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Hello all

I have been lurking here on the forum quite abit in the last few weeks. I just got a RostockMax two weeks ago and have been having quite a few problems getting it to be consistent and need some help with getting the setup right if you can give me input.

So far here is what I have been getting out of it.
Here are my settings:
I am using PLA with 1.73mm avg line.
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Any and all help would be appreciated.

I haven't printed with PLA yet.. (It had been unpackaged about 2 months, so I gave it the oven treatment...and the filament went all curly...I'll have to build a straightener now...)

So take this with a grain of salt..(but not bath salts, I hear those make your crave odd foods),but those temps seem high. If you're not getting jamming though I don't see that being your biggest issue. If you look at the print, it gets better as you get higher where each layer has more time to cool before more hot material is added, so judging by that I would suggest you first get a fan blowing on the print and if that doesn't resolve the issue then try lowering your temps. To help hone in your temperature just right for that filament, try using this calibration print. http://www.thingiverse.com/thing:35088

So for temps I am really confused. I started out at 185, 190 but I was having a problem getting the first layer to stick to the print bed with glass or tape. So I was told to increase the temps to make it stick better. I am having a hard time with the settings because I am not sure what looks good and what each layer should look like.
I will play with the temps with this model and see what I can get. from what I can see though you want the highest bonding at the lowest possible temp right?

Something else to note as well, I seem to be having a ton of trouble with small parts. I have the 0.5mm head on the printer, will it help a lot if I go to the smaller head before printing the smaller parts? It seems like it shouldn't matter..

Couple of things....

First, and most importantly, you need to calibrate your extruder. 92.65steps/mm is probably close, but it's not exact. Your print looks starved for filament. There's a sticky topic by Polygonhell about extruder calibration... it's very simple and straightforward, and it's an absolute must to get your printed dialed in and printing beautifully.

Second, try heating your bed to 55-60C, with tape. A little bit of heat can help with first layer adhesion.

Third, you're almost certainly running too hot on that filament. 190-210 is the general range, depending on where you get your filament. I use the Pro Series PLA from MatterHackers, and i'm printing at 190. I have previously used MakerBot PLA and was at 205-208. So there is a range. If your filament looks very shiny and curls up or gets stringy on corners or sharp angles, you're probably running a bit too hot.[img][img][/img][/img]

Fourth, smaller nozzles can help on smaller prints. I have both the .5 and .35 nozzles. It takes longer to print, but I definitely get cleaner, more detailed prints with the .35. It depends on what your "trouble with small parts" is, but it's likely not the nozzle. My guess is that you're printing too fast and/or too hot on small prints. For prints less than a few inches in diameter, try slowing print speed down to 10-20 mm/s, and make sure you have good airflow across the part. The hardest part with small prints is getting each layer to cool before the next one.


Lastly, every print is going to be a little different, settings wise. Because there are so many variables that aren't very measurable or controllable -filament temps, filament diameter, moisture content, etc - you'll often need to make adjustments on-the-fly.

If you look at the picture I uploaded, you can see that at the start I was not getting enough filament. This was the beginning of a new spool of PLA, and it was not the same as the last spool. I increased the extrusion multiplier a little bit at a time until the infill was correct. On my next print, I'll increase the diameter in Slic3r slightly, and watch the first layer again. If I'm lucky, it will print flawlessly, but I may need to increase the multiplier again... and so it goes...

cope413

Thanks so much for your input.

1. I have gone thru the extrusion calibration and it was very close. I will follow up on it again and see if I can get it even closer.
2. I will try my next print with the slower speeds and a heated bed to see what I get. I will keep you posted.

You said that you make tweaks as you go, after the print has started how do you make tweaks? Is that under the manual control and will that affect the whole print or just the current layer....


Thanks

If you're using RepHost, then you can increase/decrease the Speed multiplier and Flow multiplier under the manual control tab. You can also adjust extruder and bed temps mid-print there too. Any changes you make will affect the rest of the print. I would suggest adjusting flow 3% a time. Also, keep in mind that there are 16 moves in the buffer, so when you make a change, the moves already in the buffer will not be affected, so you have to wait a few seconds to see the effects of your changes.

The other thing you can try for better first layer adhesion is to 1) increase your first layer temp 5-8 degrees, then dropping down after the first layer, and 2) decrease your first layer speed to 10-15mm/s.

I see something weird in your EEPROM. You have steps per mm set to 80 for all 3 axes. My setting is 53.33 because I have a RAMBo 1.0, which does 1/8th microstepping. Your board would be a RAMBo 1.1 or above, which does 1/16th, which means you ought to have a setting of 106.66. Yet, your bed height is realistic and your prints seem to be coming out mostly OK. Did you recompile your firmware with EEPROM turned on?

For PLA, you can print without bed heat if you have Kapton on your bed. This is a good way to print PLA because bed heat will cause the first few layers to expand and appear "fatter" than the rest, and if you're printing a vase or anything with sharp corners it will promote edge curling. It does require a better height calibration and to stop some pieces from lifting at the corners it may be necessary to spray some hairspray on top of the Kapton.

Another trick is to heat the bed to 60 degrees and then just turn it off after the 1st layer. Bed heat will make up for incorrect height settings and inadequate filament flow, up to a certain point, and I think it's somewhat easier to get that crucial 1st layer to print with heat on. (By the same token, you know your settings are pretty good if you can successfully print PLA without bed heat.) You can also get away with not having Kapton (or even hair spray) if your bed is 60-80. Use as little heat as you can while still getting the stuff to adhere, because bed heat is really not your friend with PLA after the first layer, and it takes a LONG time for that heat to bleed off after the heater is turned off.

Conversely, you need bed heat for printing ABS because it encourages the layers to bond. I think most people use 80-110 for ABS.

626pilot
Thanks for the response and no I did not recompile my firmware with my EEPROM on. Should this be something that I change to make my prints better?
I have the latest version of Rambo.

When you calibrated your height, did you do so by editing the values in the EEPROM screen, and did it work? If so then your EEPROM is enabled.

New kits are shipping with 20 teeth, tooth? pulleys. 80steps/mm is correct.

When I calibrated my bed height I had to turn my EEPROM of and use the arduiono software to make some changes for my bed. It though that it was concave. I made the adjustments with the EEPROM off and then had to turn it back on. I had to make a minor adjustment but not much. Then I turned it back on as it instructed.

Did I mess something up?

IIRC, you can tell if EEPROM is enabled simply by it showing any values in RH (which you have screen shots of). But basically, if you're bed is flat and level I wouldn't worry about EEPROM or steps/mm

As far as adjusting printer_radius, you did it right. It has to be done in firmware. The rest can be done using EEPROM.

You're good You sound like all of this is really new to you. If that's the case, the biggest piece of advice you can get right now is to focus on one thing at a time. It's incredibly easy to get distracted and start changing all sorts of things.

daftscience wrote:New kits are shipping with 20 teeth, tooth? pulleys. 80steps/mm is correct.

That would explain it. If it was wrong he would have a very interesting time printing a toy boat.

poemoe9 wrote:So for temps I am really confused. I started out at 185, 190 but I was having a problem getting the first layer to stick to the print bed with glass or tape. So I was told to increase the temps to make it stick better. I am having a hard time with the settings because I am not sure what looks good and what each layer should look like.
I will play with the temps with this model and see what I can get. from what I can see though you want the highest bonding at the lowest possible temp right?

PLA is a special beast when it comes to temps compared to ABS, which is why I avoided it for now.

You're right that in general higher temps (within reason) are better because you get better adhesion between layers,but...

PLA expands in a way to cause annoying jams if you're temp is too high for the speed you're printing at, which isn't your issue right now so you're fine there. If it was you just print faster or reduce the temperature.

PLA flows more easily than ABS and that flow rate continues to increase with higher temps. It's a good thing for printing at high speeds.

PLA holds heat more than ABS. Compared to ABS where you may want higher temps for layer adhesion (the previous layer cooled so you compensate by increasing the temp of the layer to remelt the previous one), PLA usually has bigger issues it is focusing on for temperature. Since it flows better with higher temps and holds onto the heat longer, you don't want your layers to keep creeping after they have printed. That is why active cooling is suggested with PLA. An interesting one is on small prints the hotend radiates enough heat to keep the PLA from properly cooling and you get melted wax looking prints or some variation of that.

There is a learning curve to using PLA but it has some benefits that are definitely worth it. So much depends on the multiple variables, such as printing speed, print size, active cooling, layer height,etc.

If you problem was bed adhesion, you can also print directly on heated glass if you have a glass plate for the bed. Looking at that print again, that boat was relatively large. Check your bed level with a calibration print. http://www.thingiverse.com/thing:50505
It seemed the print got worse further from the center. Another thing is depending what slicer you are using, it is likely that the first layer is being printed slower than the rest of the layers, and print speed is a large part of the dynamic to the temperature selection of PLA. You might want to turn down the first layer temp if your are printing significantly slower for the first layer.

Hopefully that made sense and will be somewhat helpful.

Thank you all for the information. It has been very good, I am working on getting smaller prints to work as it seems the larger ones are good for now. Or at least until I get my new arms.

I am going to try some smaller stuff and post here for feedback.

Thanks again for your time and input.

HOw do you judge the speed of your printing....

What is standard so to speak? 20mm/s 15mm/s 30mm/s

I would like to print faster but it seems when I do I starve the filament...is there a way to set a balance.

for 30mm/s your filament rate should be x% or at minimum 30mm/s.....

etc

With the stock hotend I was limited to about 20 to 30mm/s. To print faster you need to up the temp of the hot end. That will help melt the plastic quicker. But, If you start running going too hot you risk jammimg during retracts. Also you risk damaging the PTFE liner. Don't go over 250°

If you you get an all metal hotend you can go much faster. I have done prints at 160mm/s, they aren't the best quality but I had no starving issues. For quality I shoot for 60-70. I'm sure others are going faster.

Keeping the limits daftscience spoke of in mind, printing calibration cubes to get a feel for it is really the best way to tell your limits. There are many things that can limit your maximum speed and the quality at that speed. Tricklaser arms or magnetic arms will help your print detail in higher speeds for example. I know I didn't have my original arms perfect, but I put in a lot of time getting the sanding right which still wasn't perfect but acceptable. 60mm/s was my upper limit. Since then, I have done 120mm/s with my mag arms and could go higher but I got tired of trying to tune filament settings for the speed at that point. Your layer height also plays a role in your max speed. Speed isn't the only thing that determines your print time either, there are settings such as jerk, cooling time, accel and decel limits, etc. that play a larger role in determining print time as your print speed increases.

For starters, do calibration cubes at 10-20 mms (i made a few wide and thin cubes since I didn't like waiting for a full square cube), and then just increase values to push you the limits and learn what you need them at.

It's all a balancing act between the amount you're pushing out of the nozzle, the amount you are stretching the filament, the material's temperature and ultimately what features your print has (such as gaps that need bridging).

The filament/material/nozzle output stretches more the faster you print and the smaller you're layer height. This is countered by increasing the flow rate and increasing the temperature, all of which also affect how each layer bonds. This stretching also determines how layers over gaps (bridges) turn out.

The trace width or width you're actually printing, is determined by your layer height. The range of the trace width you can print is determined by the hole in the nozzle (nozzle diameter) and the outer diameter of the nozzle's head (flat part of the nozzle tip). The minimum (reliable) trace width is going to be your nozzle diameter at the upper end of your layer height range (which is 66% of your nozzle diameter or a 1.5 ratio of layer height to nozzle diameter) and the nozzle's tip is will be your width at the lowest layer height you can reliably print, ok it could honestly be smaller than that but you're likely to have your filament snapping making holes in your prints.