PeterE builds a 3d Printer

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PeterE:
Hi picclock,

Thanks for the info re glues. I used a contact adhesive to try to glue the cork to the heatbed. I know it is on the borderline temperature-wise, but it is a try-out. As yo8u perhaps saw on the previous images, I have used thermal paste for PD processors to connect the heatbed thermistor to the bed and the glass plate will be flat on (at least from start .....)

The heatbed is now attached to the plywood baseboard on the Y axis.
I started with a piece of the left-over stainless 8mm bar.

From that bar I made three top hat-like bushings that I glued into the ply at the proper places for the screws with the springs.

To avoid having to make a 3mm thread all the way through the 13 mm bushing I drilled it out about half way from the bottom. Threading went very nice and then the bushings were glued in place in the ply board.

With the heatbed in place I started with how to lay the cabling so it does not get itself entangled in the machine. A combination of small plastic cable guides (the white ones on the base board), and spiral tubing, I think I got a setup that may work.

The white cable guides are good for just laying the cables inside to stay out of the way. They are also well protected from mechanical happenings.

The cables from the X-axis motor and its end switch got their own piece of plastic spiral tubing. The cables are held together in the end close to the motor and the spiral then enters a 10mm hole in the portal to guide them towards the electronics on the back side. Did this as it turned out that the length of the cables were is some cases just a tad short compared to what could have been for ease.

I also did the same with cables for the extruder carrier with all of its cables The heatend, temp sensor, fan, and extruder motor. They got an own 10mm hole right beside the first one.

This way I can secure the cables on the rear side nice and tidy and no cables will run over the portal which may obstruct the filament guide tube.

While re-reading your post I noticed that I did not answer your question at the end, sorry. I used two aluminium connector pieces which are slit in spiral form to allow angular differences between the Z axis motor and the threaded rod for the movement. You can see them on the image above right above the Z axis motors. So far I have not noticed any problems with that. The coupling is a standard part that was included in the mechanics kit I ordered. Since the motor and the threaded rod only have a fixed position at the motor mount, the other is at the nut for lifting the X axis movement and that point continuously moves depending on where in height the X axis is at the moment. So I think there are not much hat can go wrong angle wise.

When it comes to the end stops, I have chosen them to be placed as follows:

X axis - at the left hand side and the micr switch triggs against the stepper housing.

Y axis - at the left smooth bar triggering against the left bearing housing under the board.

Z axis - to the left, below the X axis motor mount triggering against the underside of the motor mount.

I have only used three micro switches so far but am thinking of using three more to definately define the both ends of the travel for all axis.

So far so good today.

/Peter

PeterE:
Some more done this evening together with image no 100 in this build log :bugeye: (Gosh so many pictures to no real use :zap: :thumbup:

So, what's been done? Well nearly all cables had pre-mounted connectors so I started to fit each one to the RAMPS board. I found a useful assembly sketch here: http://reprap.org/wiki/RAMPS_1.4#Wiring A description that even I understood! :thumbup:

Started with the stepper cables in the centerline between the display cables. Next was the end stops then the tempsensor from the extruder. Last this time was the extruder heatsource (the two orange cables at the bottom of the RAMPS board.)
Still missing is the extruder fan connection as the cable length was too short and needs lengthening. Will remove that connector anyway as it will use the connection for extruder two (also meaning I can control on/off and runtime of the fan.) Finally the cables for the heatbed and its sensor, but I found the supply cables I bought is perhaps too stiff and after a rethink I will get some silicone cables instead. These cables must be as soft as possible to not restrict the movement of the heatbed un-necessarily.

Also waiting for some heatsinks for the stepper controllers. Will use the standard ones now, but will look at changing if they seem to run hot.

When all that electrics are done and some minor mechanical bits in place, it will be time to switch the contraption on for the first time - duck and cover time :zap:

/Peter

picclock:
Hi PeterE

Good to see your latest pictures and progress. Like the idea of tucking all the electronics behind the gantry. I presume you already have a fan/shroud sorted for cooling.

I noticed that there does not appear to be any cable strain relief / support for the extruder/head/sensor cables. Because this assembly is likely to whizz back and forth a few thousand times the metal in the wire will become work hardened and fracture, normally at the point where the insulation stops. It might be an idea for the cables in the spiroband to be clamped using a P clip or similar. One of the motor mounting bolts, or somewhere else nearby will do. That way the bend radius during movement will be much reduced and the cable will be supported by its insulation.

Looking really good so far. Keep up the good work.

Best Regards

picclock

PeterE:
Thanks picclock!

A fan for the electronics is definately on the list, and a shroud to control the fan air stream too. Just haven't worked out placing and air flow directions just yet... :scratch:

The strain relief is going in, still to do, thanks for your ideas, will take those into account.

Also managed as smallish bit today. Changed the power feed cables for the heatbed from car audio quality to silicone quality. The silicone ones are at least three times as smooth and bendy as the car audio ones. I'll show the fitting of those in the next image series in a couple of days.

BR

/Peter

PeterE:
Good Evening again,

Some more done tonight before some coffea and a short TV break interfered.

Added heatsinks to the drivers, connected the extruder fan and the heatbed thermistor. That means that all the electrics is done so now the look from rear is as below:

I made a partition between the PSU and the buildplate from a piece of plexi laying around. It does not show that clear on the image, but it is to protect the buildplate from air flow from the driver cooling fan that seems to be necessary.

So one of the last pictures from the rear of my printer. Here the plexi partition shows better. No risk that any cable is tangled up in a build.

Looking closely it is also possible to see how I placed the cables from the heatbed. They are first of all clamped to the underside of the buildplate and then a similar clamp at the base of the portal. The cables form a "U" with the opening towards the back. That should make the connection flexible enough to avoid un-neccessary breakages.

Over all the build kind of looks almost tidy in spite of being a DIY build.

Then turning the printer around to get a shot from the front.

Here I have placed the glass plate on teh heatbed and secured it using four paper clips. Works a treat! So, the remaining things to do is to make and fit a couple of cable clamps for the extruder cables and the X-movement cables.

That will finalize the mexchanical and electrical work. What still is missing is a holder of some sort for the roll of filament. That is something I intend to get at tomorrow.

All in all, it is closing in on the exiting first time run. It may happen during the weekend depending on what is planned by the rest of the family. My "little girl" - the now 25 years old school teacher - has finally found a place of her own (apartments are very scarce in Gothenburg these days) which may require me to do some "supporting activities". We will see.

/Peter

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