Printing off at the edge

Hi guys. I have the plastic sticking now. I have both double checked my Z calibration and givent he bed a lovely clean with Isopropanol. However I am getting an issue with printing at the far edge.
I will include images. This is the OrmAxis print and it has happened both times I have tried so far. I am using autp ped plane calibration with this too.

The end parts are going a bit wobbly. Any idea what is wrong?

I think either the bed is not level, or you have a grease spot at that point on the bed. Is this an Ormerod 1 or 2? If it is a 1, do you have DaveK's alu bed support or some other mechanism to keep the bed level?

---

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].

Oh sorry, I should have said. Its a standard Ormerod 2. Would installing your new firmware help?
The bed leveling was done by sticking a ruler to a set sqare and comparing against the table. I have then used the bed plane compensation thing.

Quote
Pyro
Oh sorry, I should have said. Its a standard Ormerod 2. Would installing your new firmware help?
The bed leveling was done by sticking a ruler to a set sqare and comparing against the table. I have then used the bed plane compensation thing.

No, thats wrong. It then depends how good your whole printer is leveled which is a bit to much to ask for. Just look at the documentation, comissioning
level the bed as described there.

So what kind of differentials does the auto bed-level compensation cope with? Anything near about a 1mm between corners?

Space between the perimeters, looks to me like you are printing with the nozzle a bit too high (or under extruding), filament should be squeezed against the bed to make it stick - a look at down side of the print should show that

Try zeroing the nozzle manually, lower the nozzle on a piece of 80g copy paper (0.1mm), remove the paper and lower the nozzle those 0,1mm and send G92 Z0 to zero the nozzle at bed surface

With a nozzle diameter of 0.5mm and first layer hight of e.g. 0,25 you first layer should then be squeezed against the bed with good adhesion



Erik

One of your motor pulleys is loose on the motor shaft (check the grub screw is tight on the shaft flat), or belt is not tight enough, which is the gap between fill. The give-away is the thumbwheel - it's not round! See: [reprappro.com]

Ian
RepRapPro tech support

While printing another test (the snow man), I did notice that the Y belt did look a little loose. I will tighten it tonight and see if that improves things. The snowman print did complete, however it seemed to be welded to the print bed. I swear that there was a post here not too long ago about removing parts from the bed but I can't for the life of me find it.

Quote
Pyro
..The snowman print did complete, however it seemed to be welded to the print bed....

If I have a print that is really really stuck I use a modified wood chisel as crowbar.



I grind/smooth the sharp line between the edge and the shaft a bit..



..compared to the picture I use it upside down, with the small flat part of chisel parallel to the bed and the handle pointing up in an angle - and a slice of cardboard in between to protect the kapton tape

..then poke the sharp end of the chisel in the side of the printed part, not trying to get under the print, that would risk scratching the kapton, its fairly easy to get a good hold, either in-bedding the chisel in the PLA directly or just in between the layers

Using the handle like a crowbar gives a lot of leverage and control over force used - do go slow and give the print time to slip and when it starts, slip something in between, use a long strip of thin strong material, comes to think of it, maybe a fishing line could do (should be long enough to pull with both hand on each side of the printed part) to slice the print of the bed

..or you could just use the chisel all way around the print

Erik

For thin stubborn prints I sometimes run a wooden stick (bit of firewood) flat along the bed a few times, hammering it into the print. Taller prints I tap with a rubber mallet. You can also heat the bed up to slightly hotter than its normal printing temperature. Leave the print to heat for 20 minutes or so, then take the glass to a tap and cool both the part and the reverse of the glass under cold running water. The sudden contraction may cause the print to loosen. Once I put the glass & print in the freezer overnight which did the trick.

Dave

To release stubborn prints, I find putting the glass bed + print in the freezer for 10 minutes does the trick.

---

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].

Or use pc-duster can spray or frozen vegetable

---

All about delta 3d printers in one place [www.deltarap.org]

Hey guys
Thanks a lot for the help! I got a putty knife and filed at one corner to produce a really flat (and sharp, ouch!) edge. That took it up.
The Y azis adjustment did indeed help things along as did readjusting the Z height. I was missing the G92 Z0 step. The z commands are in a wall of text. I should probably insert the Z stupp into the config files but I find I always get a slight different number of G31 reading each time.
I have now printed another snow man and the whistle and they all look mostly good. I do still have some adjustment work I need to do on the Y because even after tightening it I still see its a bit loose. I was afraid I would snap the acrylic part if I pulled on it too hard. I'll drive a wooden wedge or seomthing down in the gap later or something.

I had a few issues getting the Y axis as tight as I wanted. Printed off a wedge to shim the motor and it helped a lot.

I found wedging the motor tended to make the motor want to twist though so I designed a spring loaded belt tensioner which has improved my prints greatly. So much so I did the same for the X axis as well. Both brackets are at a beta design stage at the moment and have issues or I would make them available to people if they think they are of use?

Hey, that looks really good! Got the files I could use to build my own?

I'm at work at the minute but will try to dig them out tonight. Think I need to amend the model slightly as there was a bit of "finessing" with a dremel required. If you want to give it a go you will need another bearing as it has two. One as per the standard bracket to keep the belt in line and another for the belt to run around on the sprung arm. Also your belt probably won't be long enough so you will probably need to get another length of that as well. The other thing is finding a spring the right size and strength. I got a few off some chap on ebay who was clearing his shed out. Not sure how strong they are. About 4 or 5 Kg I think and an inch or so long. I still have a few kicking about if you can't find anything suitable I could stick some in the post if you want to PM me your address. I was a bit worried they would be too strong and wreck the motor bearings but they seem about spot on. I've been running this bracket for 3 or 4 weeks with no problems so far.

To remove a print - here's another advice I just picked up but haven't tried yet - soak the plate with the PLA print in hot water for five minutes, should then more or less slip by itself

The advice came from designer Don Foley and he should know...BTW, if anyone should be in need of a nice printable ornament for the Christmas tree he has one available for free (this week only), might need a bit of shoe-horning to fit the ormerod though



Astrolabe Tree Ornament
[donfoley.com]

Erik

Quote
ormerod168
The advice came from designer Don Foley and he should know...BTW, if anyone should be in need of a nice printable ornament for the Christmas tree he has one available for free (this week only), might need a bit of shoe-horning to fit the ormerod though
Erik

I see that he charges money for his designs, which is OK in principle, but could be a bummer if you end up with an STL that you cannot print on your printer because of size, overhangs, bridges etc.

I suppose it won't be too long before we start seeing some sort of DRM and copy protected STL formats.

Dave

Pyro

Modified Y idler stl file attached if you want to have a go with this. It's based on the original stl file with my mods so hopefully will fit ok.Not tried printing it yet but the mods I've made are minimal compared with the one I did print so should be ok.Any probs let me know

When zeroing the z axis I drop it 0.1mm at a time onto paper and as the head touches the paper I zero the head so it's not really at zero but 0.1mm. Slic3r then Starts the first layer at this height, if its a real zero I find there is nowhere for the extrude to go and it makes a mess as its smeared around the bed.

Do this with the bed and nozzle hot so there is no chance of extruded filament ooze getting in the way.

---

Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Thanks a lot jsv555! I will have a go at printing this out over the weekend.

I have taken to using paper now actully. pinch or file off any protruding plastic then move the head down slowly until it pinches the paper. Test by sliding the paper and feeling for the resistance.

Quote
Davek0974
When zeroing the z axis I drop it 0.1mm at a time onto paper and as the head touches the paper I zero the head so it's not really at zero but 0.1mm. Slic3r then Starts the first layer at this height, if its a real zero I find there is nowhere for the extrude to go and it makes a mess as its smeared around the bed.

Actually, slic3r starts the first layer at whatever first layer height you configured. You can see this by examining the gcode.

---

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
Davek0974
When zeroing the z axis I drop it 0.1mm at a time onto paper and as the head touches the paper I zero the head so it's not really at zero but 0.1mm. Slic3r then Starts the first layer at this height, if its a real zero I find there is nowhere for the extrude to go and it makes a mess as its smeared around the bed.

Do this with the bed and nozzle hot so there is no chance of extruded filament ooze getting in the way.

As DC42 has said, the print will start with the head at the first layer height. I also find that setting Z=0 at the point you can feel the paper being gripped sets the head height correctly. I suspect that the force needed to put enough drag on the paper for you to feel has tilted the hotend up by about 0.1mm, so after the paper is removed it really is at zero.

Dave