Hey everyone!
By popular request I've begun planning my hardware store 3D Printer build. Back in the early days of the reprap project these were known as "repstraps" - basically anything you could throw together to move in 3 dimensions to 3D print parts to use in actual repraps. It's the solution to the classic chicken or egg problem presented by the reprap project and something I've always wanted to try!
The current plan is to create a triangulated frame (i3 bed slinger style) using slotted L section, and drawer slides for linear movement. Dual M6 rods drive the Z axis and fishing braid will be used instead of belts. That's the plan anyway, I would LOVE to hear your thoughts and suggestions below as this is very much a community driven project.
Happy printing!
Angus ~ Maker's Muse
Andrea` Dondolini
I need to change a job due for fisical problem, and I want to start working in a 3d printing sector with prototype and programming Marlin or Klipper.
Did you have any tips here in Sydney to start iy?
Andrea` Dondolini
Theressa Morello
Can't wait to see the finished printer too it should be a fun and interesting journey
Angus Deveson
Alvin Frederiksen
Combining those metal frame angels with some MDF board will make for very sturdy solutions.
If you give MDF a surface treatment, then MDF has the advantage of being very dimensionally stable. Even in situations with very high humidity.
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For MDF surface treatment, I have used a two-layer treatment.
A) first layer is 50% outdoor-wood-glue mixed with 50% water. Apply very liberally, so the glue penetrates as much as possible. Once outdoor-wood-glue dries up, it becomes very water and humidity resistant.
B) second layer is any paint. I prefer the Hammerite spray cans. Hammerite paint is completely overkill for spraying MDF, but I just like the very durable surface of that particular paint.
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Because the modern Marlin firmware is able to use Z-probing to deal with Z-hight, you might try to use a simple Z-probe screw solution, on your Rep-strap. This way it might be easy for you to tram the build-plate once, and then automatically get the Z-hight correct every time, for future prints.
On the other hand, perhaps GRBL ought to be the controller firmware, so you truly go back to the conditions that were reality when rep-straps were used.
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It is also possible to use the actual firmware that was available in 2010. Tonikip made the very first version.
Here I have made a few improvements/changes:
But kliment was the one who brought the Tonokip firmware to the next level:
And at one point kliment moved it all to the Sprinter firmware:
And then.... Ultimaker created the first version of Marlin:
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I do however think that it is okay to use the latest firmware and the latest slicers, and combine with whatever can be found at the hardware store.
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The very old firmwares needs the old slicers, as the method of calculation of extruded filament changed at one point. It used to be about how much filament was input, and changed to how much filament was output.
Software is a brilliant tool for doing the conversion from 3mm filament input, to 0.4 or 0.6 mm output. But at the beginning, we did not have such convenient use of software.
If you want to test those very old firmwares, I have a copy of my preferred slicer from 2010.
Repsnapper was created by Kulitorum.
Tonokip and Kulitorum were the first two people to build a Reprap Mendel using a RepStrap machine. As a chance collaboration, Tonokip made the firmware, and Kulitorum made an easy-to-use slicer he called RepSnapper.
As I recall, besides RepSnapper, Skeinforge was the slicer that was available back in 2010.
And then, some time in 2011, Slic3r became the leading 3D slicer option.
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Well, there you have some 2010 options. That no doubt will work with your RAMPS 1.4 setup.
But I still think it is perfectly okay to use moderne firmware and modern slicers, on your RepStrap printer.
Alvin Frederiksen
In the early days, 4 parts were used:
- a PTFE stick and
- a section of a M6 solid brass rod
- fiberglass insulated nichrome wire
- and a NTC bead
I believe this page shows the details: https://reprap.org/wiki/Darwin/Thermoplast_Extruder
If you use a power dril, to rotate the brass part, you can act as if you have a mini lathe, and be able to drill out the 3.5-4mm hole in the brass section. As rotating the part will create a self-centering system.
Drilling a 4mm hole in a M6 rod, will leave less than 1mm for walls. That is less than 0.5mm of cylinder wall. So it is imperative that the drilling solution is self-centering.
I once drilled such a hole, using two hand drills, making sure that the brass part always turned faster than the drill it self. So I KNOW that it is possible to create a suitable brass tube - without having access to a lathe.
Likewise the 0.4mm hole at the end of the brass section, will occur right in the middle of the brass rod, if the brass rod is rotated, and the 0.4mm dril is held in place.
A 0.4mm drill is however very soft, so sometimes it is not possible to get it to grip at the very center, and then you just need to hope for the best, as one of the pictures below does indicate.
I later discovered the center-attack-type-drill-bit, that can be used to aid marking the very center of a rod, used in a lathe-type setup.
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If you do however have acces to a lathe, it is possible to create some very interesting PTFE and brass hotend solutions.
I happen to have a few pictures of hotend experiments made some time around may 2010.
A brass rod, in a PTFE stick, will endure for about 10-12 hours of printing.
But "hardening" the solution with a strain relief system using kapton tape and a "push" limiter, it is possible to create a brass/ptfe solution that will survive for about 6 months of daily printing. So a guestimate is 3-6 hours a day, for 6 months is about 500-1000 hours of printing.
In 2010 it took about 30 hours to print the parts used for a RepRap Mendel. So it was very interesting to get to a point where the hot-end would last at least those 30 hours.
As I recall, some 23 sets of Mendel parts were printed in 2010 using the Mendel Workhouse at Labitat.dk
Some notes:
This type of hot-end was mountable on a Mendel x-carriage, using a Wade extruder/driver.
Before adding the wood-stove-window-cement, I would first cover the nicrome wire in heat paste. The heat paste would help the fiberglass-cover of the nicrome wire to survive much, much longer.
The first version of the pressure relieving MDF board would just be drilled with a M6 thread. And even though the MDF was quickly scorched (within a few hours), it would still survive about 2-3 weeks of daily use. As even carbonized wood and mdf-glue has some level of strength.
Once the MDF was further supported by an alu plate, it would endure much longer. Even several months.
An alternative to PTFE is Peek. And J-heads went down that path. But Peek is much more expensive, and more abrasive.
So in my opinion, a toughened-up PTFE hot-end design is a better DIY solution, when trying to print using PLA.
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But then again, using a modern hotend, might be just as okay, as trying to locally source a PTFT stick, and glasfiber covered nicrome wire, might not be easy. As that stuff is not typically available at the local hardware store, but needs to be found at a (somewhat local) specialty store.
But now you have some old school inspiration. If you choose to go the very DIY route even for the hotend as well.
Alvin Frederiksen
Without some specific purpose or intention, there is no good reason to complicate ones life more than what is necessary - in order to have some good maker fun.
Robert Martin