Machine Holddown

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ming
Posts: 194
Joined: Wed Mar 12, 2014 2:06 am
Location: Georgia USA

Machine Holddown

Post by ming » Sun Apr 20, 2014 2:34 pm

Has anyone noticed surface quality improvements with the machine helddown ?

Observation:
I was printing on fast mode and a fairly coarse fill part. and the machine was making lots of noise (like keys left in washing machine :lol: ) [Ok i exagerated]. and when i press down on the front of the machine the noise was still there but i felt like the machine needed some (holddown) force to prevent movement/vibration during printing. I did not notice the surface was any better but i was priniting on fast coarse mode.

My intuition says if the machine was more balanced or a tad more massive it will help with print quality. Our machine is top and rear weight bias. Kind of a opposite to low and center for stability.

Question:
What do you guys/gals think if its necessary or beneficial to holddown the machine
Dream@night / Holdit@sameday

doraemon
Posts: 94
Joined: Wed Sep 19, 2012 3:37 am

Re: Machine Holddown

Post by doraemon » Mon Apr 21, 2014 4:01 am

Haven't really noticed much difference when it's tied down vs. not tied down (have run it strapped down to a concrete block). As long as the extruder and plate are in phase with each in terms of motion, it won't be a problem.

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Machine Holddown

Post by roller » Mon Apr 21, 2014 7:48 am

Nope. It doesn't improve print quality and can actually worsen print quality if you tie it down. The inertia of the print head passes into the body causing the whole machine to vibrate ... but as the axes are locked together they stay in position relative to each other while the whole machine rocks. If, on the other hand you tie the machine down the energy of the moving printhead is not dissipated in the rocking of the machine and instead results in ringing within the axes (slightly overcoming their interaxis rigidity) causing a degradation of print quality. It's hard to tell the difference in most prints but it is definitely there.

I suspected this was the case and had a chance to test it when one of the x-end brackets starts to fail which exacerbated the issue. The best print quality was actually achieved with the printer suspended on cord and the worst was clamped to a rigid desk. I actually sit the printer on a soft bed so it can vibrate happily and that vibration doesn't results in an annoying hammering on the corner of my desk.

ming
Posts: 194
Joined: Wed Mar 12, 2014 2:06 am
Location: Georgia USA

Re: Machine Holddown

Post by ming » Mon Apr 21, 2014 11:58 am

Thanks for all the replies.
I will start to look for soft isolation feet or pads or standoffs
Dream@night / Holdit@sameday

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Machine Holddown

Post by roller » Mon Apr 21, 2014 1:28 pm

When I travel with the printer I actually use the gloves to rest it on ... they do a great job. I take the gloves to stop people cutting their hands when they remove prints using the extremely sharp scraper :)

ming
Posts: 194
Joined: Wed Mar 12, 2014 2:06 am
Location: Georgia USA

Re: Machine Holddown

Post by ming » Mon Apr 21, 2014 4:48 pm

Good tip. If you were in USA
I would send you some gloves and other. Safety products

If anyone in the world send me a self address label (0.3 kg box) I'll be more than happy to send sample safety products to them. Gloves, eyewear, ...
Dream@night / Holdit@sameday

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Machine Holddown

Post by roller » Tue Apr 22, 2014 2:45 pm

The Up comes with a set of gloves ... these are the ones a I use.

ming
Posts: 194
Joined: Wed Mar 12, 2014 2:06 am
Location: Georgia USA

Re: Machine Holddown

Post by ming » Wed Apr 23, 2014 3:27 am

is hard to stop mind in motion, since i already made the part i might as well test it out (not to challenge the recommendations but since its available why not
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Dream@night / Holdit@sameday

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