I wasn't trying to say the extruder design was at fault, with the spring removed we're outside that design. If the holes were drilled off then there could be filament path issues. I was only suggesting the b'struder as it works off the print bed and would limit the opportunity for any drilling error.

Have you tried feeding filament manually, as in with the stepper removed and the bot heated. This will isolate the problem to either the hot end or the filament pusher.

 

i would definitely extrude.. but any backpressure at all would cause it to skip or grind.. also if i went too fast..

i'm not sure what you mean by the holes being offcenter? the filament got to the mk8 without any sort of binding or anything.. the ptfe tube on the output side came pretty close to the gear..

i got the direct feed version on their today... working very well.

on a different topic.. i got the little infrared optical zprobe thing from filastruder.. got it working but seems to activate at inconsistent heights.. the required offset can vary by .1-.3mm..
so i'm going to try the printrbot style induction sensor

 

Whats your print surface? It's designed to reflect off of glass, but they've discovered it will go through PEI and reflect off of the tape (inconsistently) behind it (if that's what you're using).

 

i initially set it up on glass but i'm pretty sure it was reflecting off the bottom.. in one probe point it didn't trigger in time and hit the bed.. so i kapton'd the entire surface.. that made it trigger every time..
i dialed in the offset after the probe and got a perfect print.. but next time the probe results in a different offset.. maybe my glass is the wrong type?
just doesn't seem super consistent

 

I gave up on using the differential IR with my PEI -> 3M 468 -> MIC-6 Aluminium bed combination. Without a doubt the IR penetrates the PEI and reflects off either the aluminium bed or one of the teeny bubbles in the adhesive. The IR sensor actually saturates with the reflected light which is not how the height sensor is designed to work. I played with different values of IR emitter output as well as receive sensor sensitivity until I got it to a point it wouldn't ever saturate but alas moving the print head 0.1mm had a o.01mm Z error. Just jogging the sensor around on the bed 0.1mm at a time with it hooked to the oscilloscope you could see the that the trigger point would waver up and down across the flat surface. You can read more about my findings discussing it with dc42.

I used another one of the sensors (stock) on my i3, which is borosilicate with a piece of white paper under it, over an aluminum bed and it works just fine.

My PEI surface holds onto ABS/PETG so hard that it almost takes a miracle to remove a large print from it. I tried a dozen different bed temperatures, and Z offsets from SMOOSHED to almost failing to stick at all. Fully smooshed required like half an hour of careful prying and it damaged the print. Too far and the print warped. In the Goldilocks Zone, the print was stuck so well it stress-discolored the plastic getting it off. I tried smearing the smallest bit of cooking oil on the surface and rubbing all over really well. Then nothing would stick to it. Finally, in a last act of desperation before I trashed it, I sanded it with some 320 grit sandpaper. It works ok-ish now, some prints still cling a little too well but I squirt them with alcohol around the edges and it generally comes off.

As far as a quiet fan for an E3DV6 hotend, I use one of these Sunon 30mmx15mm MC30151V1-000U-A99 6CFM. They are 27dB which aren't even in the same ballpark as the E3D which is wicked loud. I tried their 10mm version which are 23dB but 5.5CFM and I was getting jams in my PLA retracts so I upped the specs a little. 27 vs 23 decibels is theoretically more than twice as loud but the difference is hardly noticeable. I haven't gone back to trying PLA printing though-- that nozzle is still clogged currently, and I always use ABS/PETG.

 

There is a discussion here, Google Groups , on using the ir probe, specifically David's, with pei. Cliff notes are paint the back black with bbq/header paint.

 

Yeah I can't try that though as my PEI surface is permanently attached to the heat bed. The heater + aluminum + pei + adhesive is over $150 in parts so I can't easily swap it out, and removing the PEI would be a nightmare. I just use my Hall effect Z endstop then leveled it manually with the bed screws while printing on it, which only needs to be done once in a blue moon. If the PEI ever delaminates then I'll give this a try.

 

Been lurking here for a few months watching the progress of this design. Have even gone so far as to build a frame for a 12x12x24 build area version of my shiny new C Bot. Waiting for a few more parts and the new improvements before finishing up. Wanted to say thanks to Carl, Eric and everyone for this design and improvements. Also wanted to contribute what I can to this effort. I've built a hot end mount generator for folks to play with. It's still in it's early stages but appears to generate valid hot end mounts for the C Bot. It also generates hot end mounts for Prusa i3, which is my current printer and is currently using a hot end mount created by the generator.

Currently it can produce both sides of the hot end carriage, along with a blower fan mount, bracket and very basic fan duct. It works with E3D chimera w/ V6 and Volcano hot ends, as well as many J Head style hot ends. I plan on adding an option for multiple hot ends, possibly even disparate hot ends.

The generator has a lot of customization available. Based on some of the discussion on moving the hot end up higher on the XY carriage, the generator can do that if you would like to test it, would save folks from making a lot of customized versions manually.

The code for the generator is up on github and thingiverse, where I am making use of their customizer. Would love some feedback and suggestions or even helping coding it if folks are so inclined, whatever floats your boat.

github:
croadfeldt/Roadfeldt_3d_hczf_mount · GitHub

Thingiverse:
Hot End Mount Generator - Chimera / Cyclops, E3D V6, Fan, Servo, Z-Probe by croadfeldt

Looking forward to finishing up my C Bot build.
Thanks!

 

5PCS Collision Switch Limit Switch Travel Switch for Robot brand new

 

I'm having a z-axis problem.. hopefully you guys have some idea...
I run it down to '0' using the paper method.. then i go +5mm then -4mm then i got -0.1mm until it hits the paper again... it ends up not being 5mm..
so i'm getting it closer by 0.1mm paper is moving, next 0.1 paper can just feel the nozzle, next 0.1 paper is stuck solid.. so then i move it back 0.1mm away and the paper still stuck hard.. move it away again 0.1mm and paper is still stuck hard..

i can't figure it out.. i've checked out my z-motor pulley, belt, screw pulleys.. no sounds of motor skipping etc..

any ideas?

 

First thing that springs to mind is the wrong steps / mm on the Z axis... Alternatively, some form of slippage. How's your Z axis built? I did a quick skim through, but didn't see any specifics from you (I'm assuming triple leadscrew since you're also active on the triple-c thread).

 

I've added an inductive mount and working on a servo based mount, both replace the frame based Z axis mount with a hot end carriage sensor. This will allow for auto bed compensation. I sent a PR to the marlin firmware that allows for both a Z probe for bed compensation and a Z limit switch last spring. It was accepted and should be part of the new Marlin release which is RC phase right now. So if you want to retain the Z limit switch on the frame and just add a Z probe, then grab the latest marlin RC release and try it out. The current 1.0.2 Marlin will do Z probe or Z limit only.

If you have an aluminum build plate, the current inductive mount will give you bed compensation now. Once I complete the servo based Z probe mount in the generator, then all bed types will have access to bed compensation.

I see a lot of designs that incorporate the X axis limit switch into the hot end carriage, I will add that to the generator as well.

If anyone has any other suggestions, please let me know. My goal is to provide a tool that lets you to select the options you want and have the generator create the design for you. So please send over suggestions / comments if you have any.

One thing I am struggling with is where to place the X / Y V2 limit switches. I would like them to be front / left and can probably figure it out, but if anyone has any suggestion, let me know. Thanks!

 

I have some large, flat pieces (110mm x 160mm) that turn into walls that have been a bit challenging to print on my C-Bot in ABS. The pieces themselves stick to the PEI bed so hard they are challenging to remove, but the edges curl up just a bit somehow. It all goes fine on the flat bits but the walls produce some sort of shrinkage force that can pull up the corners. They print just fine on my old i3, but it is enclosed and I think that makes the difference.

Just for funsies I decided to whip together an enclosure. The filament feed tube sticking way up and the print head being all the way at the top pose a problem for enclosing the top area-- the i3 the head is so far away the filament can enter through a small hole in the top. The printer is so big that I don't have a plastic trash bag big enough to fit it so I made this out of a couple of dowels and bubble wrap I had collected from Mouser.


Interior structure


I was trying a little proof of concept before I built it out of something I'd actually have to buy, like some hardboard and possibly some Reflectix bubble insulation.The concept is that, like a hot air balloon, the heat from the bed just heats the enclosed area. It doesn't seem to make a difference though and my recorded temperatures aren't all the promising. Ambient 25C, Bed 110C. At bed level, 10mm away from the bed horizontally: 30C. Above the bed 60mm: 40-45C. The edges still curl just the same tiny bit though.

Has anyone built any sort of enclosure that isn't just a massive box the whole printer sits in? I think the concept might be sound but I don't want to spend $50 and 4 hours building a "heat hat" that does virtually nothing except get in the way.

 

Makes sense. Come to think of it, I have another Core X/Y and I believe it does the same thing, rear / left. Think I will go the same route. Will have to see if the design I have with the fan hanging of the back still clears the rear horizontal frame. I would think it would, but can't test it out until I finish up my C Bot.

 

I got some just before Christmas from 5PCS Collision Switch Limit Switch Travel Switch for Robot brand new
Hope this helps.

 

My i3 heats up to about 50C as measured ~50mm off the bed, or 47-48C on a DS1820 temperature sensor I have near the RAMPS board. I actually have the top of my enclosure propped open because it gets too hot in there, considering the electronics, steppers, and power supply are all inside too.

My first idea was just to make a domed top (using spare 6mm PTFE tubing) with edges that hang down, but the filament tube doesn't want to stay inside the dome as it gets closer to the tubing origin. It would lift up the whole dome as the tube had nowhere to go. Repeat that motion about 5000 times during a print and it slowly pushed the whole thing off the top! Where it needs to be the tallest is the corner where the filament/bowden tubing starts. I'm thinking the back can be a lot lower or angled inward to reduce the volume a bit, but it makes the pieces a little more complex. Right now, the back mounts swivel so you can actually tip the whole thing back like a lid, although if you make the sides out of anything heavier than bubble wrap you're going to want a second support on the internal structure to keep it from being so bendy.

I'm not sure if the idea has enough merit to continue working in this direction though. The volume might be able to be optimized down below 75% of the existing volume, but it might not work any better due to the bottom being open? I've done a lot of googling and I don't see many CoreXYs with enclosures.

 

The problem is patents-- 3D systems has the patent on deformable baffles for a heated enclosure.

At the risk of completely honking off 3D systems and their patents, you could get some pleated / cellular shade material (look for "instant window shade"), and use it to create 4 panels around the z platform to form the sides of a box-- with something to hold the top of the panel in place, then as the platform drops, the baffle stretches out, and maintains the smallest possible size.

Similarly, if you had two additional baffles at the top (one attached to the rear of the XY axis and one attached to the front), then the Y axis could move front/back and the baffles would follow. Rails would be needed to guide them.

Unfortunately, this is very much what they've patented, and while they're unlikely to sue a home hobbyist, it's certainly something they could legally do.

 

Oh snap! That was my first idea, some sort of cover that would move with the print head but I never thought of accordion shades! I just thought "where can I get celluar shades for less than $200" (considering what the shades in my window cost). I didn't realize you could get then for $6 at home depot. I've also got a set of double honeycomb shades in my office that the mechanism broke and are itchin' to be replaced that I am giving the Salvage Eye to right now. Thanks for the idea!

 

I have been trying to finish up my C-Bot direct drive and running into an issue with it skipping. Seems if I try running it at anything over 5mm/sec it starts to strip the filament. I have the steps/mm calibrated and tried upping the temperature with no effect. I even swapped out the drive gear with no change. Anyone have any suggestions on what to look at next?

 

If anyone is intested, I've added a servo based Z probe to the Hot End generator. It's ready for folks to test. I would but my C Bot is still being built. I plan to add an X limit switch mount in the next few days. Not sure there is space for a typical reprap style limit switch, will probably design one with this in mind for now. If there is interest I can make it selectable for other switch types, eg; hall, reprap, round plunger style, etc...

5PCS Collision Switch Limit Switch Travel Switch for Robot brand new

 

I posted a link for the end stop a few pages back, along with a simple cad model of it for designing around. I'm on my phone at the moment, when I get to a computer I'll find the links, my BOM also has the link.

When I change a nozzle and need to fine adjust my Z height, I loosen my endstop and allow it to freely ride on the car. I can raise my bed using the belt until it contacts the nozzle, then tighten up the endstop. Re-level and I'm done. For y'all, I would compress the bed down a little extra, get the endstop close enough and then use the bed springs as your fine adjustment. Just a few mm's should be all the adjustment you would need.

 

Got to work and realized I didn't post that link, 5PCS Collision Switch Limit Switch Travel Switch for Robot brand new sorry about the mobile link.

 

I had one my belt clamps fracture, you might thicken those up by a bit instead.