TUKI Build Part 7: Soldering & Renaming.

I am going to rename this the TUKI Printer.

The reasoning is simple, yes it is a Rostock based build. However I feel it strays from the design enough to justify a new name. At least it does in my book, the advantage of the open source community is to add or subtract from a design or project and make it your own. The naming convention comes simply as a pet name. So without further delay the reason anyone comes to this blog is to read the technical details, or simply because they got lost in the web......

Increase precision, finalize sizing.

I finally shortened the aluminum extrusions within about .5mm of each other. Took some doing and some precise measuring I must say. The old saying was always measure twice and cut once. However they had no idea on how much filing it takes to reach any kind of precision with a hack saw and a file. The rods are now under stretch tension and the aluminum tubes are under compression. One of the nice things about working with wood is that it does have some compression properties. This allowed me to torque the threaded rods to a point where the surfaces were as parallel as I could hope for.

The next step is to mount the end stops.

Here is an ugly M$ Paint sketch. The goal of doing this was to have height adjustment. This leaves me with 2-3mm of height and 2-3mm of side to side adjustment with not much slop.

How it looks inside the printer. The led indicators are still visible enough once triggered and the carriage is within 5mm of the wood.


I decided while I was doing some wiring I may just as well install a LED matrix I had laying around from past projects. It won’t be anything special like Arduino controlled or anything of the sort; it will have a simple on/off switch.

You have the added bonus of seeing the end stops mounted in this picture. Another bonus for wood is that it is easy to drill and screw in.


I wanted to hide the wires in the tubes, and you can catch a glimpse of the wires in the same pic as the end stops. However this means that each end stop is 3 wires, and two more for the light. Although I could hazard a guess in having all 3 end stops on the same ground wire, I did not like the idea as I am unsure how this could translate later down the road. So I again drilled holes, ran two cat5E cables in and started securing them and then soldering the wires. I have 5 strands of wire left from the original 16 for future expansion of any sort. Maybe I’ll add a light show down the road....Maybe not.

As you can see I tried to tidy up the wires, all the connections have been soldered and heat shrunk. Being that these wires are low current and the wiring will be stationary I felt solid core network cable would be sufficient.

Being that I had cut the original cables and they were nearly not long enough to do the job I decided to throw some heat shrink on the connectors themselves. For nothing more than esthetics it seems.

The bottom of the printer. I routed the wires, secured them & soldered the connectors as necessary. The power wires will be shortened by 5-6 inches the next time I go back in to replace the floppy connectors with real 4 pin connectors, I want the wiring to be out of the way and easily accessible. Years of building computers has taught me that if you want to kill any sort of cooling wire the systems badly.

If someone is interested in the wiring code. Here it is.

Mounting the Arduino/RAMPS.

As of now the Arduino/Ramps combo is mounted in place. I used the remainder of the 1U braked I had cut up to fashion a mount for the Arduino. Some old motherboard brass stand offs and some careful measurement and drilling and taping got me a way to get air under the Arduino as well.

Tensioning the smooth rods.

Being that the smooth rod is 8mm, it will loosely tap to 5/8ths. However the nuts are not as snug as I had liked. They torque fine, however they do seem to have little to no resistance. To remedy this and also help in keeping the system tight I simply wrapped them in PTFE tape. That is plumbers tape. I liberally put on 5-6 layers and tightened the nuts with a wrench, about ½ a turn after the nuts bottomed out. The rods now have absolutely no bow in them. When moving the head in a very spirited fashion manually and taking into account the force I was exerting on the rods, none moved a mil. Time will tell. However even the bearings seem to be happier with the rods under tension.

At this point I put the printer on the floor and put my entire body weight on it. It didn’t budge or creak. IF nothing more I have made a fairly sturdy bar stool.

Until the next update! At this point I’m fighting the typical “Why won’t my end stops trigger in the software” I have a feeling I’m using the wrong pins.

I also have to tune the stepper drivers as they were plugged in as they came from the factory.

Looks like I am using the end stops backwards..... This diagram should help others. To clarify the X-MAX Y-MAX & Z-MAX are the ones I had configured in the software. It looks like I had the end stops plugged in the wrong headers. When I get home this evening I will try this out. In either case this is a more updated schematic for RAMPS 1.4

Bruno M.

Engineer, Tinkerer, Technologist, Maker.

New York

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