Re: Einsy-Rambo on mk2?
I sent a message to ultimachine asking about the board.They said that they will be releasing the board sometime this month.
Re: Einsy-Rambo on mk2?
I just spoke to support guy at Prusa. I wanted to add Einsy board to my 2.5 upgrade i ordered earlier. He said they did not allow to change the upgrade kits.
But he also said that the bed was the same for 2.5 upgrade and for V3.
I built the haribo frame and got left with original frame. Also bought new extruder just before multimaterial upgrade arrived. I bought few motors and bed carriage plus some other pieces and i am ready to build another printer when the 2.5 upgrade arrives. Just waiting for Ultimachine to release the board.
Re: Einsy-Rambo on mk2?
I also spoke with the PRUSA guys a few days ago.
Yes, it's possible to update the MK2 -> MK2.5 -> MK3 (Einsy).
He give me the tip to look for the Einsy at Ultimachine 😉
Thomas
Re: Einsy-Rambo on mk2?
I also spoke with the PRUSA guys a few days ago.
Yes, it's possible to update the MK2 -> MK2.5 -> MK3 (Einsy).
He give me the tip to look for the Einsy at Ultimachine 😉
Thomas
Hi,
the only issue i can see is that the MK2.5 heated bed MK52 seams to be a 12V version as the blower fan and Noctua fan and not as in the MK3 upgrade kit 24V.
So if you stay with 12V on the Einsy you will need to modify the firmware to get NEMA power right.
Also if you keep the Prusa i3 MK2 12V PSU there will be NO power panic function.
Re: Einsy-Rambo on mk2?
- If my information is right, the MK52 is 12 and 24V, depends on the wiring of the heatbed-PCB.
- Blowers/fans voltage can be easily modified. You can grab the power from different sources.
- it doesn't make sense if you power the motors with 12 or 24V. The steppers are current-drivern. But it makes sense for the Einsy (trinamic-drivers).
- Yes, the power supply must be changed too.
Thomas
Re: Einsy-Rambo on mk2?
- If my information is right, the MK52 is 12 and 24V, depends on the wiring of the heatbed-PCB.
- Blowers/fans voltage can be easily modified. You can grab the power from different sources.
- it doesn't make sense if you power the motors with 12 or 24V. The steppers are current-drivern. But it makes sense for the Einsy (trinamic-drivers).
- Yes, the power supply must be changed too.
Thomas
I just wanted to point out that the firmware might have to be modified using 12V.
That would be great if the MK52 is 12/24V. I asked in the chat and they wanted to reach out to de develop team and send me an update about that, still waiting.
I was looking how much it would cost to get parts missing in the MK2.5 upgrade kit compared to the MK3 upgrade kit. At the end you cannot save much, as you spend most of the savings on the shipping costs to get it from different suppliers.
Re: Einsy-Rambo on mk2?
Hi just saw the MK52 heated bed on the github.
There is a 12V AND a 24V version, so no 12/24V at this moment.
Re: Einsy-Rambo on mk2?
Hey guys,
Any more news on this?
I also contacted Prusa support about this but got no response 🙁
Re: Einsy-Rambo on mk2?
Similarly looking for any updates on this topic.
For many of us, i think we want the benefits of the Einsy board not so much the 24v part.
Just today the power went out at my place, and even with an 1800W UPS, the Mk2 skips a beat, and print at 90% was trashed 🙁
Perhaps we can come up with a hybrid method of upgrading to the Einsy board for some of the quick wins
- (A lot of the items below can be purchased in pieces from the parts store or set up as an upgrade if prusa likes the idea)
- Power interrupt resume
- Skip step resume print
- Filament sensor
- Updated Fans with RPM sensing
- PINDA 2 probe
Other conditions
- Retain current Mk42 or use a 12V variant of the MK52 magnetic bed
- Retain current steppers from Mk42
I updated my Mk2 frame and the second homebrew mk1 --> mk2 with tubular v-slot 20x40 profile so my printer is physically probably more solid or just as solid as the Mk3, just wish I could add some of the software features from the mk3 without selling off my machines.
Re: Einsy-Rambo on mk2?
Similarly looking for any updates on this topic.
For many of us, i think we want the benefits of the Einsy board not so much the 24v part.
Just today the power went out at my place, and even with an 1800W UPS, the Mk2 skips a beat, and print at 90% was trashed 🙁
Perhaps we can come up with a hybrid method of upgrading to the Einsy board for some of the quick wins
- (A lot of the items below can be purchased in pieces from the parts store or set up as an upgrade if prusa likes the idea)
- Power interrupt resume
- You gonna need a 12V power panic circuit
- The big question is if the MK2/s PSU will have enough power left to store the information to EEPROM and lift the z-axis. If i am not wrong the nemas will need more power to move the z-axis compared with 24V and i don't know how much the PSU caps can hold after a power cut.
- Skip step resume print
- Filament sensor
- Updated Fans with RPM sensing
- PINDA 2 probe
Other conditions
- Retain current Mk42 or use a 12V variant of the MK52 magnetic bed
- Retain current steppers from Mk42
You mean keep the MK2 Nemas, or not?
I updated my Mk2 frame and the second homebrew mk1 --> mk2 with tubular v-slot 20x40 profile so my printer is physically probably more solid or just as solid as the Mk3, just wish I could add some of the software features from the mk3 without selling off my machines.
I am updating my MK2 to MK2.45 as i have a good printer and don't need a 12V MK52 bed, but like to have some features:
- Got a Noctua 12V fan from Amazon (12,90€) and this will be connect it via a y cable to the existing hotend fan connector and x-max (RPM signal) -->MK2.1
- If I can find somewhere a 505015 12V blower with RPM sensor I will connect it via y cable to part fan connector and z-max (RPM signal) -->MK2.15
- Ordered the PINDAv2 (14,40 €) and this will be connected via y cable to z-min and T1 (free Thermistor connector) -->MK2.2
- Have a spare bondtech gear (50€) from my upgrade kits --> MK2.3
- Have a spare MK3 Filament Sensor (11,80€ vs. 15€) from my upgrade kits -->MK2.35
- As soon the powder coated spring steel sheets (25€) are available i will order one and clip it to the MK42 bed -->MK2.4
- Having a spare E3dv6 Prusa MK3/ Multi Material hotend from my upgrade kits --> MK2.45
I will spend around 53€ and some shipping costs.
Power at my place is very very reliable and see no need for the power panic function on the MK2/s.
BTW: I ordered
1. 'Original Prusa i3 MK2/S to MK3 upgrade kit' from Prusa and get some motors, LCD, fasteners, smooth rods and bearings from somewhere else and build a 2nd bigger printer.
2. 'Original Prusa i3 MK2/S Multi Material upgrade kit' + 'Multi Material upgrade kit - from MK2 to MK2.5/MK3' as i get more value for few bugs (+39€) more:
2.a. extra E3dv6 Prusa MK3/Multi Material hotend (80€)
2.b. extra bondtech gear (50€)
2.c. extra MK3 filament sensor (15€)
2.d. Paying 39€ more i get extra parts which cost 145€
2.e. Or if you see it from an different angle, I get the MK3 MMU upgrade kit for 223€ vs. 349€ (okay i don't get the NEW filament holders).
2.f. Or paying around 100€ more i get my MK2.45 and a spare E3dv6 hotend (80€ value).
Re: Einsy-Rambo on mk2?
Similarly looking for any updates on this topic.
For many of us, i think we want the benefits of the Einsy board not so much the 24v part.
Just today the power went out at my place, and even with an 1800W UPS, the Mk2 skips a beat, and print at 90% was trashed 🙁
Perhaps we can come up with a hybrid method of upgrading to the Einsy board for some of the quick wins
- (A lot of the items below can be purchased in pieces from the parts store or set up as an upgrade if prusa likes the idea)
- Power interrupt resume
- Skip step resume print
- Filament sensor
- Updated Fans with RPM sensing
- PINDA 2 probe
Other conditions
- Retain current Mk42 or use a 12V variant of the MK52 magnetic bed
- Retain current steppers from Mk42
I updated my Mk2 frame and the second homebrew mk1 --> mk2 with tubular v-slot 20x40 profile so my printer is physically probably more solid or just as solid as the Mk3, just wish I could add some of the software features from the mk3 without selling off my machines.
it's 24v for a reason... if you want to print faster, and quieter and have more reliable skip detection with 2130s, it's a must if it wasn't they would still use 12v. the board can run just fine on 12v as a drop in replacement really....
What i did was just wire TMC2130's externally and use a DC-DC step up to 24v..... the break out pads for the steppers to bypass the build in ones are on the back of the board. they're in dumb mode but you could probably wire ISP to the board too. was too lazy. i just wanted it quiet.
Re: Einsy-Rambo on mk2?
eric.k4
I'm thinking about hooking it up similar to your method. Was the noise reduction in this method worth it in your opinion?
Re: Einsy-Rambo on mk2?
eric.k4
I'm thinking about hooking it up similar to your method. Was the noise reduction in this method worth it in your opinion?
noise/pitch would depend on the motors, it was unbearable in my case. just an annoying "eeeeeeeee " sound that couldn't be removed with pot/current adjustment. wasn't just idle but during a print too. Stealth chop made no noise at all, but not enough torque so it usually skipped steps which would be fixed by using 24v. at least at a certain speed.
Re: Einsy-Rambo on mk2?
Okay so ... I am somewhat confused reading through this thread. My plan is to upgrade my MK2S with the 2.5 upgrade, add a flexion extruder and replace the rambo with an Einsy from Ultimachine. Seems like that should be pretty plug and play. Am I missing something?
Re: Einsy-Rambo on mk2?
Okay so ... I am somewhat confused reading through this thread. My plan is to upgrade my MK2S with the 2.5 upgrade, add a flexion extruder and replace the rambo with an Einsy from Ultimachine. Seems like that should be pretty plug and play. Am I missing something?
Hi Joey,
Plug and play hardware wise YES and NO:
As mentioned before in this thread:
NO or you have to change plugs/connectors
- MK2.5 Noctua fan is 12V and the EINSY has 5V for fans (you cannot use it on the EINSY, maybe it will work but very slow)
- MK2.5 heated bed will come with the green/black plugs to fit in the miniRAMbo the EINSY has other terminals.
- The PINDAv2 may come with a different wiring, hopefully it is just a y-slippter cable so you could use it also on the EINSY
- The MK2 PSU dosn't have the power panic circuit
- PSU plugs to miniRAMbo are different than to the EINSY
YES
- You can connect 12V PSU (other plugs/connectors), hotend heater and bed to the EINSY
- hotend and bed thermistors use the same connectors
- Stepper motors use the same connectors
- LCD uses the same connectors
- filament sensor uses the same connector
MISSING:
- 5050 5V blower fan with rpm signal to get it as close as possible to the MK3
Software wise you gonna need to make your own custom version
- as you run the TMC drivers on 12V
- the z height is different between MK3 and MK2/s 2.5 by 5mm.
- You have to disable the power panic functions as you don't have the power panic circuit in your MK2 12V PSU
- and other things i may have forgotten.
Hope it makes it bit more clear.
Re: Einsy-Rambo on mk2?
Great info. Thanks!
Re: Einsy-Rambo on mk2?
Hi, so I just discovered this thread, I'll be perfectly honest, I haven't read most of it yet, so I apologize if some (or even most) of this post is redundant. I just wanted to let everyone know that I've been running an MK2S with an Einsy board for a couple weeks now, and have everything working including stallguard and the endstop-less homing etc.
(Please forgive my atrocious wiring. I already know it's bad. I just don't care.) Here she is, in all her Einsy glory. Listen, can you hear that? Sweet sweet silence :). Everything works splendidly - homing without endstops, stallguard and counting missed steps, 256 microstep interpolation, all that good stuff. It feels like my MK2S is almost bullet proof now - I actually *can't* get it to screw up a print. Flawless operation is what you can expect! :).
Oh, and let's not forget stallGuard:
I back ported the MK3 firmware to work with the MK2S. There are still a couple of bugs I need to solve but you can check out my (in progress and on going) changes at my github fork of the MK3 v3.1.13 firmware. Be sure to checkout the 'MK24' branch (so, just shy of a MK2.5. Once my MK2.5 upgrade kit comes, I plan to make a 'MK2.8' version of the firmware which will essentially give you a MK3 minus the more rigid frame and faster print speeds that come with it).
I'm also an electrical engineer who specializes in switch mode power supplies, magnetics, motor control, that sort of thing. I have some important information about the steppers and TMC2130 drivers, but I'll get to that in a bit.
So, here is the short list of minor changes you will need to make:
Hardware:
1. You don't need to replace any connectors if you cut off their latchy bits with wire snips. This might sound barbaric, but trust me, replacing the connectors is a substantially larger pain in the butt than you might imagine. That said, you only really need to modify the PINDA connector. You can still connect it by leaving the pin furthest from the USB port on the Einsy board unconnected, the pinout is the same but with an extra pin added to that side for the temperature sensor. Here is a connection diagram that shows individual pin functions instead of just connector labels which I found extremely helpful.
2. The 12V power connectors can be removed just by loosening the screws. Then put the bare wire ends into the Einsy's screw terminals. This is easy and you can always reattach the 12V power connectors later if you want.
3. No way around it, you will need new 5V fans. But they're very inexpensive. You can print out a simple and effective adapter and buy the 40mm 5V Noctua fan, and a 5V blower from many places, as someone in the US, I got both on Amazon. Noctua for $14 and 5V blower for $9. Note, the 5V blower is not a 3 wire one, and is lacking the tachometer functionality. I've had a hard time finding a 3 pin blower that is both 5V and the right size. But knowing the RPM for the print fan (vs the hotend cooling fan) isn't too useful anyway.
4. Where we're going... we don't need end stops. Put the end stop switches down your sink's garbage disposal if you want. You aren't going to need them anymore. Or, less extreme, just don't bother connecting them (you'd have to alter the connectors to do so anyway.
5. Don't worry about the filament runout sensor. My MK3 firmware fork lets you enable or disable all filament runout sensor/autoloading functionality as needed by commenting or uncommenting out a couple #defines in the configuration_prusa file. However, I have no idea if enabling it actually works, as I have no way of testing it (yet).
6. Using 24V as the motor drive voltage is absolutely a requirement. No amount of software changes will permit the TMC2130s to correctly drive the stepper motors at 12V. Oh, and to make this clear: the MK2S and MK3 use the same motors. Or at least nearly identical. Stepper motors don't have true voltage ratings like brushed DC motors, only a max voltage limited by their windings (usually 48V+) and a maximum current. So your MK2's motors are not '12V steppers', nor are the MK3's 24V ones. They're the same. Which is why no changes are required to any of the TMC2130 settings in the MK3 firmware to work any less than flawlessly with the MK2S steppers :D.
I don't expect anyone to take my word for it, but the reasons are complicated and long so I moved them to the Appendix at the end of this post.
Using 24V is actually cheap, simple, and easy, it really is nowhere near as bad is it sounds! There is good news!
7. You can continue to use your 12V power supply for the heavy lifting, like the heated bed. I looked at how they have their power rails setup in the Einsy Schematics (this works for the mini rambo as well), and there is absolutely no problems with using different voltages for your heat bed vs. main power. You can continue to use your 12V power supply for the heavy lifting. You hook 12V up to the bed power input, and 24V up to the main power input. Since the fan voltages are now regulated by a buck converter down to 5V, they still get 5V. Same with the PINDA probe. The only thing that will see the raw 24V is the motors and the hotend heater cartridge.... at least if you connect it as is. Which leads me to...
8. You can continue to power your hotend from the 12V supply as well! Yes, even with 24V connected to the main power. You just have to be a little clever in how you wire it.
The heater is controlled by a N-channel MOSFET. What this means is that one of the two pins on the heater power output connector on the Einsy board is connected to whatever is powering our motors/whatever is connected to the main power input. So if that is 24V, there is 24V on that pin. It is never switched off, it is always connected. What IS switched off is the ground. An N-channel mosfet works by, effectively, 'disconnecting' something from ground when off, and connecting it to ground when on.
And ground is ground. That means that, as long as they share a common ground (which they do - the grounds of both bed and main power are connected by the Einsy's copper pours), we can connect one wire of the heater cartridge to any voltage, and the heater MOSFET switch will still turn it on and off exactly as before. Again, any voltage as long as that voltage shares a common ground with the main power - which, if the 12V supply is connected to the bed power input, is the case for our original 12V supply.
So all you have to do is cut the positive wire of the heater cartridge near its connector, strip the insulation off a bit, then splice it to the second 12V positive wire (since one of the 12V pairs is now sitting unused) by whatever means you like (solder, crimp, twist it really good and pray), and leave the remaining wire in the connector, connected to the Einsy's heater port as normal. Now your 12V supply is powering everything except the motors.
I'll draw a diagram tomorrow, sorry.
9. Your 24V supply can be a $9 wallwart! At 24V, even after bumping up the current by a fair amount (which I needed to do because something sticky got spilled on a leadscrew and 8mm ground rod... don't ask lol), all 5 motors combined never draw more than 700mA RMS at 24V. This drops to less than 600mA RMS at 28V. So something as modest as a 24V 1A power supply isn't just adequate, but will give you 30-40% headroom beyond the required current. This is seriously all you need. ($9)
There is already adequate decoupling on the Einsy board, the power supply does not need any real output capacitance or filtering. I am printing with my MK2S right now piping 28V down about 8 feet of speaker wire connected to the crappiest chinese mystery wallwart I could find, and there are no problems whatsoever.
This might weird people out, having two separate things powering the printer, but it is not a problem, and the boards are designed to be operated like this - that's the entire point of having separate bed and main power connections. They have oring diodes where needed. The schematic labels the bed and main power rails as 12V3 and 12V2 I believe, but these are just names - they are not necessarily intended to only work at 12V. And clearly this is the case, as the MK3 connects them both to 24V rather than 12V. Beyond that, they need not be the same voltage. Plenty of people use them with different voltages. And the entire board will act as if it is 'on' (ATMega booted and operating, LCD on, etc.) as long as any one of the two voltages is turned on. So it doesn't matter if you have only the 24V on, or only the 12V on, or which order you turn them on or off. Though, with 12V off, the heated bed and hotend heater will not work, obviously. But to turn the printer on and off, you just turn both supplies on, or off, with any amount of delay in between, and in any order. It's fool proof, and it just works. And all of this is by design and qualifies as an intendedusage case of both the Einsy and rambo mini.
OK, so I need to go to bed, this turned into a very long post, but in a few days I should have things tested well enough that I might be comfortable sharing a (TOTALLY UNSUPPORTED AND USED AT YOUR OWN RISK AND RESPONSIBILITY) firmware hex people can flash. Until then, more adventurous people are welcome to download my firmware from github - it compiles directly in the arudino IDE and should be flashed from it as well. Only to an Einsy board though, of course.
For those curious about what had to be changed, I had to adjust some of the calibration parameters (the calibration points changed position slightly with the MK3), change the position of the PINDA probe, fully enclose various filament runout sensor, heatbed v2, and power panic-specific code in #ifdef compiler directives to permit the disabling of those features... I am probably forgetting something but its all visible in the diffs on git.
Appendix:
Why won't 12V work as the motor drive voltage when using the TMC2130 drivers?
The TMC2130s are definitely the reason Prusa increased the voltage of the MK3 to 24V - out of necessity. I know this is not the news many of you wanted to hear, but the simple fact is that if you want to use the TMC2130 drivers to drive your motors, you need to use at least 24V (higher is even better - 28V seems to be the sweet spot for me).
The reasons are, unfortunately, neither singular nor simple. There are several compounding factors behind this, but I'll touch on them briefly for those interested.
• The loud whine is due to the motors' coil inductance. What you're hearing is the PWM chopping frequency. It should be around 26kHz, but at 12V, the drivers can't ramp up the current fast enough at a cycle-to-cycle level, so they compensate by reducing the PWM/chopping frequency. And it gets reduced straight into the audible range of human hearing. The whining you hear is the motor coils vibrating, and this is not a quiet sound. It is loud enough to be painful to my ears if I am within 3 feet of the printer.
• Overmodulation when motors are moving. At 12V, as soon as the motors begin turning at even fairly low speeds, the back EMF becomes too high. Back EMF is a voltage opposing the drive voltage... you know how the LCD lights up when you manually move the steppers but the printer is off? That's due to back EMF. It happens whenever the motor is moving, including moving under power. When this gets too close to the maximum drive voltage (12V) minus the resistive loses of the motor coils, this forces the TMC2130 drivers into their overmodulation region. This wasn't an issue for the A3982 because at 1/16th microstepping, these spikes were too fast and were outside the driver's modulation bandwidth.
Uh, this one is hard to explain. I suppose one might think of overmodulation as analogous to the distortion region of an audio amplifier. Or if anyone here is into hamatuer radio, I mean it in exactly the same way you understand overmodulation, but it is modulating coil phase current instead of radio.
You know how a smaller audio device, if you turn the volume up too high, begins to produce very unpleasant, distorted sound? You can kind of think of it as a similar effect in the motors. I looked at the phase current waveforms on my oscilloscope, and it became quite dirty as the motors began moving, heavily distorted with nasty harmonics. As a bonus, this also generates additional (and even more irritating) audible noise. It makes the driver chips have to dissipate a lot more heat than they would normally, and generally degrades all-around stepper performance, current regulation, and microstepping behavior. You can expect to see jerky, and intermittent movement (with the pauses marking periods of hundreds of skipped microsteps, all unnoticed by the firmware) at low to medium speeds (and faster) as a result of this.
• For the same reasons as overmodulation, stallGuard2 (required for calibration and all sorts of other minutia in the MK3 firmware) will never work with these motors at 12V. stallGuard2 requires the drive voltage to be greater than the resistive voltage losses plus the back emf voltage to correctly measure/detect a stall or missed step, and unfortunately, for all but the lowest speeds, 12V is not high enough to meet this requirement.
• The driver chips dissipate more power at 12V due to the above, and I would question their ability to not overheat in these conditions.
I really want to drive this home to hopefully save someone from wasting their time trying to use 12V. The only possible 'solution' would involve turning off 256 microstep interpolation and running the chips at 1/16th microstep mode, which would also disable stealth chop, stallGuard2, and every reason for even bothering to upgrade to the Einsy with it.
Re: Einsy-Rambo on mk2?
@metacollin
Perfect :geek: . The best description of an MK2 to nearly MK3 individual upgrade I have read until now.
One should somehow mark this as the answer, or at least add the post-link ( https://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/einsy-rambo-on-mk2--t6137-s30.html#p74913 ) to the first posting.
Re: Einsy-Rambo on mk2?
...
That is a brilliant writeup, well done.
I almost opted to this build myself, but went the way of buying the heatbed and fans from Prusa, and everything else from Misumi, Amazon and Aliexpress for two new printers.
For the motors i went with 2A per coil OSM Motors.
17HS16-2004S from here http://www.osmtec.com/nema_17_step_motor_17_hs.htm
Stock Prusa Motors have 1.2A/phase ODM Motors.
Since i have your TMC experience here and i have a question, mind if i shoot it?
On the MK2, the current for the motors was hard current limited
#define DEFAULT_PWM_MOTOR_CURRENT {270, 830, 450} // {XY,Z,E}
#define DEFAULT_PWM_MOTOR_CURRENT_LOUD {540, 830, 500} // {XY,Z,E}
the board hard the option to set the current via the digital poti and M907 X Y Z
I had to give my Titan motor a current of 800mAh, or else it wouldn't push through filament. (Stock was around 500)
On the Einsy with the TMC2130 and their what-current-does-the-motor-currently-need ability, and my 2A/phase motors, will it work automatically with the stronger motors as well, or is it limited to Prusa's Marlin set hard caps in the current again like in the MK2's drivers?
(tl:dr, will this play nice with other/stronger motors?)
Re: Einsy-Rambo on mk2?
For the motors i went with 2A per coil OSM Motors.
17HS16-2004S from here http://www.osmtec.com/nema_17_step_motor_17_hs.htm
On the Einsy with the TMC2130 and their what-current-does-the-motor-currently-need ability, and my 2A/phase motors, will it work automatically with the stronger motors as well, or is it limited to Prusa's Marlin set hard caps in the current again like in the MK2's drivers?
(tl:dr, will this play nice with other/stronger motors?)
Yeah, the Einsy works the same way in terms of setting the current, except that the current isn't given in mA anymore. In the Configuration_prusa.h file, near the bottom of the TMC2130 section, you'll find:
#define TMC2130_CURRENTS_H {16, 20, 28, 36} // default holding currents for all axes
#define TMC2130_CURRENTS_R {16, 20, 28, 36} // default running currents for all axes
#define TMC2130_UNLOAD_CURRENT_R 12 // lowe current for M600 to protect filament sensor
Those correspond to the X, Y, Z, and Extruder axes. Each number can be anywhere between 0 to 63. The actual current values can be calculated thusly:
This is determined by the value of the current sense resistor used on the Einsy, which is 0.22Ω. While the TMC2130s in that package can do up to 1.4A RMS per phase, the Einsy board has limited the maximum current (63 in the firmware) to about 0.96A.
The current is limited to .96A because the driver chips should, theoretically, not overheat even if the user sets a maximum current value (63) for a given motor in the firmware. So if your extruder motor needed 800mA, the TMC drivers should work fine.
BUT, its actually a lot more complicated than that. Firstly, the extruder is kind of a unique load in that it needs to apply a large amount of torque from the very start of movement, and if it can't produce more than that amount, we get those dreaded clicking noises instead of extruding filament.
The thing is, the torque being produced by the motor actually varies over the step. And the peak torque is not at the start of the step, but part of the way through.
This is actually a sort of subtle detail that makes the TMC2130 chips really shine, and why they, for all intents and purposes, can achieve the same torque and speed performance from the same motors using less current. Most stepper drivers will control the phase current so it approximates a sine wave. The TMC2130 lets you tune the shape and phase of this wave and alter how the torque varies over the course of a step.
In fact, a lot of their neat special features/modes like stealth chop etc. are, at least in part, enabled by this control. Which brings us back to the higher voltage. Unless a motor has very low winding inductance, the TMC2130 won't be able to make the current ramp up quickly enough at, say, 12V, but it can make the current shoot up twice as fast with 24V. This lets the motor shift the strongest part of a step towards the start of the step, where before, we were actually kind of giving the motors more current than needed if one only went by the peak torque generated by that current. We needed a certain amount of torque to be able to even begin the step under load, so the currents had to be increased to compensate. If you can get peak torque a lot quicker at the start of the step, then you don't need to compensate as much, and ultimately, you get more step for less current.
Really, stepper motor performance is largely determined by the driver, and not the motor. In fact, I would think you could get away with using the stock prusa motors to drive that titan extruder if you just use the Einsy and its drivers. But a extra chub stepper motor won't hurt matters heh.
Long story short, you can expect better torque, more torque at higher speeds, and higher maximum speeds simply by switching to the TMC2130 drivers and upping the voltage. And you can bump the voltage up to as high as 36V according to ultimachine, and you actually just sort of get a free lunch here: the extra voltage will increase the strength and performance of the motors even if the drive current stays fixed.
Case in point, the Prusa motors used on the order of ~1800mA total, but as near as I can tell, slightly BETTER performance is achieved with the same motors at under 700mA total current draw. Just by using the TMC driver chips and 24V.
TLDR: I think you'll have no problem running those beefier motors, and you will need to run them at substantially less current.
Just expect to spend some time experimenting to dial in the current values, and start lower than you normally would. You'll also need to adjust the sg threshould values. Increasing current will usually require increasing the sg thresholds as well, otherwise you will start getting false positives for motor stall/step skipping. But all of this is clearly labeled and well organized as #defines in the Configuration_prusa.h file, so it is mostly just a matter of playing with the values, uploading to the Einsy, test, rinse, and repeat.