Unit

A couple years ago I came up with a business idea for a large consumer product made to order using 3d printers. The user could customize the product to their hearts content (within reason), then hit purchase. Imagine trying to pull that off with injection molding - the tooling costs would be astronomical, if not fiendishly complex! And so began the hunt for a 3d printer that could be the basis of a printer farm.

My requirements were simple: low cost (I’m going to need at least 10 of these), a large print volume of 30cm x 35cm x 30 minimum with more being better, and a dead reliable machine. Also, the printed product would weigh a couple kilos, so a sturdy printer was needed. Oh, and hackable was also a nice-to-have, well maybe a must-have.

Easy enough right?

The search started with the usual suspects of the day: Ultimaker, Lolzbot, Zoltrax, and PrinterBot. I then moved on to other companies such as Fusion3. All the printers were great in many key areas, yet none fit the bill for size. Printers at an appropriate size, such as Builder, quickly got out of the budget range for a startup. At $5000 per printer and up, I was looking at $50k for a small 10 unit farm!

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Folger Tech FT-5 Printer Kit
Enter the Folger tech FT-5 printer kit (no affiliation). The build plate fit my size requirements at 30cm x 30cm, and the platform could easily be modified for more. It was built from sturdy 2020 extrusion and linear rails, and at $500 it was a feasible price when looking to buy up to 10. Also, while having used 3d printers at work, this was to be my first build, and it looked to be a good platform to see the strengths and weaknesses of this type of design.

The good
The kit was fairly well though-out, the instructions were quite thorough, and firmware setup was a breeze. Also, the overall size was impressive at 460 and 500mm between extrusions in the X and Y.

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The not so good
First, to keep costs down, the kit used laser cut Melamine for all the brackets, which was neither stiff nor incompressible. This was solved by running a DXF file over to my local metal working shop to laser out some 1/8 inch aluminum. The next issue I ran into was the dual motors on the Z-axis, which allows the bed sag and come out of alignment when the power if off. This required a quick fix of removing one motor and using a 1000mm belt with an idler to connect the two Z lead screws. Another issue was the large PCB heated bed running off 12V, which had slow heating and uneven print surface. I solved by switching to a 24V power supply, and a 120V silicone heater running through a solid state relay. I also tried glass, then settled on Basalt tile for a bed. The final issue I came across was a questionable hot end, which was swapped out after the first print for an E3d Lite 6 and Bowden setup. To Folger Tech’s credit, most of the above issues have been resolved with their V2 revision, though I’m not sure on the hot end.

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So now I had a printer that was in the neighborhood of just under $1000 complete, that actually produced fairly high quality prints, and could be modified to allow more X or Y travel to make test products.

But a printer farm candidate it was not.

Why?

Well, for starters, the kit saves cost by being easy to manufacture, not easy to assemble. I think it took me at least 15 hours to get it assembled and running (including metal laser parts). Not to mention I would do just about everything differently design wise given a blank slate.

So that brings me to my next challenge: designing an easy to assemble, cost effective, scalable 3d printer from scratch as a printer farm candidate. On to Part 2 of this blog, DIY printer!


Posted by Giles Medlicott on Nov 19, 2018

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