Design measuremen and actual measurments don't match

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daveinhull
Posts: 66
Joined: Fri Jan 11, 2013 2:31 am

Design measuremen and actual measurments don't match

Post by daveinhull »

Hi,

I've been trying to print the parts for the filement reel holder but when finished the 25mm tubing wouldn't fit into the holes on the parts. So, only having the g-code and therefore not completely sure what the actual diameter was, I designed my own using Creo Elements and then printed one of the lower support parts. The hole on the design was exactly 25.2mm but the printed part came out with a hole diameter of 24.3(ish, it varied a little).

Anybody else seen this or anybody got any ideas why it might be happening?

Many thanks
Dave

kerstens
Posts: 10
Joined: Tue Oct 16, 2012 4:23 pm

Post by kerstens »

Hello Dave,

I have the same issue!

regards,

Kerstens

daveinhull
Posts: 66
Joined: Fri Jan 11, 2013 2:31 am

Post by daveinhull »

Hi Kerstens,

Glad I'm not the only one - are you also using Creo Elements as the design tool? Anybody else using this design tool? Anybody else seeing the same issue and not using Creo Elements?

Would help to narrow down the potential cause?

Thanks
Dave

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

daveinhull:

Strange that the difference between designed and actual dimension is so big.

I am definately no expert on this subject, but here are my input:
- Actual filament dimension deviating from specified dimension specified in slicer profile
- Faulty slicing algorithm - I have seen reports of trouble with inaccurate dimensions with Slic3r
- If the cylinder is vertical and starts at the first layer of the print the filament could be squeezed - resulting in hole diameter becoming less than specified (the cylinder might have the correct diameter further up in the print)
- Steps per unit wrong in firmware (this should not be the cause since "all" Felix printers are "equal" and Guillaume has prefilled the values in the firmware)

daveinhull
Posts: 66
Joined: Fri Jan 11, 2013 2:31 am

Post by daveinhull »

Hi Kjetilei,

Thanks for your feedback. I am using Slic3r at the moment as I'm still having trouble getting SFACT to work so that might be a cause worth looking into.

I'm currently working in Spain :) but when I return home I need to try the new version of RepetierHost (v0.83) that Guillaume has just put up on the forum to see if I can get SFACT working and then test the dimensions again.

Also, I'll check the dimensions from top to bottom of the hole to see if its varying as it prints.

I'll also check the actual filement size using a micrometer to see what its like.

Thanks again
Dave

daveinhull
Posts: 66
Joined: Fri Jan 11, 2013 2:31 am

Post by daveinhull »

Hi,

Just an update on this topic. I've now got the SFACT slicer working and have tested the same part printed using that slicer and it appears, give or take a hundredths of mm which is too be expected, to match the design measurements - so I guess it must be related to the Slic3r slicer?

Dave

jjelier
Posts: 4
Joined: Thu Jun 27, 2013 7:38 am
Location: Holland - Utrecht Area

Post by jjelier »

Hi,

I have a the same problem, but only in the Y-direction with my Felix 2 printer. The Y-dimension of the print are larger than designed (for example 106 mm in stead of 100 mm). The X-dimension is perfect. I adjusted the steps per unit in the firmware, that more or less works. I mean that for big prints, the Y-dimension is still too large (101 mm in stead of 100 mm), but too small with small prints (29mm in stead of 30mm) again, the X-dimension is always perfect.

I tried several slicing applications, but have the same issues with every slicer. Besides that, I had to change the steps per unit already for the 3rd time. The x-stepper motor has 76,20 the Y- stepper motor has now 67,00. I think the tension in the belt is ok.

What could be the cause? Should I change the stepper motor? Or could there be another cause?

Thank you in advance.

Jos

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