Printrbot Play to SKR Mini E3 V1.2 board.

I have been working on my Printrbot Play 3D Printer to a newer 32 bit control board. The Play is at least 5 years old. In fact it is actually older than that, Mine started Life as a Simple Makers Kit. Then it was upgraded to a Play with a kit from Printrbot. It still has the Ceramic UBIS hotend but has a V2 extruder drive. The Printrboard is a F5 and newer than the rest of the printer due to a broken Micro USB port, a common problem with the F5 boards.

Printrbot Play printers are very solid and robust printers that really deserve an update to newer control boards. They were accurate and reliable printers for there time but budget 3D printers can out print them due to the age and size limitations of their firmware and control board. Considering the move to a 32 bit board is only $37 plus $8 in JST-XH connectors it should be well worth the effort.

Firmware for this move is not really available as yet, sort of, but is in the works. I am rolling my own build with help from files for a V1.0 board to printrbot (Phillip Mally). There is a adapter set of boards being developed right now to make this switch “plug and play” by a guy named Phillip Mally. He is in fact assembling the prototype Beta test “Adaptrboard” release boards as this is being typed. These, with a few additions, should make the swap into a half hour and done deal for most people with no crimping or soldering needed. Firmware is a simple install of a BIN file onto the SD card to install. He has setups for the Play, Simple Metal and the Metal plus (SKR 1.3 board there) being developed. So if you are looking to revive a Printrbot it could be really easy in the not too distant future!

SKR Mini E3 V1.2 Control Board

The main problem with the upgrade is the connectors. Printrbot used mostly Molex style connectors with some Dupont connectors thrown in. The SKR Mini E3 vV1.2 Board uses JST-XH connectors throughout. It took me about 3 total hours to remove, Strip crimp and install the new connectors. I am sure that those with more experience at this part could get it done in about an hour. TIP; label all of your wires before starting this job. You will save yourself all kinds of heartache if you do.

changed to JST-XH. picture has a Creality 1.1.4 board for tests.
Creality 1.1.4 board (the SKR Mini E3 V1.2 is a direct install replacement for this board) and showing the 12V optocoupler to make the induction probe operate correctly.

WARNING: Realize that Printrbot used a short lead induction probe cable, that went into a dupont connector that is different colored wires. You will need to make sure that that you pay attention to this interchange and label the wires under the printer correctly. While you are at it Printrbot, for what ever retarded reason, chose to put uncovered male Dupont connectors to the fan and the induction probe. These pins are powered and exposed if they come unplugged. This will cause a short and destroy your board if it is not corrected. My brother lost a 2 month old printrboard in just this way. So while you are at it, crimp some JST-XH which lock and provide at least a shield for these pins. Not all of the Printrbot’s are this way so make sure yours is not one of these. If it is make sure you correct it!

The next feat is to wire up the induction probe to make it work properly with the new board. To do this a 12V to 5V optocoupler board is used. You can also use a voltage divider circuit or diode circuit to accomplish this. The induction probe works best if it is supplied at least 6V. But a direct connection to the board only provides 5V. The sensor can operate from 6V to 36V. But if you put more than 5V to the Z stop connector you will damage the board. The Optocoupler allows 12V to power the probe but have an output of 5V to the board. I saw how to wire this up on a post on Facebook in the Prinrbot page by Darren J. Green

Next hurdle is to design an adapter board mount that goes from the printrbot format to the SKR format. Only one hole lines up as far as I can see. Also there will need to be a hole cut in the body to allow access to the MicroSD port and the Mini USB B ports.

Another thing to do is design a LCD holder to use the Creality LCD board for controlling the Printer. I will remount the Laptop to the printer and control it from there as I used to, but there are some unique features to using the LCD like setting the nozzle height just by dialing it up or down with the LCD control knob.

This is it for now so far. The SKR board is delayed until Monday. I will get some more pictures of it and it’s install in the coming days. The induction probe/optocoupler setup needs to be tested to make sure only 5V is output and that it is wired correctly before being plugged in.

Well the SKR Mini E3 V1.2 came in. I drew up several mount adapters to install the board. In the end I rotated the board 90deg. and lined the MicroSD port up with the SD port in the chassis. The USB port is covered but that will be fixed at the next chance with a drill and Dremel with cutting wheel.

MicroSD card lined up with chassis.

After I got the board installed I installed a firmware from Phillip Mally. It immediately showed a “TMC connection error” on the LCD display. But all the steppers were working and it was able to home, including the Z Probe. The Extruder motor was running backwards but that was fixed by swapping the wires in the connector. All of the stepper connectors are wired the same. Left to Right; Red, Green, Yellow Blue, when looking at the board.

Lots of thanks to Philip Mally and Darren J. Green on Facebook. Their post and help made this easier and turned me back from some dead ends. Phillip Mally’s Adaptrboard set will make this project possible for others to resurrect those old solidly built Printrbots with modern control boards.

The extruder is still reversed in this photo. The parts cooling fan wires were moved from the block connector to FAN1 with a JST-XH connector installed. The Probe power was moved from FAN1 to the cool zone fan block as it remains powered. neither of these is correct in this earlier photo. As you can see shortening the wires really cleaned up the wiring mess that was the original Printrbot printers. In some cases more than 20″ of wire was removed.

This lead me to installing VSCode and the PlatformIO extension to build my own firmware. I finally had to watch a video on how to set up the environment properly. Then lots of time trying to figure out build errors. Many of the settings I copied over from the Play/SKR GitHub config.h and config adv.h had to be messed with until the errors mostly went away. Finally I got a working firmware built and it still had the TMC error.

I reinstalled the original firmware and there was no TMC error, so I knew it had to be settings.

I found that he had set Slave address settings and that was causing the error. Of course it took a whole lot longer than this to figure it out. Once they were all changed to zero the error was gone

No TMC error message.
Yep, it was printing even with the error, but it hardware problems never let a print finish.

So after I fixed the error I then had to track down some hardware problems that were causing failed prints. After screwing with the cables the cabling was catching on the bed. And the pulley on the X axis was not centered and had to be loosened and re-centered. I am still hearing some noise from the X rods and bearing, they need to be removed and have a good cleaning. My parts cooling fan was plugged together backwards at the upper end and was not working. And the dreaded “banding” is still there. I need to upgrade to a 4 lead Z screw. A future project.

Butttt,,, It is now printing.

So overall the project was a success. I replaced the heart of the printer with a 32bit upgrade and made it work. It is unbelievably quiet compared to it’s original board.

Next upgrade projects:

4 lead Z screw

Hotend upgrade. I am thinking of going to the CR 10 hotend, mounted Direct Drive,(same as Ender 3/5 but at 12V) or going to a UBIS 13S. Frankly the UBIS 13s is an easy upgrade with this board. It is more expensive than the ender unit but would not be easily added to the Printrbot extruder drive. A new extruder and a mounting plate would be needed. In the end a 13s will probably end up in it.

An upgraded build surface!!!!! tired of the Blue tape regimen. I am thinking of using a cut down magnetic build plate from one of the Enders. A spritz of hairspray and they work real well.

I also want to get the laptop(control center) back to work on this printer. that means opening up the SD card port to expose the Mini USB connector on the board. The SKR board uses a CH340 connection. It came with the right cable and it is short enough that it might just be right for the job.

Not planning to upgrade:

Heated bed. I have always used this printer for primarily PLA, so I really just do not think it makes sense. BUT! this board, SKR Mini E3 V1.2, was designed for a heated bed, if you want to upgrade yours. You will have to go to a 350W PSU to upgrade the bed. I used a 6A, laptop style, Brick to power this printer.

More on the Control center

While messing around with the Hipstreet tablet I dropped it and cracked the screen. I bought a Unbranded (that is the brand name) 10″ tablet. It had the same Intel Z3537F quad core processor and 2GB main memory. It was also a 32GB storage. It also was upgraded to Win10. I then tried the OTG cable with the power injector. A no go. One end worked for Data, the other for power. It would not work as data and power no matter what I tried.

Side view 10″ Tablet on Play

Next I tried to get a data connection through the keyboard connector. No luck there. It needs a pull down to activate the data port. No firm information on the resistance value. It could be 10K or 100K ohm. After checking the keyboard connector I could no longer charge the Tablet. If it wasn’t for bad luck I would have no luck at all.
So I opened the tablet up. I cut the battery leads. I soldered a small Molex connector into the board. I reduced the LM2596 to 4.1V. Now the tablet is directly powered. Now I had power and Data both. The power system is not optimal. I would like to have the battery in the system as a surge source. I have had some power crashes.
The Control Center works well, but it can take a while for the date and time to correct themselves. The 10″ screen is not as clear as the 8″ was. And the scaling is different. Overall I liked the Hipstreet 8″ tablet better. It was faster (better SSD I believe) and the single cable was a cleaner installation. Size wise the smaller tablet was better overall.
I found it is nice to use a Bluetooth keyboard in conjunction with the tablet. Makes it much easier to change print settings. I setup a public account within my local network. This allows me to send files from my other computers to be used on the tablet. The one problem is the inability to use a USB stick in the tablets for file transfers.

Windows 10 up and connected to printer.

What to look for in a control center Tablet:
Separate power and USB ports. Much easier to setup to operate with the printer
2GB main memory. Allows you to open a web browser while operating the printer.
Decent quality screen.
An extra USB port.
Bluetooth keyboard or Keyboard connector.

I will get you some pictures later.

3D Printer with Tablet for Control Center.

Dell 3168 2 in 1 laptop/Tablet for proposed control center upgrade to 64 bit.

In the past I have written a couple of articles about my Printrbot Play with Control Center. And not a lot has changed on this.
Since the Last CURA has advanced to the point that it’s newest version is 64 bit only. this rules out it’s use on a a cheaper tablet, most tablets. So I have been looking at future options. The fact is true Tablets are on the wane. in their place has risen the 2 in 1. These are Laptops that have a keyboard that folds all the way back so that they can be used as a tablet. On the good side many of them have processors better than an Atom based CPU to choose from. On the bad is most of them use a laptop power supply at 19.5V.
The Atom based Tablets mostly used 5V power in from a cell phone charger. So getting 5V from 12V is relatively easy. You can get 19.5 volts from 12V but it is more expensive and larger in size. Some printers are 24V so this would not be a problem on those.
Since these 2 in 1’s come with a keyboard there is not the problem of trying to find a TRUE Bluetooth keyboard and mouse for ease of use. And they are lightweight so there is no reason they cannot be mounted to the side of a printer. They are found in sizes from 11″ to 17″.
The primary one I have been looking at is the Dell 11″ 3168 2 in 1. It has a Celeron N3060 Dual Core processor, 4 GB memory and 32GB SSD, 64 bit Windows 10. It has a lot of connection options which are nice compared to Tablets. It has 2x USB 2.0, 1x USB 3.0, a MicroSD card slot. So much better connection options than the tablet. You have enough USB ports that you can use a cheaper mouse with dongle. and you can use a USB3.0 stick to backup your files or transfer files to the 2 in 1.
New this costs about $249, outlet $203. Considering the 64 bit operating the 32GB SSD might be a bit on the small size. But it has an upgradeable drive bay as they can also be found with a 500GB HDD. A SSD is preferred for use as a control center because of vibration from the 3D printer. I think a 64GB SSD drive would be large enough. But the Micro SD card could be used for that extra storage to keep the price down.

There are two ways to power this from the printer. 1. Tie it into the 110V to the printer. when the printer gets plugged in so does the 2 in 1.

  1. A Boost converter to raise the voltage from 12V to 19.5V.
    I do not consider running off battery a viable option. Even with screen blanking and such active you could easily end up with a print that is longer than your battery life. You cannot let the system power down as it is streaming the code to the printer.
    Overall I am contemplating the move to a newer control center computer. Newer software is all going to 64bit. The added memory will really help with programs like Sketchup. The CPU is not a whole lot more powerful than the Atom in the tablet.
    I recently let my Nephew borrow the Play with tablet. He did not have any experience with a 3D printer. He found it very nice to have the right programs and drivers already waiting rather than have to install all of that on his computer, then try to figure it all out. He was printing on it in minutes and had a very good experience. He now has an upgraded play his dad gave him. Then he found out what it takes to get everything working right versus it is setup and ready to go. He also agrees that having a computer integrated into a 3D printer would help bring them into the mainstream. He liked that he could use the printers tablet to get into Thingiverse then download and be printing very quickly. Currently he sneaker nets a SD card to the printer which he runs in his wash room due to noise.
    Good printing everyone!