Rambo FSR's

[Qdeathstar]

Does the Rambo work with FSRs or do FSR's require a duet or smoothieboard to work? If I can use them with the Rambo it's an upgrade I can do soon, otherwise I'll have to wait. I did a search on hear and it seems like most of the fsr discussion is directed towards them working on a duet, while the one topic I did see about Rambo/fsrs was that they didn't do much together.

[Jimustanguitar]

The FSRs are wired in such a way that they just appear to be an endstop. You can wire them to any system that allows a Z minimum endstop. In the case of the Rambo, you have to do a slight firmware tweak to enable probing, but after that it'll work with the board and firmware, yes.

NOTE:
The autocalibration routine that everybody's raving about is baked into the RepRap firmware that the Duet board runs. AFAIK there isn't a way to run it on a Rambo board right now.

[Xenocrates]

AFAIK, there is no easy solution (Beyond OpenDACT, which is it's own can of worms. The dev seems to have tried and tried to patch up all the issues, but it seems the walls are falling down and the emperor has no pants). One would think that in theory since the ERIS can use an SPI based accelerometer to do calibration that a simple endstop based solution would work, but I'm not aware of anyone getting that working, nor have I seen a build of the firmware for it yet (I will probably go looking soon, despite having no functional rambo, just for troubleshooting resources). I'm basing it solely on the theory that if there's a more complicated version that works, it should be possible to get a simpler one working too.

[Qdeathstar]

yeah, but it doesn't seem like the Eris' autocalibration is full proof. Oh well, Working on a heated enclosed right now


my next upgrade will be an aluminum heat spreader/pei sheet once the enclosure is done, but I guess I'll have to wait a little longer for autocalibration...

[DeltaCon]

Yeah, it is quite silent on the OpenDact front... However it turned out rather nice for me in combination of the fsr's.

However the FSR upgrade in itself is worth the small price even without auto calibration. It takes the hassle out of z-leveling, and also gives accurate data needed for manual calibrations. However I too hope there will be an Iris-like firmware for the Max once the accelerometer upgrade gets introduced. That will most certainly be very helpful for fsr setups too! The duet is of course a very nice upgrade, but not very cheap...

[mhackney]

Gents, David Crocker - author of the auto cal in RepRapFirmware - has a web-based standalone version that is exactly the same code under the covers. It works and it's fast. http://escher3d.com/pages/wizards/wizarddelta.php

[DeltaCon]

Gents, David Crocker - author of the auto cal in RepRapFirmware - has a web-based standalone version that is exactly the same code under the covers. It works and it's fast. http://escher3d.com/pages/wizards/wizarddelta.php

Indeed mhackney, and glad to hear from you again!
I tried this some time ago with very varying results. I guess my mind is not capable to do negation consequently right after 20 or more iterations...

[mhackney]

That's the painful part - collecting the data. Once that's done, the web interface works great. But that's why we use FSRs and other probing devices! FSR probing and Duet autocalibration work so well that I run it several times a day on each of my working printers.

[Jimustanguitar]

FSR probing and Duet autocalibration work so well that I run it several times a day on each of my working printers.

Are there any setting that you could manually capture and add to the config files to have a reasonably close calibration at startup?

[mhackney]

Not sure what you are asking Jim?

You can certainly run auto calibrate and capture the calibrated settings and copy/past info (2 lines) to the config.g file. That way the next time you reboot the printer, you have the latest calibration. But it is so fast that I can calibrate faster than copy/paste!

The editing can be done in the Duet Web Interface directly on the Settings->Configuration file. Here are the 2 lines in config.g:

Code: Select all

M665 R133.87 L269.0 B120 H372.57 X0.194 Y0.72 Z0.00		; set delta radius, diagonal rod length, printable radius and homed height
M666 X-0.32 Y-0.09 Z0.41		                           ; put your endstop adjustments here, or let auto calibration find them

After you run auto calibrate, go to the G-Code Console and execute M665 and then M666. Without parameters, these will return the current settings (which got set with auto calibrate). EasyPeasy!

[Jimustanguitar]

You nailed it. I wasn't sure what parameters the calibration effected, I just knew that it didn't 'save' them. If it's just those two lines, that's quite simple.

I'm curious because I end up with intermittent results sometimes. This way I'll be able to spot the outliers and track down what might be happening.

[geneb]

The auto-cal on the Duet is so fast, I don't even bother recording the values. I just issue a G32 before each job.

g.

[Qdeathstar]

op wants to know about his Rambo, not how nice your shiney duet is! FFS.




:p

[mhackney]

@Qdeathstar, at this time there is no firmware that runs on RAMBo for delta auto calibration. You can play with Marlin (various branches) but I tried multiple times and gave up. Repetier is worse. So if you intend to keep your RAMBo your best options are:

1) manually calibrate - many of us did that for years
2) use the Duet web calibration that David graciously developed and put on line

Those really are your best options. You can play around with OpenDACT if you'd like to experience true pain.

[Qdeathstar]

^thanks.


maybe lol just wait on messing with the heatbed/autocalibration until I can get my hands on a duet... I hear there is a new version comming out soon, so I might as well wait for that.

[IMBoring25]

It's out, for pre-order...

https://www.duet3d.com/DuetWifi

[DeltaCon]

You can play around with OpenDACT if you'd like to experience true pain.

Can you elaborate on this? I know the OpenDact thread is a really long one, with a lot of trouble in it. I experimented myself with this but all the trouble I had with it was from my pre-FSR-era trying to do a "manual-autocalibration". Once I got the FSR's installed correctly (and put my pc into US locale settings...) it worked like it should. The calibration calculations are exactly the same to the ones in DC42 firmware and the ones in the Escher webpage you suggested a few posts back (as far as I understood).

While I agree with you that it is great to have sensible calibration before each print and that OpenDact is not the way for that, I think it suits the need of incidental calibration just fine for the moment. It kept me from spending a lot of money on a Duet upgrade. I guess I'll find out if I should be happy about that after I get a Duet...

Anyone that feels the urgent need to migrate from Duet 0.8.5 to the Duet Wifi is welcome to offer me his best price for the old one

[geneb]

op wants to know about his Rambo, not how nice your shiney duet is! FFS.

Well excuuuuuuuuuuuuse me!

g.

[DeltaCon]

op wants to know about his Rambo, not how nice your shiney duet is! FFS. :p

OP can start his own thread! Oh wait...

[mhackney]

You can play around with OpenDACT if you'd like to experience true pain.

Can you elaborate on this? I know the OpenDact thread is a really long one, with a lot of trouble in it. I experimented myself with this but all the trouble I had with it was from my pre-FSR-era trying to do a "manual-autocalibration". Once I got the FSR's installed correctly (and put my pc into US locale settings...) it worked like it should. The calibration calculations are exactly the same to the ones in DC42 firmware and the ones in the Escher webpage you suggested a few posts back (as far as I understood).

While I agree with you that it is great to have sensible calibration before each print and that OpenDact is not the way for that, I think it suits the need of incidental calibration just fine for the moment. It kept me from spending a lot of money on a Duet upgrade. I guess I'll find out if I should be happy about that after I get a Duet...

Anyone that feels the urgent need to migrate from Duet 0.8.5 to the Duet Wifi is welcome to offer me his best price for the old one

Sure, firstly I have NEVER been able to get it to calibrate any of my machines. Constant crashes, crashing heads into my expensive PEI bed surfaces, computer hangs, etc. Secondly, it changes steps/mm and other parameters that, in my opinion and many other's, should not be changed as part of calibration, thirdly - and I haven't looked at OpenDACT for several month - it is not based on DC42's auto calibration code. (and I just went to the OpenDact thread and searched it to see if this might have changed and found nothing). Only the "Escher" web page uses DC42 code as that is actually David's web site. Finally, in the early days of OpenDACT I jumped in to help out with the coding. All of the communication coding was broken (it wasn't surprising that people couldn't connect to their machines), I reorganized it, made many suggestions to the author for modifications needed to prevent deadlocks and other issues and he basically proceeded down his own path of "NIH". I finally realized this and discovered DC42 firmware, and moved on. I don't want this to be a flame war, I appreciate the author's intentions but frankly, he is inexperienced and takes the "throw something new in there" approach to software development without shoring up the foundation. David is at the other end of the extreme, he is a professional software developer (as am I) and has a great understanding of delta kinematics. He developed the kinematics in DC42 firmware that calculate every point of movement rather than the segmented movement other firmwares use. He gets it, his auto calibration not only makes sense from a conceptual perspective (least-squares fit), it actually works very well in practice.

And to sum up, OpenDACT's author has not contributed since 2/20/16 and read the most recent post from a "user" from 6/22/16:

"I'm having issues using this tool. I can connect it to my Kossel, load my EEPROM settings in the advanced section, and I make sure that the probing method is Z-Probe, but when I check hieghts, it crashes into the build plate and wants to keep going. Any idea as to what might be causing this?"

This is exactly the kind of problems I had - and I had the source code to debug what was going on at the time. I have not looked at the source for many months but can't imagine it has improved much.

As I sit here ready to click "Submit" I'm torn about having my position be perceived as "negative". It isn't meant to be, I'm a pragmatic scientist and try as best as possible to be objective and base my comments on facts, experimentation and results. But, it really bothers me that so many people have lost so much time (and even damaged their printers and print surfaces) that this nonsense has to be stopped. OpenDACT is a Grail, people WANT it so bad they believe it. But today there are options that actually work and do so in 1 iteration very quickly:

for off-printer auto-calibration: http://escher3d.com/pages/wizards/wizarddelta.php
for firmware-based auto-calibration: RepRapFirmware (either DC42 or CH's forks - they both use David's code)

There may be others, I've heard of a Smoothie port for instance, but these are the 2 I know about and have personal experience with.

[DeltaCon]

That's elaborate enough, thanks!

I share your opinion on the problems, and I had a few of those myself. So it is not that I think you are negative. Your opinion is a firm base on which others around here form there own (including me), so it is much appreciated. It is a pitty though that no-one is picking up on the idea of a calibration app outside of the firmware. The development seems to be dead indeed. I think it COULD work very nice, but I lack the skills to code.

[mhackney]

So to change the subject just a bit...

I've been running FSRs on all 7 of my delta printers. I only have 1 Rostock Max though, the others are mini Kossels and Kossel 250s. I get EXCELLENT calibration results on those smaller printers and acceptable results on the Max. But in the pursuit of perfection it has been driving me crazy as to why the Max doesn't quite calibrate as well (DC42 on Duet returns a deviation value that can be used to determine the fit). Earlier this week I slowed waaaay down and watched and discovered that as the nozzle touches the first point on the outer perimeter of the bed, that it actually slides outwards (laterally) a fraction of a mm. At first I thought this might be because I have a 4 nozzle Kraken and the nozzle I use is off center to the effector towards where that first probe point is. So I took this as an opportunity to make some changes I've wanted to make. Here's what I did:

• replaced the Kraken with an E3D V6 with a water cooled jacket
• replaced the stock effort (a V1 even) with the TrickLaser milled aluminum effector
• replaced the arm cross pieces on the carriages with the TrickLaser parts. The carriages had been previously replaced with TrickLasers last year

So now, with the nozzle dead center on the effector, I didn't expect there to be a problem. But, I am still observing the nozzle sliding slightly when the probe touches. I've tested for backlash (basically none) and rotated all carriages and arms but the problem persists. I've also verified that my FSR mounts are free and trigger reliably with very little tapping force. This is driving me nuts! I'm about ready to implement a new mount system that constrains in the X-Y plane and not overly constrained like my original mounts. I run a fairly heavy bed on my Max that has the snowflake, Onyx, aluminum heat dissipator, glass and PEI so the mass may be affecting sensitivity.

Has anyone else observed this?

[Mac The Knife]

If all of the mechanicals are tight, I'd be looking at belt stretch. According to the Gates literature, polyester reinforced belts have 14% elongation at break. Kevlar or glass is 2.5% elongation at break. The longer the belt, the longer the stretch,

[mhackney]

Ah! Good idea. I suspect my belt on the X tower (where the first probe point is located) is a bit loose. Certainly worth investigating.

[mhackney]

@Mac The Knife - you nailed it I think! I tightened up the suspect belt and the calibration fit improved. I still have a bit of observed movement but the belt is also a bit looser than I would like. I think this is the right track though.