is it normal for printer to make a big rattle noise every time its

3D Printing
,
1

is it normal for printer to make a big rattle noise every time its turned on? also my z axis goes up and down just fine pressing the manual button but when i click home it makes a nasty noise again. any idea why? i also can’t seem to ssh into my board. every time i do i get this
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
51:bd:d2:e1:fb:ea:1f:4e:84:c2:a0:7d:79:01:10:50.
Please contact your system administrator.
Add correct host key in /Users/admin/.ssh/known_hosts to get rid of this message.
Offending RSA key in /Users/admin/.ssh/known_hosts:3
RSA host key for 192.168.1.11 has changed and you have requested strict checking

2

Edit your .ssh/knownhosts and go to the line mentioned and delete it. If you ssh’d into a system with the same IP address it will remember it and complain.

3

how can i get to that file? i searched for it but can not find it.
must i always delete every time i want to ssh into it?

4

What computer OS are you ssh’ing from?

5

mac os 10.9.5

6

also, after raising the usteps all the way up theres no more high pitch noise. but my stepper motors are real hot! is that bad?

7

From the command prompt type in:

vi .ssh/known_hosts (and then enter)
Press :3 (then enter)
Press dd (two d’s) the the line should go away.
Press :wq (then enter)

Try the ssh again.

8

i types vi ssh/knownhosts and got this…

~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
– INSERT –

9

i tried typing vi. ssh/knownhosts, exactly what you typed but it said command not found
so i tried various combinations and this was the only one that worked. vi ssh/knownhosts

10

Sorry, I editors the comment right after, use known_hosts, also your current is set too high in your config. You need to figure the correct settings but I would set them all to 0.3 right now until you figure it out.

11

@Hauvert_Pacheco that is

vi .ssh/known_hosts

12

@Hauvert_Pacheco My motors have a current spec of 1.2 Amps per phase, I started setting them to half that: 0.6
I ended up with x,y set to 0.8, z set to 1.0 (i have two z motors connected together driven by the z driver alone. if I set the z to 1.2 amps, I get an Alarm from redeem) and E up to 1.0

Microstepping for x,y and z is 8 and for e it’s 7

13

@James_Armstrong so i delete it the txt but how can i save? if i close the window and try to ssh the same warning appears. i must not be saving it or deleting it right

14

Read this: http://labs.hoffmanlabs.com/node/1116 to help understand ssh. What you are seeing is caused by flashing the BBB with a new image, resulting in a “new” computer that ssh doesn’t trust by default. You can reduce the security (not really recommended) or simply delete the old entry.

As others have said, your motors are running way too much current. Running them hot for too long will damage them.

15

I’m pretty sure the current is half what you would normally use or at least in RMS. I am running 1.5 amp motors with the 0.5 setting. Elias would have to chime in. I don’t think the setting is exactly 1 to 1 (like you said, I would normally run 1 amp or so but entering in 1 is way too high for this setup).

16

Yes, the current, decay and the microsteps for these drivers is a bit new to me. Specially the microsteps. Being used to the Arduino boards with Pololu drivers and Marlin firmware, I usually do 1/16 micro stepping like everyone else and that’s it. These drivers setting of 8, which is 1/16 microstepping, Stealth chop and interpolation down to 256 microsteps is totally new to me.
It’s the only setting that eliminates the motors from making a high pitch hissing noise.
It seems to be working fine, though. I have been running a test print for 6 hours and the steppers are warm but not unreasonably. Any guidance about current/microsteps/decay from Elias is always welcome!

17

Try this: http://dkc1.digikey.com/us/en/tod/STMicroelectronics/StepperFundamentals_NoAudio/Stepper_Fundamentals_NoAudio.html

18

i wasn’t able to delete with via terminal but i was able to find the ~/.ssh/known_hosts file and i simply edit it with textedit and it worked. now i just need to figure out how to change the current

19

It’s in /etc/redeem/. How did you set the current so high in the first place??

20

too be honest i don’t know how i could have. i was able ssh the first time but did nothing because it was still the beagle board. once i flashed it couldn’t figure out how to ssh again because i kept getting that warning.