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Quentin’s printed leadsrew is designed for an Alpen drill. I don’t think it will work with a drill bit from a different manufacturer.
You may use a standard trapezoid thread for the z-axis as a replacement. And two screws for that thread with a spring against backlash between them.You should enclose your printer in a cabin (made of e.g. acrylic glass) to keep the print warm as a whole.
And: What’s puzzling you about the RepRap-Wikipage?
The only part that still misses in the virtual model is the hotend. I’m not sure if I will add that to the model (others can do that work as well 😉 ).
I’ll not add the electronics or the extruder to the virtual Morgan, because these parts are not so important to understand Morgan.Of course, if there are dedicated wishes for additional parts in the model, I’ll see what I can do. So just let me know.
And thanks for the title ;), I’m feeling honored.
@ate:
You can find a complete model over here too:
http://reprap.org/wiki/RepRap_Morgan_extended_BOM
There’s an archive with all Inventor-Files and another one with all STL-Files as well.
You may use the (free) student version of Autodesk Inventor to use the Inventor files.
You can download several drawings with assembling instructions over there too.Just a comment on your plan to expand the building height:
There is almost no limit, as long as you take the stability of your build in mind. The molten plastic that is placed on a layer may apply only minimal forces to the model, but at that height even that may cause the model to bend. But adding stabilizing structures to the model can surely compensate that.Greetings
RobertThe correct wire thickness for a single section should be 0.75mm diameter (0.44mm²) for 38m length (and that’s almost the actual length; could be 37.xm as well).
I used nails to form the loops. I’ve drilled holes for the nails before pressing them into the wood (I have a small handpress for that, bit you can hammer them in as well). The I but the nails off with a saw. This lets me form the loops, stabilize them with some tape and lift them off the bed of nails to place them on the downside of the building platform, which is made of 3mm aluminum plate. It doesn’t bend with this thickness and the required width of 627mm but I still can use a standard jigsaw to cut the pieces I need and it still is not too heavy for Morgan’s z-axis mechanic.
I’ve tested the platform yesterday and it easily heats up to 110°C, but of course this needs a bit time (didn’t stop it, but app. 10 min. I guess). But I’ll have to use a different adhesive, because the hit glue I used doesn’t meet its specifications and begins to melt at app. 80°C (instead of 160°C).
But that’s no problem. I just need a different glue that withstands 110°C.
Here’s the completed platform:
I had to devide the wire in three sections, because the wire was too thin (0.3mm diameter) and therefor gave a bigger resistance than needed. Now it gives 1.4Ohm. The platform should consume app. 100W at 12V with this setup. Will test it this afternoon.
The bed of nails is ready and the first wire is attached to it:
<url=http://reprap.org/wiki/File:Bed_of_nails_for_heat_wiring.JPG>Full res picture be downloaded here</url>Update on the method to fix the wire to the platform:
If the temperature stays below 100°C a good hot glue will do the job. The glued wire can easily be lifted off the “bed of nails” (e.g. after removing the screws, that marked the distances and loops) and then be glued to the building platform.… trying to keep things simple …
First try will take place next weekend. I have to order some additional aluminum first.
@DDevine:
You will somehow have to arrange the wire with equal distances between the loops. Doing that “freehand” seems quite impossible to me, esp. because there are app.80 loops required to cover the building area.
I don’t know how good the glue on the Kapton-tape is, but I think it will be difficult to keep the tracks apart, because only a small part of the wire surface would have contact to the tape (tape -> flat, wire -> round) and this small contact might not be strong enough to keep the wire in place. The tape would also have to keep the wire in contact with the building platform, but on one hand the gaps between the wire-loops are too small and the tape would have to be bended many times over the whole surface (between every loop) to glue the wire to the platform (an air gap between wire an surface would lead to less heated areas on the platform). I don’t think this can be done because Kapton-tape is not flexible.Temperature is not important here, because the platform will not be heated significantly above 100°C.
About size and form:
Correct. One would use overall width and length of the platform for slicing and avoid the Morgan-unreachabe regions when placing the objects.
Cutting the platform to the circular form is no problem. I’m using a standard jigsaw with blades for aluminum. Works like a charm.I use the toner transfer method to mark the profile and the drill positions onto the aluminum.
I would place the thermistor in a small notch in the underside of the building platform (my one is made of aluminum though), sticking its connectors through the film. This way the homogeneity of the heating wire layout could stay undisturbed.
I’m already using a thermal conductive adhesive (arctic silver) to glue the thermistor into a notch in the platform. Works like charm.
And another remark on etching bigger heated beds: Even the normal size is difficult to handle with the toner transfer method, because it can’t be printed on a legal size (DIN A4) printer in one piece.
And finally it is very cheap to use normal insulated wire for the job. If the “bed of nails”, the wire is formed with, is used for several wire-films for several heated beds, it should not only be faster but also cheaper than etching.
Anyway: The thickness of the wire is far more precise over the length, than the best etching could ever achieve.
Like ever I’ve had more time to construct the new idea, than to realize it first:
I’ve constructed the wiring for a maximum building platform for the Morgan. In this example, the copper is 0,75mm thick. The screw is 2.5mm by 5mm and the plate is 3mm thick. The distance between the loops is 2.45mm, so I placed a 2.5mm screw as an example for a “nail” to form the loops.
This version will have a resistance of 1.45Ohm, using 38 meters of 0,44mm² insulated copper wire (38.080055m to be precise).
The Inventor file was intended to let me test several wires just by typing there diameter, but something went wrong. But for a first try it’s good enough.
Here are the dimensions of the maximum building platform for the Morgan, all this was constructed for:
And here an overview over the complete platform wiring (so you can see it is completely constructed already):
The measurement of the wire-length was done on this basis.
I’m thinking of a bigger building platform too. Having just finished a new building platform with a new PCB heated bed design, I was thinking about how to heat a bigger platform effectively.
After my experiences with PCB layout and etching for heated beds I came to the conclusion, that PCB is not effective for bigger platforms. It would be easier to use copper-wire instead. The only challenge would be to ensure euqal distances between the wire-loops.
I think I will make a kind of bed of nails and tense the copper-wire between the nails. The bed of nails could be made of aluminum and the “nails” should be e.g. M3 screws. The sections that have to be connected in parallel to achieve the requested electrical resistance, can be calculated by the wire-length used.
After tensioning the wire between the screws and flat on the bed, it can be fixed with Urethane lacquer:
It is stable up to 130°C, very insulating (>80kV/mm) and clear.
The first layer of Urethane lacquer will fix the position of the wire loops. After removing the screws, another two or three layers will form a film with the wire loops in it, that can be aluminum bed. One layer of lacquer on the backside of the film will be the insulation to the building platform onto which it can be glued with a fresh layer of the same lacquer.I’ll test this within the next few days. Should be much easier to realize odd forms and sizes of heated beds with this technique.
