@tomasf:

Awesome idea. I want to try this. But do they exist in Micro SD sizes? I can't seem to find any.

Not that I've found - but the LCD has a standard SD socket. You need an extra lead to connect it to the Duet.
https://duet3d.com/wiki/Connecting_an_LCD_control_panel#Using_the_external_SD_card_socket_on_the_LCD_panel
Keep the lead short - much over a foot and it doesn't work. Mine (after some re-jigging) is 6" long and works pretty good.

David, I thought it was the SD initially - but I'm on card No 4 now and it's the same. That's why I wired up the SD socket in the PanelDue - but found it wasn't supported in the web interface for file upload due to speed considerations (ironically). The previous Micro-sd's seem to work fine in the PC speed wise.

When you first start uploading, it runs at 1-2Mb/s then rapidly slows down to a crawl - almost as if it's filling up a buffer then slowing when it's full?
Were it not for that, I would assume it's a signal strength issue - but it it can achieve fast transfer at the start, I suspect it could continue.

With the WiFi SD plugged in to the PanelDue it's OK.

Si

Yup - that's exactly what I'm doing. Not found any suckyness. I still use the Web interface on the Duet, just not for file transfer.

Si

For whatever reason, the file transfer on mine is S-L-O-W. It starts OK then just gets slower & slower until it settles at about 50kb/s.

As an experiment, I bought one of these: https://flashair-developers.com/en/about/overview/
Mine is 8Gb, bought from Amazon for not much more than a standard card.

If you edit the Config file & put in something like this:
Leave these as they were supplied:
VERSION=FA9CAW3AW3.00.00
CID=02544d535730384731c2dee47900ec01
PRODUCT=FlashAir
VENDOR=TOSHIBA
LOCK=1

Change / Add everything else:
WEBDAV=2
UPLOAD=1
DNSMODE=1

ID=DuetDelta
APPMODE=5
APPNAME=DuetDelta
APPSSID=###Enter your WiFi SSID###
APPNETWORKKEY=###Enter your WiFi Password###
DHCP_Enabled=NO

Edit for your network settings:
IP_Address=192.168.1.123
Subnet_Mask=255.255.255.0
Default_Gateway=192.168.1.1
Preferred_DNS_Server=192.168.1.1
Alternate_DNS_Server=192.168.1.1
Proxy_Server_Enabled=NO

It supports fixed IP or DHCP - and is pretty quick - I'm getting 12Mb/s typical. The printer is in my workshop, 25m from the access point. Quite a lot of devices struggle with signal strength (my phone for example) but this (and the Duet I hasten to add) work fine!

I just have it mapped as a network drive under Windows - and save the GCode straight to it from Cura.

Si

That's odd, mine wiped itself on Monday! No apparent reason - I was printing something, it finished & I de-powered the machine for a couple of hours. Re-power and the card is completely blank!

It was a brand new card when I installed the Duet - so only a few months old. Is there anything in the code which writes repeatedly to the card? I wondered if it could have exceeded the write cycle life?

I'll put the card in my PC when I have time to fiddle to see if it's recoverable.

Si

Thanks Jackal - you're a star!

Si

I've also had a few issues with this. My heater is over-powered, but it was intentional in the hope that I could print fast and be able to reach higher temperatures (300C). The auto-tune worked brilliantly and it prints with no errors so long as the print temperature is below 220. If I increase it to 260 (or higher), it will fault mid print usually with the temperature going too high.

At higher temperatures, I think the thermal inertia is such that an excursion can last more than 5 sec. This usually happens on fiddly bits where the material flow reduces.

If it were possible to relax the thermal fault detection (perhaps with a strongly worded warning about fire, death & destruction?) I think it might help this.

On the fire front, I have a DIY thermal fuse. A short length of solder mounted a couple of cm above the heater. Even at 300C, it does not melt the solder - but either a flame or a temperature above 400 will. It required a bit of experimentation to get the separation right - but it seems to work. If the solder link breaks, it kills the mains via a SSR.

I suspect that an off the shelf thermal fuse with poor thermal contact to the heater would do just as well.

Si

@StephenRC:

Use this: https://www.sparkfun.com/products/13118 and then all you need is a pin on the Duet to trigger it.

Using this, you could attach a physical toggle switch to the board and use the print head to move the toggle switch from one state to the other - then just add the G Code for the movement to the Home / bed level macros. Then it doesn't require any further integration or firmware updating.

@dc42:

Not only is BLTouch closed source (unlike my own IR sensor), it also has patents pending. This is completely against the spirit of RepRap, and is why I have no desire to add support for it.

In my previous printer, I used an inductive proximity sensor made by SICK (one of their IME Series). It is closed source and I suspect subject to patents. Is it against the open source principle to use it? Of course not. We just accept that it's a component and we don't need to know exactly what goes on inside, like the countless other components used.

Is this really that different? Can you not treat it just like any of the other components? I'll bet for example, the microcontroller on the Duet board is patented and you don't have the internal schematic for it. However, you have chosen it as being the best tool for the job - and that overrides the lack of open-sourceness!

I have one of your differential sensors - and have had problems with it. It works perfectly on new BuildTak but after a few prints, because the surface reflectivity changes, it reads differently in one place compared to another. I've tried using it with 6mm thick BS Glass with the underside painted black. That's a no-go as it's too thick and by the time it detects, the probe is touching the glass surface.

Don't get me wrong, your board is superb - but it's not universal. Some situations will demand a different solution - and it seems crazy not to support one of the current decent options.

Si

P.S. Although I've not tried one of these, most RC servos are happy with the PPM signal at 3.3v. Anything above 2.5v seems to work. Where they have not, you can buy a 'Servo Pulse Booster' similar to this: https://www.amazon.co.uk/HobbyKing-Turnigy-Rx-Servo-Booster-2-7v%7E5v/dp/B01EE0V6UO/ref=sr_1_fkmr0_2?ie=UTF8&qid=1479990820&sr=8-2-fkmr0&keywords=servo+pulse+booster which will boost 2.7v up to 5v. I used one to drive a BIG semi industrial servo.

I imagine crashing the nozzle into your build surface could cause quite a bit of damage!
And you'd be right!
However, the magnetic ball joints let go before it does any damage.
The torque multiplication was part of what I wanted. Fast printing needs high acceleration which requires torque.

On a different (commercial) project I found the stretch in timing belts to be an issue moving the end effector fast - it needed high precision and the elasticity in the belt caused judder in the position. That was solved using lead screws - and hopefully they will benefit this for the same reason.

Si

The screws are 8mm/rev - so half to 1/3 the speed of a belt drive. Running RAMPS, speed could easily be a problem - but not with the Duet!

This is the very first time it moved under power (no microstepping so motors are not quiet - sounds cool from a SiFi Robot point of view though)
https://www.youtube.com/watch?v=RHBkGtcOjoc

This is a week or so on with the very first successful print:
https://www.youtube.com/watch?v=rIT03o2w2TM
This was before the SSR to drive the bed arrived - hence using painters tape. This is pretty slow, with low acceleration. Once the gear for the extruder shows up (should have arrived Friday!) I'll video some more at decent speed!