Upgraded from a mini 2 to a workhorse. Can’t make it work.
The Assembly was easy, I notice that the filament delivery system is odd when compare to the mini 2.
I was able to feed filament, extrude at the home position. As soon as started a new print, I noticed filament being fed but no extruding onto the print bed. Abort, clear, start again. This time got clogged.
Very frustrating.
I contacted support. for what I can read I might never get a response.
I think support is mostly through the backlog. There was a period when Aleph Objects laid off workers. When Fame3D acquired them, they moved the company to North Dakota and this meant there was a period where they had to be mostly shut down while re-locating equipment and staffing.
There might be a bit of a backlog … but if you phone the support phone number they do answer.
You might be running your print temps a little too cool for the Workhorse.
The Workhorse has a ‘hardened steel’ nozzle … it’s much more durable but it doesn’t transfer heat as quickly. For this reason the nozzle needs to run hotter than you were probably used to doing on your old printer. I print PLA at 230°C and PETG at 260°C on mine … and those settings work great.
As I recall, the Mini 2 uses the same AeroStruder … but not a hardened-steel nozzle.
Thanks Tim !! I’ll try that. Yes my mini temp for PLA or PLA + Was 215°.
First I have to disassemble the tool head and clear the clogging.
Tim,
You were right on the money. I increased temp to 230°. Printing w/o a hiccup.
Thank you my friend. Stay home, stay safe.
Short lived , is clogged again.
Sorry to hear that.
If the printer is jamming, things I check are:
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Are the teeth in the feed gear (hobb) clean? If it has been chewing up filament, the teeth get jammed with dry filament. It needs to be cleaned out. Since this was cold filament, it does not “melt” into the teeth … so a can of compressed air (e.g. I use the common ‘Dust Off’ compressed air cans from any office supply store) will blow them clean.
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Is the print temperature correct? You can print a “temperature tower” to test this. This is a part that looks like a tiny tower. There is a Cura Extension that lets you tweak settings at a given layer number of at a given height (in mm) above the build plate. Think of the tower is a tiny building with several “floors”. Each “floor” of the tower can print at a different temperature. You inspect the quality when the part is done and decide which temperature did the best job.
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Is the heat-sink fan working? On the left side of the extruder is the aluminum heat sink. This has a fan attached to it. That fan is not the part cooling fan… its job is to cool the “cold end” of the extruder in order to prevent “heat creep”. Filament is supposed to be solid while passing through the cold-end and only melt into a goo when it reaches the hot-end. If it softens in the cold-end it can cause a jam. This fan keeps the heat from the “hot” side from creeping up into the “cold” side. This fan is normally always running whenever the printer is powered on (whether or not you are actively printing anything.)
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Excessive retraction can chew up the side of the filament and result in a jam.
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Poor tension (ether too loose or too tight) on the idler arm at the hobb gear can also result in slippage or excessive chewing of the filament and result in a jam. The adjustment knob pushes a small hex-nut and this is what increases or decreases tension on the spring. You can see a slot where this nut is visible. If you completely back out the tension… then re-tension it so that the nut is roughly at half the travel… or a little less than half the travel. I set mine to be roughly 1/3rd to 1/2 of the travel. (1/4 is probably too loose… 2/3rds is probably too tight).
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Bad filament. I’ve had some experience with poor quality filament – not a lot of experience since these days I tend to stick to the stuff that gives me good results. But I’ve tried some “interesting” filaments. One particular filament was quite brittle and it snapped a lot.
Of these settings… excessive retraction count is usually high on my list of things to suspect. This will vary based on the part. If the part is calling for a high number of retractions without extruding a lot of filament. This is really dependent on how you ‘slice’ the part.
In Cura in the “Materials” section, there are three things to check:
- Retraction Distance
This should normally be a low number for a direct-drive printer like ours. e.g. 1mm is common. Few materials need a value greater than 2mm.
- Maximum Retraction Count
This establishes a limit on the number of retractions it will perform in a given length of filament. e.g. you could set this to ‘5’ (I think it defaults to 99 … which is basically like saying there is no limit).
- Minimum Extrusion Distance Window
This is the length of filament for which the max retraction count is enforced.
E.g. if:
Retraction Distance = 1mm
Maximum Retraction Count = 5
Minimum Extrusion Distance Window = 2mm
Then it means that each time a retraction is performed, it will pull the filament back by 1mm (on the “cold” side … unmelted filament length), but if the job calls for retraction more than 5 times before the filament advances by at least 2mm then any additional retractions will be ignored.
Think about the mechanical nature of the feed gear. It has sharp teeth that jam into the side of the filament to force it to advance or retract. If the filament only ever advances then you’d see teeth marks in the side of the filament after it passes the feed gear. But if the filament moves up and down through those teeth a dozen times… it will chew up that filament until it breaks down and bits of plastic are falling away.
The idea is to prevent the feed gear (hobb gear) from chewing up the side of the filament. If it chews it up too much then you get a chunk of filament gouged out of the side and it gets stuck just spinning without any filament moving … in other words it’s jammed.
If a job calls for a LOT of retractions there are usually tuning settings you can adjust to fix it. For example… top and bottom layers set to ‘zig-zag’ instead of to ‘lines’ prevents retractions at the end of each row. For walls that are just barely thick enough to need ‘infill’ … sometimes you can increase the wall line count (or wall thickness … either way works) and it will just print a solid line instead of trying to print a lot of infill lines … which can result in a lot of retractions.
There is also a setting to tune the minimum move needed before it will even bother with a retraction.
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Hi Tim,
Thank you for such a thorough review.
The retraction settings changed helped a lot allowing me to print about a 1/3 of the benchy’s hull.
However, I noticed the heat sink fan is not spinning before, during or after printing. That might be the whole issue.
Thanks
Without that fan running you’ll get heat-creep which will eventually result in a filament jam.
The extruder has a “hot” and “cold” end … separated by a gap they call the “heat break”. The design is to allow the hot end to get hot… but the gap prevents heat from easily transferring to the cold side. The heat-sink and fan on the cold side deal with any heat that does manage to creep across the heat-break gap. But if the fan isn’t running, heat will migrate and eventually heat the cold end to the point that it is hot enough to pre-melt filament and result in a jam.
Check to make sure the wires have not come loose on the board.
Unplug the printer from power. Open the left side-panel of the printer, you can access the board.
Along the top, you’ll see the heavy wires that run the power to the hot-ends. The Workhorse is “wired” to run two hot-ends even though it only has one (if you look at the back of your printer control box … next to the USB port … you’ll see the plug to connect the wire for a 2nd hot-end). Those plugs along the top run the hot-end heat and also the blower-fans (part cooling fans). Those are not the fans that cool the cold-end of the extruder.
To the left of that row, you’ll see (circled in the image I uploaded) two pins… those provide continuous power and that’s where the heat-sink fan is connected. The board is labeled “5V AUX OUT” (it’s a 5v fan).
It may have become disconnected (I’ve noticed it’s not a particularly firm connection). Make sure that’s plugged in.
Reconnect power to the printer and switch it on. After it boots to the main status screen the cold-end fan should immediately switch on and stay on. It is normally always powered as long as the printer is on.
Since it’s just a simple 5v two-wire connection, it should be pretty easy to make sure power is connected. If necessary… you could use a multi-meter to test continuity to make sure there isn’t a break in the wiring.
Stay health & safe.
Tim
The machine is on warranty, is one week old. I don’t know if opening/disassemble anything would void warranty.
I can’t speak for them… give LulzBot support a call. Their number is on this page:
Hi Tim,
Well , I went ahead open the side panel and you were right! The connection was loose.
Plugged it back in a voilà I was able to print a benchy. It came out decent, there were like stringy/webby filament in between windows etc. Minor details.
I just want to thank you for all your help. Noway I would’ve ever gotten to that conclusion about the fan. I have learned more this week than the six months I’ve had the mini2.
If you have a website, YouTube channel, Patreon let me know and I’ll subscribed or support.
Thanks again.
Thanks for this detailed explanation. I have been struggling with this problem.