Folger Tech 2020 Prusa i3 Build Log

[rcwingman]

woohh 90k but thats a large one.....

 

[Balu]

Well, the http://bigrep.com/ isn't bad either. But you'd have to ask for a quote on the price. They just say it's "slashing the cost of a full-scale machine to 1/16 of its competitors’ market price"... Whatever that means

AKeric build a pretty big Open Hardware machine based on the Openbuilds C-Bot: http://www.akeric.com/blog/?p=3291. It has a build volume of 12″ x12″ x24″...

 

[rcwingman]

cool!
Thank you balu! This is exactly I was searching for.
I will take a closer look into that printer

I found this one with a good price:
https://www.kickstarter.com/projects/1683546801/the-gmax-3d-printer-print-bigger/description
But the shipping from the US would be too high.

 

[dkj4linux]

MPCNC can be a large-as-you-want-within-reason 3d-printer... bordering on unreasonable if you wish

 

[jhitesma]

Well, my daughter has been sick all week with a horrible case of the flu. Thankfully she's about over it now and feeling much better today. But I managed to find a small silver lining in it by taking advantage of having someone home all day and running some longer prints.

Did a geared extruder:



I still have to hob the bolt, and pickup a few more washers to fully assemble it. But overall it came out ok.



I'm not huge on the design though. It doesn't seem to put much tension at all against the filament, I can't run a 4mm PTFE right to the hobbed bolt without modifying and reprinting...though the existing hole is too small for any of my 1.75mm filament to actually fit through so I'll have to drill it out if I use this and if I'm careful I can probably make it a tight enough fit that the lack of PTFE right to the bolt won't be a big issue.



I also still need a shaft for the ilder bearing, it's just floating in there right now.

But The tolerances came out so tight I wondered if I had a problem with my printer and went back and printed a bunch of tests - only to confirm that my printer is dead on it's just this design.

Plus this design sits lower on the x carriage than my current extruder so I'd loose some of the Z I gained with the current setup.

So while I still want to try a geared extruder...I'm not sure that this is the geared extruder I want to use. I'll have to figure out a way to mount my inductive sensor still too if I use this. I may still give this one a go but am thinking I may try printing a different design later today instead.

 

[markyoe]

Let me know how your next geared extruder works out. I have been looking on thingiverse, but it is just sooooo overwhelming!

 

[PHugger]

I've been pursuing a dual extruder fan and throat heatsink fan upgrade for my Taz. I understand what Markyoe is saying about being overwhelmed. Taz has a very active user forum and I found some very good material there from folks who are experts. One of these guys pulled together a great "Thing" with all of the required parts needed and some instructions. Instructions are sadly missing from most everything on Thingiverse. This gets really bad when any assembly has multiple parts. Just printing the listed parts doesn't mean you can turn off your "engineer" brain. I'll post some pictures tonight, but so far I've gotten everything printed (16 hours total with a few minor false starts)-

• 3 fan ducts (left, right, throat)
• Proximity Sensor holder
• Hot-end Support and Guide (modified to attach new ducts)
• Strengthened Hot-end

They came out great (matching black ABS), but I really want to build an enclosure. My makeshift temporary "box" works well at getting these heavy structural parts made without any lifting, but having to balance the enclosure walls is a pain (think cardboard, DTF and towels). The main extruder part had two small over-hung areas that needed support. I could not get Cura to start the support any lower than layer 10. The area that needed support was maybe 30-40 layers above that so I let it make a mess (air printing support onto the bed) and after around 10-15 layers the support had firmed up and came out great. I'll have to go through the Cura settings with a fine toothed comb to see if I can figure out why. Maybe it was just the model.

I ordered some bolts and thread inserts (hot-set).
I'm using all fluid bearing 40mm fans. Two of them are supposed to be 24v, but I'll but I only have 12v models on hand. I'm ordering a Zener Diode to knock the fan voltage down to 12v and still have a full range of speeds available.

Once everything arrives, I'll be able to disassemble the existing hot-end and convert it over. It's a bit more than I really wanted to do (it wasn't broke...), but the new extruder parts are much beefier and should theoretically work better. When it's back printing again I'll tackle the auto-levelling upgrade.


Best regards,
PCH

 

[PHugger]

Here are the parts I've been working on -



There are a few parts of the Extruder that are being reused. The main bracket that attaches to the rails and a few smaller parts like the idler lever arm and latch.


Best regards,
PCH

 

[markyoe]

How did the extruder work jhitesma? The current one I have is driving me crazy. Do you have a link to the one you made?

 

[jhitesma]

How did the extruder work jhitesma? The current one I have is driving me crazy. Do you have a link to the one you made?

The non geared one I'm currently using is working well. I still need to tighten up the tension on it more but it's good enough - and I'm not worried about the slight pattern I get in the surface finish for these MPCNC parts. Once I finish reprinting the MPCNC in PETG I'll refocus on dialing it in better.

The geared extruder I've set aside. I'm not big on this one. This is the thing for it: http://www.thingiverse.com/thing:725082

But I'm just not sold on it. The hobbed bolt is more hidden than on a greg wades and there's no easy way to setup a quick release on the idler. (which is just an idler not a guidler like on the latest greg wades designs.) I solved the issue of the motor mount and gears not lining up well by adding an extra washer between the big gear and the extruder body. But the big issue that has convinced me to set it aside and try something else is the way the e3d V6 mounts.

I really want to try some flexible filaments soon and this just isn't a great design for that. The distance from the hobbed bolt to the hot end is a lot shorter than on the extruder I'm currently using...but...the hole the filament goes through between the bolt and the extruder is too small. I can't even fit filament through it without drilling it out. And the hot end mount leaves no room for the PTFE coupler on the top of the V6. The designer of this extruder suggests just pulling it off...but I'd rather leave it on and run the PTFE all the way to the bolt for best performance with flexies. I could do a bit of work with some drill bits and open the hole up to 4mm to allow the PTFE to go through and use a larger bit to open up the top of the mount area so the coupler on top of the v6 will clear...but....I'd rather tweak the design a bit and reprint it than do that and this design doesn't have source files. I could just import it into openSCAD and brute force the changes...

But that still leaves a few other issues. Like there's no good place to put my inductive sensor and a layer fan...I could fit one or the other but both would mean some ugly sacrifices like putting the inductive sensor almost 50mm away from the nozzle.

So instead I'm looking at doing a traditional greg wades...but there are so many variants I'm having a hard time deciding on which one to try. Looking for one that has a 4mm passage so I can run the PTFE right to the gear like I have it on my current extruder. But...haven't found one yet.

And since the machine is really tied up reprinting the MPCNC in PETG right now it's kind of low priority. These PETG parts are coming out great but are printing SO SLOW! And I haven't had time to run the longer ones. Trying something new about that tonight though. Got a new fire alarm to go right over the machine so I feel safer about letting it print all night long. I've let it go an hour or two past my bedtime but never had the guts to do an all night print. It's been nice and reliable for a few weeks though (I regularly start prints from my phone while 2 rooms away now.) so with the new smoke alarm I'm going to give the overnight thing a try. Actually just started a roller_f which takes 9 hours...fingers crossed it will be done in the morning and I won't have a pile of spaghetti or a smoldering ruin instead.

Also got two new rolls of filament today from Atomic...and it's their actual 1st quality not their bargain bin B grade stuff that I tried last time (and had no complaints about.) One roll of gunmetal grey PETG for the MPCNC - which looks really nice...it's a dark gunmetal not a light grey as it looks on their website. And a roll of "cinnnamon red" PLA which is almost brown and will be perfect for the Hovalin I'm going to print for my wife. She got really excited when she saw the color...it's perfect for a violin.

Hopefully doing overnight prints will help me catch up. The next few weekends are going to be really busy (country fair and a co-workers wedding this weekend, home improvement project next weekend) so overnight is the only way I can get these big prints done.

 

[PHugger]

I've been busy helping a cow orker set up a new Home Theater every night this week.
Pulling wires through walls etc. I haven't had time to even look at my Taz.... )c8
My bolts, threaded inserts and Zener diode are all here so I may make some progress this weekend.
I got a late birthday present from my son last night - Raspberry Pi v3 and a web cam for an Octoprint controller.

I was listener to the 3D Printing Today podcast yesterday and one of the hosts was talking about printing with flexible filament. The big problem he sees is how the filament often mis-feeds just below the hobbed bolt (or whatever you use). The first time you notice the problem is when the un-melted filament squirts out of the extruder via whatever path it can find. There are several designs that help by shortening the un-guided path. The host had just worked on one of these designs and added a clear acrylic panel to the side so you could see any feed problems when they first started. I thought it sounded pretty cool.

I have a very good Smoke and CO detector within a few feet of my Taz in the shop. It's part of my security alarm so I don't worry too much about fire. I do worry about messed up prints. 6 hours of extruded filament can may a big mess. I always make sure I can watch it for an hour or two (or through any tough to print areas) before I let it go unattended. If there are going to be problems with support or overhangs I usually see them early and restart with some adjustments. I'm learning to spend time studying the object and how it will be sliced before I begin. I really can't wait for the DWIM v1 Printer and Slicer package to be released!


Best regards,
PCH

 

[jhitesma]

I got a late birthday present from my son last night - Raspberry Pi v3 and a web cam for an Octoprint controller.

Nice, beats the pack of cream eggs I got from my daughter this year I wanted to like Octoprint but was really underwhelmed by it. If I used cura as my slicing engine I could see it simplifying things but since cura drives me crazy it just made things more complex for my workflow. Rep-server on the other hand I'm absolutely loving. Really need to recompile the kernel on my C.H.I.P. so I can get a webcam going soon still....

I was listener to the 3D Printing Today podcast yesterday and one of the hosts was talking about printing with flexible filament. The big problem he sees is how the filament often mis-feeds just below the hobbed bolt (or whatever you use). The first time you notice the problem is when the un-melted filament squirts out of the extruder via whatever path it can find. There are several designs that help by shortening the un-guided path. The host had just worked on one of these designs and added a clear acrylic panel to the side so you could see any feed problems when they first started. I thought it sounded pretty cool.

Yeah, that's why I'm not a fan of the extruder I printed. The trick seems to be keeping the filament constrained as much as possible from as close to the bolt/gear as possible. The geared extruder I printed has a channel for this but it's just not accurate enough. The extruder I'm using currently has the PTFE right up to the gear so it should do fairly well...but I'm not big on how long the PTFE is - could make retraction tricky with flexies...not as bad as with a bowden setup but same idea.

That's why I'm looking at a greg wade design that will let me run the PTFE right to the bolt like my current non-geared extruder only hopefully with a shorter path and the gears to help ease the strain on my extruder stepper. The setup e3d shows on their site is a greg wade cut open:



Just most of the designs don't have the 4mm passage for the PTFE and I think that may be a 3mm version because I don't see the coupler at the top of the cold end.

I will say filament changes with the e3d are way easier than with my old hotend. Before I had to heat things right printing temp before I could pull the filament out. Now even with the longer PTFE tube I can pull it at much lower temps because it doesn't stick in the heat break. I must have really messed up the PTFE liner in my original since the whole point of PTFE is to not be sticky

I have a very good Smoke and CO detector within a few feet of my Taz in the shop. It's part of my security alarm so I don't worry too much about fire. I do worry about messed up prints. 6 hours of extruded filament can may a big mess. I always make sure I can watch it for an hour or two (or through any tough to print areas) before I let it go unattended. If there are going to be problems with support or overhangs I usually see them early and restart with some adjustments. I'm learning to spend time studying the object and how it will be sliced before I begin. I really can't wait for the DWIM v1 Printer and Slicer package to be released!
PCH

Yeah, I've already printed all these parts so I know what to watch for And they all have big footprints so adhere well which is nice since the only time I tend to get spaghetti anymore is if a print comes off the bed while printing - but that only happens on things with small footprints - and then usually only with ABS.

The 9+ hour roller_f went great last night. Finished just after I woke up Three down one to go....then I get to redo the feet and corner blocks...and 3 more center pieces....

Only issue was I remembered why we had disabled the fire alarm in my daughters room...darn thing went off twice for no reason last night waking both me and her each time. Need to replace that one still. Her room is right next to ours, we all sleep with the doors open and the alarm in our room works fine so hers is mostly a backup...but I'll pick up a new one for her this weekend. Then again it may not have been the alarm...the new one over the printer went off twice yesterday evening for no reason. It could just be the crazy amount of dust/pollen in our air right now. I didn't know the pollen count could go over 10 :black_eyed: our allergies have been off the wall this spring. Killing me that we've got great cool evenings but are having to run the A/C just because there's too much junk in the air to sleep with the windows open

 

[PHugger]

...the new one over the printer went off twice yesterday evening for no reason.

I think any filament type produces particulates in various amounts and toxicities.
Heated beds have a large impact on the amounts.
Smoke detectors hit these particles with radiation and ionize them. The ionized particle can be easily detected in low quantities.

A somewhat scientific study (lots of holes and variables) -
Univ of Texas Emissions Article
http://pubs.acs.org/doi/ipdf/10.1021/acs.est.5b04983

I'm going to do an enclosure this year......



Best regards,
PCH

 

[PHugger]

I meant to ask about the guide tube at the top of the extruder.
Is it permanently attached to the extruder?
the Taz has a similar guide tube that seems of a larger diameter (looser fit) that extends back closer to the spool.
It's not attached to anything at the extruder end. There is little to no resistance from it during retractions. If the filament couldn't slide back the guide tube would just lift.





Best Regards,
PCH

 

[jhitesma]

I think any filament type produces particulates in various amounts and toxicities.
Heated beds have a large impact on the amounts.
Smoke detectors hit these particles with radiation and ionize them. The ionized particle can be easily detected in low quantities.
PCH

I forgot to mention that the printer wasn't even on when the alarm went off

But the window was open. And we've been inundated with PM10 warnings this week so I suspect it's crud in the air causing the false alarms.

 

[jhitesma]

I meant to ask about the guide tube at the top of the extruder.
Is it permanently attached to the extruder?
the Taz has a similar guide tube that seems of a larger diameter (looser fit) that extends back closer to the spool.
It's not attached to anything at the extruder end. There is little to no resistance from it during retractions. If the filament couldn't slide back the guide tube would just lift.

I don't have a guide tube at the top on my extruder. There is a small passage through the extruder body on the one I'm currently using that helps guide the filament to the idler/gear but that's it. The cutaway from e3d shows one but I don't currently have one and don't really plan on adding one. I've heard they can help with filament binding but I haven't had any issues with that since I added bearings to my spool support.

 

[jhitesma]

So the MPCNC parts are coming out quite well. The new Atomic gunmetal grey PETG took a bit of dialing in...I was hoping it would go easier since the owner of Atomic is proud of how his filaments supposedly all print the same from color to color - but the same settings I was using with his transparent blue didn't work quite as well with the gunmetal. It could just be that the blue was b-quality though - the grey is a little thinner but more consistent. My extrusion seems good but my retraction seems a bit less optimal than it was on the blue.

Last night I decided to do a little experiment and printed the washers that keep the belts on the bearings of the MPCNC - instead of the 0.2mm or 0.1mm layer height I've used to print them in the past I gave it a go at 0.05mm.

Wow! That 15 minute print became a 40 minute print...but...the quality is amazing! They came out so much smoother than I've got them to print in the past. Even when I printed them in really dialed in PLA they didn't come out this nice. The slightly tapered top surface really benefits from the ultra low layer height.

And I seemed to have less issues with crud on the outside of the nozzle than I did at higher layer heights which has been the on-going issue with this gunmetal grey. Not going to be using 0.05 for a lot of things...but when I want super ultra quality and don't mind waiting forever it sure does seem to do a great job!

 

[PHugger]

I've never printed lower that .1mm layer height, which looks very nice to me. The Taz uses 85% infill for all of it's Printer parts so I guess I am valuing Structure over Aesthetics on them.
I got the Zener Diode I needed to drop the 24v control for the fan down to 12v.
Now I need to put the new Extruder on and wire it up - maybe this weekend - I have to work late tonight.
I also want to start bread-boarding the Raspberry Pi. I ordered some relays that can be controlled by the GPIO ports for lights and whatever.
Get some Perl running and Octoprint (I'm using Cura) and I'll be golden.



Best regards,
PCH

 

[jhitesma]

Yeah, 0.1mm was the lowest I had ever gone and didn't seem to make enough of a difference to be worth bothering with.

These washers for the MPCNC bugged me though. I've gotten good prints of them but like my accucell replacement button and the top of the 3 string CBG nut I designed the other day the slightly tapered surface just doesn't come out very well even at 0.1mm Still has obvious rings and feels rough. So I wanted to see how dropping down to 0.05 would do. Turns out it does great!

Now I want to try and reprint the nut and button as well....except I already glued in the nut so I could do some serious string bending. Oh well. It works well just isn't very cosmetic despite being printed at 0.1mm

 

[PHugger]

Curves on the Z axis are really hard for these XY and Z printers. We only print 2D in a lot of slices. I have seen a true 3D printer where the Z axis changes all the time, but they aren't common. A bit of sandpaper and polishing can do wonders depending on your filament.




Best regards,
PCH