Retroplayer's SD4 Major Upgrade/Rebuild - heated enclosure (Page 1 of 2)

Wow   Jumping in with both feet and one borrowed from a buddy good luck keep us updated  great pics

Looks spiffy! Can't wait to see it done.

As far as the Z volume goes, I don't own an SD4. However, SD2 and 3 are virtually identical, and the 4 is just the 3 with just a few additions. With that said, looking at my 2, you may be able to get about another inch in height...any more and the top of the plaform would crash into the drive rod. For the bottom, the platform, if the 4 is the same as the 2/3 aluminum once, already has a notch cut out to fit around the motor. While playing around with custom gCode settings, I once plunged my platform all the way to the bottom metal panel and never touched any part of the motor.
....but if it feels good...

Keep the pics rolling!

Only limited bursts of time to work on it so it will be slow going, unfortunately. That is why I set the goal to have it finished by end of the year (hopefully sooner, it is my only printer!) I tried to prepare by buying many parts over the last few months leading up to this, but I expected that there will be many times I didn't foresee something. Unfortunately there isn't really any sources for parts around where I live, so I end up having to order just about everything.

I also have to fight my perfectionist disability! I almost ordered another E3D just because I wasn't happy with how my grinding job looked. It works. I need to tell myself to let it go and move on.

I am hoping this weekend to redo the enclosure heater once I pick up some sheet metal (I'll be using ducting material.)

Getting back to the SD4 upgrades. I forgot to mention one of the upgrades planned: internal mounts for the rods. This means that the rods will no longer be going through the metal case. As mentioned above, when I got the entire thing disassembled, I found the sheet metal was bent especially around the points where the metal rods were mounted. I suspect that this caused some of the misalignment of the rods and troubles with prints in some corners and nearly impossible circles.

I used flat pliers to straighten it out, but I think a more sturdy way of mounting the rods is in order. I'd like to do this also with the transmission roller in the back and stop that never-ending adjusting because the rod can slide side to side.

Of course, that will mean cutting down the rods a little.

how will motors, hotends, electronics etc stay cool if inclosed in a hot environment? some can be placed outside and air used to cool them ducted into enclosure to aid pushing fumes out through filter but some must remain inside unless bowden type extruders or some flex tube feed design for filament as bowdens wont retract since they melt plastic into dif angled/sized compartment and/or flex tube lets filament move inside making accurate retraction impossible. cooling fins, heat sinks need ambient air temps at least 35 degrees F below desired stable temp to achieve it just like radiators.

also be hard to cool print for bridges etc unles using outside source like I do an aquarium air pump with hose pointed at nozzle tip

also keeping filament rolls being used inside enclosure would help keep them dry. for easy removal of finished prints, removable glass plates would let them be taken out to cool and fresh plate installed for next print so reheating time is reduced and less chance of damaging printer parts during removal.

also keep side panels easy to remove for access to prints if needed

just putting things out there that I have been thinking of doing similar re-manufacture upgrade to duel extruder with best mods since SD WB failed at it by this >=< much lol

Some good ideas and suggestions here. Here's the planned system:

1. Insulated panels
2. Digital temperature controller controlling the heater and fan.
3. Installed at the bottom to suck in the cold air from the bottom of the chamber and heat it
4. Exhaust fan with vanes (dryer vent) to suck out the hot air from the chamber for cooling.

In heating mode, the top fan is off, the heater is turned on, and then the bottom blower is turned on.
In cooling mode, the heater is off and both fans are on to push the hot air out of the chamber.

The electronics are going to be located on the outside of the enclosure. That was one of my mods anyway. Left inside will be steppers, heated build plate and hotend. The hotend and build plate will be higher than ambient already, so not much concern there. The steppers are the only real concern. But the goal isn't to heat the enclosure to the levels of an easy-bake oven. It is just to provide a consistent environment so the ABS part stays the same temperature throughout.

Warping and splitting of ABS occurs when there is a temperature differential between layers. Even with a heated build plate, it only really heats a few layers and the layers recently put down by the hot-end cool pretty quickly. So, the center of the part is significantly cooler than the top and bottom layers. Obviously this causes contraction of the center layers which end up curling the part and lifting it from the build plate or cracking layers apart.

The phase change of ABS is pretty small, and it cools rather quickly so it is very sensitive to this.

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Now to some of your suggestions:

1. Cooling for bridges and PLA. The heater is obviously not meant to run constantly. So, I wouldn't use it while printing PLA. As for bridge and overhang cooling, you make a very good point. Piping in air from the outside does seem like a good idea. I had been monkeying with the idea of using a peltier for the chamber heater. This creates a cold and a hot side. Perhaps the cold side could be used for the external source? I happen to have one to experiment with!

2. Spools inside. Definitely. I have been trying to work this out in my head and I think I finally have some pretty decent designs for this. It would be awesome to be able to leave the spools installed and not have to worry too much about moisture. It would also help with feeding and preventing the filament from getting tangled. I am picturing a drop in area on the top, spools on their sides supported on hubs (similar to CD hubs.) A wall around the spool keeps the filament from coming unwound at guides it. The hubs are on bearings of course to make the spools very easy to spin. Getting crazy and going further with this, it is even entirely possible to drop in a spool and have it load itself! A project for a later time, though.

3. I am not sure I understand the concept of the removable glass plates. If I let an ABS part cool before trying to remove it from the build plate, it is cemented to the glass! The easiest time for me to remove an ABS part is immediately after it finishes. PLA definitely needs to cool to remove the part, but then you don't really need the heated bed on there for PLA. And of course, I disagree about shortening the re-heating time. How would putting a cold build plate in there shorten the heating time. Perhaps you can elaborate on the advantages to this concept.

- I use a borosilicate slightly textured glass and I spray hairspray on the glass prior to printing.

4. The fumes have never really bothered me. Not sure this a problem I am concerned about fixing.

So, I quickly threw together a little test with a peltier and some heatsinks I found in my junk box.

The hot side has a huge copper heatsink, but all I had on hand was a cheap aluminum heatsink for the cold side. Regardless, I was pretty impressed with the results.

The cold side stabilized at about 5 deg C and no pressure on the heatsink (and no thermal paste on this side.)

The hot side started slowing down around 61C (but still climbing slowly) at the copper plate of the heatsink. It is resting also on the aluminum of the power supply which is perhaps drawing away some of the heat. And again, no real pressure to couple the pletier to the heatsink. I do have thermal paste between this heatsink and the peltier, though.

With proper heatsinks, clamps, insulation, and ducting, I think I might just be able to make this work. The hot side for a chamber heater and the cold side for bridge cooling.

Looking on ebay at some Dell PowerEdge large flat solid copper heatsinks. I will likely need to cut them down to the 40mm of the peltier. They are about $8 a piece used.

Off the top of my head, I am thinking of cutting a port in the back of the enclosure and building a box around the peltier system isolating and insulating the hot side from the cold side (peltiers work by temperature differential.) Hot side inside the chamber with blower. Cold side on the outside. I would need to work out a way to deliver the cold air to the hot end on demand.

The whole arrangement heated up rather quickly with the 30A supply I am using. This is an old pletier, so I don't remember the specs, but based on what I see online, I think about 20A is the max current. Though I think this was just a small 6A one I bought to experiment with. Certainly a more powerful peltier would heat/cool much faster and most likely achieve more temp differential.

Another nice thing about peltiers is that if you switch the polarity of the current, the cold and hot sides also switch. So it is possible to switch to using it to cool the inside of the printer as well. These are used in the personal refrigerators.

thats basically an Bi-electric refrigerator plate like small car coolers use developed by NASA in the 60s. and they cant handle much heat load like 90 degrees F they start loosing ground. also no room for liquid cooling. but if you use Bowden extruders and the Y/Z motors mounted outside as stated then only the X motor needs cooled as long as the printing material is not over heated. making it easier to deal with so just attach that cooling wafer to that  motor.

as for glass beds, thats what I was asking about in my other topic but nobody really replied to it, just posted what they do mostly for PLA. and I use ABS (you need to read the MSDS on ABS! have you noticed blood shot eyes etc?)

as for borosilicate thats not really glass but a composite and it can flake/chip easy trying to remove prints as many posts on this forum say. I prefer tempered glass and if removing without cooling then thicker than 1/8th inch to prevent cracking when prying with razor blade etc.

the aquarium air pump I use works good for bridging only its not got hose attached as it needs a metal tube bent and fastened to extruder like those on scroll saws for blowing dust away from blade so you can follow lines on board. but I just use a straw in hand for hose to blow where needed for now. the pump was found NOS for $1 at yardsale a cheap Walmart one.

filament rolls come in many shapes and sizes so I intend to make a duel roll holder similar to  Thinaverse http://www.thingiverse.com/thing:169045 as it can be made to acomidate all types and for duel bowdens.

A peltier is capable of 70 degree C differential between sides. But if you don't effectively remove the heat from the hot side and keep the cold side cold, the whole thing warms up and just turns into a heater, then it stops working.

I have played around with different heatsinks, and the large copper one on the hot side and a fan works very well unless you run it for hours (which would not be happening in this case.) It pulls the heat away from the peltier, so the heat doesn't heat up up the ceramic as much. I believe it can be made to work. I am doing my research. If not, no big deal. I have other heater options. The peltier is nice mostly because it provides a cold side as well. I bought a water cooler block that I will experiment with pushing air through to see if I can move chilled air through tubing.

You might need to diagram up what you are talking about there because it isn't clear to me. First, there is no water cooling going on. I was only planning to experiment with pushing air through the water-cooler block (it would be mounted on the cold side, not the hot side) to pick up the cold air and push it through a hose.

The point of this is:

1. A heater to heat the inside of the build chamber
2. A cooler to create chilled air to be piped in and directed at the print nozzle to support bridges in the heated environment

You have a point about moisture in the air, though and I will probably need to take steps to remove it.

thats why I posted earlier about air heat transfer has more limits than liquid chillers do. but simpler to design and implement