cant print proper circles I have a Solidoodle 4 and have this issue. Might be a problem not specific to this printer other users here might recognise and know the solution to. 10mtv2u.png mod_embed_images_loadimage('7cc74156435d7f4ee04b0aa226cd8762', '/forum/thumbcache/208/4d4/85c/5a4/be1/6fe/9b6/408/5f2/335/0d_800x400.png', 'http://i57.tinypic.com/10mtv2u.png', 'https://reprap.org/forum/addon.php?262,module=embed_images,check_scaling=1,url=http%3A%2F%2Fi57.tinypic.com%2F10mtv2u.png', '', 424330, 800, 400, 'Loading image ...', false); The extruder makes sharp turns at 5 oclock and 11 oclock. Red dots in this illustration, MEu4AMq.png mod_embed_images_loadimage('5f9e631e74ecdaa118858ca0794ba9ed', '/forum/thumbcache/4f6/80a/c5a/dc3/73a/f49/cad/57a/79b/a01/67_800x400.png', 'http://i.imgur.com/MEu4AMq.png', 'https://reprap.org/forum/addon.php?262,module=embed_images,check_scaling=1,url=http%3A%2F%2Fi.imgur.com%2FMEu4AMq.png', '', 424330, 800, 400, 'Loading image ...', false); The printer prints this circle counterclockwise. Red dot 1 in this image is when the Y motor has slowed down and started rotating the opposite direction (to go up), Red dot 2 is when the Y motor has slowed down and started rotating the opposite direction again (to go down). I say this after dozens of experiments with printing circles and checking the motion of the X and Y motors when these sharp turns/dents/bulges happen. So the sharp edges on the circles happen when the Y motor has slowly stopped rotating on one direction and starts rotating the opposite direction. This might give you a hint on what is wrong. If the same issue was with the X motor, the areas in green circle (point where X motor starts rotation in the opposite direction) I think would be deformed instead and they are not. https://reprap.org/forum/read.php?262,424330,424330#msg-424330 Fri, 12 Jun 2026 10:11:53 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?262,424330,430057#msg-430057 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,430057#msg-430057
The left side had little glue/epoxy that didn't hold it at all.

Here I have removed the extruder, hotend, motors and belt from it.

top view:


bottom view:


left side:


right side:


Again, the left side wasn't glued properly, so it just came off.


Left part of the carriage:



(Horrible quality, btw)

This is how much the rods were sticking out when I noticed it wasnt glued in place:


I think this kind of made the Y rods bend a little and made calibrating such a pain.
So the thing is I'm not sure how to glue it, if the rods should be sticking out as much, or not at all ("how much should the length be?"). And what glue to use. I've contacted Solidoodle about this problem and about getting a replacement.

I don't even know if this will solve my circlular problem. Thoughts?
]]> jaques Printing Mon, 10 Nov 2014 00:12:43 -0500 https://reprap.org/forum/read.php?262,424330,429586#msg-429586 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,429586#msg-429586 k.p. Printing Sat, 08 Nov 2014 11:43:49 -0500 https://reprap.org/forum/read.php?262,424330,427430#msg-427430 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,427430#msg-427430 www.soliforum.com]

At this point these are the problems I can think of:
Quote

Mechanical problems

1) Problem with the motors (unlikely to be 1. underpowered for what it is intended for, unless everyone else owning a SD4 hasnt noticed this, 2. all 4 of us having faulty motor(s), odds of that are also extremely low)

2) problem with the rods (still bending?) or problem with the bushing setup

3) problem with pulleys and belts and all of us fail to calibrate them properly (unlikely)

Software problems

4) Problem with this version of Repetier Host and Slic3r? (unlikely, jagowilson tried with Simplify3D as well)

5) Firmware (still)

6) Driver? (at this point, who knows?)

Electronics problems

7) PSU (at this point unlikely, jagowilson uses a very poweful PSU, Ive tried running with a car battery)

8) wires?

9) motherboard (unlikely, jaqowilson tried with Rumba board)

If you can think of something else, please let me know.

And yes Romel, we've all done that already.
k.p., what axle?

Romel and everyon else owning a Solidoodle 4, please print this 1 layer circles STL, it is very simple and prints in few seconds. And then make a top-down photo of the result and post it here.That would help us very much to know other SD4 owners do not have this problem.]]> jaques Printing Mon, 03 Nov 2014 02:44:58 -0500 https://reprap.org/forum/read.php?262,424330,426703#msg-426703 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,426703#msg-426703 k.p. Printing Fri, 31 Oct 2014 16:09:33 -0400 https://reprap.org/forum/read.php?262,424330,426645#msg-426645 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,426645#msg-426645
I'm almost certained that you have already loosened all the pulleys attached to the back rod and then slid the y axis back and forth, causing all the pulleys to "fall in place" to their natural alignment with the rod right? Then re-tightened them all back up? Then verified again that the back rod doesn't stick out? =) I'm thinking that there's a possibility that one of the pulleys from the y axis, either the one from the left y carriage or right y carriage is not alligned straight with the pulleys attached to the back rod.

Romel]]> Anonymous User Printing Fri, 31 Oct 2014 12:49:23 -0400 https://reprap.org/forum/read.php?262,424330,426513#msg-426513 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,426513#msg-426513
Quote
romels33
Im not really sure what that other bearing is doing there (the one marked with the red arrow). I don't have that on mine. Also, it doesn't look like it is attached to anything, except for the rod itself. Probably wouldn't hurt to try and take it off, and see what happens.
I took it off and it didn't affect the print.
I noticed that without it, the back rod got a little bend on the left part. Maybe was added to protect the back rod and keep it straight.

Quote

When you said:
"I have checked this too. The rod sticks out equally from both sides and doesn't change its offset as the x carriage moves."

You are referring to the Y axis right? =) So you grabbed both carriages and slid it back and forth and saw that the y rod was equal on both sides as you slid it? The x axis has no effect on this rod.... =) Just making sure.... =)
yes]]> jaques Printing Fri, 31 Oct 2014 01:50:40 -0400 https://reprap.org/forum/read.php?262,424330,426476#msg-426476 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,426476#msg-426476
When you said:

"I have checked this too. The rod sticks out equally from both sides and doesn't change its offset as the x carriage moves."

You are referring to the Y axis right? =) So you grabbed both carriages and slid it back and forth and saw that the y rod was equal on both sides as you slid it? The x axis has no effect on this rod.... =) Just making sure.... =)]]> Anonymous User Printing Thu, 30 Oct 2014 19:22:12 -0400 https://reprap.org/forum/read.php?262,424330,426086#msg-426086 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,426086#msg-426086
Quote
romels33
Since you said you tightened all your belts, have you also made sure that the Y motor pulley is aligned straight with the pulley right on top of it?
Yes, I have. I will try it again though.

Quote

Also, make sure that your "Y smooth rod" (the thinner one that sits horizontally on the back of the printer) is properly aligned. If you take off your side panels, and slide your Y axis back and forth while looking at the sides where that bar sits, that bar should stay in place and should not stick out of the bearing holder to the left nor right. If it does, you have alignment issues.
I have checked this too. The rod sticks out equally from both sides and doesn't change its offset as the x carriage moves.

My belts are as tight as I can get them, so I'm not sure what the problem is anymore. Tried everything Solidoodle suggested as well.
Last thing that keeps me suspicious is this thing marked with red arrow.

Maybe it is bending the rod slightly, or something.
]]> jaques Printing Thu, 30 Oct 2014 02:22:27 -0400 https://reprap.org/forum/read.php?262,424330,425981#msg-425981 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425981#msg-425981
Let me know if you still have this issue and I will try to walk you through it the best I can. Take care.

Romel]]> Anonymous User Printing Wed, 29 Oct 2014 17:14:48 -0400 https://reprap.org/forum/read.php?262,424330,425696#msg-425696 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425696#msg-425696


here's a video showing the extruder printing circle and a close up of the y motor at the same time.
[www.youtube.com]
]]> jaques Printing Wed, 29 Oct 2014 06:16:40 -0400 https://reprap.org/forum/read.php?262,424330,425456#msg-425456 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425456#msg-425456 To me the extruder head also seems to go a bit higher than it should before the "peak" and a bit lower when drawing the circle from top to bottom respectively. Or maybe its lower than it should be in the middle.]]> jaques Printing Tue, 28 Oct 2014 15:48:00 -0400 https://reprap.org/forum/read.php?262,424330,425441#msg-425441 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425441#msg-425441
See the attached diagram I generated from a spreadsheet model of backlash. This was for a backlash of 5% of the radius. (i.e. a 20mm dia circle would look like this with 0.5mm of backlash in the system).

If anyone wants to play with it I've uploaded the spreadsheet to my website: [silent9.com]

-Rob A>]]> RobA Printing Tue, 28 Oct 2014 15:17:28 -0400 https://reprap.org/forum/read.php?262,424330,425410#msg-425410 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425410#msg-425410
Quote
RobA
No, it is clearly x axis backlash.
Im asking this because Im a newbie: if its an x axis backlash it means the problem is with the x belt or motor?

Quote

or flex in the attachment point of the belt to the x carriage
Those holders seem to be as tight as I can get them too.

Quote

or a loose gear on your stepper that walks back and forth slightly on the shaft when changing directions
You mean inside the X motor? Sure hope not.

Quote

gear/belt slip (are they printed gears or machined gears?)
gears (pulleys) are not 3d printed.

Quote

or mechanical slop in your carriage that lets it rock
I dont think I understand this.

If a video of something will help, let me know what I should record and I'll upload a video.]]> jaques Printing Tue, 28 Oct 2014 14:12:11 -0400 https://reprap.org/forum/read.php?262,424330,425393#msg-425393 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,425393#msg-425393
Quote
jaques
That's a very good explanation, and something I was thinking about myself before.
However, I've made the belts as tight as possible (more causes binding) and as loose as possible. Results are the same.

I also don't notice any slack on the belts while printing those parts.

I've also printed the same circles at 50% and 150% speeds with the same results, if this helps.

Could it be a power supply issue? The stock power supply has problems running the fans and lights at full speed and brightness respectively when printing and when I turn on print bed heating and hotend heating to prepare for printing, the fans slow down and lights dim. Don't know if the motors get enough power and what happens in practice when they don't.

One last thing I havent tested and adjusted are the stepper chip voltages on the motherboard. Could that affect this? I don't know electronics and so i don't know what setting more or less voltage to the y stepper can result in.

No, it is clearly x axis backlash. It could either be in the belts (but you say those are tight) or flex in the attachment point of the belt to the x carriage, or a loose gear on your stepper that walks back and forth slightly on the shaft when changing directions, or gear/belt slip (are they printed gears or machined gears?) or mechanical slop in your carriage that lets it rock, or a loose hot end that is rocking slightly. Those are the main issues with backlash (I've had them all at one time or another).

-Rob A>]]> RobA Printing Tue, 28 Oct 2014 13:20:58 -0400 https://reprap.org/forum/read.php?262,424330,424986#msg-424986 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,424986#msg-424986 However, I've made the belts as tight as possible (more causes binding) and as loose as possible. Results are the same.

I also don't notice any slack on the belts while printing those parts.

I've also printed the same circles at 50% and 150% speeds with the same results, if this helps.

Could it be a power supply issue? The stock power supply has problems running the fans and lights at full speed and brightness respectively when printing and when I turn on print bed heating and hotend heating to prepare for printing, the fans slow down and lights dim. Don't know if the motors get enough power and what happens in practice when they don't.

One last thing I havent tested and adjusted are the stepper chip voltages on the motherboard. Could that affect this? I don't know electronics and so i don't know what setting more or less voltage to the y stepper can result in.]]> jaques Printing Mon, 27 Oct 2014 12:52:23 -0400 https://reprap.org/forum/read.php?262,424330,424829#msg-424829 Re: cant print proper circles https://reprap.org/forum/read.php?262,424330,424829#msg-424829 polyglot Printing Mon, 27 Oct 2014 06:42:07 -0400 https://reprap.org/forum/read.php?262,424330,424330#msg-424330 cant print proper circles https://reprap.org/forum/read.php?262,424330,424330#msg-424330

The extruder makes sharp turns at 5 oclock and 11 oclock. Red dots in this illustration,


The printer prints this circle counterclockwise. Red dot 1 in this image is when the Y motor has slowed down and started rotating the opposite direction (to go up), Red dot 2 is when the Y motor has slowed down and started rotating the opposite direction again (to go down). I say this after dozens of experiments with printing circles and checking the motion of the X and Y motors when these sharp turns/dents/bulges happen. So the sharp edges on the circles happen when the Y motor has slowly stopped rotating on one direction and starts rotating the opposite direction. This might give you a hint on what is wrong.
If the same issue was with the X motor, the areas in green circle (point where X motor starts rotation in the opposite direction) I think would be deformed instead and they are not.
]]> jaques Printing Sat, 25 Oct 2014 19:17:35 -0400