Congratulations on getting a shiny, new B1. It is a great machine for beginners and experienced users alike but like all machines you will need to do some things just right to get the most out of it. This is a brief guide which explains how to put together your B1 to ensure that the mechanics will just work.
When installing the uprights it is crucial that they be at 90 degrees to the base and not the bed. The bed will be sorted out later. If you fail to ensure this then you are likely to experience later issues with ABL and/or the nozzle scraping across the print.
In order to ensure that both uprights are at 90 degrees you will need to use a set square. Eyeballing it alone is not enough and relying on the provided brackets is also not enough since they include some play by design in order to allow you to manipulate the frame to overcome manufacturing tolerances. Place the set square up against the frame and the base as can be seen in the image below (note that it is not pushed all the way against the frame in the image but you should) and ensure that both sides of the frame are a perfect 90 degrees.
After the uprights have been installed you will need to install the crossbar. Of course you will need to be sure that the crossbar is at 90 degrees horizontally to both uprights. You can once again do this using a set square as shown in the image below.
In the images you will see that I have placed the set square flush against one upright at the top of the uprights and then run it until it reaches the other. Mine was out by about 1mm which I was happy to accept although I have seen others who have been out by way more and this is where issues creep in. Note that correcting an offset may require you to loosen the screws at the base of one or both of the uprights and then to re-measure the angle between the base and the uprights and the base, iterating until you have it within acceptable tolerances.
Once you are done you should find that the uprights sit flush with the crossbar as can be seen in the image below.
This section is directed mainly at those with a probe but it is a good read even for those without one.
X-gantry twist causes many a nightmare for novice and experienced users alike. Chances are you have never heard of it before because it is not something that is spoken about often. Hopefully this section will help you to learn something that you will in turn be able to share with others.
X-gantry twist happens when the left and right uprights are are not at 90 degrees to the base. Let's say that the left upright is leaning slightly back and the right gantry is leaning slightly forward. After you have bolted them tight into the base they are not likely to want to straighten out. Then let's say that you now go and bolt the X-gantry to the two uprights. Obviously it has a flat face on either end that is supposed to sit flat against each upright but it can't because the uprights are not parallel with each other. So what happens? You tighten the bolts on the one side of the gantry and the gantry twists slightly so that the face on that end is flat against that upright. On the other side of the gantry the face is definitely not flat against the upright because the gantry has twisted to accomodate the end that you just tightened. Still, you need to tighten those bolts too so you tighten them and as you do the gantry twists in the opposite direction so that it can sit flat against that upright. The net effect is that the gantry has been twisted as if it were a rag and you were trying to twist it to get water out of it. How does this affect your print? Massively!!! Watch the video below to find out:
https://www.youtube.com/watch?v=rPU4ZAPJTNc
Now that you have watched the video you have a better visual understanding of what is happening. In the video, imagine that the red tip is your nozzle and the blue tip is your probe. Watch the video again and see how the z-distance between the tips of both varies as the print head moves across the x-gantry. At one point the blue is slightly below the red, then they are even and then the red is below the blue. This is exactly what will happen if your uprights are not parallel with each other. Your z-offset will simply not be constant over the whole x-range and there is no way that Marlin can compensate for this regardless of how fine a mesh you have.
An uneven first layer, regardless of the resolution of your mesh, is the first indicator that you have this issue. Another good indicator is that your mesh has a consistent tilt, either positive or negative, along the x axis. To check for a tilt you can connect to your printer using a terminal app like pronterface and run a G29 command (ABL) or G29 T (UBL). Copy the results into a notepad application and remove the column and row markers. Paste the resulting matrix into the bed visualizer website here: http://lokspace.eu/3d-printer-auto-bed-leveling-mesh-visualizer/
So how do you fix it? Your best move is to get the uprights perfectly parallel. However if you have tried and tried to do this and are still suffering from inconsistent first layers then follow the steps below.
- Lower the z-axis to the point where the nozzle is about 1mm away from the bed.
- Remove the tensioner from the right hand side of the x-gantry.
- Loosen the bolts that hold the x-gantry to the plate that runs up and down the right upright. You should see something that looks as follows:
The yellow arrow shows you the gap caused by the uprights not being parallel. You need to release the gantry from the plate enough to shove paper into the gap. The idea is that the paper will fill the gap and prevent the gantry from twisting again after you tighten the bolts. Sometimes the gap is so tiny that you may even need to select a thinner type of paper to avoid over-filling it. Sometimes it is a little larger and you may need to use more than one sheet of paper. Whatever you do, don't rush it and get it right.
After the paper has been inserted, bolt everything back together and test ABL/UBL again.
It's possible that the center of the lead screw axis may not align perfectly with the center of the lead screw nut as it comes in the box. If this is the case then the rotation of the lead screw will actually force the base of the lead screw to move in an elliptical shape which creates z-banding on your prints. To remove the pressure on your lead screw you should loosen the bolts on the brass nut so that it has freedom to move within the hole where it is mounted as can be seen in the image below.
Each axis has eccentric nuts which allow you to adjust the pressure with which the v-wheels roll against the aluminium extrusions. Too much pressure and the wheels will bind and impede movement of the axis. Too little pressure and there will be play on that axis resulting in print imperfections. You need to get these nuts adjusted just right and then continue to adjust them every few prints.
The correct adjustment is one where you are able to hold the axis in place and roll the wheels on that axis against the aluminium extrusion using your fingers, allowing them to slip. You should not have to force them to slip against the extrusion by straining but you should also not be able to turn them so easily against the extrusion that it requires very little effort. The sweet spot is sometimes just a fraction of a turn of the eccentric nut away from a bad spot.
The images below show where you will find the eccentric nuts for each axis.
Finally, from a mechanical standpoint, you will need to level the bed. This guide does not touch on that since there is already extensive information available on the internet to help you to get it done right.
Related to bed leveling is the angle of the nozzle relative to the bed. You want the nozzle to be at a clean 90 degrees relative to the bed otherwise it will cause it to drag over the print and possibly dislodge it from the bed. With some B1 units the carriage either pushes the nozzle outwards or in other cases it allows the nozzle to lean inwards. In either case you will need to make adjustments to get it to sit at a clean 90 degrees.
A fellow B1 user made a great mod which will help you to get this right if this is an issue that you are experiencing. Information about the mod can be found at the links below:
https://www.reddit.com/r/biquB1/comments/mazes7/filled_out_the_space_behind_the_backplate_nozzle/
https://www.facebook.com/groups/721158168658899/permalink/933859857388728
https://www.thingiverse.com/thing:4805270
https://www.thingiverse.com/thing:4809757
Cura has built in profiles for the stock B1 and the ABL B1. Don't expect these profiles to be a silver bullet that will buy you perfect performance with all filaments. Essentially they define everything that they can possibly define that is not dependent on the filament that you are using and then leave the rest in your hands. To get the best performance you will still need to tune the profile for each different filament that you use.
The settings that need tuning include:
- Retraction distance (some have tuned down to 3mm with the bowden setup).
- Retraction speed (the B1 likes a faster speed with most PLA filaments, 60mm/s+).
- Nozzle temperature.
- Bed temperature.
- Flow.
- Number of top layers (filament with good bridging may need fewer top layers to get a good finish).
You will also need to tune the e-steps value but that is not a slicer setting. To help you to tune the profiles you can use the guide made by TT at this link: https://teachingtechyt.github.io/calibration.html
People often ask what the best mods are for the B1. The best mods are the ones that you need for your use case or that cost almost nothing but get you something. In most cases I recommend four things:
- A BL touch or 3D touch clone. Both work well. - https://www.biqu.equipment/products/antclabs-bl-touch-v3-1-original-auto-leveling-sensor-premium-3d-kossel-printer-reprap-for-skr-v1-3-3d-printer-parts?_pos=2&_sid=b2556aada&_ss=r
- A flexible stepper coupler for the z-axis (5mm x 8mm x 25mm). - https://www.biqu.equipment/collections/stepper-motor-board/products/3d-printer-stepper-motor-flexible-coupling-coupler-shaft-couplings-5mm-8mm-25mm-flexible-shaft-freeshipping-1
- Printing a bearing based spool holder which seats the filament spool next to the printer and reduces the friction in the filament path (DO NOT underestimate just how much of a difference this makes!!!). - https://www.thingiverse.com/thing:2047554
- Applying the hotend fix before your very fist print so that you don't need to worry about cleaning out the hotend. - https://www.thingiverse.com/thing:4626617
Other than that you need to decide what you want and how much you are willing to spend. Remember that the B1 can produce stellar results out of the box. The above mentioned mods can help to improve print quality for very little spend which is why I generally recommend them.
If you would like to produce sharper corners then you can look into going direct drive and using linear advance for which there are some modifications available on thingiverse.
People have also created cooling mods, dual-z mods and the list goes on.
Above all else, NEVER work on the hotend with the power applied. I literally see at least a post per day on one of the groups where someone has killed their motherboard by doing this. What happens is that people short the thermistor wires to the heater cartridge wires when they are trying to hold the heater block with a pair of pliers. This sends 24V directly into the motherboard on a line that is only designed to handle 3.3V. The result is your printer either gives you the incorrect temperature or it tells you that no printer is detected.
If you want to work on the hotend but need it to be hot (removing the nozzle) then rather heat it up to about 20 degrees over the temperature that you need it to be at, turn the power off completely and then start working on it.
If you have a point which is related to getting started with the B1 then please feel free to add it in the comments below.
A user on reddit noticed a Gap between the Hotend Assembly and the X-Axes Carriage that seems to exist on (most) printer. I had this on mine too. I've created two fixes on thingiverse and applied it to my printer.
https://www.thingiverse.com/thing:4805270
https://www.thingiverse.com/thing:4809757
Maybe check it on your printer and include it here if you like.