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click 4 months ago.
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Hello everyone,
Here is a little intro before I ask my question, in order to help you understand my problem… My team and I are working on creating a new bridge design, in which we utilize 3D printing technology and post tension cables to create a bridge that can be built, quickly and cheaply. We have a 3D printed model of a valley, with steel wires stretched across.
We are attempting to use the Robox to print over those suspended wires (see attached image of our design). I am not worried if it will or will not work, but rather how to offset the print head to a certain height in order to print the bridge deck on the cables. Any help would be appreciated, thanks.
@nwrobotics If your model is short enough, you would need to build an artificial plate to simulate the print bed since the printer does a bed map at the start of the print. The problem is that when you are doing this, you risk damaging the printer. I would not do this. I would print the part and glue it to the cables. If you damage the printer while you do this, it will be up to you to repair it.
I operate two Betas and four Production Robox.
I am the US/Canada Technical Support engineer for the Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/benHello,
Thank you for your reply, I appreciate the help. I do not wish to use super glue as that is not the point of the project. The point is to literally print the bridge deck on the cables. We are attempting to demonstrate that for a science/engineering fair project. The print head would begin printing about an inch and a half off of the print bed. At that height, would that be possible? Could I possibly create my own G codes, and if so, does anyone know how I would go about that without breaking my robox?
Thanks in advance,
Aiden
@nwrobotics Technically you could create your own gcode but you run a very high risk of breaking the Robox. I would not consider this project with the Robox because of the needle valves and the difficulty of manually writing gcode with the needle valves. You will be much better off using a traditional printer where you don’t have to worry about the special moves needed for the Robox.
I operate two Betas and four Production Robox.
I am the US/Canada Technical Support engineer for the Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/ben@nwrobotics I think you should be able to do this. It will take a fair bit of experimentation but wont be too difficult, positioning the bridge model on the bed needs to be very repeatable. Of course you will be responsible for any damage to Robox as the warranty only covers normal use.
Design the part to fit the bridge and slice it as if it was printed directly on the Robox bed.
You can cancel the print before it starts and find the sliced code in your PrintJobs folder.
If you view the gcode you will see that there are comments which show the start of each layer.
Before the layers start there are several steps eg bed levelling and minipurge. You could add a pause after this so you can place the bridge model and get things set up.
M1
Above is the code for a pause. To resume you can press a button in the software or just tap the Eject button on in the middle of the reel.
You would need to edit every Z entry after this point. You will see that every entry is unique and increments up to match your layer settings. There are lots of ways to edit this entry on each layer, a mistake could damage hardware.
For official support please visit www.cel-robox.com/support/ and create a ticketThis is quite interesting. @pete‘s idea seems fine but I am sure it can be enhanced a bit, too.
But before I would let printer print a few layers of ‘anchors’ - place holders where you can slot your model of the valley. If, for instance, that model has 4 tiny, round legs, you could print 4 very shallow wells those legs would slot into. That way you could make re-creatable process.
Next is to design your bridge at top of cube - cube that is open on the top. That last bit is interesting so Cura produces nice code for bridging (there’s set of parameters that change when printer tries to bridge a gap).
Last is to go through generated gcode as @pete said and remove all commands in layers for the cube but one - one that moves head one layer up. (they are easily spotted! :D) And of course M1 command after ‘virtual cube’ has finished. You could be even slightly more adventurous and move head even higher before M1 command and lower it again immediately after M1 command. That way you would have enough space for your model to slide in.
That way you are pretty much on the safe side - can let Tobox do what it knows the best in one go (save for the M1 command where you insert your valley in).
Oh - in above model you’ll have lower part of the cube (at the high of the wells) printed anyway - but it shouldn’t be a problem as your valley is going nicely to rest on it, too.
If you need it I don’t mind making your a script to detect cube layers and remove all unnecessary gcode (save for moving up) and add raising head, M1, lowering head before ‘real’ bridge starts. Worse case scenario gcode preview can help you identify which layers you want to ‘skip’ and make script even simpler - just enter starting layer and finishing layer you don’t want + amount to raise head and it can lower it after inserted M1 command.
Let me know - I don’t mind challenge like that! And it should be hard probably ~ 1 hour playing with it plus I can do it without needing anything from you in terms of models, etc…
BTW just remembered that I’ve already did something similar. I was trying to print skids for RC helicopter and as ABS would cool it was pulling material upward and original sliced gcode would make head catch it (coming from the ‘wrong’ side) and knock it over. So I made script to amend gcode so head always ‘approaches’ pillars from the ‘right’ side and add more material on it without catching it and knocking it over. Here:
good ideas click.
For official support please visit www.cel-robox.com/support/ and create a ticketI understand having to print anchors, but the rest is a little confusing. Any help would be greatly appreciated. Let me know if you need anything from me. Also, if it would be easier, we could only print one or two layers of the bridge deck just for a quick demonstration, instead of all of the layers.
Thanks,
Aiden
Cool. Give me an evening or two and I’ll return to you. I’ll try to make little demonstration for you and explain the process.
Oh, BTW it just occurred to me that anchors can be just another very short box around where your model will go into. Anyway pictures are worth more than thousand words… 🙂
Thank you very much for your help, I appreciate it!
Here are the anchors that I made to print (see attached image). We should be able to set our valley model in the same spot every time on the print bed with these.
Aiden
Let me give it a go first. When I get home I’ll make a simple sketchup of what I meant by making a box which we will remove by script and move head through those layers. It is going to be quite obvious from the picture…
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