Where do I go from here

I was getting some OK prints just with a bit of dribbling, however x axis sag was starting to lay the hot end in the print it was working on. I decided stupidly perhaps to use the spare time I had to do all the upgrades in one hit so I would finally have a reliable printer that I could start to make my own parts on. Mistake!

Things I did, in order;

- Updated to 0.54 of the firmware and changed to python based ponterface with USB fix.

- Changed y-axis belt tensioning to Matts design and ran the y-belt teeth in over idler as to not create tension near Y0. Tightened belt quite a bit. Maybe to much?

- Decided to tighten the x-axis while I was at it to see if it would help x-axis sag. Found I had put the x-axis pulley on backwards in original build and had been wearing belt (tiny amounts of rubber shavings). Corrected this and tightened x-axis belt as best I could, it is now a lot tighter than it was.

Head was still sagging so aborted print and printed a new x carriage.

- Changed x-axis carriage also to one Matt kindly provided with an enlarged runner bearing slot. Now my hot end is square and touches with both fan duct and sensor 1-2mm above bed

The print of this part was the ugliest I have had since my first snowman. Each layer is visibly noticeable more than any other which I think means they are very slightly out of line it had dribbles/blobs in a lot of places and over hangs were not as smooth looking as the original piece it was to replace.

I hoped this was due to the sag and fettled it to a nice fit and reassembled with it.

Links show a piece I printed before the "upgrade" a picture of the nozzle mount I had printed before attached to the carriage printed mid way through the changes and a few of a test piece I just created and printed to highlight issues which now shows 3.

1) Massive layer shift a few layers in and most layers out of line.
2) Corners have not bonded or are over extruded?
3) The printer stuttered 1/4 of the way through first skirt for maybe half a second but was fine after that. I will try to replicate this and grab a video of it if it keeps occurring.

Printed using DC's slic3r ini files but with temp 185/180 for first and rest and extrusion factor 0.92 as I always have had it.

Any help would be greatly appreciated as I have gone backwards and as what I have done is to apply known fixes I'm not sure how to fix it.

One other issue that I'm sure I had seen here, the wall above the hot end mount screw holes in the x-carriage bulged and I had to sand the outer ones for a smooth mount but put this down to having not changed temperatures after firmware upgrade but I just cant find the post about it.

Thanks,
Dan.

Original Print

Carriage&Mount

TestBlock

Test Block

Test Block

P.S What is clear is that a thank you to DC and Matt is needed for there help and offerings here. The post above is not a complaint or blame on them for what they have provided. It is I that has caused an issue with my hardware (and software)?

Firmware 57a is the latest - though I'm currently only printing from SD card, so not personally sure if this is working with the pronterface USB fix
I would try adjusting Sli3er settings:
See other posts for details, but here is what's worked for me:
Retraction to 4mm,
Temps: 1st layer, 195/70 then: 180/65
Fan always on (don't know if this makes a difference, but seeing as the fan is always on, Sli3er might as well know about it)
Randomize starting points
First layer at 30%
The printer stuttering... is it the x axis motor? Could be because the belt is rubbing against the rib where it's joined in the carriage.

Make sure you've recalibrated your z axis after printing the new carriage - test with a piece of paper to make sure. I found mine was more accurate after printing the x carriage in black - maybe yours has worked the other way around as it's white?
I'm sure other people will be along with more experience to advise

Hi Dan,

The 0.54 firmware is quite old now. I suggest you use either the 0.57a firmware from the RRP master branch, or my own 0.57g or 0.57h firmware and Matt's new web interface. See [forums.reprap.org] for details. Note there appears to be an issue with using Ubuntu linux with my firmware and web interface at present, which can be worked around if you are running a local web server.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks Guys

I have updated to 0.57h from yourself DC and set my slic3r settings back to those provided by RRP and worked my way through changing the settings one at a time. Lowered temperature to Squags. Changed retraction 4mm then 6mm and changed extrusion factor to 0.92. I have printed at all combinations. 1mm gave me strings across cut outs and moving to 4mm removed them. 6mm made no difference. My layers are now aligned and the prints are looking good even tried a 0.1mm layer height.

The only remaining issue I have is the dribbles, I know a few are to be expected but mine are excessive and they seem to be when the hot end changes height and extrudes again it extrudes a little to much or doesn't start moving soon enough that a blob is formed. I guess that's why they are always in the same place (I have turned on randomize start location but it still seems to start in the same few places and switch between them).

In pic on left is 0.24mm height, 4mm retraction, randomize start. On right 0.1mm height, 4mm retraction, randomize start. Always the blobs when the head extrudes at the start of a layer.

Getting there

Thanks for the help so far, any ideas what to change next?

Dan.

Edited 1 time(s). Last edit at 02/02/2014 12:54PM by FalseIdle.

Those bloody blobs!

If you find out a way to stop them, please share the secret!

It might be worth adjusting the extruder temperature for layers other than the first. I use 195 for the first layer and 190 after that, instead of the 180 that Squags uses.

Edited 2 time(s). Last edit at 02/02/2014 01:53PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Will give it ago on next print. thank you.

Can I just confirm on your prints you are not getting the blobs or at least far less of them and that getting rid of them is an achievable goal?

Thanks,
Dan.

Glad things are getting better. From observing printing, I think most blobs occur during layer change/ when the extruder starts again. I would guess therefore the most important things are the tip temperature (the optimal could well vary with different filaments) and extruder settings. I haven't yet played with the later, though there are several variables in slic3r under printer settings - extruder 1. When I've got more time i'll pay around, but it'd be interesting to know if you have any luck adjusting things there.
Squags

I often get a few large blobs on the skirt, otherwise almost no blobs at all. The few that I do get are very small and mostly associated with overhangs. I'm using 4mm retraction.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I get blobs alot, especially when printing cylinders. Each time the z axis moves up it seems like the extruded starts and the nozzle moves a fraction of a second after, leaving a blob

Quote
PaulHam
I get blobs alot, especially when printing cylinders. Each time the z axis moves up it seems like the extruded starts and the nozzle moves a fraction of a second after, leaving a blob

Which version of slic3r? Do you have "Retract on layer change" checked? (I do).

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42

Quote
PaulHam
I get blobs alot, especially when printing cylinders. Each time the z axis moves up it seems like the extruded starts and the nozzle moves a fraction of a second after, leaving a blob

Which version of slic3r? Do you have "Retract on layer change" checked? (I do).

@Paul That's exactly what I observe, changes layer extrudes to remove extraction distance, blob, then the head moves.

@DC I know not addressed to me but while we are collating Slic3r 1.0.0RC2 I do have retract on layer change on, If I don't it blobs with the pressure on the hot end and if I do it blobs as it extrudes after retraction.

I will try both hotter and colder once current print finishes. Looking in the wider RepRap community there quite a bit of talk about it especially with a bowden extruder.

Edit:- Question for you both, what filament are you using original or a new one? I'm still on original with a new reel on order.

Dan.

Edited 1 time(s). Last edit at 02/02/2014 02:35PM by FalseIdle.

Same as FalseIdle - Slic3r 1.0.0RC2 I do have retract on layer change on

Not sure i have the temps correct though, why do you use?
im on a new roll of filament which i got on ebay. i ordered purple and it turned up as a pink colour. I really wanted some colour in my 3d printing life as white wasnt doing it for me.

I've had good prints both with the filament supplied with the kit and with PLA from [stores.ebay.co.uk].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].