Gen7-ARM released! February 18, 2016 05:09PM |
Registered: 13 years ago Posts: 7,616 |
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 18, 2016 07:26PM |
Registered: 10 years ago Posts: 14,672 |
Re: Gen7-ARM released! February 19, 2016 01:29AM |
Admin Registered: 13 years ago Posts: 730 |
Re: Gen7-ARM released! February 19, 2016 04:06AM |
Registered: 9 years ago Posts: 4,977 |
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dc42
What firmware do you plan to run on this board?
Triffid Hunter's Calibration Guide | --> X <-- Drill for new Monitor | Most important Gcode. |
Re: Gen7-ARM released! February 19, 2016 05:13AM |
Registered: 13 years ago Posts: 7,616 |
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dc42
software adjustable stepper motor currents.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 19, 2016 05:23AM |
Registered: 13 years ago Posts: 7,616 |
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MattMoses
I would definitely like to try my hand at milling a board. Is there a guide and/or advice on how to prepare the files for milling and drilling?
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 19, 2016 07:27AM |
Registered: 10 years ago Posts: 14,672 |
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Traumflug
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dc42
software adjustable stepper motor currents.
There are certainly a number of things I'd consider if there were extra pins. Software adjustable stepper current is one of the last things I'd spend pins and parts (money) on. These trimpots have to be adjusted only once in the lifetime of a printer and it's a matter of a minute to do so.
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Traumflug
Also this board uses an standard ATX and the firmware support this. I think for users who never handles 230V this is much more important. You have never issues to connect it the wrong way. And you also don't have any open 230V cables.
It's a shame that other boards don't go this way. winking smiley
Re: Gen7-ARM released! February 19, 2016 08:29AM |
Registered: 13 years ago Posts: 7,616 |
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dc42
Only if you know what you are doing - and the evidence from these forums is that many people don't.
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dc42
1. The regulation on the 12V rail is typically poor.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 19, 2016 03:18PM |
Registered: 10 years ago Posts: 14,672 |
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Traumflug
If you don't know what you're doing when turning a trimpot, learn it, or don't build a printer.
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Traumflug
Much less one with a DIY'd controller.
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Traumflug
Part of the problem is certainly that there are people who trumpet complicated software and hardware as a solution. Even with a software control you still have to know what "current" means, so such a control solves nothing.
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Traumflug
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dc42
1. The regulation on the 12V rail is typically poor.
Doesn't really matter. Heaters are slow anyways, so fluctuations should be barely noticed. I even removed a smoothing cap from the heater rail for this reason.
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Traumflug
@dc42, why did you stop your own board efforts? You had the chance to do everything so much better. Now you're back to lamenting about board concepts which have been proven to work well for many years. Disappointing.
Re: Gen7-ARM released! February 19, 2016 05:20PM |
Registered: 13 years ago Posts: 7,616 |
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dc42
To an electronics engineer, the hardware to do digital stepper motor current control is simpler than using pots.
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dc42
Most people have some idea of what current means. Far fewer people have the ability to identify the sense resistors on their drivers, decode the print on them to determine the resistance, apply a formula to work out the relationship between the voltage on the put wiper and the motor current, and adjust the pot to the correct voltage without shorting it out in the process (almost nobody has a ceramic screwdriver).
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dc42
I'm lamenting about board concepts that have been shown to be problematic, by the large numbers of posts on these forums from users having trouble with them.
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dc42
[...] But is made no sense for me to take that financial risk.
Arduino/RAMPS is showing its age and I believe the RepRap community deserves something better, even if it's not as sophisticated as Duet or Smoothieboard. But I have a living to earn, so I can't afford to do the necessary work without a good expectation of recompense for the costs I incur and at least some of my time.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 19, 2016 07:22PM |
Registered: 10 years ago Posts: 14,672 |
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Traumflug
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dc42
To an electronics engineer, the hardware to do digital stepper motor current control is simpler than using pots.
OK. If you show me on how to do such software controls without using additional pins (there are none left) and with these popular Pololus (this is what people can get everywhere), I'll implement it.
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Traumflug
There is no need to read the print on the resistor.
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Traumflug
...
How about fixing this lack of knowledge? Adjusting the trimpot is really easy. Crank it up until the motor starts to stutter (due to overheating), then about 1/8 of a turn back. Then you have the maximum possible current, which is always as safe as the hardware allows.
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Traumflug
Gen7s work so well that they're almost unknown. This silly effect that the best designs get forgotten, because there are no problems, so nobody asks or writes about them. I'm again and again surprised where Gen7s appear by accident and all of them just work.
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dc42
[...] But is made no sense for me to take that financial risk.
Arduino/RAMPS is showing its age and I believe the RepRap community deserves something better, even if it's not as sophisticated as Duet or Smoothieboard. But I have a living to earn, so I can't afford to do the necessary work without a good expectation of recompense for the costs I incur and at least some of my time.
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Traumflug
Either do your own board or stop lamenting about other efforts. It's pretty rude to yell at projects which differ from your ideals while you sit on your ass without doing any actual work, much less a working design. I'm not your servant, not your financer and much less your wishlist fulfiller.
Re: Gen7-ARM released! February 19, 2016 08:46PM |
Registered: 10 years ago Posts: 14,672 |
Re: Gen7-ARM released! February 20, 2016 06:04AM |
Registered: 13 years ago Posts: 7,616 |
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dc42
If you have run out of pins [...]
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dc42
Sadly, that's not true in my experience. Some drivers use 0.1 ohm resistors, others use 0.05 ohm resistors.
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dc42
I did a lot of work on my design, including all the component selection, the schematic capture except for the expansion connectors, and about 75% of the PCB layout. I'll gladly publish it for someone else to finish.
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dc42
- The resistor from +12V to the gate of be bed heater mosfet has a rather high value (10K), which will lead to quite a slow turn-on of the bed heater mosfet.
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dc42
you are taking a risk by driving the IRLB8743 extruder heater mosfet with only 3.3V gate drive when the datasheet only gives a guaranteed specification at 4.5V
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dc42
- Choosing a 1K series resistor for the extruder thermocouple may not be such a good idea. [...]
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dc42
you could save several by using a common DIR pin for all the stepper drivers, and setting it in software just before sending each step pulse
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dc42
- The design appears to have the same USB-over-serial scheme as the atmega2560-based boards. So I guess you expect most of your users to add an SD card socket in order to provide the gcode data fast enough.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 20, 2016 01:46PM |
Registered: 11 years ago Posts: 64 |
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Traumflug
Surprise, surprise, venerable Generation 7 Electronics made it to a new release: [reprap-diy.com]
... and it's three times faster than the Gen7 before. Enjoy!
Re: Gen7-ARM released! February 20, 2016 07:48PM |
Registered: 12 years ago Posts: 15 |
Re: Gen7-ARM released! February 20, 2016 07:53PM |
Registered: 10 years ago Posts: 14,672 |
Re: Gen7-ARM released! February 20, 2016 07:57PM |
Registered: 12 years ago Posts: 15 |
Re: Gen7-ARM released! February 21, 2016 05:27AM |
Registered: 13 years ago Posts: 7,616 |
Re: Gen7-ARM released! February 21, 2016 10:49AM |
Registered: 10 years ago Posts: 14,672 |
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Iceflow
dc42, show us your board, not for the posible profit you could get, but for the reprap movement, as you said, to advance...
Re: Gen7-ARM released! February 22, 2016 06:57AM |
Registered: 9 years ago Posts: 1,035 |
Re: Gen7-ARM released! February 22, 2016 05:42PM |
Registered: 13 years ago Posts: 7,616 |
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realthor
You smart people should somehow get along, consider the criticism and at least have a "what if he's somewhat right?" attitude.
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 23, 2016 03:37AM |
Registered: 9 years ago Posts: 4,977 |
Triffid Hunter's Calibration Guide | --> X <-- Drill for new Monitor | Most important Gcode. |
Re: Gen7-ARM released! February 23, 2016 03:38AM |
Registered: 10 years ago Posts: 14,672 |
Re: Gen7-ARM released! February 23, 2016 05:49AM |
Registered: 13 years ago Posts: 7,616 |
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dc42
1. I said I think it's a shame
Generation 7 Electronics | Teacup Firmware | RepRap DIY |
Re: Gen7-ARM released! February 23, 2016 06:44AM |
Registered: 10 years ago Posts: 14,672 |
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Traumflug
The only shame here is that you do "suggestions" but can't come up with solutions.
Re: Gen7-ARM released! February 23, 2016 07:13AM |
Registered: 9 years ago Posts: 4,977 |
Triffid Hunter's Calibration Guide | --> X <-- Drill for new Monitor | Most important Gcode. |
Re: Gen7-ARM released! February 23, 2016 08:07AM |
Registered: 10 years ago Posts: 14,672 |
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Wurstnase
1. Does Pololu-Stepper has a Pin for current-adjustment?
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Wurstnase
2. Should the disconnected temperature be at 20°C?
Re: Gen7-ARM released! February 23, 2016 09:47AM |
Registered: 9 years ago Posts: 1,035 |
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dc42
The chip does, but it on Pololu modules it is connected to a pot. I am suggesting connecting it to a 9th pin on the input side of the module instead. The electronics will have the 9-pin connector, so it will accept both traditional Pololu modules with pots, and modified Pololu modules with the 9th pin.Quote
Wurstnase
1. Does Pololu-Stepper has a Pin for current-adjustment?
Re: Gen7-ARM released! February 23, 2016 02:15PM |
Registered: 9 years ago Posts: 4,977 |
Triffid Hunter's Calibration Guide | --> X <-- Drill for new Monitor | Most important Gcode. |
Re: Gen7-ARM released! February 23, 2016 03:55PM |
Registered: 10 years ago Posts: 14,672 |
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Wurstnase
The cool stuff on standard Pololus is, there are a lot of different. DRV8825, A4988, RAPS128, TMC2100 to count the popular ones.
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Wurstnase
I've never missed firmware current control
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Wurstnase
The temp stuff can be handled easily. When we have a bad ARM-ADC take it. Temps can be checked also when ADC is showing too high temperatures. Most thermistors have a range of 5%. At 250° they show us 270°. But hey, we can print with'em.