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Topic: Permanent bed calibration?

Constantly fiddling around with calibrating the bed seems to be something everyone hates.

I'm wondering what causes beds to become misalligned in the first place. If the bed is solidly mounted on a solid platform, why would it not stay forever calibrated after being done once?

Is it the spring mounted set up that gets out of wack?

What I was thinking about was what if after getting a bed dialed in using the spring set up, measurements were taken at all four corners and the springs were replaced with custom length sleeves, snugged down with lock nuts?

Would that work or am I missing some other factor that affects calibration?

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Re: Permanent bed calibration?

I think it just gets out of wack mainly by being shipped thousands of miles on UPS trucks. Once I made my dial indicator railmount (http://www.thingiverse.com/thing:171900) I was able to get the bed actually level and it hasn't really been a problem since then. 90% of my fiddling with it was because I didn't have the right tool to fix it correctly :-).

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Re: Permanent bed calibration?

Would that work or am I missing some other factor that affects calibration?



From What I see the sodid doodles are a bit flexible in some of the design features.
the bed holder is subject to twist and flex. and right t end of the x axis rods assembly hangs as it pleases.
So  in the event of an accidental crash things move rather than break. so you need to figure out what moves and correct it.

I found placing a level on the top of the x asis rods and leveling them out solves some of the issues I had, one being exceive movement /slp on the extruder.

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

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Re: Permanent bed calibration?

The solidoodle print platform is pretty wobbly, having adjustment is kind of necessary.
Even with a really rigid setup, I'd like to be able to tune out the last tiny bit at the bed, particularly if using a removable bed surface like glass...

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi

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Re: Permanent bed calibration?

Thanks for the replies. I'm currently working on putting an Ord Bot together. As near as I can tell at the current stage of construction, it seems to be a very solid platform. While it's possible to wiggle the bed a little bit, to get movement it takes more fingertip pressure than you'd ever get from printing. There isn't much doubt that the kind of vibration generated by a printer moving about is the sort that has the potential to cause screws to loosen. However, the screws that appear most inclined to be loosened by vibration are the spring loaded ones used to support the bed.

At the end of the day, I suppose the only way to tell if it's possible to permanently calibrate a bed using custom length sleeves is to try it and see how it works. I was curious if anyone else had tried experiments along those lines or if there was information available suggesting it would not likely work.

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Re: Permanent bed calibration?

Don9mm wrote:

Thanks for the replies. I'm currently working on putting an Ord Bot together. As near as I can tell at the current stage of construction, it seems to be a very solid platform. While it's possible to wiggle the bed a little bit, to get movement it takes more fingertip pressure than you'd ever get from printing. There isn't much doubt that the kind of vibration generated by a printer moving about is the sort that has the potential to cause screws to loosen. However, the screws that appear most inclined to be loosened by vibration are the spring loaded ones used to support the bed.

At the end of the day, I suppose the only way to tell if it's possible to permanently calibrate a bed using custom length sleeves is to try it and see how it works. I was curious if anyone else had tried experiments along those lines or if there was information available suggesting it would not likely work.

The concept is interesting; especially considering the stability of the Ord Bot; but I think one of the other challenges will be the ability to adjust the build surface for equidistance across all corners X through Y in relation to the nozzle. There are still factors of Z screw differences affecting the X carriage and the Y Makerslide being off a bit as well, throwing the build platform at least a few thousandths of an inch in one extreme to another.  A difference of even .004" from one side to the other may begin to affect the print adhesion.  On an 8" plate, it does not take much to cause that...

SD2 - Stock - Enclosure - Heated Bed - Glass Plate - Auto Fire Extinguisher
Ord Bot Hadron - RAMPS 1.4 - Bulldog XL - E3D v6 - 10" x 10" PCB Heated Build w/SSR - Glass Plate
Thanks for All of Your Help!

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Re: Permanent bed calibration?

IronMan, I'm not sure if I completely understoon your post, but if you're saying it'd take some rather fine metal work to get it right, yeah, that crossed my mind also.

On print adhesion, I've played around a bit with Cura software. One of the things you can do with it is set it to put down a thicker first layer. For example, if you want a fine print of .1mm, you can still set it to put the first layer down at .04mm, or about .016". Like you say, if you're printing at .1mm and the print bed is off by .1mm (.004), I can see where it might cause problems if the first layer isn't going down thick enough.

It'll be interesting to see where the technology goes over the next few years. IMO, it's very comparable to personal computers and Windows 95 two decades ago. My first computer had a 1.7 gig hard drive, which was thought to be kind of wonderful at the time. Today you can squeeze more memory than that on a card the size of a thumbnail.

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Re: Permanent bed calibration?

I do think it is worth trying...but yes, the spacers would most likely have to be custom machined for a specific length at each corner to compensate for angular discrepancies...but once you get it nailed down, I do think the rigidity of the Ord Bot design could maintain itself quite well.

Perhaps the spacers could actually be a "screw within a screw"...mini screwjacks!

SD2 - Stock - Enclosure - Heated Bed - Glass Plate - Auto Fire Extinguisher
Ord Bot Hadron - RAMPS 1.4 - Bulldog XL - E3D v6 - 10" x 10" PCB Heated Build w/SSR - Glass Plate
Thanks for All of Your Help!

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Re: Permanent bed calibration?

IronMan wrote:

I do think it is worth trying...but yes, the spacers would most likely have to be custom machined for a specific length at each corner to compensate for angular discrepancies...but once you get it nailed down, I do think the rigidity of the Ord Bot design could maintain itself quite well.

Perhaps the spacers could actually be a "screw within a screw"...mini screwjacks!

Hmmm... An interesting thought. I get a picture in my head of a sleeve with something along the lines of male and female pipe threaded fittings. Just slap some loctite on the threads, and go around to each corner to swap out the springs with an adjustible sleeve. I'm not 100% sure, but somewhere in the back of my mind I think I've seen brass compression fittings that look sort of like what I'm thinking of. They're used for making connections on copper tubing and are hex shaped so they can be tightened. The next time I'm at a hardware store, I may poke around the plumbing section to see if they have something that might work or could be modified.

I like the idea and it'd sure be easier than going after a stock size sleeve with an angle grinder and a file.