Making a scaled down version of the Frankenbot to sell and possibly as next year’s entry kit for the kids at my school. Any suggestions as to what I should change for the smaller version? It will be 6x6x6in or 150mm cubed. 8mm rods all around. Haven’t decided if I want to try some 8mm delrin bushings yet or stick with LM8UU. It’s going to be a basic printer with no heated bed and single extruder. Definitely going for more laser cut parts as well
I have been meaning to put a smaller 8mm starter kit together… What would you change from the kit you started with?
I love the kit how it is but I would make a few tweaks. Firstly, I think smaller rods wouldn’t hurt. I love how stiff the 12mm ones are but the printer gets bulky. 8mm should do fine. I know you were discussing the possibility of injection molding some delrin bushings. I don’t know your cost on LM8UU bearings but I would bet that we could use bushings and get the cost down/make a quieter and smoother setup. I would also like to see another 608zz added instead of the smaller 623 (correct me if I’m wrong there). That one is just preference though. One more thing is the print plate. After many months of use, I have found my glass with a strip of aluminum on the edge to level quite well. It needed a little firmware change to get the leveling points and safe leveling working but that was fairly easy. Just a couple things that come to mind. I would love to work with you on another kit design if you would be interested @Brook_Drumm . This one is great but hitting a little smaller and possibly cheaper kit for makers to fiddle with would be awesome! Let me know what you think.
I am still testing the Delrin bushings idea. Today, I assembled a simple with all Delrin bushings. The real test would be injection molding, so we are going to make a test mild to decide.
I get the lm8uu bearings so cheap, it’s hard to beat my cost, but we shall see. I think a kit may benefit from lm8uus for accessibility right now.
The bed: I used to ship glass and it was a pain. They broke too easily. A 6x6 in aluminum is really cheap for me and very resilient.
I have a new v2 extruder that we mold in plastic- huge cost savings for a kit like this.
Smaller motors saves a few bucks. T
he play also uses a single z acme rod to save cost. If done right, it might be worth looking at. You have to trap the tops of the z bars for this to work
The 608zz is fine instead of the smaller one
I also have a cost savings idea I’ve been wanting to try on the y build plate… More on that off-line.
If low cost is the ultimate goal, there are a couple of tricks I have that I never used but would be a good fit here. It would be fun to see if they have merit.
Are you thinking no printed parts? Just laser cut wood/acrylic?
Brook
Any thoughts on using bowden extrusion instead of direct? Wouldn’t that help reduce extruder weight and vibration?
@Brook_Drumm I’ll shoot you an email and we can discuss further. I figured you get the bearings fairly cheap haha. Delrin bushings just interest me but either way works fine. No problem with strapping the z rods together. I’m aiming for rigidity as always so as long as it stays stiff. As for the bed I see where you are coming from. I’ve broken some glass beds here and there and if aluminum comes cheap then by all means I would go for it.
As for the printer parts vs laser cut, I’m thinking more towards all laser cut. I am getting tired of printing the same sets of parts for the printers this year and cutting them in 30 seconds would be so much nicer than a 3 hour print for a piece.
@Diego_Pablos I’ve had both setups and I honestly love my direct drive. It’s just so easy to swap filaments and it does add weight but offers some advantages over Bowden. Both are great but having that nice extruder body and motor right there is just well… Easy haha.
I think direct drive is so much easier for beginners. Low cost, laser cut and rigidity don’t usually go together ;). Low cost usually means “good enough” to start. I’ve always seen the price as the first barrier to entry, so just helping people get in the door is a good thing.
Brook
Thank you both! I asked to close an idea for using it from my coworker, this way I have the opinion of two makers additional to what I thought about it. Nice job in the Frankenbot @Griffin_Paquette ! Have you made any videos of it working?
@Diego_Pablos thank you!! I have a couple super rough videos off my iPhone if you check my YouTube channel. It’s the same name on there. Friday will be when I do my comprehensive overview and print example of the printer as the files are ready to be released.
Let’s develop the new kit in the wide open 
no need to take it offline. Community feedback is welcome as long as they understand it’s a bumpy road
Maybe a frankenbot 2.0 post?
Brook
@Brook_Drumm I love that idea!! Once we get a first revision of the theoretical kit worked out we can start developing the frame. I’ll try to incorporate what I have learned from the original Frankenbot! How should we set the build up?
@Brook_Drumm , @Griffin_Paquette , my vote is for printable nylon bushings, better (new or maybe open source electronics), included lcd and preloaded firmware, autolevel. I should be able to turn it on and go.
@Samer_Najia the beauty of the printrboard is that it has a sd slot that lets you print untethered already. I like the idea of printable bushings. My thought is making it compatible with normal LM8UU sized bearings and also allowing for printable/ injection molded ones if the user wants to switch.
@Griffin_Paquette , I used nylong bushings in one of my SmartRaps. Had to give it a little grease but otherwise worked like a charm. They are drop in replacements for LM8UUs and fit nicely in the pillow blocks too. Oh one more request…no more bushings secured with zip ties!
The Delrin bushings we are testing have screw holes that make it easy to mount to a flat surface.
We are abandoning the LCD for several reasons. One being that we are moving to wifi/LCD touch screen…, it’s s big plus for beginners but adds cost. Bare bones printrboard is cheap but lacks the ease of use of our new interface we are working on
I look forward to seeing/buying that
@Brook_Drumm this is my thought. Could we get a parts list together and then I could work on a design similar to the current Frankenbot but scaled down. If you want to go one z motor that’s cool. I think maybe a combination of printed parts and laser cut could be nice as I like the ability for people to iterate without needing a laser cutter after the initial set. What are your thoughts?
I like that approach! Keep it simple and get some success under your belt quick. I have all the hole spacing needed to trap the bearings from the old laser cut plus. You gotta build one to see how you like it. I’ll put together the parts and send them off. You can keep it or donate it. I’ll include the plastic extruder.
Sounds good!!! Still have the address or do you want me to re-email it to you? I’m excited to work with you again!