From BenchyBot to V1.8

[happylittlePCBs]

So, my V1.8 started life as a completely different printer, in fact it started life as a s***post

My friends and I wanted something silly to bring to ERRF 2019. We tossed around a few ideas, but one we decided on was building a bedslinger that looked like a Benchy

We called it BenchyBot. I designed it myself in Inventor, using cheap Aliexpress parts and like 5 rolls of Atomic orange PLA (I regretted this choice the more rolls I used, as it is $$). The mechanicals and frame brackets were printed on a gCreate gMax 1.5 (still one of my favorite printers to use) and the rest was done on his Prusa farm

As you can probably tell, I am not nearly as talented in printer design as the Voron team, so while Benchy was a very cute very silly printer, it was a HORRIBLE printer to use, and mostly took up space under my desk. So early 2020 I started looking into alternatives of what to do with the parts. I have an Anycubic delta as my other main printer, though that was gutted at the time (we stole parts for Benchy when something broke or didn't fit). My friend let me borrow his Prusa to bootstrap the Delta back to life (didn't particularly love the Prusa but it got the job done) and decided I wanted /something/ cartesian as Benchy's replacement. I considered designing my own, again knowing what to do this time, but that's still a lot of work. A friend recommended I see what other options were out there for pre-built kits or canned designs. I stumbled across Voron right around the time the V0 was released, and thought it looked like a cute little machine. My original plan was to take Benchy's parts and do a modded V0, but after watching some of Nero's early videos I started leaning towards the V1: I had the motors I needed, the frame wasn't /that/ expensive, and I already had some electronics. Ultimately a lot less of Benchy got used but the motors, belts, Z-screws, and quite a bit of the hardware definitely made it in to my build. The self-source path really vibed well with me: I could choose what I want, what upgrades, what mods, etc. Perhaps a little too well: there are some very quirky mods on my printer, but I'll get to that later. I also ordered my frame about a month before Printed Solid started carrying them, oh well (next printer I'm getting colored extrusions, they're so pretty)

 

 

 

Edited February 3, 2022 by happylittlePCBs

[happylittlePCBs]

One of the running themes here is cost savings: I tried to justify every purchase, and keep the BOM of *new* parts for the V1.8 alone under $500 (I even had a spreadsheet I used to tally and justify the cost to my wife!). Even with a few deviations and splurges I know I'm very solidly less than the cost of a Prusa. Frame was ordered (misumi parts were going to be a while, all the Ali stuff showed up in a month lol) and I started printing parts. I was a bit worried about ABS at first, but I used Inland with rafts and was extremely lucky to get very few warps/total fails

Once the frame did show up, it was time for tapping. My wife was not thrilled with the oil on everything, the smell, and the metal shavings. Had the LDO kits been available at the time I definitely would have gone for one, it's worth the extra cost

[happylittlePCBs]

So after everything was tapped (took a couple weeks) and bolts were ordered it was time for assembly. My wife let me use the kitchen table as a flat surface, before moving to its permanent spot behind me on a cabinet.

So now with the frame together came the first few deviations from spec: I had ordered the wrong linear rods from Ali (and didn't feel like ordering new ones) so my rods were too short. Easy fix though: I CADed up some extenders that bridged the extra distance (visible at the bottom of the frame) and they work great! I also wanted to reuse Benchy's leadscrews, but after accounting for the shaft coupler they were too tall, and going to hit the gantry. I solved this by adding some 25mm spacers between the stepper and the stock stepper mount. This then put the motors lower than the rest of the frame, so the rest of the frame was going to have to be raised/stabilized.

 

In the short term, I made some cups to fit over the stock feet. These kept falling off and were extremely annoying. The long term fix was some 25mm printed pieces that fit between the feet and the frame, held in by M5x40 bolts, but it took a while for me to get around with it. They work great now though! If you want either mod for whatever reason let me know! (applies to any of my CAD, I'm always happy to share!)

Edited February 3, 2022 by happylittlePCBs
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[happylittlePCBs]

The next major deviations from stock had to do with the bed and electrical system. I'm an electrical engineer, so I had some stuff lying around that somewhat influenced my decisions here, and made for a wildly different bed setup than most Vorons. My friend gave me some used server Dell power supplies, which turned out to be perfect for my build (other than being 12V, but I can live with that, it makes other things easier). I printed up some brackets for one, and found that it fit PERFECTLY at the bottom of the backpack. My only problem was cooling: they were designed for active cooling, and would thermal shutdown without it after about 20 minutes. Solution was a quick bracket and a blower fan, works great!

The other part of the decision to go with the 12V supply was the possibility to significantly simplify the wiring/bed setup by using a DC bed. I had used a somewhat crusty Anet DC bed on Benchy, and actually really liked it!. I looked around and saw a 220x220 DC bed was available on Ali (same/similar manufacturer) and got that instead of the normal bed. It heats up super slow, but from what I'm hearing it's not like other beds are /that/ much quicker, and given it was $20 for bed and heater that was an easy sell (I now have the makings of a 250 mains heated bed, but haven't made the upgrade yet). This did mean I was on my own for mounting, but I made up some quick spring blocks in FreeCAD to fix this problem

The only other significant deviation from stock is using a Duet 2 Maestro/RRF instead of Klipper. I had ended up with this board through a friend of a friend, and decided it would be a good fit. This means I've only got one control board for the entire printer, which is pretty helpful (no RasPi to deal with). Really liking RRF so far, it was mostly really easy to configure. What took the most time in configuring was getting the axes/limit switches set up, and figuring out why my bed heater kept erroring out. Turns out with such a slow heating bed RRF thought it was broken. It's not, it's just that bad  

The rest of the build was extremely fun and generally uneventful, other than one belt routing goof the gantry came together really easily. I'm using a Dragon regular flow (got mine just before they became significantly harder to get from TriangleLab). Wiring was an ordeal: I actually like cleaning up cables and making things neat, and even I thought this was kind of ridiculous. I ended up doing all my wiring inside the backpack, having a single control board for everything definitely helped make that possible. 

For the first couple weeks of testing I used blue tape on the bed. I had gotten a nice Energetic PEI sheet, but something I learned from Benchy: your printer WILL decide it wants to be a milling machine and gouge your bed, at least a couple times. I didn't particularly feel like ruining my PEI sheet on its first run, and sure enough I got one or two gouges as I learned how to level and set offsets, but after a couple weeks I took the training wheels off and added its current bed. I've almost entirely used textured PEI, just haven't had good luck with adhesion on the smooth side. PLA prints beautifully in the printer's current form (no panels yet, but I have them to install). ABS prints beautifully as well, just need a brim, though with the mains bed I'm planning on adding (and build chamber) this should be less needed I hope. PETG prints horrible, but I think it might just be this brand of PETG not being that great. The purple I'm using for accents is super stringy and blotchy, but it looks good at a distance

Definitely a couple more upgrades planned before going for the serial, namely panels to hide the wiring, enclosure panels, finishing the skirt, making a nicer switch panel, and general improvements in aesthetics. Long term I'm adding lighting, a mains bed, better filament storage and feeding, and probably upgrading to Stealthburner. But for now it's an awesome workhorse printer and I'm enjoying using it, just have to find more projects to print!

 

[Demosth]

Awesome guide, thanks for the detailed explanation of why you chose what, and for the build photos through the process!

Looking forward to seeing the completed finished project - looks so much more professional than the BenchyBot!

[happylittlePCBs]

Since I haven't logged in in ages, couple decent upgrades were made, probably the most noticeable was moving the entire electronics bay underneath the machine, so now it's some sort of unholy V1.8-Trident mishmash (BUT IT LOOKS SO CLEAN!) Added lights, enclosure, and skirts w/ integrated power button