Jump to content
Ultimaker Community of 3D Printing Experts
Sign in to follow this  
gstewart

It's trying to make me hate it. Y problems. Connect problems.

Recommended Posts

I just bought the Ultimaker and it's giving me some horrible problems.

Firstly. I can't connect to the printer using Cura 13.04. I'm using Cura 12.12A and that connected, did the firmware and has been able to connect reasonably.

I printed a few things fine and then this happened.

 

 

The three beards were support struts I made. The main problem seems to be that every layer the Y axis goes further and further off in the same direction. As you can see it did fix it's self for the head but it's happening again on other prints.

 

hopefully someone knows what is going on and can help on either or both of my issues.

 

Share this post


Link to post
Share on other sites

The gradual shifting in the Y-axis is probably due to one or other of the pulleys for the y-axis not being tightened properly. Check all the grub screws and make sure they are really tight - including the one on the stepper itself. It can be hard to tell which one is shifting - you can use a sharpie to make a mark on the pulley and shaft in order to better see if one of them is slipping.

What OS are you running Cura on?

 

Share this post


Link to post
Share on other sites

There are many things that can cause this shift. Most likely it's mechanical. Figure out which axis it is. There 6 pulleys and tighten the set screws on all 6. Not just the 4 on the long belt - all six. Also your UM should have come with spare set screws. Those are better quality so if after tightening the hell out of those tiny screws, if it still slips you can replace with the newer screws.

Having said that, the second most common problem is that the short belt is touching the wood. While you are printing, look at the short belts (the ones to the steppers). Each time the axis changed direction, does the belt twist? Does it twist a different way each time it changes direction? If so then you are rubbing against the wood. It's subtle and hard to believe but this can cause small amounts of shift on each layer. It's easily fixed by adding washers under the 4 spacers.

There are a few other things that can cause this but these are the most common two. If neither of these fix it, please post your cura settings. You can save your "profile" and post that for us.

 

Share this post


Link to post
Share on other sites

By the way, for a test, I recommend slicing only the neck as that is where you seem to be hitting higher accelerations. There is a setting in cura where you can lower the part below height 0 and it prints starting at a particular z height. This will allow you to see if the problem is fixed without waiting an hour first.

 

Share this post


Link to post
Share on other sites
Also your UM should have come with spare set screws. Those are better quality so if after tightening the hell out of those tiny screws, if it still slips you can replace with the newer screws.

That's what those screws were for !! I was wondering. I ended up with the little bag of unused screw, it did not say anywhere in the doc what they were for. I'll definitely put them on, because those pulley ruined several good print of me.

 

Share this post


Link to post
Share on other sites

thanks for all of your quick replies.

I've tightened all the belts and moved the steppers slightly away from the wood. It seems to be behaving much better now.

Couple of questions still though...

1. How can I tighten the belts more. I've loosened the little screws holding down the timing belts abd that has helped, but they still don't seem very tight. Any suggestions?

2. Why won't Cura 13.04 connect to the ultimaker. 12.12A works fine but 13.04 just doesn't connect. It did manage to update the firmware after i manually set the baud rate up, but it didn't connect to do the heating test. In the actual program it just refused to connect at all. I can still shove gcode files onto an SD and use that, but it's not ideal since I'm still in the "figuring things out" stage.

Thanks again for the help.

 

Share this post


Link to post
Share on other sites

1. How can I tighten the belts more. I've loosened the little screws holding down the timing belts abd that has helped, but they still don't seem very tight. Any suggestions?

 

It's unlikely you need to tighten them any more then. The latest UMs come with the proper length belt. If you tighten them up too much you will increase the forces/friction needed to move the head. Did you watch/listen to the video that shows exactly how tight the belts should be? It uses pitch/frequency which is sensitive (accurate) to tension. The video is somewhere in the build instructions.

If after watching the video you are absolutely convinced the belts are too loose then there are a number of solutions. Search for tensioner or "loose belt" on thingiverse. But you are probably better off not going for any of those solutions - at least for a year (total guess) or so.

 

Share this post


Link to post
Share on other sites

Thanks for the help everyone.

Things are definitely improving. I tightened all the belts and that made a big difference. My next test was a simple pyramid with a hole in it and that worked perfectly. So it was time to do something trickier: a 38mm miniature.

Testing continues 001

 

No idea what went wrong with the top of the spear cause I was out while it was printing but more importantly than that Getting a fair number of little blobs still. Perhaps slowing it down will help with that I don't know.

Any suggestions?

 

Share this post


Link to post
Share on other sites

You're probably over-extruding a bit. Make sure your filament diameter is specified correctly. Also, that spear tip is going to be tough to do. It's so thin and after the head of the figure finishes it's the only thing to print on each layer so you will be running at your minimum layer time. What tends to happen is the plastic stays soft between layers and continues to build up heat and warp up a little. Then when the print head comes by to print the next layer it catches on the previous layer and moves it around which is why the spear looks all crooked and wavy.

 

Share this post


Link to post
Share on other sites

I'm glad you are happy with the results so far but you should be able to do much better.

The next thing you should concentrate on (like armstrom says) is cooling.

Under "cool" There is a "minimal layer time" and that should be set to at least 5 seconds. I prefer 7 seconds. Whatever you have it set to it needs to be higher for that spear to look better. Also make sure the fan is on ("enable cooling fan").

Now all your settings so far may be fine - the problem may be in the expert config menu. Under "cool" there should be a setting called "minimum feedrate". I recommend you set that to 0. When it isn't zero there is a bug but also with the newer ultimaker's you probably don't need a minimum feedrate. That may be the single problem related to the spear.

 

Share this post


Link to post
Share on other sites

Thanks for the cooling tip. That is probably going to make a big difference.

Things are getting better with each print mind you.

Testing continues 002

 

Took the temp down to 206 for this guys and 40mm/s No big blobs and only a few minor errors. I didn't use CUDA generated supports cause they seem to mess up such a small model so a couple of places the overhangs were a little too much.

 

Also the latest version of CUDA connects fine with the machine so I can measure things correctly now. I'm definitely going to try your cooling suggestion though.

 

Thanks again gr5.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Our picks

    • "Back To The Future" using Generative Design & Investment Casting
      Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.
        • Like
      • 12 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!