Sunday, July 29, 2012

It's Alive! It's Alive!

My Rostock 3D printer is now moving. This is a video of the home positioning routine.

videoSome interesting facts on this part of the build:

There was no information at the time of where the steppers go (as in which axis is X, Y or Z in this design).  On standard printers this is pretty straight forward but on this not so much. I placed them as X and Y at the front and Z at the back. It all behaves as expected so either I fluked it or the little dance it does in the video works out the orientation.

Also there was no info on whether the min sensors go on the top or bottom. As it starts at the top, I put Min sensors up there. That was the wrong choice, and there was much stepper stalling and belt skipping. It took a little while to work out what was going wrong as it is not obvious in this design and many random things happen in this configuration. After swapping them around and having min sensors at the bottom, it behaves properly.

My next steps are:
  • add some supports in the back corners that can be used to "pull" the axis perfectly square if required and also provide a spot to mount the electronics. The original design has the Ramps underneath but I prefer to have them where I can see them and give them better air flow.
  • Get it all moving level and install the heated bed.
  • I will also print out the pen holder today on my other printer and see if I can get it to draw something in 2D. My Teflon tubing and hot end has not yet arrived for the extruder so no test prints with plastic yet.

Friday, July 27, 2012

Rostock 3D It moved for the first time..

Last night I did a test of the electronics and it Moved !!!!!
It was fully assembled just enough to get the motors and carriage to move as a test. I will finish wiring in the stop sensors tonight and see if I can suss out what motor to wire to what axis as it does not have a specific X,Y or Z and also no wiring docs as far as I can find.
My plan is to hopefully have it drawing in two D with a pencil by the end of the weekend.

Wednesday, July 25, 2012

Rostock basic assembly done

Yay!!! The smooth rods finally turned up..   So I was able to start the final assembly of the Rostock 3D printer.
The smooth rods are longer than I need at the moment but I purposely have not shortened them. Currently the belts I have allow me a build height of just over about 200mm which is plenty for me. The nice thing about the Rostock design is that simply by adding longer belts I need only raise the top an I get more build height.

Monday, July 23, 2012

Smooth rods and bearings soon to arrive

Just a quick update.
Finally the smooth rods and bearings have appeared back on the radar again. They have cleared Aussie customs so I would expect to have them in my hot little hands within a day or so.


In the meantime I did some fiddle little jobs. Have wired up the steppers and put the connectors on the ends and put together the print carriage assembly. Once the rods turn up, she will finally start to take shape.

Thursday, July 19, 2012

Waiting for smooth rods

Well now I have the fittings attached to the top and bottom. Steppers and Idlers attached... if those smooth rods would just arrive, I will be ready for assembly. Note the cardboard box is not part of the build, I put it there to show the top above the bottom for the photo :-) )
The smooth rods cleared the sorting office in LA on July 9 and are supposed to be on their way to Australia. Its now the 19th. I hope they didnt sort them onto a rowboat instead of a Jet.

Sunday, July 15, 2012

Some of the other bits required

Here are some of the other bits required for the job which I ordered through http://create3d.com.au/
They have been very helpful.
There is an extra stepper motor and a set of belts and pulleys in the kit on the left that I do not need for this Rostock project but I will be using them on my existing printer.
The Ramps controller in the kit on the left comes preassembled.
For the Rostock an additional 3 micro switches are also required.



Still to come the long smooth rods and 12 bearings (on the way from the USA) and I am yet to order the PTFE tube for the bowden extruder.

Making the Base and the Top

The Images below how using the printed Jig to mark out the board. I used a protractor to get the 120 degree angles as accurate as possible, secured the jig at the centre position and then marked the points on the board.
This was harder than I thought it would be... Initially I did not have a protractor and just using the jig (which has sides at 60 degrees) was not as accurate as I would have liked.
I wanted the front mounts to line up with the existing edge on the board so as to save two cuts. After some trial and error trying to work out the best way to find the centre, I used the following procedure to mark out the board:
  1. Start off by using the protractor and a ruler to draw a line in from one edge just above the corner (about 31mm up from the corner)   Draw the lin in towards the centre from the edge of the board at 120 degrees.( In the image on the left below its the line starting from the bottom right about 31mm in from the right )
  2. Position the jig in the right orientation across the corner and use the hole at the top of the jig to mark the center of the board along that line.
  3. Use the protractor to mark out the other two 120 degree lines from that centre point and draw them out from the centre
  4. Screw the Jig in place and align it with the angle and mark the holes and edges etc.
  5. Finally cut and drill 2 copies, one for the bottom and one for the top.
I used 11mm MDF board.



Update: I have created a modified version of the diagram from thingiverse that showed only one axis and have it showing the full layout.  I found it more fool proof using a full printed http://www.billd.net/images/RostockBaseDims.pdf

Rods Assembled

Here I have attached the printed rod ends to the carbon fiber rods. This was not fun. Each rod has to be exactly 250mm hole to hole.
I made a jig with pin in it so I could fit the ends to the rods and make sure they were exactly the same size. They are glued with an Epoxy. I hope it lasts.
As this relies on printed universal joints, I don't know how it will go in regards to wear over time.  I think in the future I might replace the printed ends with Heim Joints (http://www.vxb.com/page/bearings/CTGY/HR)

Printed Parts Ready to Go

Here are the printed parts.
It took me about 16 hours to print all of the parts on my Sells Mendel Printer.
They are printed in PLA.
The push rods required for the Rostock were too long to print on my printer so I have printed the rod ends and bought some 6mm carbon fiber rod from a local Kite shop. They have been cut to size and I will glue the rod ends on.
The large blue triangle in the top right is a Jig that is used to position the parts.