Sumpod – New Prototype For Reliable Printing

3D printers have been in use for several years now, but usually, their price has been too high for ordinary people to purchase it. With the development of new technologies and fierce competition on the market, manufacturers have decided to implement new solutions and to present low – cost printers.


Sumpod is one of the companies which will offer your unique solutions, and it provides several devices for different purposes. Their price varies significantly, but since we finished our prototype, we can guarantee you our buyers will get a safe and reliable printer. The most challenging part was the melting speed, but now the temperature can get up to 60c in 2min and 40sec.

Heated Build Platform Prototype
I’m well on my way to getting a heated build platform on the SUMPOD.
Just got my first draft working after spending all night on it. Got the bed up to 45c before switching it off, I realised the Mosfet was reaching melting point so I had to cut the test early. I’ll try another test once I get a heatsink on the Mosfet.
Here are some specs:
3mm window glass. That’s all I could get but the small size and evenly spread heating elements should be ok. I’ll just have it warm enough for printing PLA.
I made 3 elements out of Nichrome wire about 450mm long each and 3.8 Ohms each. The Nichrome wire is about 7 Ohms per/m.
The 3 elements are fitted in parallel so total resistance come to about 1 Ohm giving a power of 144 Watts at 12 Volts.
For testing I’m using 555 timer so I can adjust the duty cycle to control the temperature.
I’m using Kapton tape to stick the wire to the glass and exhaust wrap for the thermal barrier.
I’ll guess that will do for now. I’ll make the build details available once I finalize the details.
Any input and questions are welcome. I must warn you though, as far as electronics is concerned I’m no more than a hobyist.

Edited by: Richard Sum on 01/14/2012 – 05:34
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Fri, 01/13/2012 – 22:43
Heated build platform finished & installed
The heated build platform is now installed in to the SUMPOD and wired up to the Ramps board. I’m very pleased with the results, temperature getting up to 60c in 2min 40sec and infrared thermometer within a degree or 2 of the thermistor.
I’ve had the window glass as hot as 80c and that’s just about the limit for this type of glass.
50 to 60c is enough for printing pla on to glass and pla sticks to glass very well, as long as you give the glass a wipe with acetone first. Printed parts just pop off easily after the glass has cooled.
All the parts to build the platform came to less than 10 pounds.
Some pictures of the SUMPOD with heated build platform:
SUMPOD flickr pics
Also, some pictures of the largest part I’ve printed so for and printed on the glass platform. The layer height on this print is 0.3 and 20 percent infill and taken 1 hour and 40mins to print. Dimensions are 30x25mm.
Herringbone Pinion Gear Pics
Unfortunately pla does not stick to glass very well at 185c nozzle temperature which lead me to use the temperature module in Skeinforge, so that I could get the first layer print stuck down at 200c. Then print the rest of the layers at 185c.
This is what happened: Print started at 200c and first layer looking good, Then printing stops at next layer while waiting for the nozzle to drop to 185c. While waiting for the 185c the print head moves round the first layer at high speed.
I suppose this high speed print head manoeuvre was used to to keep the first layer hot ready for the next layer. Well, the side effects of this was clumps of plastic appearing on the build, making a mess of the base layer. I think this was caused by plastic oozing out of the nozzle and dragging across the base layer.
Not found a solution to this yet but keen to get it sorted as I’m after building much larger parts without warping.
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Sat, 01/14/2012 – 02:43
Brixham Engineer
Brixham Engineer’s picture
Excellent news re heated platform and great gear printed!
Well there was a question about print quality, you certainly seem to have cracked that! If anyone doubted the project Richards started and others here have added to, then they should not with your photo’s.
For a simpleton like me can you list where your supplies came from, ie the wire and the circuit components? I want to replicate your design whilst the picture is good I don’t know where to start?
I know you said you will make the build details available and do give your components, having suppliers saves a lot of time and confusion when there are lots of listed items.
Once again, inspirational, most impressed.
Mike (Brixham Engineer)
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Sat, 01/14/2012 – 03:23
Brixham Engineer
Brixham Engineer’s picture
Have you a circuit diagram yet
Have you a circuit diagram yet? Remember I am not an electronics wizard so a picture of where the components go would be helpful, think of me as an idiot when it comes to explanation! Thanks in anticipation.
Another Q: Can this be controlled via ramps board and Arduino?
Found some Wire on Rapidonline Nichrome Wire 10m 42swg is this ok?r
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Sat, 01/14/2012 – 05:37
Is there any reason, other
Is there any reason, other than cost, that anyone hasn’t used a PCB heatbed on a Sumpod?
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Sat, 01/14/2012 – 06:22
Richard Sum
The SUMPOD will be able to
The SUMPOD will be able to mill a pcb heatbed. I will be testing it in the next few days using double sided pcb boards.
airtripper excellent progress.
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Sat, 01/14/2012 – 09:46
(Reply to #5) #7
Brixham Engineer
Brixham Engineer’s picture
Cost and its 200mm square
Cost and its 200mm square whereas the size of the Glass one is 160mm x 200mm and I guess you can cut it without destroying the circuit?
I have bought a couple of pieces of glass (well they gave them to me when I said what I wanted them for, they thought they may break…) and already have the heat resistant materials so I am going to have a go at building one, once I have the circuit diagram etc.
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Sat, 01/14/2012 – 13:07
Brixham Engineer
Brixham Engineer’s picture
I have bought some constantan
I have bought some constantan wire from Maplins UK and its a different spec from yours. It is 28swg 0.375mm dia and a resistance of 4.2 ohm/metre.
Could you suggest a pattern of wires ie, length, number of elements etc. I tried working it out and got to 34 watts per metre but then applied the same formula to yours and it didn’t get your figures so I must have gone wrong. Can you advise?
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Sat, 01/14/2012 – 19:03
The huxley bed is closer in
The huxley bed is closer in size. Although i still prefer your idea of milling one, especially when the Sumpod
size upgrade packs come out.
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Sat, 01/14/2012 – 18:12
Richard Sum
Im sure very soon there will
Im sure very soon there will be an option to buy one.
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Sun, 01/15/2012 – 23:13
(Reply to #8) #11
Heated build platform build details update
Brixham Engineer, sorry for the late reply, got deep in Openscad scripting all day Saturday and neglecting everything else, and I work Sundays. Keen to start printing my own designs.
Firstly, the print I did is awesome. If you had it in your hand, you would not see the layers, It’s only through the magnification of the camera lens that you can see the details. It almost looks like a moulded part. I’m going to try .25 layer height next, and that will be with the new nozzle that I got off Richard.
Now to business with the heated bed.
The bits
Nichrome wire – 26SWG, 6.828 Ohms – from Ebay 99p
Exhaust Wrap – Ebay 1.25
10 mm Kapton – Ebay 3.00
Thermistor 100k ATC Semitec 104GT-2 – part 61-0452 95p
Window Glass – local glaziers 2.50
The circuit you saw in the pictures is not required in the final build, the wires from the heated bed go into D8 on the Ramps board. You will need to upgrade the SUMPOD power supply to one like a modded PC power supply. This would supply power to the 11A and 5A connectors on Ramps.
I had no thermistor when I first tested the bed and used a heat sensor gun instead to test the build. The circuit I put together was used to control the power to the bed to adjust heat. This allowed me to get some use out of the heat bed while I was waiting for the thermister.
The thermistor must be installed in to the heat bed and connected to T1 on ramps board before you can use heat bed via Ramps.
Once all sorted, fire up ReplicatorG and play with the heat bed settings there.
Bed Build
The Ramps board says 11Amps for heat bed and so with a 12v power supply with 1 to 1.5 Ohm heating element resistance, we can have a fast warm up without blowing a fuse. To maintain around 70c you will only be using less than a third 144watts of power at 1 Ohm resistance.
To level the glass on the X axis I used 4 screws, one placed in each corner of the bed. Have the print head close to the glass and adjust the screws, feeling the gap with a scratch card or something and test each corner of the bed with the print head. Start with the screws low enough so that the glass is touching the thermal barrier. To avoid splitting wood, drill pilot holes for the screws.
If you see the picture in the first post you will see that I’ve used 3 lengths of nichrome wire arranged in a U shape so I finish with 6 wire ends coming off one side of the glass. Each length measuring 3Ohms. With the nichrome wire connected in parallel, I get 1Ohm and that’s our target. Ideally, you should work out the wire arrangement first and then buy the wire with an Ohm rating to suite.
Brixham Engineer,
you have 28swg 0.375mm dia and a resistance of 4.2 ohm/metre.
For your arrangement you’ll need 2 lengths of wire around 670mm each at 2.814Ohms. With these wires connected in parallel you should end up with a 1.407Ohm heating element giving you 102Watts of power at 8.5Amps.
Each wire should span across the glass 3 times with the ends of each wire on opposite side of the glass. The arrangement will look similar to the one in the image in the first post of this thread.
Both wires should be exactly the same length, and arrange around 25mm apart and 15mm from the glass edge. Where the wires loop round, the loop is about 10mm from the glass edge. Blutack the ends of the wire in position with the end of the wire at the edge of the glass, then blutack the rest of it till it looks right. Then finally stick the wires down with Kapton tape.
After fitting the nichrome wire to the glass you should have the ends of the wire at the edge of the glass, two pairs at opposite ends of the glass. One pair you’ll choose to be positive and the other negative. Connect the positive pair together with standard wire and do the same to negative. You could pass the wires from one pair under the heat bed thermal barrier and in to the same connector block similar to what I’ve done. Use a multimeter to measure the resistence of the bed before connecing to Ramps. Then you want thicker wire to connect the bed connector block to the Ramps D8 connector. The thermistor needs to be placed in the centre of the bed away from the nichrome wire and then route the wires to the Ramps T1 connector.
If you look at the images I’ve posted on flickr you’ll notice an LED in the connector block which has a resistor soldered to one leg, it’s not essential but a useful indicator.
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Tue, 01/17/2012 – 03:13
(Reply to #11) #12
Brixham Engineer
Brixham Engineer’s picture
Thanks Airtripper, I will be
Thanks Airtripper, I will be having a go later in the week. Got all the bits except the thermistor. Appreciate the effort and will let you know when I am done.
Addition: have you a suggested circuit Airtripper? Or does it just link to the ramps and your circuit was for testing?
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Tue, 01/17/2012 – 08:14
You don’t need the circuit,
You don’t need the circuit, it was just for testing over Xmas holidays until the shops were open again to order a thermister.
Test the thermister first on ramps board and check the reading in ReplicatorG. If that’s ok test the heater with a multimeter for shorts. Then connect directly to D8 on Ramps.
The post below shows my wiring in the image:
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Tue, 01/17/2012 – 11:12
Brixham Engineer
Brixham Engineer’s picture
Corner Brackets for heated bed – print them in plastic?
I have designed some corner brackets for the heated bed by Airtripper. I don’t know if they will work and will use them as a test print as soon as I reassemble the Resistor and thermistor (broke when dissassembling them!).
If the work and you want a cop I will upload them to Thingiverse, or you can email me but I must say I have yet to print them to see if they work. You can have the stl file or the gcode.
For more information http://3d-printer-