Garden Railway Forum

Cheers Steve, that does ease my mind somewhat, for the future.

Atm, I'm still hoping that Qidi can sort me out. The more I look at new machines the more I realise that I'm happy with what I've got ( when it works!). They came back to me very promptly this morning, asked some questions, asked for pictures/video's of the problem, asked for my stl and x3g files so that they could check them for problems, and sent me a test file to print. I'm pleased to say that their test file failed in exactly the same way as my own files, so it is definitely down to the machine in some way.
Interestingly, their test cube has a smaller footprint that the files I've been playing with and it printed higher than my files did before stopping extrusion. Makes me wonder if it is somehow time related i.e after a time something overheats and shuts down, although the print temp readout remained steady at 200 degrees. Anyway, I'm waiting to see what they say when they wake up.

philipy wrote: Mon Feb 28, 2022 7:11 pm Cheers Steve, that does ease my mind somewhat, for the future.

Atm, I'm still hoping that Qidi can sort me out. The more I look at new machines the more I realise that I'm happy with what I've got ( when it works!). They came back to me very promptly this morning, asked some questions, asked for pictures/video's of the problem, asked for my stl and x3g files so that they could check them for problems, and sent me a test file to print. I'm pleased to say that their test file failed in exactly the same way as my own files, so it is definitely down to the machine in some way.
Interestingly, their test cube has a smaller footprint that the files I've been playing with and it printed higher than my files did before stopping extrusion. Makes me wonder if it is somehow time related i.e after a time something overheats and shuts down, although the print temp readout remained steady at 200 degrees. Anyway, I'm waiting to see what they say when they wake up.

Lesson one, never trust readouts, lol Everything is not always as it appears.

As i said my printer does the same every now and again, I got to see the tell tale signs on mine, it starts printing in little dribs and drabs and then stops the filament, which always causes a huge blockage which means cutting the end off the tube. The readout is always spot on, but I know it's just too cold to carry on melting filament.

-steves- wrote: Mon Feb 28, 2022 7:25 pm I got to see the tell tale signs on mine, it starts printing in little dribs and drabs and then stops the filament, which always causes a huge blockage which means cutting the end off the tube. The readout is always spot on, but I know it's just too cold to carry on melting filament.

Thats interesting, the last thing I got off was a half thickness wagon floor ( it stopped before it got up to the sides) and the surface was covered in lines of little spots of filament which I thought was the beginning of the bottom of the plank lines but I was surprised by the spottiness rather than thin lines.
I have to dismantle the whole hot end because the nozzle and Bowden tube cool down but the filament is still being forced down by the drive, so it gets forced around the feed mech rollers and swells in the ali block between the feeder and the heater. They all fit close together so it's difficult to cut the filament to separate them. Then dismantle the feeder. Then use a scalpel to chip away the visible swollen filament sticking out of the ali block so that I can push it down through the heater ( it isn't long enough to pull up.), having first removed the nozzle! Then put it all back together again.

philipy wrote: Mon Feb 28, 2022 9:12 pm

Thats interesting, the last thing I got off was a half thickness wagon floor ( it stopped before it got up to the sides) and the surface was covered in lines of little spots of filament which I thought was the beginning of the bottom of the plank lines but I was surprised by the spottiness rather than thin lines.
I have to dismantle the whole hot end because the nozzle and Bowden tube cool down but the filament is still being forced down by the drive, so it gets forced around the feed mech rollers and swells in the ali block between the feeder and the heater. They all fit close together so it's difficult to cut the filament to separate them. Then dismantle the feeder. Then use a scalpel to chip away the visible swollen filament sticking out of the ali block so that I can push it down through the heater ( it isn't long enough to pull up.), having first removed the nozzle! Then put it all back together again.

That sounds like the exact same issue to mine, the only difference is that mine is very simple to fix and easy to do, oh and inexpensive. I would guess you will be needing to change your equivalent of my thermistor and heater to get things working properly again, it might be worth suggesting that to them and see if they will just send you the parts?

-steves- wrote: Mon Feb 28, 2022 9:19 pm I would guess you will be needing to change your equivalent of my thermistor and heater to get things working properly again, it might be worth suggesting that to them and see if they will just send you the parts?

Yep, I think it sounds the same basic problem. I did suggest it was the thermocouple when I emailed them, but I guess they have a set troubleshooting procedure and want to rule out any faults in my drawing, etc, before sending bits halfway round the world.
When I first got the machine I had an intermittent fault whereby the print head zoomed to the RHS and crashed into the side. Again they asked for pictures and video's and then they diagnosed it as a faulty plug on the microswitch cable and they shipped a complete replacement cable foc by Express Chinapost, which arrived in 48 hours. However as soon as I loosened the P-clips holding the cable to the cabinet side the problem went away, I think they had just over tightened it in the factory. It's been running perfectly well ever since with the original cable and no P-clip, for almost 5 years!

I've just had a look at the Anycubic FDM machines, something I hadn't even considered previously. This review from TomsHardware is really impressive and I've been really happy with the Anycubic Photon S resin printer, so if I do need to buy a new FDM, this is definately on my radar.
https://www.tomshardware.com/uk/reviews ... 3d-printer

Well, the bullet is bitten! After going round in ever decreasing circles all day and narrowly avoiding losing my head up you know where, I've gone for the Creality CR-20 PRO.
Qidi got nowhere in the end, kept asking me to do tests etc that I've already done and then said I needed a complete new dual head extruder. She gave me a link to their official Ebay US store where the extruder plus shipping came to 120 USD! That is half the cost of a brand new small Creality so it's a no brainer to cut my losses and get something more up to date.
I was very tempted by the Anycubic, but reading around there are a fair number of negative comments about reliability and the availablity of spares so I reluctantly knocked it on the head. After that it was an uphill struggle to weed out the Creality's but a major consideration was the physical size, most of them are too big to fit the space I have available, but eventually I came across the CR-20 Pro which does fit and has the bed levelling built in, etc. The bed is 10mm shorter than my Qidi but 70mm wider, so not much in it overall.
Plus, SWMBO decided that I was having it as an early birthday pressy, so who am I to argue!

PS If anyone knows anything bad about it, I don't want to know, thank you!

philipy wrote: Tue Mar 01, 2022 6:40 pm
PS If anyone knows anything bad about it, I don't want to know, thank you!

Oh no, not the Creality CR-20 PRO:!: Don't you know about the halfshank gribble affecting the angle of the dangle?
What do you mean, I know nothing about 3D printers?
Oh, that's right - I don't
I hope it works well for you

I’ve heard the CR-20 pro has notorious flux capacitor issues…

-steves- wrote: Mon Feb 28, 2022 6:53 pm all you need to do is get hold of a Raspberry pi Zero 2 W,

Steve, I found a very nice detailed video step by step guide on YT which also has a print version.
On the subject of which Pi version to use he says this:

"Best Raspberry Pi for OctoPrint

It is recommended you use a Raspberry Pi 3 or 3+ to run OctoPrint since the cheaper Raspberry Pi Zero is not quite up to the task. In particular, the Zero can suffer from massive Wi-Fi interference, negatively impacting your prints. "

I've also seen other recommendations to use the 3 without saying why.

Is that something you've found to be an issue? Obviously there is a big price difference from about £13 for the zero to £50 for the 3, and as is common, the guy is an Amazon Affiliate so, being my usual cynical self, he would presumably get more commission from the more expensive unit ( as if he would take that view....!).

philipy wrote: Wed Mar 02, 2022 7:00 am Is that something you've found to be an issue? Obviously there is a big price difference from about £13 for the zero to £50 for the 3, and as is common, the guy is an Amazon Affiliate so, being my usual cynical self, he would presumably get more commission from the more expensive unit ( as if he would take that view....!).

I had OctoPrint on a 1st generation Pi, which has the same processor as the Zero. It worked, but if the Pi got a bit stressed e.g. you were uploading the next job while printing, it could affect the print quality, as the printer could stutter or slow down while it waited for the Pi to send commands.

I now run on a Pi 3, and its totally adequate for the job. The Zero 2 has similar performance to the 3, so either would be OK.

Good luck with finding a Pi right now most of them are out of stock!!

Let me know if you get really stuck, I might have a Pi3B+ that I can liberate and let you have for half price if that helps.

I've very successfully used one for running Octoprint. I'd definitely always advocate having a little headroom as you don't want it affecting print quality.

Thanks both.
I've just had a quick look at the Pi Hut as a f'rinstance, and as you say they are out of stock of most Pi's but they do have the Raspberry Pi 3 Model A+ for £23.40, would that be OK? If not, I might take you up on your kind offer Hugo.

I am getting a wee bit ahead of myself here since I don't have an actual delivery date for the printer yet ( hopefully Friday), but I'm trying to get my head around things in advance so I don't get caught out by anything - like Pi's being unavailable.

HugoFitz wrote: Tue Mar 01, 2022 9:48 pm I’ve heard the CR-20 pro has notorious flux capacitor issues…

You could try reversing the polarity of the neutron flow...

SimonWood wrote: Wed Mar 02, 2022 8:54 am
You could try reversing the polarity of the neutron flow...

Nah, I'm not going polar, I don't do cold.

philipy wrote: Wed Mar 02, 2022 8:49 am Thanks both.
I've just had a quick look at the Pi Hut as a f'rinstance, and as you say they are out of stock of most Pi's but they do have the Raspberry Pi 3 Model A+ for £23.40, would that be OK? If not, I might take you up on your kind offer Hugo.

I am getting a wee bit ahead of myself here since I don't have an actual delivery date for the printer yet ( hopefully Friday), but I'm trying to get my head around things in advance so I don't get caught out by anything - like Pi's being unavailable.

I was just about to recommend the Pi Hut.
A Pi3 model A doesn't have ethernet capability, so if you're happy with WiFi it will be more than adequate, compared to older models. Make sure you get a good power supply - they stock the pi brand powerbrick - many issues with pi's are due to inadequate power.

Lonsdaler wrote: Wed Mar 02, 2022 9:00 am
A Pi3 model A doesn't have ethernet capability, so if you're happy with WiFi it will be more than adequate, compared to older models. Make sure you get a good power supply - they stock the pi brand powerbrick - many issues with pi's are due to inadequate power.

Thanks Phil. I don't use ethernet anyway, so that shouldn't be an issue. As for power I was planning to piggyback off the printer rather than have yet another thing to have to find a mains socket for.

philipy wrote: Wed Mar 02, 2022 9:10 am

Lonsdaler wrote: Wed Mar 02, 2022 9:00 am
A Pi3 model A doesn't have ethernet capability, so if you're happy with WiFi it will be more than adequate, compared to older models. Make sure you get a good power supply - they stock the pi brand powerbrick - many issues with pi's are due to inadequate power.

Thanks Phil. I don't use ethernet anyway, so that shouldn't be an issue. As for power I was planning to piggyback off the printer rather than have yet another thing to have to find a mains socket for.

So long as you are confident there will be a sufficient 5v supply - most goods come with a power supply rated to the equipment they are supplied with, zwith little extra capacity. I wouldn't risk it personally.

Lonsdaler wrote: Wed Mar 02, 2022 9:14 am
So long as you are confident there will be a sufficient 5v supply - most goods come with a power supply rated to the equipment they are supplied with, zwith little extra capacity. I wouldn't risk it personally.

I would have double checked anyway, but the YT video I mentioned above did exactly that with instructions and even has the splitter cable available, although he was using an Ender 3 printer not mine.

I've just looked at the PiHut blurb on their A+ and it seems to suggest that it is actually newer than the B+ but on various Reddit forums posts there are comments about the USB capacity of the A+, it only has one port, and the B+ having more which is necessary for a camera.
If all that is true, then I think I'll need to take up Hugo's offer. Perhaps you'd would drop me a PM with your price, please?

Lonsdaler wrote: Wed Mar 02, 2022 9:14 am

philipy wrote: Wed Mar 02, 2022 9:10 am

Lonsdaler wrote: Wed Mar 02, 2022 9:00 am
A Pi3 model A doesn't have ethernet capability, so if you're happy with WiFi it will be more than adequate, compared to older models. Make sure you get a good power supply - they stock the pi brand powerbrick - many issues with pi's are due to inadequate power.

Thanks Phil. I don't use ethernet anyway, so that shouldn't be an issue. As for power I was planning to piggyback off the printer rather than have yet another thing to have to find a mains socket for.

So long as you are confident there will be a sufficient 5v supply - most goods come with a power supply rated to the equipment they are supplied with, zwith little extra capacity. I wouldn't risk it personally.

I'd second making sure you have enough power!
I get not wanting more plugs, I'm the same.
The good news is that Octoprint will let you know if it's suffering under voltage. Give it a go powering it off the printer but be prepared to use a separate PSU if you get under voltage warning...