I purchased a used Wanhao i3 v2.1 3D printer for about $280 (UK eBay) shipped. I then spent many hours watching youtube videos, browsing thingiverse, and reading forums about what I would need to do it. It already had some modifications done to it, but it had some other issues. The insulation is mostly worn off of the hot end and the carriage plate is super warped (common problem on these). The worn insulation makes me have to print at very high temperatures because the nozzle ends up being far colder than the thermistor. Either that or the thermistor is failing. I think it's also causing the layer adhesion and some other problems I've been having. Interestingly, I haven't had any issues with first layer adhesion, which seems to be a common problem. Overall though, I haven't been satisfied with the prints, but I did manage to successfully print a 3DBenchy and a few XYZ calibration cubes.
Anyways, here's the list of upgrades it has now. The first 5 came with the printer.
- PEI sheet on original aluminum bed
- Z frame braces
- CiiiCooler shroud + blower fan
- removed spring belt tensioners
- Z axis stepper dampers
- Re-squared everything
- Attempted to align y axis belt
- brace the cantilevered y belt pulley with a zip tie
- Medium loctite most screws
- longer screws where need zip ties
- oiled bearings
- dial indicator + mount (cheap dial indicator, 3d printed mount)
- Sunon MF50151VX-A99 fan for cooler. At least 2x flow rate of common ones for just slightly more.
- Replaced PEI build plate with borosilicate (I know, not necessary, but it was cheaper and precut) glass + thin PEI sheet. Held down with blue painters tape on edges.
- Added a second spring inside the main spring for the extruder arm. See below.
- Turned motor sideways so wires clear top edge. Have to pull some more wire through guides.
- Ball bearing spool holder
- Fixed z steps
- Calibrate extruder steps
- extra screws kit
I went through 3 different spool holders. The original is too short for most spools. This is the one that worked best for me, though I had to sand about 0.2mm off the width to get it to fit in the stock spool holder.
The cheap 5015 blower fans commonly sold for 3D printer coolers suck. I spent a few hours looking for a better one that wasn't expensive. The Sunon MF50151VX-A99 has at least 2x the flow rate of the one that came with the printer's CiiiCooler (one of the mods that came with it).
The original extruder idler didn't exert much force on the filament. With the extruder off and PLA filament inserted, you should be able to push it in/out and see visible teeth marks. Link. If you don't see teeth marks, then the behavior can be exactly like too low of a temperature. Also see this link. I ended up having a spring that happened to fit inside the old one, so I did just that.
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| Spring inside spring |
If you do this, I suggest getting an inside spring that's just a little shorter (~2mm) than the original spring so that the original spring can still compress fully. There's just barely enough travel on the lever for me to relieve pressure on the filament so I can pull it out. There are some modifications that you can print that allow to precompress the original spring more, but this is way easier.
My z axis was going up a few microns too much each layer. I discovered this by measuring the Z height on a test 3DBenchy print. Turns out that these Wanhao's ship with a somewhat random z axis steps value in their firmware. You need to download Repetier host, install it, connect with a USB cable (make sure the FTDI drivers are installed first), shutoff Repetier server (which will try to autoconnect and keep Repetier host from working), and connect to your printer. Then under the firmware (under a menu), you can change the value of Z steps. This should be 400 exactly.
Removing the adhesive holding the old plastic build plate on was a pain in the ass. The best method I found was to heat the build plate up and use a razor to scrape most of it up. Then let the plate cool off and use acetone to get the rest.
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| Goo. Washcloth to protect heater from steel carriage plate |
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| No goo |
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| New glass plate with thin PEI sheet adhered to it |
eBay has been a great place to buy screws in small quantities. I highly suggest it.
Next modifications:
- Install the bed spring cups I printed to keep springs aligned.
- Install the x and y axis belt tensioners I printed, along with new belts. Spend some time aligning the belts so they don't rub
- New heat block insulation and thermistor. Going to replace ptfe tube while I have it taken apart.
- Install DiiiCooler I printed. Used PLA, so might have to replace this with PTEG eventually.
- New y-axis carriage plate. I bought one from tehnologika.
I'm currently sanding down all the crud off of the heater block. I would be replacing the heater core/cartridge, too, but the one I bought was 6mm and the hole is 6.35mm (1/4"), which are difficult to find, so I'll keep the original for now.
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| Caked on gunk |
There are a few other mods I'm considering, but I want to get it put back together with the new thermistor, cooler, and heater block insulation to see if that improved the print quality a lot.
Potential future mods:
- Microswiss all metal hot end
- New heater core
- Z axis flex couplers
- PETG cooler
- Encloser for ABS
- Ultrabase build plate
This printer (and I think all Wanhao i3's) suffer from X axis wobble. By that, I mean if you hold the extruder carriage by the front and move it up or down, you can twist it about the X axis a few mm. My X axis rods are locked down by the way...they are not at all loose. This behavior is caused by two things. One: the Z axis bearing holders and bearings have some play. This is partially caused by the fact that the 45mm linear bearings are only be held by their top ~5mm. Two: The Z axis smooth rods are not fixed in place. They can slide up and down, and they are not fully constrained radially (loose holes). Since the upper mount points are the same triangular metal blocks as used on the x and y axes, I think I can add a set screw to them, but it requires disassembling most of the printer. There's no obvious fix for fixing the lower Z axis smooth rods in place. I'm planning to design and print two things: 1. A pillow block/brace for the z axis bearings and metal brackets, 2. brackets to hold the lower end of the Z axis smooth rods. If you look at the Prusa i3, you can tell that they have a far superior Z axis carriage design...the smooth rods are full constrained and the Z axis bearing bracket/carriage things are one solid piece with the bearings in full pillow blocks. They also have a X axis belt tensioner built in. *sigh...
My goal is to get really nice prints out of this thing. In summary, I've spent about $500 so far (including two rolls of filament and some spare parts I haven't used yet). I've also probably spent about 50 hours working on it, not including printing time. If you include the hours (at a rate of say, $10/hour), then I'm up to about $1000. A genuine prusa i3 mk3 kit is about $1000. So yeah...I've learned why more expensive printers are more expensive...they just work. If I could do it over again, I'd probably consider some of the more expensive printers.
I just found out about the folgertech 2020 i3, which looks easier to modify, though might need even more work than this one did. There are about 100 cheap options, and it seems like some people get lucky and get amazing prints out of them without much effort, but it takes others ages to get good prints.
I just found out about the folgertech 2020 i3, which looks easier to modify, though might need even more work than this one did. There are about 100 cheap options, and it seems like some people get lucky and get amazing prints out of them without much effort, but it takes others ages to get good prints.
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