Help! Dual Extruder E3D V5

[longshot]

Really need some help with this. . .

I have 2 E3D v5s on a v1 Rostock Max. I am using Repetier v91. I am highly successful in printing PLA using a single nozzle using the stock Rostock Max extruder. I am using tricklaser's arms. The extrudes are a variant of my own design.

My first issue is adhesion. Like so many others, i googled my way to find what works and what doesn't. I've tried the following:

• straight glass,
  painters tape,
  painters tape with elmers,
  painters tape with glue sticks,
  painters tape with other glues,
  straight kapton tape (about 1/2" wide, so you can imagine the number of rows)

Still working on kapton tape with abs juice. The only thing I'm worried about is how much tape i got to go through, and how do i clean up the abs that's stuck to the glass from the abs juice?

Do i need to upgrade my power supply? Is there enough juice to get the two hot ends up to 230 C and the heated bead up to 110 C? Having some issues getting the bed up to temp. Are there low temperature methods to help insure abs first layer adhesion?


2nd question: (tough one)

I cannot for the life of me properly calibrate this thing. It always seems like one nozzle is slightly higher or lower than the other. So the big problem happens is when one nozzle hits the part while traveling and breaking off the part.

My nozzles have springs under the mounts so i can turn and level them out. when I zero (0,0,0) them out they are level at the center of the bed. As I move out one nozzle gets higher or lower than the other. My guess is that the printer radius is off. So i adjust:

Zero the machine (level the heads)
Put a piece of paper underneath to check each head, check to see i'm pulling the same amount.
Go to each tower and adjust the z screws on the carriages to make sure the nozzles are touching.

...so here is where things get fuzzy, if i got one nozzle higher than the other what do I do?

• I can't adjust the nozzle screws because i just zero'd it out at the center, i'd be off if i did that
  I can't adjust the z screw because adjusting one doesn't fix the other
  I can't adjust the printer radius without knowing my z screws are at least in the right ballpark

I've been reading the manual for calibration steps but it only lists steps for one nozzle. . .

How do I work this with 2 nozzles?
Is there an orientation i should have the nozzles in? should they be lined up with an axis?
how long does it take to calibrate? (hours? Days? weeks?) I've been at this for about a week and no more closer than where I started?

Please help.

[gestalt73]

ok, I feel your frustration. Many of us have gone through the same thing.

Firstly, I have no idea what your effector design looks like, but the hot ends need to be mounted securely to the effector, with no vertical or lateral play whatsoever.
If you're using springs between the posts and the top of the effector plate, there's going to be too much play.

So, assuming that your effector construction is rigid, and your delta geometry is perfect, try this.

Adjust your effector so that your first extruder is lower than the second. you are going to calibrate the x y z endstops and print radius using extruder one.
It doesn't matter what height you set it at, because you can always adjust max z later.

Use the setscrews to get within a few tenths of a millimeter for each of your endstops, then use the eeprom values to really dial it in.
When you're doing this, set them up so as you drag the piece of paper underneath the nozzle, you can feel the friction and pattern of the paper grains. the paper will have a characteristic vibration you can feel with your fingers.
too low and you're just using force to trim, too high and there's not enough feedback.
after a bit of practice, you should be adjusting the offsets to within 0.025 or 0.050 of perfect.
remember, you're just trying to get them dead-nuts level. you can always adjust your max z afterwards.

So, set your x, y, z offsets in eeprom, then check them all again.

Now check your clearance at the center. make sure your first nozzle is hitting exactly the center of the build plate.
If there is any difference in feel between the center, and one of your endpoints, you need to adjust delta_radius or printer_radius (I forget which) until the heights match exactly.
This should also be set within 0.1mm or so.
Every once in a while, check your other endstops again, and adjust if necessary.

Every time you change your printer_radius or delta_radius, you need to recalibrate your max z.
But that will be done at your x, y, z positions. Not in the center.
Every time you change printer_radius or delta_radius, you will recalibrate your max z from either the x y or z position

Once you have that all completely dialed in, you can start adjusting the height of your extruders so they match.

bubbasnow's dual extruder design lends itself well to shims to adjust.
For his style, I was using a 0.1mm shim of plastic, and gradually moving it way from the two mounting screws to change the height of the higher extruder
http://www.thingiverse.com/thing:278076

On my design, you can just crank down on the nuts in the posts to change the relative height of each extruder.
http://forum.seemecnc.com/viewtopic.php?f=41&t=5747

After following all those steps, I am really really close to perfectly level.

Although this theory is not yet borne out of experience, I'm wondering if you can't get it completely even, if you leave your main extruder just a smidgen lower than your support extruder. it may be better to mar the supports than it is for the support extruder to mar your model.

[longshot]

Wow, that is awesome . . . thank you for taking the time to write all that up.

I will give what you said a shot. . . . might take me some time.

Any word on the PSU? are you able to get to 230 on both heads and 110 at the bed with the stock PSU?

[gestalt73]

Ya know, one of my first upgrades was to replace the stock psu with a 750watt unit.

using 12v, I struggle to get above 100c, 80-100c is straightforward though.

I can hit any temp up to my limit of 300c on both extruders.

but, doing some napkin calculations...
if the bed is around 20 amps
if each stepper is about 1.2 amps x 5
if each hotend is about 3.33 amps x2 (40watt heater cartidges)

That's about 391 watts max, assuming everything is running at 100% duty cycle.

Or another way of looking at it, your E3D V5s come with a 40 watt heater cartridge, so it will increase your power needs by 40 watts.