3DPrintMi - Print. Make. Innovate.: cheapest 3dprinter

Sunday, January 18, 2015

Build Log #? - Introducing the Aluminum 3DPrintMi

Back again and reviving this good ol' build blog with some new content. I mentioned on my last post I was working on revamping the 3DPrintMi by switching to a more robust frame. After that, I got tied up with work and never found time to post my progress. Since I didn't post anything for a whole year, this post will show off all the cool new frame and features from the last post up to today.

Alpha Aluminum 3DPrintMi

This was the last picture I took of the new 3DPrintMi. I replaced the threaded rod frame with aluminum extrusion 2020s and boy, they are surprisingly cheap. I purchased them through Misumi and I can get one 370mm extrusion for $2.10 pre-cut. You can even select the length too. Even though threaded rods are cheap as dirt, you save on labor time. No more measuring, cutting and grinding.

IIRC, I was trying to retain the original design into the new frame to see if it was feasible. It wasn't. The Y gantry (build plate direction) had some major wobble when you apply pressure to the top frame.

The Aluminum 3DPrintMi

Here it is! Looks very different from the alpha version. I completely toss all the threaded rods out It's my workhorse right now, hence all the tools lying around. This little guy already put in 300+ hours of service and still going.

Trying to remember the steps I've taken to get to this stage. Below is a series of re-design stages from the past year.

Removing the Y Wobble

(a) Parallel bars

(b) Z Motor mount

The solution I came up to stabilize the frame was by simply laying another 2020 parallel to the bottom frame (a). I redesigned the Z motor mount (b,c) to hold the 2020 and it came out really sturdy. Adding more function to a part reduces the part count needed.

New Y Gantry

(a) Y End

With the new framing in place, I had to toss the Y Gantry setup which were the same parts used on my original 3DPrintMi. I didn't want to keep wasting my limited stock of 2020s so I challenged myself into designing a Y gantry using only one. What I came up with didn't look very robust at all (a) but after bolting it on and applied some tension to the belt, it remained seated.

Top Z Stabilizer

(a) Top Z Stabilizer

Replaced the top threaded rod with a 2020. The threaded rod at the top was meant more to hold my spool while providing some rigidity to the frame. It was a bit too bulky and ugly to look at so I designed a new Top Z Stabilizer (a) that turned out better and requires less plastic.

Tangle free spool mount

(a) spool mount system

(b) System with spool

The spool mount is a re-imagination of my previous spool design and mounted on the 2020 (a). It was originally placed in the middle with the filament going straight down to the extruder but later moved to the far left (b). I have this issue where my spool would dismount during mid-print. I thought it was from the vibration shaking it off but it realized that when the spool nears be empty, it becomes lightweight. Coupled with the filament moving left and right during printing, it will fly off.

I came up with this filament feed tube guide (c) similar to the MakerGear M2 setup. The filament enters the feed tube that's fixed in place but free to move around at the other end. This setup removes outside forces to the spool and firmly seated.

Re-designed Vert-Xtruder

(a) Vert-Xtruder with ducted fan

The new Vert-Xtruder. I modified a MBE (Makerbot Extruder) lever to pair with the Vert-Xtruder motor mount. On the right is ducted fan for cooling PLA prints. Using a blower fan that delivers a good amount of air to the build plate.

(b) Modified MBE paired with Vert-Xtruder

Redesigned the Vert- Xtruder motor mount to be completely flushed with the MBE lever. This is necessary for printing with flexible filament where it tends to buckle during mid-print. I'll be uploading the new design on the thingiverse page.

Closer look at the ducted fan setup. I plan to bring the duct closer to the nozzle. It works really well printing with PLA but I the fan is so strong that I have to increase the nozzle temperature to 240C to prevent the extruder from jamming due to the nozzle cooling down too much

That's it so far and I still have a lot more to do. Here's a few things I'll be working on in the next few days:

- Finalize the BOM

- Redesign the ducted fan

- Start on preliminary designs for auto leveling probe setup

Tuesday, January 7, 2014

3DPrintMi turns one year old

Happy Bday to 3DPrintMi.

Haven't touched this blog in a while and it's long overdue for a post. New developments for the 3DPrintMi has been put on hold for now. I've been pretty busy lately since I'm currently involved in a 3D printing startup. Launching soon! When I have time, I usually work on the 3DPMi but I really need to prioritize what I want to get done since I keep expanding my laundry list of new ideas. Actually, the only thing I should work on is implementing a duct fan mount for PLA printing. Another thing I've been doing is printing parts for customers through MakeXYZ.com. I didn't think I would get any customers through that site but after adding a few pictures of my work, people started asking me to print a few jobs. To date, I have made about $400!

The only project I have going on right now is completing my 4th 3DPMi. The difference here is that I'm going for the absolute cheapness build. My main goal is to get the 3DPMi price down to below $300 and release the BOM with all the vendors listed. There were a few sacrifices that had to be made for this build. It would have to be PLA only printer with no hot plate installed. The build plate was also limited to a 6" x 6" aluminum plate with window glass.

After much browsing and scouting, I realized that the motors, board and the Hot-end makes up most of the cost of a RepRap printer. The hardware is not a big deal to me, cost around $90 and it's a bit inflated too since some of the purchases come in a pack of 100 which is more than enough. The two vendors that really made a dent in the pricing was Robotdigg.com and GEEETech.com. For the hotend, I went for the QU-BD's anUBIS hotend which I will write about down below. I will now show you what I purchased from each site

Motors + additional hardware
Robotdigg sells Nema17s for $6.80 a pop which really knocks down the price. They also sell other hardware such as LM8UUs, GT2 pulleys & belts, 608s skate bearings, etc for a cheap price. They are now offering chrome plated smooth rods and 200mm x 200mm hot plates at a bargain price. The only con with them is that their paying system is a bit outdated. You make an order, they email you back with the shipping price (by weight) and then you pay through Paypal. You never get some sort of shipping confirmation so you basically sit and wait for 2 weeks, hoping you didn't get scammed. Not to worry since they deliver as promised and the quality of the parts is quite good. Shipping prices depends on the weight but it's as bad as I thought. When I ordered 10 motors and enough GT2s, LM8UU, & bearings to build 4 reprap printers, the shipping came out to be around $60.

Electronic Board
GEEETech has a huge list of boards to purchase from. They have other 3D printer products but it's a bit pricey. The only thing I get from them is their cloned Printrboard since it's so easy to use. The initial price is $89.99 but sometimes they have weekends/holiday specials, knocking 50% off the initial price. You can't go wrong with a $45 board! Although, when I purchased 4 of their boards at the time, they were dinky 2 layer pcb boards that can't even handle more than 10amps. Ugh! The trace wire burnt out on all four but easily fixed with a jumper wire. I recently heard they resolved this issue and updated their current stock with beefier ones.

Hotend
The cheapest Hotend on the market was the QU-BD's MBE v9 for $34 w/o motor. Having dealt with two of them, it totally sucks with PLA. I looked at the Jhead but it was a bit pricey for a 1.75mm version. I had my eye on the Makerfarm's Jhead for $55 but then came along the anUBIS hotend from QUBD. It's a complete copy cat of the Ubis Hotend from Printrbot but for $29.99, i just couldn't pass this deal so I bought two to play with. When recieved, I was expecting it to be the ceramic version (no pictures provided) which I'm more familiar but instead got the aluminum block version. It works OK but not as good as the ceramic UBIS hotend. I can't compare with the Printrbot's aluminum block version but I'm not too fond of it. It takes a good amount of force to extrude by hand and the filament will randomly slip from the MK7 filament drive gear when extruding at a constant rate. I'm already pushing 220C for PLA and it's not looking so great. Honestly, I have no idea how it can't perform the same as the UBIS, it's almost identical. Well, I will have to print real slow with this guy and give it a go. I still have a E3D on backup.

If you're all wondering how much this machine cost me, here is the price
$231.73

BOM RIGHT HERE

If I add the hot plate from Robotdigg ($9.80), it only adds another 5 bucks to the total price. I didn't account the shipping price into this but if you wanted to keep it under $300,you have $70 to spare for shipping. Just don't mess up your orders!