Now we have the chassis built it’s time to start putting the rest of the parts together that will start to make this a very interesting 3D printer indeed. The next step for me was to start attaching the 608 type bearings to the corresponding printed parts that I had printed earlier. The parts that need to have bearings fitted to are as follows:
Z_Roller_L.19.9mm and Z_Roller_R.19.9mm
These are used to run along the Z-axis upright tubes and hold the X-axis carriage. These parts require 2 x-5/16 x 1.5 inch bolts. That’s 8mm x 38mm in new money. They also need 8 x 5/16 x 1-inch bolts and that’s 8mm x 25.4mm. You will want 10 5/16 or 8mm nuts. For the record, I used nyloc nuts for added usability. Last but not least you will need 10 608 type bearings.
X_Roller_Double.19.9mm and X_Roller_Sing.19.9mm
These are used to hold the extruder mount that runs across the X-axis tubes. You will need 4 x 5/16 x 1.5 inch bolts (8mm x 38mm) 7 x 5/16 x 1 inch bolts (8mm x 25.4mm) and 11 608 type bearings
These are what the heated bed attaches too. you will need 4 x 5/16 x 1.5 inch bolts (8mm x 38mm) 8 x 5/16 x 1 inch bolts (8mm x 25.4mm) and 10 608 type bearings
Basically, you are going to need a lot of these.
Once you have all these parts together you can start putting the hardware on to the rollers. The longer bolts with bearings and nuts will go through the back or the thick part of the object. and the shorter nuts and bolts will go through the wings (as I call them). This is what effectively traps or keeps the part held on to the tubing
When you are putting these together don’t over tighten them (easy to do). What you’ll find is that when you over tighten them, they will start to deform the printed part. This is not because the printed part isn’t strong enough. It’s because the force that can be applied to these bolts deforms it very slightly and makes it a little more difficult to slide on the tubing and can make it stiff when moving. When placing on the tubing they should go on and easily roll from one end of the tube to the other niccccce and easy.
I did mine up way too tight and the parts were actually nipping the tubing making it hard to move. If you find yourself in the same position just slacken off the nut half a turn or so until it moves more easily.
What I found, was make sure I left a small gap between the printed part and the bolt like so (picture below). Just enough gap to get a flat-end screwdriver end in between the bolt and the raised area of the printed part.
When you are finished putting that lot together just make sure that all the bearings are running freely and not being obstructed by wayward plastic. Run your finger over each bearing to check that it spins freely.
Now we need to slide the parts on to the corresponding axis tubes so let’s start with the Z-axis upright tubes. If you followed my first instalment you will have put the top part (top tube along the X-axis) of the printer in place. Now, you need to take that off so that you can slide the X-axis rollers on to the Z-axis tubes.
When you have attached the X-axis roller mounts look to make sure the face of the bearing is laying flat or as central as possible to the face of the tube as seen in the picture below. If you notice that the tube is touching the outer edge of the bearing then you may have tightened the bolts holding the bearings up too much. To counter this, back the bolts (loosen) off half a turn to allow a little more movement and you should see that the centre of the bearing is in contact with the face of the tube.
When you are happy with how the bearings are centred against the tubing move the X-axis roller mounts up and down a few times. Check that all the bearings are touching the tubing and turning and that the carriage moves easily up and down. Try to get a feel of the carriage being moved over or pushed off as you slide them up and down. This could alert you to something on the tube like a blob of galvanising that needs to be sanded off. When you are happy with the way the bearings are working and you are sure that all bearings are touching the tube face it’s time to put the bed mounts on the Y-axis.
Undo any bolts that are holding the Y-axis tubes from easily sliding out. This is so you are able to get access to attach the Y-axis bed mounts. Be careful here because you want to keep the force that you are using to pull the tubing away from the Y-axis rail holder “lateral” What I mean is, don’t pull out and up or don’t pull out and down. Otherwise, you risk snapping the tube holder. Better to take an extra 5 minutes gently moving this particular tube than 3 hours to reprint another one.
When you have them both in place make sure they move up and down nice and smoothly when you are happy to tighten the Y-axis rail holder bolts to keep it all in place.
Now, it’s time to put together the X-axis. Get the tubes that you cut out earlier these will be (in my case for my build the 300mm model) 2 x 577mm tubes and the X motor mount. I added a little masking tape to the ends of the tubing that was going into the motor mount. The reason I did this because I wanted to take up a little slack that I found in the motor mount and also to stop any potential vibration from making it’s way to the hot end. I have seen this on another one of my printers and so I added this as a little precaution.
Once they are done just tighten enough to keep everything in place while getting the other components together. Now, you will want to attach the X belt holder to the X-axis carriage. As seen in the picture below. Undo the nuts and put the X belt holder onto the bolts that you can see in the picture. tighten (not too much) but enough to make it secure.
Now attach the extruder mounts to the X-axis tubes making sure they move without a feeling of tightness and making sure they are smooth as you move them. If you find any lumps or bumps mark with a pen so you know where to sand later.
As you can see from the picture above we now require to add in 16 nuts into the holes provided as far as the nuts go I got mine from here
I will show you what I did to make getting these in a little easier. First off lay the parts flat and then put the nuts in the holes then screw the corresponding bolts into the holes so that they catch the nuts. Then screw them in about half a centimetre, just to hold the nuts in place. If you have a hot glue gun plug it in and get it hot (if you don’t – just go out and get one, they are a must in this hobby) If not you could do this with a little epoxy glue, but be careful you don’t get it all over the threads of the bolts.
Using your hot gun or epoxy glue put a dab of glue at the entrance near the nut thus keeping it in place.
When the glue is dry or set, carry on with the assembly of the X-axis. Whilst the printer is in it’s laid back position you can lay the X-axis tubes and the attached motor mount and extruder mount assembly. Lay it in the channels found on the Z-axis uprights. We need to attach the Z_Roller_bracket to hold the X-axis tubes in place these will be with 16 x M4 x 16mm bolts.
Lay the printer so that the area you want to work on is horizontal this will give you a better angle to do the next steps. Lay the X-axis carriage in the channels like in the picture below.
This will keep it stable while you fit the Z_Roller_bracket and tighten it down. When tightening the bracket start from the two centre holes, but do not tighten fully until they are all in. I noticed with mine if I put the top or bottom bolts in it made it difficult to get the centre ones to go in straight. Once they are all in tighten them up. Do this on both sides.
We have now fitted the bearings to the parts that will be moving and we have fitted the X-axis carriage to the printer chassis. If there are any bolts that need a tighten or any that weren’t put in to allow access it’s now time to add these as well. Go round the printer making sure things move smoothly that should move and make sure things that are tight are indeed tight.
In the next part of the Piper build we will be fitting the rest of the hardware like the leadscrews, motors, pully belts, and fitting the extruder parts before moving on to the wiring and RAMPS board placement which I need to find a place for.