Improving Rigidity?

[MSURunner]

I've been finding that there seems to be a lot of variability in my z height/bed level on a day to day basis. I just went and cut some acrylic to stiffen up the hot end adapter for the E3D over the printed parts I had in the past so hopefully that helps, but I'm suspecting there is some variability due to the rigidity of the frame itself. I'm okay making small adjustments in screws, but I don't want to have to track down zero everyday I want to print for twenty plus minutes. Thoughts?

[lordbinky]

Make sure the end stop screws are using the flat part of the microswitch lever, if not just move the microswitches over.

I removed the feet from my rostock and placed some cork board under it, then clamped the base to the table. I was having issues with not enough weight in the frame more than rigidity, although that still may be a small issue.

[Jimustanguitar]

It's also worth checking that your heated bed screws are snug.

Check the t-slot screws and top clamp too.

[geneb]

This is kind of weird. I've printed hundreds of parts on Orange Menace and I've only calibrated it once. I've changed the max Z when changing hot ends, but that's it.

Are your going to be at MRRF in March(?). Apparently I'm going. I wouldn't mind taking a look at your machine.

g.

[Flateric]

I'm finding that my machine is losing it rigidity a small amount over time as well. it's not a design flaw really in my opinion, but more an issue with the wood relaxing, the screws settling into/compressing the wood over time. Vibrations etc take their toll, it is not even something that can be denied from happening to ANY type of material into ANY machine that produces vibrations.

Snugging up your screws throughout the machine will help things a lot if your build was sometime ago.

I'm also currently exploring some additional mods to help with this issue, I'll let you know how they go soon.

[geneb]

Glue!

g.

[lordbinky]

Ate it all, and sniffing this paste isn't doing anything.

[MSURunner]

I'm not, unfortunately being a teacher that is still a year from tenure means I'm not really encouraged to pack up the school's equipment and take a couple days off from work and drive halfway across the country yet The new acrylic pieces seemed to have really improved some of the print quality issues I was having on the test piece I was printing today after class, but I missed on my retraction/flow settings on it so it hit a clump and tossed it off kilter (learning that the filament settings on this need to be much more precise than my Ultimaker). So it being two hours after I'm cleared to leave and having dogs waiting at home for me to come back, I'm calling it a night. I'll see if the machine was able to hold z tomorrow as I had it pretty close today.

For what it's worth, I've been chasing upgrades/modifications round and round to try to print at the same quality and reliability and repeatability in PLA primarily as the Ultimaker. I would also like to be printing in the nylons but don't really have any desire to print in ABS, which was what it seemed the sweetspot for which the Rostock was designed around. So mine's probably about 20% not Rostock Max anymore (Rev. 1 at least).

[bubbasnow]

print this and put it on the screw ends after adjusting

https://drive.google.com/folderview?id= ... sp=sharing

[Eaglezsoar]

print this and put it on the screw ends after adjusting

https://drive.google.com/folderview?id= ... sp=sharing

Simple but effective, thanks!

[GarageBay9]

This is kind of weird. I've printed hundreds of parts on Orange Menace and I've only calibrated it once. I've changed the max Z when changing hot ends, but that's it.

Are your going to be at MRRF in March(?). Apparently I'm going. I wouldn't mind taking a look at your machine.

g.

Wait, wouldn't different length hotends cause a change in delta radius? I had to recalibrate when I went from the stock hotend to the E3D v5.

[Jimustanguitar]

This is kind of weird. I've printed hundreds of parts on Orange Menace and I've only calibrated it once. I've changed the max Z when changing hot ends, but that's it.

Are your going to be at MRRF in March(?). Apparently I'm going. I wouldn't mind taking a look at your machine.

g.

Wait, wouldn't different length hotends cause a change in delta radius? I had to recalibrate when I went from the stock hotend to the E3D v5.

In short, nope. If the effector platform is moving in a straight level way, the hot-end could be an inch long or a mile and it would still move straight. If your arms or aluminum extrusions changed, that would affect your delta radius.

[geneb]

Yep, that's exactly right. When I drop in differently shaped nozzle that changes the height, I just stick it a paper width off the bed and do an M251 S2 and it's done.

g.

[MSURunner]

print this and put it on the screw ends after adjusting

https://drive.google.com/folderview?id= ... sp=sharing

And subtract the 5 or so mm for the top of the cap from your length, correct? If so, knowing the exact distance of that cap would be helpful

[MSURunner]

FWIW, the acrylic pieces seemed to limit much of the variability I was having around the hotend and the zero was very close today.

[626Pilot]

FWIW, the acrylic pieces seemed to limit much of the variability I was having around the hotend and the zero was very close today.

Can we see a photo of this acrylic piece?

I designed some tower alignment clamps but they are only intended for use with the Onyx and EZStruder dismounted. I have a backburner project to move the threaded rods outside the print radius, so that the clamps can be left installed with the bed and extruder. This would help alignment, and add some rigidity to the structure.

I also had the idea to take the Onyx's wooden standoff and mill a new version that extends all the way out to the towers and wraps around them, helping to hold them in place.

[bubbasnow]

print this and put it on the screw ends after adjusting

https://drive.google.com/folderview?id= ... sp=sharing

And subtract the 5 or so mm for the top of the cap from your length, correct? If so, knowing the exact distance of that cap would be helpful

These only help if you can currently print a decent object. I put them on, then start the calibration steps in the manual. when i need to make 1/4 turn to the screws i just slide the plastic stops off, turn the screw and slide them back on. because of the tight tolerances i have no play as they wrap around the screw so they go exactly back in place. My observations was, when i would turn the screw 1/4 turn without these, sometimes it would contact the micro switch in a different place... which would effect calibration. so with these, all of my screws contact the exact same place on the micro switch every time.

[Eaglezsoar]

Could you just epoxy them on the screws and leave them in place?
Makes a great way to turn the screw and increases reliability.

[bubbasnow]

Could you just epoxy them on the screws and leave them in place?
Makes a great way to turn the screw and increases reliability.

I like the idea of not having to remove them, im just not sure if the force required to turn the screws inside the cheapskates would break the epoxy bond of the metal to the plastic

[geneb]

What you might want to do is replace the pan head Philips screws with socket head cap screws. You'll be able to adjust them more easily and it wouldn't be hard to print a cap that would fit on the cap with a more positive lock.

g.

[Eaglezsoar]

What you might want to do is replace the pan head Philips screws with socket head cap screws. You'll be able to adjust them more easily and it wouldn't be hard to print a cap that would fit on the cap with a more positive lock.

g.

Excellent idea, now we need someone with cad skills to make it for us.
I can't even draw a circle that looks round.

[bubbasnow]

What you might want to do is replace the pan head Philips screws with socket head cap screws. You'll be able to adjust them more easily and it wouldn't be hard to print a cap that would fit on the cap with a more positive lock.

g.

Excellent idea, now we need someone with cad skills to make it for us.
I can't even draw a circle that looks round.

I've been using the ones i made and they work great, so i wont be purchasing any other types of screws. but if you get new screws thrown the dimensions on here and i can make something for ya

[MSURunner]

FWIW, the acrylic pieces seemed to limit much of the variability I was having around the hotend and the zero was very close today.

Can we see a photo of this acrylic piece?

[img]http://i.imgur.com/E9r0gyM.jpg[/img]
The entire effector plate can now be moved by moving the bowden clamp. Before that would have simply moved the nozzle about a bunch.

I designed some tower alignment clamps but they are only intended for use with the Onyx and EZStruder dismounted. I have a backburner project to move the threaded rods outside the print radius, so that the clamps can be left installed with the bed and extruder. This would help alignment, and add some rigidity to the structure.

My machine was ordered pre-Onyx so that's not a big problem and I have moved my Steve's extruder up above the top plate. Any idea on the impact of these?

I also had the idea to take the Onyx's wooden standoff and mill a new version that extends all the way out to the towers and wraps around them, helping to hold them in place.

I was thinking along the same lines and with another piece across the top that could tie the towers together up there and double as a mounting platform for the filament spool (kinda like the ones sold at tricklaser with a spool attachment integrated). But I didn't want to go waste school money on acrylic if the rigidity of the frame isn't my problem.

[626Pilot]

The problem isn't with the heated bed, but with the arms. You take the bed off in order to get the clamps as close to the bottom of the towers as possible, so they can help pull the towers toward center and add friction between them and the lower plate so they don't move around when you tighten them. The threaded rods cross directly over the printable area, so combine that with the width of the effector platform and you won't be printing anything over an inch wide. Up top it's even worse as you have the carriages to worry about. The redesign involves moving the threaded rods well outside the area where the carriages travel.

I also find that my bed height can seemingly change over time. I think this is because when I first turn the printer on and heat up the bed, the 1/4" oven glass I'm using may "heat up" in a few minutes, but it doesn't really get to equilibrium for a long time because the mass around the edges has more volume and gets less heat. The expansion probably takes around half an hour to play out, if I had to guess.

I don't think that is necessarily anything to do with the machine being loose. I used to calibrate with a depth gauge accurate to 1 thou, and it would always settle within half a thou of where it should, and the average of where it settles doesn't seem to move. I've done that so many times that now I can just use paper, and then observe the first layer of a .1mm layer print and adjust the screws by sight. I doubt that's any better than 10-20 thou of accuracy but it works just as well.

[0110-m-p]

now we need someone with cad skills to make it for us.

I got some CAD skills, just give me some specs and I'll crank it out.