As quick as that I am back to the original 1.8 motors. I now remember why I never used the ones I posted about.

They are 2.4 amp motors and I had them running at 1.8 amp and they were still skipping steps. I think I’ll get some 0.9 at some point, just need to research the best model. Didn’t take long to swap them back.

I will update GitHub accordingly soon.

Since I last wrote a blog post, I have carried out several changes to my current setup. The aim of this post is to try and consolidate all of the changes I have made to try and put a stick in the ground for the readers.

Summary of changes so far

The controller board has been changed to a duet 2 Ethernet. This has been detailed here and here. As well as this, I have changed the effector to a smart effector. This change also meant changing the hot end from the standard v5 clone to an authentic E3D v6. These changes were detailed here.

Arms

My setup summarised above was using the original arms that came with the machine. If you follow the Facebook group for the predator, or any other social media channels, you may have heard about the issue of the rapidly wearing rod/arm connectors. This is where the ball in the middle of the connector becomes loose and introduces play into the system. I was suffering from this issue, and it meant that the calibration deviation on my machine was getting worse and worse. One fix for this issue suggested by the community is to replace the rod connectors with ones made by IGUS. These would be great for a normal unmodified machine, but as we’ve already fitted a smart effector, these aren’t really the way to go. It would also be very difficult to make sure that the rods are the same length. This is critical to ensure that the printed parts are accurate, especially as resolution decreases the larger the part.

I ordered a set of arms from Haydn Huntley. He has been known for supplying high quality, high precision arms to the delta community for several years now. I decided to stick to a length of 440mm for the arms, although it has been suggested that arms as short as 405mm will still work. The reduction in length to 405mm will counter the loss in height when fitting a smart effector (which is around 30mm due to the different position of the hot end). I’m not going to tell you which length to order as I have not read anywhere of anyone ordering 405mm and getting them to work over the whole print area. If you feel you will need that extra z height, maybe go for 415 or 420mm. If you are planning to use any sort of multi material changer at some point in the future and will be planning to purge the material outside of the build platform, then I would stick to 440mm arms. The order came within about 2 weeks or so. Just keep in mind that when getting them delivered to the UK that you would be paying somewhere in the region of £30 import duty. They come well packaged, in a cardboard tube and have the length of each arm written on a label. All the ones I received were 440.38mm.

To enable the arms to be mounted to the carriages of the predator, some custom mounts are required. It would be great if the adaptors included with the smart effector fit, but unfortunately, they don’t. I used the adaptors designed by Nealz Engeland but I found that some modification was required to get the holes to line up with the carriage. Don’t forget to swap the little ‘flag’ over required to activate the optical end stops.

Carriage Adaptors

I carried out this change while also carrying out some maintenance on my machine. One of the good design factors of the predator is the ability to remove an upright from the machine without much hassle. The predator even stays in place without requiring any other support. I removed each upright in turn and stripped it down to parts. This way, I was able to check that all the rollers of the carriage were correctly in contact with the extrusions and that no play was present. Fortunately for me, there was no play present, but I have read on Facebook, about a number of other predator owners that have had to adjust their rollers to make sure they are all in contact. I also swapped the original 1.8 degree motors with 0.9 degree motors and re-tensioned the belts, but more on that later.

As mentioned earlier, I have previously upgraded the effector from the original to a smart effector. I had modelled up a mount to allow use of the original arms and to mount three radial fans for cooling. The design can be found here.

I have since updated this design to allow the fans to be mounted to the smart effector while using magball arms instead. The design can be found here.

When mounting the arms to the printer, make sure you alternate the polarisation of the magnets. With mine, Haydn fixed the labels on each on at the same polarisation, which made it easier to alternate the arms. Basically, mount one arm label in to the effector, then one arm label to the carriage and then alternate. This helps reduce magnetic interference of the fans etc. Also make sure that you apply lubricant to each of the ball cups. I used bike chain lubricant as per Haydn’s advice.

Arm alternating

Motors

The motors are very easy to change from one type to another. I had a bunch of motors left over from then I had to send a 3D printer to 3D printer heaven. The main thing to check is that the toothed gear is fitted with the same offset as the gear at the bottom of the printer. Wiring is the same as a 1.8 degree motor. If you’re lucky, you’ll get 0.9 degree motors with removeable cables, in which case, you just plug the old cable into the new motor. Don’t forget that the steps per mm need to be changed from 80 (for 1/16 microstepping) to 160. I’m still assessing whether changing the motors has been a good change or not.

Motors I Used

PanelDue

Only a small note to say I’ve added a PanelDue 7 inch. I have mounted it to the top of the frame as shown below.

Duet firmware updates

Along with the above hardware changes, I have been trying to tweak my duet config to improve my settings. I have uploaded my current config to a separate branch on my github for your use. You will notice that the acceleration and jerk are quite high. Below are a couple of pictures of an example part. Ignore the bottom of the part, I am currently working to improve the quality. I will endeavour to keep github up to date.

I have moved a couple of items out of config and into my start gcode. I now do the following.

G32 ;This carries out a delta calibration at the start of the print
G29 S2 ;This reloads the mesh height map which is cleared when carrying out the delta calibration.

That pretty much brings you up to speed.

I had converted my predator to a BMG clone (a fysing one) fairly soon after getting it, after using one on my linear plus. I had purchased the same brand based on the assumption that if the first one works well, why shouldn’t this one. But on receipt, I noticed that the plastic gear fitted to the main shaft wasn’t mounted perfectly concentric. I fitted it anyway and for a few weeks it worked as expected.

I then noticed a piece of plastic had fallen off, and on further inspection, it was the plastic holding in the little bearing on the main body. This missing piece of plastic resulted in a reduction in the amount of pressure that could be applied to the plastic when extruding. After super gluing it back in place, to enable printing to continue, I decided that I should be looking for alternative brand.

That’s when I came across the Sanjiu all metal BMG clone extruder on aliexpress. The main difference between this and other BMG clones is that the whole body is made of machined aluminium rather than being injection moulded plastic. There are even threaded holes to allow you to mount a fan if using it as the heatsink of the hot end (although working with a delta, this isn’t an option). So I took a punt and ordered one.

IMG_20190705_172148IMG_20190705_172154IMG_20190705_172841IMG_20190705_172845

When I received the extruder, I stripped it down as far as I could and took pictures of all the components. Everything is made from metal (apart from the roller bearing cages for the one gear). It all assembles really easily and is obviously well made. The main difference between this extruder and a plastic equivalent is the weight. This weighs 68g compared to 131g of a clone. We all know that weight can make a difference but I believe the better rigidity of a metal extruder outweighs the cons of added weight.

I have since fitted it to my machine and I haven’t had any issues with skipped steps. Only time will tell if it works well or not. I shall give an update on it soon.

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.

Required Printables

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

Required Vitamins

You’ll also need some extra parts.

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.

Duet Installation

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.

Photos

Please find some photos below of the finished installation.

So its been a while since I’ve updated you on the status of my predator. Since changing over to a duet, I have a number of further changes to my machine.

The upgrade I’m going to concentrate on in this post is the installation of a duet smart effector. With changing this part I am also forced to upgrade to an E3D V6 all metal hot end, which for me is better, as the one supplied by anycubic is limited to a maximum temperature of 260 degrees Celsius.

So what does changing to a smart effector gain you? I would say there are three main advantages.

  • It makes it easier to change your delta arms to mag mount versions later down the line of the type produced by Haydn.
  • The hotend is now the Z probe. The smart effector has a piezo switch built into it that then uses the pressure of the hotend touching the bed to trigger it. This allows you to call a probing routine whenever you wanted without having to install an extra switch.
  • The smart effector is made from a PCB so it is nice and lightweight but also strong.

To be able to use the smart effector with our machine, a number of extra parts are required if you aren’t going to be changing the arms straight away. I’ve modelled all of the parts required and made them available on thingiverse.

You’ll need to print

  • 1 x converter
  • 3 x fan brackets
  • And 1 of each fan duct. It’s designed in a way that you can choose how many of the fans you fit. I have all 3 installed on mine.
  • You’ll also need
  • 12 x M3 nuts
  • 12 x M3 x 20 screws
  • 6 x M3 x 6 screws
  • 3 x 5015 radial fans
  • 3 x M4 x 30mm screws
  • 3 x M4 nuts.

Make sure you’ve assembled the smart effector as instructed on the wiki.

Start off by running a tap down the 6 mounting holes in the converter for the smart effector. Then mount the smart effector to the converter and secure in place using 6 of the M3 x 20 screws. They do thick out the underside of the converter a fair bit, but that is because we will use them later to mount the fan brackets. Now mount the converter to the 6 arms using the other 6 M3 x 20 screws and the 6 x M3 nuts. You can do this either with the arms attached to the machine or with them removed. Make sure the screws are done up nice and tight so they don’t come loose. Then tap the 2 inner holes on each fan bracket using an M3 tap. Mount the fan duct to the to the fan bracket using the M3 x 6 screws, followed by the radial fan to the bracket using M4 x 30 screws. Repeat for the other 2 assemblies. Finally, mount the fans in the correct position under on the smart effector. Each fan should be wired in parallel and plugged into the part cooling fan port on the smart effector. See below for photos of it installed

For the wiring on the predator to the smart effector, I actually ripped out what was originally there and installed a new harness. This is due to requiring extra cables etc. Just follow the guide on the wiki and you’ll be fine.

Also remember to make the changes to the firmware for the probe and to retune the hotend using M303.

The delta arms supplied by Anycubic are shocking. There are three main problems you will find with them.

  • They are not all the same length
  • The rod eyes on them can be slack
  • The glue holding them together comes unstuck

I have mainly had issues with them not being the same length and the glue coming unstuck. But I have used the glue issue to my advantage.

I would highly recommend removing the whole end from each arm. That’s the black tube that’s glued on the end and the rod eye.

I made a rod setter out of a piece of hardwood and a couple of M4 threaded screws.

The key is to reglue every arm you are using on your printer. The length between the mounting points on the eyes is 440mm. So I separated one end, and using superglue, fitted the end and set them all to the same length using my jig.

One arm was longer than the rest, to the point where I had to cut the carbon fibre tube down to be able to get the end piece set to the correct length.

I’ve had my predator converted to a duet board for almost a week now. It seems to be running really well. I’ve tweaked so I am getting consistent prints. The details are nice and clean etc. I still have some more work to do regarding overhangs, bridges and some slight ghosting but for the moment, its all issues I can live with.

I also seem to be getting the odd layer that doesn’t seem to extrude 100% correct but this seems to be an issue that most people are having and not just on this printer. It appears to be down to the hotend that anycubic use so at some point that will be getting an upgrade. What I will probably do is upgrade the effector to a smart effector at the same time and kill two birds with one stone. Then I only have to order the extra E3D parts required as the effector comes with a custom heat sink.

The above images are of Phil A Ment. As you can see, I still have some issues with overhangs. This will be my next issue to tackle. He was printed at 0.1mm layer heights and 60mm/s print speeds. He took 6 hours to print. I know he has a hole in one foot but that was from me messing around with the print settings on the fly.

The above images are of Cali Cat. Again, the overhang issues can be seen going up the underside of the tail.

All in all though, I am happy with the printer so far. I have moved my config files to GitHub for easy management.

Installing the Duet

At the moment, my duet is sat on one of the mounting pegs that were used to secure the trigorilla pro. Not ideal but I’m waiting for a panel mounted ethernet port to arrive before I go ahead and mount my board properly. Once it gets here, I’ll document the process and post the mount I design to thingiverse. I have already found a mount I like the look of, so I may remix that to make it fit our printer. That of course depends how well I get one with freecad.

That’s all for now. Keep your comments coming.

After building my printer on the dining room table, I knew I would have to move it out into my workspace in the garage. My wife has a “no wires in the house” policy that I have to abide to.

Whilst moving the predator, which is just about doable by myself, I managed to damage the SD card slot. The main annoyance with this is I won’t be able to update the firmware and I won’t be able to use the printer without plugging it in via USB. I could control it using Octoprint but this wasn’t my ultimate plan. This meant that converting the printer to a duet controller has been brought forwards.

I have a duet 2 ethernet v1.04. It’s a controller that I was using to control my Anycubic Kossel Linear Plus. I was planning on selling the linear plus machine, but seeing it next predator, I may just keep it so I have something a little more portable. At the moment, I’ve fitted the linear plus with an MKS Sbase V1.3 but its not performing as I would’ve liked. I may end up buying either another duet or a Bigtreetech SKR.

Anyway, back on the topic of installing the duet to the predator.

Connections

  • There are 4 x motors connections. X, Y, Z and E.
  • There are 3 x optical endstop connectsions. X, Y and Z.
  • There is one probe connection.
  • There is one filament sensor connection.
  • There is one fan connector for cooling the board.
  • There is one fan connector for the 2 sets of fans mounted to the effector.
  • There is one hotend thermistor connector.
  • There is one heated bed thermistor connector.
  • There are bare wires for the heated bed, hotend and power in cables.

Each of the connections need modifying in some way or another to be able to fit them to the duet. One of Anycubics bad habits is to tin the end of the bare wires with solder. This is widely accepted as being bad practice. Therefore, the end of each bare cable needs to be cut off, stripped back and either left bare or crimped with a bootlace ferrule. I prefer bootlace ferrules that are uninsulated so its easier to get them in to the terminals. You’ll also find this applies to the cables which run to the heated bed mosfet.

The endstop wiring needs to be wired differently in the connector to work with the duet. The three images below are from looking at the connector from the top as it it was connected to the board.

The above images show the original connector on the left and the duet connector on the right. Apparently, Anycubic haven’t been consistent with their wire colours so just check your cables match mine. Otherwise use the before and after pictures to help configure yours.

The z probe connector should be wired as shown below. It doesn’t matter whether your wire colours match mine as its just a mechanical switch.

The filament sensor should be wired as shown below. Same principal applies with the original on the left and the duet connector on the right.

The motors can be wired as they are. The duet wiring shows the red and blue connectors the other way round but this doesn’t matter and can be wired in the order they are installed on the trigorilla pro.

Fan connections at the effector end of the wiring

The only connections that need any major change are the fan connectors. The trigorilla connector had both set of fans ran off one connector, but the duet doesn’t have this capability. All three fans are connected together using the positive as shown in. The duet switches the fans on and off using the ground connector so you may be able to split off the negative for the one fan and have that in a single connector. I decided to run another cable and fully separate out the fan. The wires are as follows:

  • Red – Fan 2 (Hotend fan) ground
  • Blue – Fan 0 (part cooling fans) ground
  • Yellow – Positives for all 3 fans wired together.

You can now connect everything to the duet. I separated out all 3 fans. The part cooling fans are connected to Fan 0 and Fan 2 and the hotend fan is connected to Fan 1. The z probe is connected to E0 and the filament sensor is connected to E1. The rest should be self-explanatory and if you get stuck, use the duet wiring schematic here.

Here are my config files for the duet. I now have a GitHub repo with all of my config files. The only one that may need adjusting is the filament sensor as I have not tested this yet and it may need changing from active high to active low.

When turning the machine on, home all the towers. Then go through the delta auto calibration and you should be good to go.