Author Topic: 3D printer - cheap as chips  (Read 5992 times)

Online Jo

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Re: 3D printer - cheap as chips
« Reply #165 on: February 27, 2020, 01:04:41 PM »
While we wait for the links from John  :stickpoke:

The next upgrade for my printer has arrived from China: an insulation blanket to go under the print bed. This was vastly expensive (I think about £2  :toilet_claw: including postage  ). The reason for buying this was when Mike visited we discussed why thing not sticking very well to my print bed. Mike thought it might be caused by the bed being a bit cool as he could put his hand on it so the blanket is to see if I could get a more consistent and higher heating of the print bed.

On more expensive printers the entire print bed is a heater, on these cheap as chip ones it is only the middle 100mm square is above the actual heater. The idea of the blanket is to prevent what heat there is lost under the bed and hopefully the heat generated will go where is should be and the bed will keep warmer. My initial testing both with my hand and a digital thermometer shows that about twice as much surface is rather too warm for the hand (>60 degrees) but the outside is still cooler ( ~50 degrees), when the sensor is claiming the bed is at 70 degrees. Of course a little soak heating will improve the spread of the heat as will another blanket put on it prior to printing.

Now I need something else to print   :)

Jo
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Online Vixen

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Re: 3D printer - cheap as chips
« Reply #166 on: February 27, 2020, 01:34:06 PM »
Hello Jo

I found the sticking problem solved itself by raising the bed (aiming) temperature to 80*C . The actual bed temperature was then 67*C in the middle and the prints now stick very well.

Mike
« Last Edit: February 27, 2020, 02:14:54 PM by Vixen »
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Offline Jasonb

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Re: 3D printer - cheap as chips
« Reply #167 on: February 27, 2020, 03:10:04 PM »
I had one of Myfordboy's videos pop up yesterday as a suggested Youtube video, it was of a resin printer that looks to give a very good surface quality, although not cheap as chips it looks reasonable value for the quality of output and the only assembly is to screw the knob on to the front door.


Certainly tempting if I was wanting to cast a part but as I've just CNC'd a nice cast iron flywheel will probably pass on it for now. They also do a resin that can be melted out for investment casting.

Offline JC54

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Re: 3D printer - cheap as chips
« Reply #168 on: February 27, 2020, 08:26:10 PM »
Sorry for the delay Jo, my lungs haven't wanted to play last couple of days. Anyway got into the other computer and these are most of the printed upgrades that I have done so far.
        Y axis Braces, www.thingiverse.com/thing:1751317
        Y axis Motor mount, www.thingiverse.com/thing:2809788
        Y axis Tensioner, www.thingiverse.com/thing:2786671
        LCD Front Case, www.thingiverse.com/thing:2070983
        PSU Cover+Switch, www.thingiverse.com/thing:2820627
        Jet Intake, www.thingiverse.com/thing:2302064
        Air Duct, www.thingiverse.com/thing:2353994

The LCD cover doesn't have a back to it but I have drawn one up and will print it when I am fit. If it fits OK I will put file on here. I didn't like the idea of no cover over the live wires and also no on/off switch so PSU cover has aperture for switched socket. I got switch/socket off eBay.  Hope this lot will keep you all amused for a while. I like the idea of the blanket as have had same problem. I did as Mike suggested and upped bed temp. also printed on a raft. It sometimes curls up rather than the object. John  :old: :DrinkPint:
When the Fun Stops,, Stop!

Offline JC54

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Re: 3D printer - cheap as chips
« Reply #169 on: February 27, 2020, 08:31:19 PM »
 Evening Jason, The idea of a resin printer really appeals but machines and running costs are still out of my pay bracket. One of the members at my local club brought some parts that he had someone print for him with resin and the detail was really amazing. He had also had some cast in brass and once painted you could only tell difference by the weight. John :old: :DrinkPint:
When the Fun Stops,, Stop!

Online Jo

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Re: 3D printer - cheap as chips
« Reply #170 on: February 27, 2020, 09:05:14 PM »
Thank John  :cheers:

Jo
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Online Jo

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Re: 3D printer - cheap as chips
« Reply #171 on: March 01, 2020, 01:35:59 PM »
Following on from a couple of PM's from Vixen I am trying some new print settings. I should mention that I am using Cura to print and they have just updated it to 4.5 and they have changed the default settings and it was giving me problems and not sticking to the bed  >:( I am now using the following settings:

Bed temperature setting: 80 degrees     (Measured actual temperature 65 degrees in the middle, varying down to 51 degrees on the outside of the bed  )
Print head temperature:180 degrees.
It is set to retraction between layers      (which means it doesn't push the print material out as it moves to start the next layer)
It is set to retraction between printing parts (= it won't string between printing bits - hopefully )
Retraction is set to 4.5mm

I also found the new version of the software has turned off the brim function that helps the printed part stick to the bed.


My printer is now sporting a Silica Borate (Pyrex) printing plate, which has been held in place with some fold back binder clips which have had their wires removed so they don't hit the frame as the bed moves around. The glass plate helps the printed hot plastic stick  ;)

Jo
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Online AOG

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Re: 3D printer - cheap as chips
« Reply #172 on: March 01, 2020, 05:39:04 PM »
Jo, your nozzle temp is to cold. Assuming you’re printing with PLA, at 180 it will be hard to extrude and not stick well to the bed. For the first layer you want things on the hot side. For cheap generic PLA I print my first layer at 205 and drop back to 190-195 for the second layer on up to improve print quality.

Tony

Online Jo

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Re: 3D printer - cheap as chips
« Reply #173 on: March 01, 2020, 06:01:50 PM »
 :ThumbsUp: Thanks Tony. I noticed the extruder was making more noise than it was when I was printing at 200 degrees.  I found you could vary the initial layer temperature and subsequent ones but was not sure what that provided. I'll give it a go tomorrow  :)

Having measured the actual bed temperature I might up that to an indicated 85, which should give 70 degrees actual. I do like my digital temperature measuring gun it makes checking the temperature so easy.

Jo
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Online AOG

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Re: 3D printer - cheap as chips
« Reply #174 on: March 01, 2020, 06:48:17 PM »
On a related note, make sure your part cooling fan is off for the first layer as well. Bring it up to speed on the second layer. From a physics perspective, we want to prevent the first layer from cooling down too quickly and contracting to the point it releases from the bed. On the subsequent layers we want the exact opposite. The PLA needs to cool down relatively quickly to prevent stringing, blobs at zits.

Tony

Offline JC54

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Re: 3D printer - cheap as chips
« Reply #175 on: March 01, 2020, 08:07:49 PM »
I have been using 210C for extruder and 80C for the bed plate, using pritt stick on the original and not been too bad. I have found that it is very critical to bed leveling and extruder to bed gap. I tried insulation under the bed and couldn't get filament to stick at all. :shrug: I have tee'd my filament cooler fan to the main fan so may have a look at rewiring it to Fan2 on main board. Thanks for the physics and reasons Tony.
             For larger flimsy parts I have found a raft really helps make things stick and keeps the part flat even though the raft may curl at the edges. Oh well back down the rabbit hole to hone the cylinders on my 7 cylinder radial engine. :old: :DrinkPint:
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Online Vixen

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Re: 3D printer - cheap as chips
« Reply #176 on: April 05, 2020, 12:22:11 PM »
As someone "who would never want to own one" and "would find no use for one"; I have been following this thread with unexpected interest. It certainly seems that with a bit of extra work, it is quite possible to make a 70 quid printer do something which could be useful (but I am still unsure what that something useful may be).
Mike

Back in January when I posted this, I said " but I am still unsure what that something useful may be". Well a few months later I found that a "something useful" has become "something vital" My printer is now full time printing disposable 'one use' face visor frames to help protect our health care workers, nurses and doctors.



If you have capacity and want to join in then contact www.3DCrowd.uk. They will give you STL files to download for you to print face visor frame parts. They each take as much as three hours to print so getting as many printers involved is important. They arrange for the door collection of your prints and are sometimes able to provide replacement filament. They have other teams assembling the transparent plastic face shield and distributing the completed visors to hospitals, care homes and GP practices.

Get involved if you can and help protect our vulnerable health workers

MIke

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Online nj111

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Re: 3D printer - cheap as chips
« Reply #177 on: April 05, 2020, 01:27:19 PM »
Good production there Mike! Well done
Nick