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View Full Version : 3D Printing doing my head in - Help please!



cropwell
09-11-2019, 03:29 AM
Hi, I am trying to print two files which make an extractor nozzle and a lamp adapter. File Lampbase C is the plate for attaching to the profile on the Z axis and the ducting to get the air past other gubbins on the machine and Lampbase E is an adapter to fit C to a vacuum cleaner hose.

The drawing was done on Sketchbook, which explains why they are so 'blocky'

The .stl files are here:- https://www.dropbox.com/sh/0xns0z0m94botq6/AADqHhs9owRWYgeu1r4umA_Aa?dl=0

The problem is that with file E the funnel part gets filled in as a solid and I have tried all the tricks I know, but nothing works. I have tried Makerbot, Cura, Microsoft and Fusion360 to create a printable .x3g file and they all see the .stl as an open funnel, but close it up on the print file.

What have I done wrong ?????

magicniner
09-11-2019, 11:52 AM
Cura allows you to preview the layers so you can see what will print, the only time I had problems like this is when the model was not manifold.

cropwell
09-11-2019, 03:41 PM
Hi Nick,

I am sure there is a fault in the design. I have used triangles to get rid of problems with non-coplanar points. I have tried Cura and also used an online service to check the .stl and it looks fine.

Can you explain 'manifold' please? I have looked at the model for open areas in the wrong place and could not find any.

Life is just getting me stressed at the moment. I have severe arthritis in my knees and hips and the constant nagging is getting to me.

After a lot of problems with my extruders, I decided to replace them lock stock and both barrels. The replacement was £170 from Wanhao UK and £75 from Wanhao China. Delivery was £25 by UPS and Import VAT was £19 but then UPS added £11.50 for Customs Handling. So £130 all in (roughly). Fitting was 2 screws and a load of cables to plug in. Level the bed and away we go! First print was superb, but subsequent prints will not stick to the bed. So I have some furtling with print temperatures to do.

In the meantime I tried to cut a door push plate as my cream perspex sheet had arrived. Change collet to 6mm to cut the chamfer on the plate, then back to 1/8 for the engraving and cut-out, but 1/8 collet has disappeared off the face of the earth - now into 2nd day of collet search. It is a Kress collet and clamp nut, so can't just nip down to Arc to get a new one!

Cheers,

Rob-T

AndyUK
09-11-2019, 04:46 PM
Hi Rob,

I've downloaded your STL and replicated the problem in Cura.

I then opened it in solidworks, and it looks hollow... resaved the STL and same problem.

Then I ran the import diagnostics tool in solidworks on your STL. It had a LOT of faulty faces and tiny gaps in it. I used solidworks auto-repair tool, saved as STL, then hey-presto, it slices as it should.

Here is the fixed STL.

26706

Hope this helps!
Andy

cropwell
09-11-2019, 05:19 PM
Thanks Andy,

It sliced OK with Makerbot.

I have downloaded Netfabb to see if I can sort out this and other future drawing fails, but there is a whole new vocab to learn. I use Sketchup for quick and dirty prints, but it woefully lacking for anything tricky.

Nick, I found the collet. It had obviously slipped into another dimension through a wormhole on my CNC machine desk and reappeared underneath it, behind some sheet materials.

Cheers,

Rob-T

cropwell
10-11-2019, 04:08 PM
After a couple of failures with Sketchup and considering how unwieldy it becomes when trying to do anything with roundedness in it ( a swept elbow joint for instance), I have decided to learn Fusion 360.

I tried a couple of Youtube videos, but after a few minutes of an irrepressibly chirpy Californian youth going on about cloud storage, I decided to buy a book. Just need to wait for some peace in the house after the grandchildren have gone home, before I can get down to study it!

Rob-T

cropwell
15-11-2019, 02:00 AM
I printed the file that Andy fixed for me and then the printer refused to extrude evenly, to the point where prints were failing. After raising the nozzle temp to 240C, I finally got a print, but I had to do it in bits and glue them together.

The object is a nozzle for the vac, to be fixed onto the profile at the bottom of the Z axis. I have added a 10W Cob LED and heatsink (I had 3 of them left over from a job).
2674126742

The offset is because there is the Z home switch target in the way, but I may be able to shift that and reprint with a full width nozzle.

Cheers,

Rob-T

Washout
15-11-2019, 11:32 AM
Hi Rob

What material are you trying to print with?

If its ABS or PETG then that will need higher temps than say PLA and also an enclosure is preferable (especially with the colder weather we have atm). If its PLA then that's something different and might be an extrusion speed issue (your photos suggest it maybe over extruding, but hard to tell without video and the glassy surface looks like you're acetone smoothing after printing?).

Another issue that is prevalent in the winter weather is cold and damp filament (most are hygroscopic) and whilst I also need a desiccating oven/heater, I have had some filament "come to life" just by sticking the reel on a radiator for an hour before printing with it.

Hope that helps, but post more on printing and Fusion if you need more.


Chris

cropwell
15-11-2019, 06:38 PM
Hi Chris,

I have had my printer now for 5 years, it is a Wanhao D4S. I have had little trouble with it up to the last few months, when it started to extrude badly. (Apart from a motherboard failure two years ago).

I have always used ABS on a heated bed (glass with slurry) at 110C, with an extrusion temperature of 230C and not needed to change this.

So recently I have changed the extruder driver (as I had the ones from the old motherboard), the extruders for a new pair, complete plug and play from Wanhao and this did not cure the problem. In the course of fitting them I found the extruder carriage mount faces for the extruder bar were distorted and had to shim the left side by 0.40mm. I could have corrected this by adjusting the nozzle heights, but this would have meant dismantling the extruders.

My next 'fix' is to change the guide tubes for PTFE in case there is any ruboff of the ABS onto the inside that is causing dragging.

This recent print was done with filament from Rigid Ink and I find it will print OK if I go up to 240C.

Yes, I use solvent smoothing, but I use MEK not DMK as ABS has a slightly lower solubility and MEK evaporates quicker, so I can give it a quick wash spray from a trigger bottle and then hang it to dry for 10 mins.

I have the feeling my printer needs a professional service and so I am sending it off to the Wanhao agent in Dorset soon.

In the meantime, I am awaiting delivery of a printer kit https://www.ebay.co.uk/itm/Latest-Version-3D-Printer-Prusa-i3-Reprap-MK8-Extruder-LCD-Controller-MK3-hotbed/202788697508?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 which seems too cheap at £70 (you could not buy the bits for that). It will be fun assembling it and I will have to see if it was a waste of money.

Cheers,

Rob

Washout
15-11-2019, 11:24 PM
5 years means you need no egg sucking lessons from me then :-)

That said its hard to see in pics, but does your printer use the bowden type extruder with the stepper separate from the hot end, or is the extruder stepper integrated onto the hot end? If the latter then its probably similar to my printer and one area that can cause blockages is if the threaded tube with the ptfe is not securely mated to the top of the nozzle when they are screwed into the block together, then seepage of molten filament can occur between them, which over time gets "burnt" into the gap and causes a blockage (or partial one). In fact by "luck" I have just had this happen to my printer this evening and I keep a stock of the threaded tube and nozzles, so I can do a "quick change".

cropwell
16-11-2019, 12:02 AM
Hi Chris,

The D4S uses what is referred to as the Mk10 nozzle which comes in two variants.

A - a nozzle and metal feed tube with a PTFE inner tube, which must be an exact length, too short and the melted filament goes everywhere inside the hotend, loo long and you crush it down and the filament will not feed in properly.
B- the 'all metal' hot end from Micro-Swiss at £35 an extruder. It ain't cheap and the advantage is a bit meh. Also they cannot be dismantled for servicing and cleaning without a high risk of destruction.

The extruders are of the type with the stepper motor attached and I have just spent far too much money replacing them with factory fresh ones, inclusive of nozzles, heaters, thermocouples, fans etc (Plug and play replacement) Here's a pic of the old ones 26745

I still have half a metre of the PTFE liner tubing left btw.

Cheers,

Rob-T

cropwell
18-11-2019, 05:57 PM
Well, I seem to have sorted most of the problems as the machine is printing reasonably now. I found that replacing the guide tubes (Filament reels to extruders) with PTFE tubing, allowed the filament to feed easier. So maybe there was some build up on the walls of the old tube that was dragging the filament.

Cheers,

Rob-T