These are the data that I could extract from the video: A4988 - 1/16 150 g - 1/8 160 g - 1/2 150 g DRV8825 - 1/32 210 g - 1/16 220 g - 1/2 170 g First of all, having 3 data points per experiment does no allow for any statistical analysis. Descriptively though, what I see is that the factor with the greatest impact is the driver. For A4988 I would say that the stepping rate does not really show to impact lift. For the DRV8825 the 1/2 rate decrease lift while for the other 2 step rates there is barely a difference. In reality you would need to assess what happens on all available stepping rates available for each driver and secondly repeat the measurements, at lest 3 times each. Then you could graph the results for a better idea on how stepping rate affects lift (and implicitly torque). There is also a source of variation in your measurement that can impact your results. And that is the width of the bucket. Although the pivot of the bucket is constant, the position of the weights inside the bucket can change and tilt the bucket left or right varying the pulling torque i.e.if the weights are placed in the left side of the bucket it will be easier for the motor to lift compared with having all the weights on the right of the bucket.
I believe the location of the weights within the bucket should have no effect. The whole load is suspended from the point where it attaches to the arm, and will self-align so the centre of mass is vertically below the pivot point. The only proviso is that the tape used to suspend the bucket may not be as flexible as something like a fine cord.
i like these electronics videos with aspergers guys. theyre always full of good info. its more refreshing than the hyperactive 'personalities' on youtube
Have you tried to put these data into a graphical chart? As a summary of all your measurements at the end of video. Maybe you have a spare tmc right now and can perform similar test as a comparison.
I'm in the process of building a paste extruder and the number of steps is 2x important: you need control over the extruder speed (steps/mm) and also keep a reasonable torque to push the ~30 mm 'filament' (the paste inside the syringe). Even with 10:43 gearing and 1/16 stepping it is not an ideal setup to extrude from 30 mm to 0.6 mm... I may need to add more gearing, to buy a geared stepper or to decrease the "filament" size (smaller syringe)... Thank you for this test it helps a lot! I'm glad I've bought the DRV8825 :) (I'm too cheap to buy the 2130...)
Do you mean by that test which microstepping is better for certain weight ? if using full step the torque will be less ? if using 1/2 step it will increase torque and can handle more weight ?
I have an Anycubic i3 mega and I'm replacing the stock drivers with the DRV8825, I saw that the latter have microsteps (1/32), but I have to change something on the printer to be able to take advantage of the microsteps or the printer is ready to use the microsteps ?
I don't understand anything. Drv8825 is super jerky and noisy in optical tests. I have used them for years. If your linear motion uses above 400 steps /mm then you won't care about this inaccuracy
These are the data that I could extract from the video:
A4988
- 1/16 150 g
- 1/8 160 g
- 1/2 150 g
DRV8825
- 1/32 210 g
- 1/16 220 g
- 1/2 170 g
First of all, having 3 data points per experiment does no allow for any statistical analysis.
Descriptively though, what I see is that the factor with the greatest impact is the driver. For A4988 I would say that the stepping rate does not really show to impact lift. For the DRV8825 the 1/2 rate decrease lift while for the other 2 step rates there is barely a difference.
In reality you would need to assess what happens on all available stepping rates available for each driver and secondly repeat the measurements, at lest 3 times each. Then you could graph the results for a better idea on how stepping rate affects lift (and implicitly torque).
There is also a source of variation in your measurement that can impact your results. And that is the width of the bucket. Although the pivot of the bucket is constant, the position of the weights inside the bucket can change and tilt the bucket left or right varying the pulling torque i.e.if the weights are placed in the left side of the bucket it will be easier for the motor to lift compared with having all the weights on the right of the bucket.
I believe the location of the weights within the bucket should have no effect. The whole load is suspended from the point where it attaches to the arm, and will self-align so the centre of mass is vertically below the pivot point.
The only proviso is that the tape used to suspend the bucket may not be as flexible as something like a fine cord.
Thanks a lot! I know drill bits are not the best measurement units but still it's a good video!
Well made, mate!
Excellent thank you. 👍
i like these electronics videos with aspergers guys. theyre always full of good info. its more refreshing than the hyperactive 'personalities' on youtube
Nice testing video, very informative.
Have you tried to put these data into a graphical chart? As a summary of all your measurements at the end of video. Maybe you have a spare tmc right now and can perform similar test as a comparison.
That's a good idea. Thanks.
I'm in the process of building a paste extruder and the number of steps is 2x important: you need control over the extruder speed (steps/mm) and also keep a reasonable torque to push the ~30 mm 'filament' (the paste inside the syringe). Even with 10:43 gearing and 1/16 stepping it is not an ideal setup to extrude from 30 mm to 0.6 mm... I may need to add more gearing, to buy a geared stepper or to decrease the "filament" size (smaller syringe)...
Thank you for this test it helps a lot! I'm glad I've bought the DRV8825 :) (I'm too cheap to buy the 2130...)
The paste extruder sounds super exciting. Hope it goes well.
Do you mean by that test which microstepping is better for certain weight ? if using full step the torque will be less ? if using 1/2 step it will increase torque and can handle more weight ?
I have an Anycubic i3 mega and I'm replacing the stock drivers with the DRV8825, I saw that the latter have microsteps (1/32), but I have to change something on the printer to be able to take advantage of the microsteps or the printer is ready to use the microsteps ?
To show is to teach.
A chart or table would be great to include in your summary! :-)
Thank you.
I don't understand anything. Drv8825 is super jerky and noisy in optical tests. I have used them for years. If your linear motion uses above 400 steps /mm then you won't care about this inaccuracy
Can you show the effect of input voltage on maximum speed (before stall)
good review
I suspect your experiment when microstepping is increased it decreases the torque.