Month: November 2016

D-Bot Core XY progress update and lessons learned

All the 3D printed parts for the D-bot Core XY were already printed but the issue was quality of the prints and the overall strength. The creator of the D-bot noted that PETG should be used instead of PLA due to the strength of PETG and an infill around 75%-100%. I did not have PETG at the time and I decided I would print out the parts in PLA and when the D-Bot was complete, I would re-print every single structural part on the D-bot in PETG. This was a mistake since I didn’t realize how monotonous building the frame was. Every part of the frame required precision so trying to get the nuts to slide into the V-slot extrusions were a pain and inserting bearings into the parts as well. I received my Hatchbox PETG filament a bit late but PETG is not an easy material to print as it requires a higher temperature, a heat bed, and tons of experimenting. PETG is supposed to not warp as much as PLA and adhere well but I had warping issues and had to switch back to PLA since PETG wasn’t working well overall.

Somehow, my UBIS hotend jammed and in the midst of cleaning up the thermal sock, the wire for the hotend must have dislodged internally so a $69 hotend lived for 6 weeks and I got a E3D Lite V6 for $30 but the heat break snapped on the first print. This is how I ended up looking into Aliexpress, eBay, and Amazon. I ordered an E3D v6 extruder from each site since they were all cheap and about $11 or less and so far the one from Amazon is the best and had fastest shipping. It took a bit of modification to work on the PrintrBot Simple but it was worth it… sort of. Hack-sawing aluminum is not fun and I highly don’t recommend it. Unfortunately, some printed parts warped so I can’t finish the frame and I didn’t go in order of the D-bot guide so I will have to do some disassembling. Now that my hotend is temporarily fixed, I can re-print some of the parts.

Best Places to Source Parts and Filament

On my quest to get the right part for the right price, I had become complacent going with Amazon. Overall, they are a great vendor with fast shipping for Prime members but I realized Amazon is not as competitive in pricing as many people believed. In most cases, if you are sourcing a part, it is best to go directly to the manufacturer but this is not always possible as some manufacturer do not directly sell to customers but rather large vendors such as the 3 giants below and prices may seem uncompetitive.

There are smaller or more specialized companies such as Filastruder which is the official U.S. distributor of Britain’s E3D’s hotends and Germany’s Watterott Electronic’s Trinamic TMC2100 stepper motor drivers. If you are looking to source quality specialized 3D printing parts such as V-slot extrusions then there is OpenBuilds or if you just need a ton of nuts and metric bolts, Mr. Metric has everything you need.

Each online store has its strengths and weakness and below is a list of best places to source filament and parts in terms of price and quality.

Filament Price: eBay – For PLA and ABS, eBay has the most competitive pricing with brands like California’s Excelvan selling 1KG of PLA for ~$15, ABS for ~$14 and unbranded PLA  and ABS for $11. Excelvan’s filaments have good overall print quality but is sold on Amazon at $23 for 1KG spool.

Filament Quality: Amazon – Hatchbox PLA is well known for their quality and they sell on eBay and Amazon but you get the benefit for 2-day Prime shipping with Amazon for about $23 for a 1KG PLA spool. Amazon is also better source for TPU and PETG as eBay vendors have not caught onto the diverse filament market competitively.

Hotends Price: Aliexpress – I was shocked to see Aliexpress had a variety of hotends at a much lower price than eBay. From a discussion on Reddit, the general consensus is that the knock off hotends are a hit or miss. Some companies have perfected the trade while others continue to source the cheapest materials and/or inaccurate machining the parts. Buyer beware, you should always check the vendor’s sell history for reviews of the items before making a decision to purchase.

Hotends Quality: E3D, Filastruder – It is best to go directly to the manufacturer or redistributor when you can afford to. These vendors are the pioneers in either designing or marketing the product and generally have the most experience and best communication and support plus the idea that you are supporting a company that is working hard to provide you with a high quality, innovative product.

Printboards, Stepper motors, etc: Aliexpress, eBay, Amazon – In that order as far as pricing. Quality should be the same across the board. Amazon does generally have the advantage with their fast shipping which compensates for the small extra cost.

Nuts, bolts: Mr. Metric & OpenBuilds – Mr. Metric provides a wide variety of parts at competitive prices. Amazon does sell nuts and bolts but you are limited to the specific sizes or packs they are selling. OpenBuilds has a wide variety of specialized parts for 3D printers. They are currently most noted for their V-slot extrusions for the D-Bot Core XY.

If you believe there is a vendor I missed or agree or disagree, please feel free to comment below.

Disclaimer: 3D Print Creations is not associated with any of the companies mentioned in this post nor is receiving any paid sponsorship or financial gain.

 

The next big project: D-Bot Core XY

PrintrBot becoming Obsolete

The next big project underway is the D-Bot Core XY 3D Printer. Currently, I am using a PrintrBot Simple Metal which was an overall good printer at the time of purchase but is becoming a bit obsolete. The original PB Simple came with a small print bed size of 150mm cubed and without a heatbed but there is an X axis and heatbed upgrade for about $130. Another issue is the bed itself not being very level and their solution to this problem is the automatic bed level that measures 3 points which is not very effective since it lacks enough information to fix the issue. Older unofficial PB firmware measures 9 to 12 different locations and other printers such as the new Prusa i3 MK2 measures 9 different points on the bed. Another major issue is the non-metal parts warping over time. The two rubber Y axis grommets holding the Y axis level are now stretched overtime due to use over time and the contributed weight of the extruder motor. The effect of this is that after every print, the Z axis moves up or down 0.5 to 1mm which means constantly having to recalibrate after each use.

Why D-Bot?

The D-Bot Core XY has many benefits over the PB Simple and although I list a few issues with the Core XY, majority are not very relevant or solvable with some extra cash. It was a hard decision whether to go with the Prusa i3 MK2 or build the D-Bot but I wanted to build my own printer and with the overall shipping and extras, the D-bot is slightly lower in costs.

Pros:

  • Strong structure
  • Highly detailed build guide, possibly the best detailed guide
  • Strong following and online support community
  • Proven design; has been created by dozens of people with great results
  • Large print bed ( 300mm x 300mm x 312mm approx 12” cubed)
  • Fairly small overall frame size for its large printing area (XYZ, 503mm x 333mm x 520mm)
  • Extra Z axis support (dual stepper motors to move bed along the Z axis)
  • Optional Heated bed
  • Compatible with TMC2100 stepper motor drivers for reducing sound (unlike PB Simple)

Cons:

  • V-slot extrusions instead of T-slot extrusions which can be difficult for people outside of the US to obtain
  • Not for new people, this is not a kit, it’s a guide and requires many tools and several dozen parts
  • Long lead time from date of order (heavy reliance of eBay parts to be cost-effective leads to many parts coming from China that will take about a month or longer)
  • No automatic Z-axis calibration but it is an optional upgrade that the designer justified that it is not really needed due to the stable Z axis