Titan Stepper Driver Recommendation

Discussion in 'Titan' started by Dark, Sep 13, 2018.

  1. Dark

    Dark Member

    Joined:
    Sep 13, 2018
    Messages:
    2
    Likes Received:
    0
    What are good drivers for the Titan extruder stepper?

    I am currently running A4988 drivers for my current bowden direct-drive extruder. I’ve attempted to use TMC2208 drivers, but under some circumstances they shut down leaving the extruder unpowered and non-responsive. Apparently this is a safety feature, and seems to be triggered by the intricate stepping introduced by the Linear Advance pressure control feature in Marlin.

    What I would like is nice smooth prints, and of course quiet printing is always nice to have.

    Given the Titan gearing, the new setup will run the stepper faster so I’ll experiment with the 2208s again, but what I’m wondering is - is there a recommended or suggested driver to run the Titan and it’s compact motor, especially when smoothness and quietness are desired?
     
  2. mhe

    mhe Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    129
    Likes Received:
    32
    If you'd be willing to do a board swap, a Duet would solve all those issues and give you twice the amps of the 2208s to boot.

    Have you tried deactivating linear advance pressure in Marlin?
     
  3. Dark

    Dark Member

    Joined:
    Sep 13, 2018
    Messages:
    2
    Likes Received:
    0
    I'd love to upgrade the board, but that's a bit beyond the scope of my experimenting (and budget) at this stage! :)

    If I turn linear advance off the problem goes away (as far as I've discovered), however having pressure control enabled seems to be necessary with my setup to get good clean corners. I have noticed a significant increase in wall smoothness while running the TMC2208 drivers without Linear Advance, so I think the microstepping interpolation is helping with smoothness immensely.

    The guts of the problem is that I'd like to have:
    • Linear Advance for neat corners
    • 16->256 Microstep Interpolation for smooth walls
    • Silently driven steppers to counteract the extra movement needed for both Linear Advance and the higher speeds needed to drive the Titan

    Some calculations I've been throwing around - the Titan has a 3:1 ratio, and new motor is 400steps/rev, so with A4988 at 16x microsteps I'm going from the current setup (1) to the Titan (2):
    1. 1:1 gearing, 200steps/rev = ~94.99 steps/mm
    2. 3:1 gearing, 400steps/rev = ~837steps/mm (about 8x more)
    Interpolation of 16->256 microsteps with TMC drivers (16x more) would increase 1) to ~1500steps/mm, and would increase 2) to 13392steps/mm

    Experimenting with the TMC2208s with Linear Advance disabled, I determined that 1500microsteps makes a significant visible difference to my prints, however the TMC2208 has a reputation on not being able to drive extruders due to high changes in velocity/current causing shutdowns
    Sources:

    It may be that at ~837 steps the wall smoothness is adequate enough to be able to run an A4988 on the extruder, however this doesn't address noise levels.

    I have a few further experimentation options moving to the Titan and the new 400s/r stepper
    • Stick with A4988 at 16x microsteps, compare the quality and see if the noise is tolerable with the new setup
    • Try changing the A4988 out for a TMC2160 and see if it can handle the load
    • Try TMC2208 (or TMC2130) in SpreadCycle mode
     
  4. mhe

    mhe Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    129
    Likes Received:
    32
    Well if you go for 256 microsteps on an 8-Bit microcontroller, things will get wonky because you might reach the point where the chip can't do the math fast enough. That problem is either resolved by lower microsteps or by having more computing power (Duet, Arduino Due w/ RADDS, Smoothieboard etc).

    The other way to do it is the klipper firmware you linked above where motion computing is done on a Raspberry that is orders of magnitude more powerful than the 8-Bit microcontroller. It is surprisingly simple to set up, maybe that would help you a bit. However, that would not resolve the problem if it comes from the drivers.

    Noise you'll only resolve by better drivers, Trinamic is on top of this game. You can either go for the TMC2100/TMC2130 ones that top out at 1.4 amps at best. Or you can go for the big daddy TMC 2660. A Duet board happens to come with 5 on them already on board and they make all the difference (let alone the superiority of Duet over Rumba/Arduino in pretty much any quantifiable metric let alone software features).

    In the end, time is money as well, you might want to consider that because all the "let's try it out" approach of yours will burn through money and time. If you add the time spent to the money spent, you'll quickly reach the point where you could have said screw it and just get a Duet.
     

Share This Page