Qidi Tech 1 - Replicator 1 clone

[caall99]

So, did a bit more experimentation: My motor VREF setting is 90 for X and Y. I was printing at a peak feed rate of 90mm/s and 130mm/s travel-only speed. Object sliced with Cura 2.1.2 and acceleration in Sailfish firmware was limited to 300mm/s^2 for X and Y. I notice that occasionally, acceleration is ignored and the print head races to its next starting point at the full 130mm/s travel speed! This results in a "bang" and the stepper motors skip and printing continues at a new location killing the print. I did some reading here: http://www.sailfishfirmware.com/doc/sailfish.pdf (READ SECTION 9.4). Sounds like Sailfish cannot "accelerate" a move if it doesn't know the last location (e.g. last location not saved in EEPROM). I wonder if Cura 2.1.2 does something to the gcode that could cause this "NON-accelerated" move phenomenon to occur randomly MID PRINT. 130mm/s without acceleration on a dual direct extruder Cartesian setup is painful to watch.... I am sure my 90 VREF setting is also reducing the amount of holding torque resulting in the steppers having insufficient force to overcome the momentum of a 130mm/s un-accelerated move - resulting in skipping of steps. thoughts?

[jfkansas]

The print head never knows where it is at on a grid. The gcode isn't a coordinate system, it just says whereever it is now, next move 13mmX and 12mmY and extrude this much E plastic. Then repeat that 1000s of times. So did the belt skip a tooth? Maybe you shouldn't travel faster than say 90 with a fully loaded print head. Take the left stepper off if you want to do 120+ travels. As far as acceleration, all "sailfish" knows is it has to move 40mm in X direction and 30mm Y or whatever the move is. It doesn't care where it has been. It calculates accell based on how far it has to go.

[Mjolinor]

The print head never knows where it is at on a grid. The gcode isn't a coordinate system, it just says whereever it is now, next move 13mmX and 12mmY and extrude this much E plastic. Then repeat that 1000s of times. So did the belt skip a tooth? Maybe you shouldn't travel faster than say 90 with a fully loaded print head. Take the left stepper off if you want to do 120+ travels. As far as acceleration, all "sailfish" knows is it has to move 40mm in X direction and 30mm Y or whatever the move is. It doesn't care where it has been. It calculates accell based on how far it has to go.

Gcode does absolute and relative. It depends what you have set in the file.

[jfkansas]

True, and acceleration would be calculated by the distance between where it is now and where it is going. Both Absolute and Relative the the processor knows how far the move is and accelerates/decelerates as needed.

[caall99]

Thanks for the information, but I am already aware of this and have taken measures to make sure that everything is tight and working properly. My issue is non-accelerated print and travel moves occurring mid print, which cause the motors to skip. I should be able to print at 90 mm/s and travel at 120 mm/s, or even twice those amounts, if my max acceleration setting of 300 mm/s^2 was working consistently... but it's not.

[jfkansas]

What are your max speed changes? X and Y at about 7 or 8 is good. Max accell for X and Y at 750 is good. Even with those settings I wouldn't go over 90 with a fully loaded print head. 120-140 for travel is easily obtainable with the left stepper removed.

[caall99]

What are your max speed changes? X and Y at about 7 or 8 is good. Max accell for X and Y at 750 is good. Even with those settings I wouldn't go over 90 with a fully loaded print head. 120-140 for travel is easily obtainable with the left stepper removed.

Max speed changes are 7. Max acceleration for X and Y are 300mm/s^2. None of this matters when it comes to my problem. I am talking about intermittent loss of "acceleration feature" in the middle of a print... I could set my travel speed to 200mm/s and it shouldn't matter with my acceleration value of 300mm/s^2.

[DaveB]

I may the last guy to the party, but I just found about a dozen videos on YouTube from QiDi. They cover basic maintenance activities for the Qidi printer, and include replacing: the extruder, half the extruder, the filament drive gear, the Zaxis motor and threaded rod, the thermocouple, and the extruder drive steppers. Also leveling the build platform, testing the X, Y and Z limit switches, tightening the screws on the X and Y drive stepper pulleys, building and installing the acrylic covers, and replacing the nozzle and PTFE tube (I always wondered what that big freakin bolt was for).

All of these turn up on You Tube in response to a search for "QIDI 3d printer", then apply a filter for this week (or today if you're snappy).

I expect that Qidi will eventually post these in their sticky thread.

[rcleav]

I may the last guy to the party, but I just found about a dozen videos on YouTube from QiDi. They cover basic maintenance activities for the Qidi printer, and include replacing: the extruder, half the extruder, the filament drive gear, the Zaxis motor and threaded rod, the thermocouple, and the extruder drive steppers. Also leveling the build platform, testing the X, Y and Z limit switches, tightening the screws on the X and Y drive stepper pulleys, building and installing the acrylic covers, and replacing the nozzle and PTFE tube (I always wondered what that big freakin bolt was for).

All of these turn up on You Tube in response to a search for "QIDI 3d printer", then apply a filter for this week (or today if you're snappy).

I expect that Qidi will eventually post these in their sticky thread.

I've been in touch with Qidi Tech support recently and they are definitely taken a more proactive support role.
Example the changes on this forum and new help videos on Youtube.

[DaveB]

I've been in touch with Qidi Tech support recently and they are definitely taken a more proactive support role.
Example the changes on this forum and new help videos on Youtube.

That is all positive news. Their new printer is a good incentive I guess.