1

Topic: circle tolerances

I have replaced the x/y rods and carraiges,belt tensions appear to about equal.   I just can't get a Perfect circle, best I got so far is .13mm  out of round.Am I too picky?  LOL

SD3, E3D hotend,linear bearing on x/y axis',pillow block bearing on y conneting rod, ball bearngs on front y axis, fan on y stepper motor.

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Re: circle tolerances

Depends on what "out of round" means :-). If you are getting nice smooth ovals rather than circles, maybe you just need to adjust steps per millimeter in either X or Y? On the other hand if the end point isn't joining the start point, privan's gadget worked well for me:

http://www.soliforum.com/topic/8357/y-s … belt-slop/

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Re: circle tolerances

I have replaced the x/y rods and carraiges,belt tensions appear to about equal.   I just can't get a Perfect circle, best I got so far is .13mm  out of round.Am I too picky?  LOL

yea wher is the deviation you should measure in 4 places not 2.
also would not hurt to run a cube.  if the sides of the cube are not equal you will want to adjust steps.

+- 0.005 inches is a pretty standard general machining tolerance.
if you want to build a working steam engine with your print you may want a more precise round circle.
General carpentry plus minus 1/8 .125 in
Finish carpentry +- .0625
Cabinet makers +- .032
Machining layout +-.015 in
A lot depends on what you are doing with your parts you make and how precise you need it.
There is an old saying in machining precision is expensive and not always a good value.
Young engineers often specify a higher tolerance than what is needed . and this increases the cost of machining.
Additive manufacturing is a bit different. once the part is made you can not add a lot .

comes back to how precise does it need to be how much time do you want to spend tinkering and would you rather just use the printer.
Tin

Soliddoodle 4 stock w glass bed------Folger Tech Prusa 2020 upgraded to and titan /aero extruder mirror bed
FT5 with titan/ E3D Aero------MP mini select w glass bed
MP Utimate maker pro-W bondtech extruder
Marlin/Repetier Host/ Slic3r and Cura

4

Re: circle tolerances

Maybe this might not make any sence but here goes. Has anybody Plucked the belts and listened for the sound it makes?.Equal tension should make the same sound. LIke tuning a guitar.I have a TIN ear so I can't realy tell.

SD3, E3D hotend,linear bearing on x/y axis',pillow block bearing on y conneting rod, ball bearngs on front y axis, fan on y stepper motor.

5

Re: circle tolerances

satman49 wrote:

Maybe this might not make any sence but here goes. Has anybody Plucked the belts and listened for the sound it makes?.Equal tension should make the same sound. LIke tuning a guitar.I have a TIN ear so I can't realy tell.

if belts resonate then they are too tight ;^P

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs

6

Re: circle tolerances

satman49 wrote:

Maybe this might not make any sence but here goes. Has anybody Plucked the belts and listened for the sound it makes?.Equal tension should make the same sound. LIke tuning a guitar.I have a TIN ear so I can't realy tell.

That has been discussed at length and is how I adjust/tune my belts and also fish line.  I would disagree with the statement "If your belts resonate they are too tight".  I would take that one further and say if they don't resonate they are too loose.
All that being said, I think we all have valid ideas and things that work for us and our printers smile
Find what works for you and stick with it.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

7

Re: circle tolerances

Gates makes or markets a belt tension tester based on resonance. Way too pricey for hobby use.
Tin

Soliddoodle 4 stock w glass bed------Folger Tech Prusa 2020 upgraded to and titan /aero extruder mirror bed
FT5 with titan/ E3D Aero------MP mini select w glass bed
MP Utimate maker pro-W bondtech extruder
Marlin/Repetier Host/ Slic3r and Cura

8

Re: circle tolerances

thats for commercial use belts like on HVAC blowers with much stronger shafts and bearings with steel pulleys. high tension on an SD 3d printer can bend or break components.

they also make belt tension deflection measuring tools for those applications

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs