Slow feed rate extruder

[Scott Turner]

I flipped the extruder motor cable at the RAMPs to fix the extrusion direction but now I am getting very slow rotation of the toothed pulley. It turns in the correct direction but 1mm takes about 15 seconds to execute. The max feed rate is set to 45mmps so it should whip the step pulses right out there to the motor.

The X, Y and Z motion is normal.

[John D]

I'm assuming you are setting 45m/s in your host program?  If so, it's worth checking your firmware and seeing what the max feed rate is for your extruder.

[Scott Turner]

I am speaking of the value returned from m503

I have adjusted it to 10000 just to see if it had any impact: none.

--
You received this message because you are subscribed to a topic in the Google Groups "trinitylabs-talk" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/trinitylabs-talk/9NLz7N0Seyg/unsubscribe?hl=en.
To unsubscribe from this group and all its topics, send an email to trinitylabs-ta...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
 
 

[Glenn Beer]

I hate to ask this but, Is the connector properly aligned on the ramps card. Not shifted one pin over.

[Scott Turner]

Yes sir, all plugged correctly. It now spins in the correct direction, just painfully slowly.

--

[Glenn Beer]

Does it go back to reversed, and speedy, operation if it is put back the way it was?

[Scott Turner]

Nope, still slow, even back the other way.

I've also done the restore to fail safe values.

[hellphish]

Scott, the firmware limits the max feedrate, it doesn't SET the rate. When you command the extruder to move forward, the log in your host should spit out a few lines. Can you paste them here and we can figure out what is going on?

--
You received this message because you are subscribed to the Google Groups "trinitylabs-talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email to trinitylabs-ta...@googlegroups.com.

[Scott Turner]

In this case I am attempting to load filament and cut off the extruded filament in preparation of hitting print eg I'm using the extrude button with some value between 1mm and 14mm selected in Ponterface.


Sent from my iPad mini 4G

[Glenn Beer]

Some bits of info from my limited experience.

If the hot end isn't up to temp, there is a software prohibition against extrusion.

If the temp set is a bit too low for the specific material, the extruder won't be able to push material thru.

If the pinch wheel is too tightly clamped, there is a risk that the extruder body will flex allowing the hobbed gear to rub against the back side. That can lead to anything from grinding material from the extruder body to outright stalling of the extruder motor. This will be evident if flecks of color corresponding to the extruder body appear on the hobbed gear, its setscrew or even in the teeth.

If there is to little pressure on the pinch wheel, the hobbed gear can grind material off of the side of the filiment, the teeth of the gear fill up and it becomes unable to grip the filament.

[Scott Turner]

Yep, all good points Glenn.

Right now the Trinity One is resting on it's side with a Kysan 5.5KgCm stepper plugged into the E on the RAMPs. The hot end is run up to 185C and Merlin quite happily makes the shaft turn as slowly as it did for the 50:1 gear head.

That bugs me since the 50:1 gear ration means it should be going like a 50X bat out of hell with the Kysan not the same sluggish rotation rate.

[hellphish]

Not helpful. Please run the command and paste the output from the log. Typically the host is setting the mode to relative, then issuing a move command, then switching back to absolute. I want to see this on your log before we try other troubleshooting tips. You can't control the printer from you ipad mini 4g, so maybe make your next post from the computer running the printer if you can.

[Arthur Wolf]

Hey Scott !

The stepper motor on the extruder has a 5.18:1 gear ratio, not 50. That could explain some of what is puzzling you.

Cheers.

2013/3/12 Scott Turner <scott.tu...@gmail.com>

--
Courage et bonne humeur.

[Scott Turner]

Hi Arthur,

Yep, sure would! Those darn pesky decimal points can be a challenge. Thanks!

I have also been seeing delayed results on the console for M503's I issue, as if Marlin had on lead boots.

I've built and used Marlin on RRD RAMPs for many different mechanical platforms and this is the first time I've seen this.

I would swap out for another one I have on the shelf but Trinity Labs hard wired the hot bed switch for the 400W Kapton heater directly to the RAMPs.

On Mar 12, 2013, at 13:02, Arthur Wolf <wolf....@gmail.com> wrote:

Hey Scott !

The stepper motor on the extruder has a 5.18:1 gear ratio, not 50. That could i 

[John D]

I"m confused - why would you swap it out before you diagnose the problem?  You have 100's of Nema17's sitting around, it would be trivial to simply plug on in and see if it turned 5x as fast as your geared stepper?  (It's a reduction geared stepper...)

[Scott Turner]

I was checking to see if the geared stepper had experienced some form of gear failure. I am thinking back to last night and while it wasn't the expected 50x faster it might have been 5x faster on the shaft spin rate (but I was too tired to process it at that time.)

[John D]

It's a reduction gearbox, isn't it?  It's going to be slower not faster.

[Scott Turner]

Right, so I hook a non-reduction stepper and it turns faster.

Sent from my iPad mini 4G

[Josh S]

Scott, one time I had slow movement of all the motors.  I unplugged the machine and reset it.  This solved my issue.    Also, I have found a high quality USB cable is required, as I had some issues using a cheap one.  

On Tuesday, March 12, 2013 4:33:41 AM UTC-7, Scott Turner wrote:

[John D]

Correct - but as I said earlier, the max rate is defined in the firmware.  The actual extrusion rate is set as normal in G-code using feed rate, so you can set it as you like, but it's never going to exceed what's defined in the firmware.

[Scott Turner]

Josh, i purchase a brand new 10 foot Belkin usb cable from Amazon Fresh for each RAMPs board as I put them into service.

Upon advice from someone else here I will be checking Ponterface to see if when I got "clever" and typed in -10mm to see if I could soft reverse the extruder motion I may have left a persistent skid mark on it's psyche. :-)

--

[Scott Turner]

Yes, I forgot the F on my G0 last night. I will re run the test tonight.

Sent from my iPad mini 4G

[John D]

Yeppers! 

[hellphish]

I was the 'someone' who suggested he look at the feedrate defined in the move. I'll copy what I wrote in private in case the community can benefit from it:

what we are looking for is a G1 or G0 command with an F parameter, which sets the feedrate. So if you are extruding 15mm it might look like this:

G91  //use relative coordinates

G1 E15.0 F10000  //this tells the E axis to move 15mm forward at 10000 mm/minute

G90 //go back to absolute coordinates. 

We want to see what the value for F is during this move. I have a theory that your host is setting it to a very low number.

[Scott Turner]

Thanks Dude!

The final issue was Ponterface!

I will figure out how to fix what I did to it and post that.