[How to print matching threads?]

I've run a couple more tests using Fusion360.

I have a pipe with a M30x1.5 thread on the outside. I then create a ring which has an internal diameter of 30mm and on the inside of that I create a M30x1.5 thread.

After printing, the ring is too tight on the pipe.

The next test was to give the ring an internal diameter of 30.2mm and the apply a M30x1.5 thread. After printing, the ring is again too tight on the pipe.

After playing around with Fusion it appears that no matter what size I make the internal diameter of the ring, as soon as I apply a M30x1.5 thread, that's what I get. Applying the thread changes the internal diameter of the ring back again and makes it 30mm. All that's happening is I'm getting a thicker wall on the ring and the internal diameter stays the same at 30mm.

[How to print matching threads?]

I'm attempting to print a 30mm diameter bolt and a corresponding nut.

I'm using Fusion360 and have created a 30mm cylinder onto which I create a M30x1.5 thread. The nut has a 30mm hole and I create a M30x1.5 thread on that too.

Both just fit together but because there is no slack they're extremely tight and sometimes too tight to put together.

How should I build in a bit of tolerance? Just make the hole in the nut slightly bigger before applying the thread or is there a more elegant way of doing it?

I print both on an Ultimaker 2+ using a 0.4 nozzle and fast print with PLA.

[How to print moving joints in one print job?]

I'm new to 3D printing so there maybe an obvious answer to this question. I'm fascinated with the idea that you can print built-in joints into a 3D model all in the same print job. e.g. articulated legs on the elephant and ball bearings in a roller bearing.

I'm using Fusion360 and as a test I have drawn a ball and socket joint where the ball is set into the socket so it can't pull out. I've added a little tolerance between the socket and the ball but when I try to send it to Cura it only allows me to select one body at a time. Do I need to manually put joins in between the two bodies to fool it into thinking it is one object?

[Fault line through print]

Several more prints later and all is great. Thanks for the advice stu_le_brew and SandervG. It must have been contamination on the Z screw.

Only had this thing for 36 hours and I wonder how I ever survived before without one! The list of things I want to make gets longer every minute.

[Fault line through print]

Fingers crossed it may now be OK. I manually exercised the bed up and down a few times near the top of its travel using the wind-round control on the front. The manual raise lower on the maintenance menu didn't take it high enough. This test print is only 20mm high but it's higher than where the fault occurred on the previous prints.

Another bracket print I think for a test.

[Fault line through print]

It's done it again. About the same place so it does seem like the Z is sticking/jumping.

I've done a few manual raise/lower the bed runs before this print and it seemed OK.

[Fault line through print]

I'm running another 40 minute print of a right angle bracket it'll have a bit of height quite quickly so I'll see if I get the same fault line.

Just heard the "bzzurt" sound

[Fault line through print]

Thanks for your comments.

The cup was taken directly from the SD card with no changes.

The fans don't start immediately the print starts but come on very shortly afterwards.

The sticking Z sounds likely. The printer has been whirring away behind me today while I've been working and I'm sure I remember hearing a clunk early on so maybe it is the Z axis sticking. The elephant is nearly finished so I'll make the checks as you suggest and report back.

It's good to have people to talk to on the subject. Cheers

[Fault line through print]

I'm only on my second print since I've had my Ultimaker2 printer but on both prints I've had a similar fault. The first test print was the stackable cup and that had a line about 1cm from the bottom where the layers don't seem to have stuck and with very little pressure, the cup split at that point.

I'm now printing the famous articulated elephant and that appears to have a similar line round it but not at the same point - probably about 1.5cm from the bottom this time. All the rest of the print seems OK but it just seems to get the jitters at one point in the process. I'm using the issued grey PLA so the line is visible as a lighter shade than the rest of the print. I installed the latest firmware last night after the cup print and before the elephant.

Any suggestions please?

Thanks