New to 3D Printing and need some help.

[BLKKROW]

I would some help with my current print.

As you can see in the photo provide I am printing a Saturn V, not a big surprise for a rocket nerd like me.

But the fins are horrid with the recent print, what settings should I look into to fix this? It is printed in the same orientation as pictured.

[3DPBuser]

you can bump down the speed doing a bridge while at the same time reducing the amount extruded. That makes the line being done pull tighter.

Doesn't a tighter bridge need a faster pull?

[RobH2]

This is a timely discussion. I've been printing bridges all day. I just recently purchased Simplify3D and am tweaking it to find the sweet spot for PET+. I did 12 bridge tests today with a custom bridge model that I built. It tests bridges of 5mm, 10mm, 15mm, 20mm, 30mm and 40mm in one print.

http://www.thingiverse.com/thing:421046

I found that if I slow the print speed down I get a much worse bridge. I had to print at a speed of 200% to get it clean. I also used a fan. You could actually see the filament sag a bit and then pull up and tight as it cooled. The "sag to pull" occurred in about 1/2 second. It was interesting to watch. I got a fairly good 40mm bridge. The 30mm bridge is nearly perfect. Interestingly, the 5mm bridge was the messiest.

BridgeSettings_Sample_01.jpg

[Roxy]

I found that if I slow the print speed down I get a much worse bridge. I had to print at a speed of 200% to get it clean. I also used a fan. You could actually see the filament sag a bit and then pull up and tight as it cooled. The "sag to pull" occurred in about 1/2 second. It was interesting to watch.

This is the opposite of what I always thought was true. I've been having trouble with bridges lately. I'm messing with speed settings this morning using that ThingiVerse file you posted.

UPDATE: For my printer, high speed bridging fails horribly. I'm going to keep playing with it, but Bridge Speeds of 20mm/s with a filament rate of .9 works on all the different size bridges. The biggest flaw is the gap in the center of some of the bridges. That almost looks like a Slicer issue???

0808141014-00.jpg

[RobH2]

It's intersecting how different the settings need to be for various slicers. Well, maybe more frustrating than interesting. Your bridge looks pretty good from the top (except for the gap). So that was at a slow speed? I just calculated my speed (200% of my default speed) and it was 35. Slower than that and I had major issues. My test at a speed of 21mm/s completely failed and 'no' bridges were connected.

I've attached my data. Four of my first tests are not there as I didn't think to make the chart until after I realized I was having trouble. I rearranged the rows from worst to best. Just found out you can paste tables from Excel and they remain intact. Nice...

				Simplify3D Bridge Tests
	Other/Bridging				Layer	Infill		Cooling	Temp	Extruder		Notes
#	Unsupported area threshold	Bridging extrusion multiplier	Bridging speed multiplier	Default Speed	Primary Height	Interior fill	Outline Overlap	Fan	Temp	Retraction Dist.	Extra Restart Dist.
3	NA	NA	NA	NA	NA	NA	NA	NA	NA
5	9	80	175	2400	0.1	20	35	YES	230C	1.00	0.00	Filament detaching as it left tower so no connection.
6	9	25	60	2400	0.1	20	25	YES	230C	1.00	1.00	Complete failure. Complete detachment as head moved to next tower.
1	9	100	100	1800	0.25	20	15	NO	235C	1.00	0.00
2	9	50	200	1800	0.25	20	15	YES	235C	1.00	0.00
4	9	90	200	2400	0.15	20	25	YES	235C	1.00	0.00
7	9	70	200	2100	0.15	20	30	YES	230C	Retraction OFF	Retraction OFF	Great bridges. Just a couple very minor sags. But, very stringy. Retraction OFF is obvious.
8	9	70	200	2100	0.15	20	30	YES	230C	0.50	1.00	Great bridges. A little less stringy. Need to work with retraction a bit more.

[Roxy]

On that 'nice' print in the photograph, the bottom side is almost as good, but there are some strands that did not adhere. I'm half tempted to go grab the Slicer source and add an extra parameter. I want a setting that lets me say how much extra to extrude just prior to starting or just after ending a bridge operation. I'm thinking if the nozzle parked right at the edge where the bridge is going to run, and a user selectable amount of filament is extruded to force a 'tack', a lot of my bridge problems go away.

Alas... I don't know Python.

[RobH2]

On that 'nice' print in the photograph, the bottom side is almost as good, but there are some strands that did not adhere. I'm half tempted to go grab the Slicer source and add an extra parameter. I want a setting that lets me say how much extra to extrude just prior to starting or just after ending a bridge operation. I'm thinking if the nozzle parked right at the edge where the bridge is going to run, and a user selectable amount of filament is extruded to force a 'tack', a lot of my bridge problems go away.

Alas... I don't know Python.

Same here.
My bridge is really nice too but there was just one strand that didn't tack on both ends. Your idea to add a parameter is exactly what it needs. When I turned off ozze control, I had really good bridges. I think there was a slight retraction just prior to starting the bridge. It needs the opposite to, like you say, tack the filament down.

I am using Simplify3D now and it allows you to have different controls on different layers. I'm going to play with building a specific set of parameters (they call it a profile) for the first bridge layer and see what results can get. I've just had S3D for a week so I have a lot to learn. It might be able to give me better bridges, although, I'm pretty happy with what I have now considering.

Come on, you are so good with other code, you can learn Python overnight...yea?...lol...

Seriously, there does need to be some extra bridge parameters. I bet Skeinforge has it. I played with it a bit and became less intimidated by it. But in the end, other slicers were just so much easier so I haven't touched it lately. If I recall, it had lots of parameters that could control bridges.

[BLKKROW]

Thank you so much for all of this information! I am so happy to see the amount of information in this thread. It really helps me and I am sure it helps others.

I am becoming more confident in printing. I am still learning about raft's and when they are needed and working with bridges.

RobH2 I may check up with you in a week or two, I am really interested in Simplfy3D but not interested in the price. I did notice that slic3r has an experimental version out that looks promising.

[RobH2]

RobH2 I may check up with you in a week or two, I am really interested in Simplfy3D but not interested in the price. I did notice that slic3r has an experimental version out that looks promising.

Sure, no problem. I'm glad you are finding this forum helpful. We have some great people here.

I wasn't excited about S3D's price either but even as much as we all like free stuff and open-source stuff, there comes a time when having a budget to develop something brings with it advantages. I've tried just about every free slicer out there. I even spent two hard weeks with Skeinforge. If you want to exercise your brain and magnify your weekly beer requirements, dive into that one. I became less afraid of it and built up a lot of respect for it but it suffers from what a lot of potentially good software does, lack of interface design. It's intimidating because it's just a mess visually.

I like using Cura because of the great 3d window. But, I like Pronterface for the connection to the machine and easy controls. I like KissSlicer because it's the cleanest printing slicer I've ever used but it's SD Card only, no USB connection. So, no matter what slicer I was using, I always kept Pronterface open so I could connect and control my machine manually. I know there are some recent interconnections that are promising but I just could not find and all-in-one slicer. I was searching for something that did it all. If 3DS Max integrates 3d printing in to the next release, watch out. That would be incredible especially if they were able to top Simplify3D. You'd then have a truly powerful single piece of software as you'd be able to design a part and print it without ever closing a window.

I wrote Simplify3D and asked if they had a demo. I already knew the answer because I'd done a bunch of reading but it can't hurt to ask. While I waited for an answer, I viewed every single tutorial and read the entire site. It doesn't take too long because oddly enough, they don't have a manual. What I decided was that in reality $140 was not going to break the bank. Thats only 4 rolls of filament. So before I had the answer, it was, "no" by the way, I had already purchased it. I have to say, it's not perfect yet but it comes pretty darn close. I don't think anyone would complain about the $140 after using it for a few weeks. I'm really starting to like it and believe that it will be come my only slicer.

So don't be afraid to jump in with both feet. That's the way to bolster that confidence you are building. You'll wind up with a pile of useless prints but you'll learn so much along the way. I learn something new every time I print and it just as fascinating now as it was a year ago when I built my printer.

[jimc]

i have to say that i have been using only simplify 3d for over a year now. i dont even mess with anything else. great piece of software. as rob said its not perfect but has made leaps and bounds since i first bought it. it still has the occasional bug but noting that has ever kept me from having full functionality. the one good thing about just using that one slicer instead of bouncing around trying them all is that i know it really well and how it works with my printer so i can usually just look at my model and know exactly where all my settings need to be without really thinking about it too much. the one thing it does seem to lack on is dual extrusion. from guys with dual extruders they say it could use some improvement in that area. in due time though.