Before buying the Anycubic ‘D’ Predator, I purchased an Anycubic Linear Plus. I’d been after a delta type printer for a while, after becoming fasinated with the way they work. After all these years, I still find 3D printers mesmerising as they lay down plastic.
As a printer, I’ve generally been happy with how it performs, but I’ve found its bed size a little bit limiting. Its also limited in its processing power, as its fitted with a trigorilla 8-bit board which is being pushed to its maximum capability by the delta geometry.
The design of the Linear Plus is that all of the electronics sit under the bed. This can lead to the electronics being submitted to more heat than would be preferable. It also has a very long bowden tube ~700mm long which requires long retractions of at least 5 or 6mm to eliminate stringing and if you want to move into more flexible materials, its definitely too long.
Before carrying out the conversion, a number of items require printing. If you don’t have another 3D printer, these will need to be made before you start stripping the printer down. They are as follows
- 1 x set of duet mounts – https://www.thingiverse.com/thing:1998280
- 3 x sets of mounts – https://www.thingiverse.com/thing:2924231
- 1 x extruder mount (this may work with the original extruder but I’ve upgraded to a BMG clone) – https://www.thingiverse.com/thing:2888692
- Some sort of top mounting filament holder – Used the one off my predator – An example would be https://www.thingiverse.com/thing:996695
You’ll also need some extra parts.
- 3 x M4 x 30 screws
- 3 x M4 nuts
- Some cable ties
- Some Catapult Tubing – I got the yellow one – https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR12.TRC2.A0.H0.Xcatapult+tubing.TRS0&_nkw=catapult+tubing&_sacat=0
- Some sort of Mosfet for controlling the bed
The Frame – Strip Down
First thing I wanted to be able to achieve was to flip the frame so the electronics were at the top. This would give me easy access to the controller if I wanted to make adjustments to wiring etc without having to remove the bed. This would mean that in theory, I would never have to remove the bed again, reducing any requirements to probe the bed for calibration or meshing.
I’m not going to go too in depth into what I did to achieve this conversion as most of it is self explanatory. What I will do, is provide a brief overview of each step I carried out, in chronological order.
- Remove the effector, along with the arms.
- Remove the belts
- Remove the endstops and associated wiring for them
- Remove the bed, bed clips and associated wiring
- Remove the linear rails, making sure to not let the runner fall off the end (because if you do, out come all the ball bearings!)
- Measure the distance from the base of the frame (where the bed sits) to the bottom of the plastic stops which sat under the linear guides. From memory, mine were roughly 70mm.
- Remove the PSU and associated bracket.
This leaves you with a frame and some electronics. As I was changing the controller board, I also stripped out the controller and screen. This left me with a frame with some motors attached.
The Frame – Assembly
I’d previously printed some feet for the Linear Plus, so the first thing I did was swap these over to the other end of the printer. I then turned the printer so it was now the way up I wanted. I then installed things in the following order.
- Set the plastic stops to the correct height for the linear rails
- Installed the linear rails the correct way up (denoted by the orientation of the rod mounts)
- Installed the endstops at the top of the linear rails. I made sure these sat right against the top of the frame to keep them all consistent.
- Refitted the belts. I don’t use springs to tension them and instead use the screws at the bottom (originally top) of the frame to move the top and bottom sections apart. I’ve tried to adjust all of them the same to maintain the frame squareness
- Install the arms and effector
- Install the 3 sets of mounts to the rod carriages. I also installed one end of the catapult tubing to each mount. The tube should be long enough to reach the centre of the frame if looking from the top. I used 2 cable ties to secure the tubing.
- Install the extruder to the extruder mount.
- Install the extruder mount to the tubing. It needs to be tight enough to support the weight of the extruder with little sag. Do the cable ties up enough to hold it but they should still be adjustable.
- Cut the PTFE tubing coming out of the hotend so it is around 80-100mm long.
- Fit the PTFE tubing into the extruder. Adjust the catapult tubing so the extruder is held level and in position. The tubing should be under tension but should still be able to allow the hotend to move around the bed. Move the effector around to verify the movement and then tighten the cable ties. If there is lots of spare tubing, cut it off, otherwise leave it incase you need to make adjustments down the line.
That’s the frame assembled.
Basically, follow the online wiki and my post on installing a duet to the predator. For the endstops, the wires should be connected to the 2 outer pins of the 3 pin connectors. I will post my config on github shortly. Its also worth noting that I am running the duet etc off a 24v PSU that i had lying around. 24v is recommended for the TMC stepper drivers although its not critical.
For the heated bed, I’m using the original power supply connected to a mosfet to control it. I ran cables for the mosfet and the thermistor down the inside of the 2020 extrusion. I will be printing a mount for the mosfet at some point but at the moment its not important.
Please find some photos below of the finished installation.