Putting the axis together is fairly easy but it still created me some headaches so here is where you can do better than me.
First of all make sure the printer parts you are making are done on a well calibrated printer. I though my AM8 was well calibrated when I realize that some hole where about 1mm out ! Ouch ! So I recalibrated my AM8 and printed most of the parts all again !
There is some great videos on explaining how to put the axis together on you tube made by Ben Levy ( thanks again for that ! ) However there is always something missing.
First of all, the X Axis. What could go wrong, you have only one rail and one profile. True but make sure it is perfectly aligned. Put the rail on the profile with all the screws on. Ty only the extremity screw lightly. Using a caliper measure the distance between the side of the rail and the size of the profile. Both distance have to be as identical as you can get them on both sides. Make also sure that the distance from both end to the rail to the ends of the profile are identical, this will place the rails perfectly in both direction in the middle of the profile and you are go to go !
Now mount the X axis profile on the two holder from Y Axis. If you follow my post on how to mount the frame, it should already be mounted on the frame. Only use the bottom parts and ty the screw lightly, just enough it won’t fall apart.
Lose the screws on the Y rail on one side of the printer and move the rail forward to the front of the printer to 30 mm away from the frame. Make sure you get that pretty accurate using a caliper. Ty up slightly the screw at the front end of the rail, so the rail is not moving. Move the X axis close to the front, but still far enough so you can reach the screw at the front of the second Y rail. Do the same procedure and place the rail at 30 mm from the front. Now both rails are placed at at 30 mm from the front profile, and because you build your frame perfectly, they are both at the dame distance. By using the X axis, you can be sure that the rails is going to move.
Adjust the left Y rail to make sure that the distance from the side of the rail to the side of the profile is identical at the front and the back of the rail. If it is the case, you can ty up the screw at the back extremity of the rail. Move the rail back to almost the end. You left the back screw of the second rail lose to the rail can move freely and position perfectly. When at the end, ty up the back screw of the second rail. If you measure the distance from the side of the right rail to the side of the right profile, they should be Alamo identical. I n case there is only 0.1 mm difference between the front and back.
Not you can ty up the rest of the screws from the rail, one after each other slightly, they do again a bit more and finally all again with more force. You can ty the screw per hand and without to apply ton of force.
You can check again by measuring the distance of the Y rails at the back and at the front of the frame, they should be pretty parallels.
Now, we have to make sure that the X Axis is perpendicular to the Y Axis. To do that it is really easy. Move the X Axis to the end of the Y rails, so that the carrier is nicely closing with the end of the rail on one side. Check on the other side. If you are lucky, it should be also perfect at the other side. If not, lose the two M5 screws at the bottom of the X Axis from the X Carrier bottom ( assuming you did not put the top part yet ) and twist the X Axis until the two carrier are nice closing with the end of the rail on both side. Now it should be clear to you why I mentioned that the positioning of the two rails at 30 mm from the frame should be done accurately.
That it it! Now you have a perfectly square X and Y axis, and the X axis moving freely ! You can start mounting all the printed parts and belts. It is fairly easy. See you on the next blog on how to kick start the Duet Board.