Printerbots Delta Kossel 250vs / Print Ridges

[prjoe]

Hello all,

New to this great hobby, but it's turning not so fun anymore. I'm printing 1.75 PLA on .35 nossle There's no way I can get my Kossel to print smooth layers. My first 2 0r 3 prints were nice and smooth. Then I really don't know what I did but started to loose quality, to the point where my prints have sorts of ridges on the sides (I've attached pictures for refference) I've :

The printer was auto-leveled with FSR's to a .01 precision.
Changed temperature,
Changed slicer
Changed Speed
Changed the perimeter % for the slice
Re-torqued all the frame screws
Bed doesn't seem to move
The mag arms have no play
The belts are tight (Not that stretched either)
It's very strange my first print were acceptable, but the rest are just worthless.

I honestly don't know what else to look for, I've changed so many things that I don't remember the settings I had that worked.
Any ideas what to look for will be appreciated.

Regards.

[Wolfie]

How are you storing your PLA? Is it in a dry environment? PLA does absorb moisture from the air.
http://reprap.org/wiki/PLA#Moisture_Issues

This may be your issue. I use ABS almost exclusively myself so I have limited experience with PLA.

[prjoe]

How are you storing your PLA? Is it in a dry environment? PLA does absorb moisture from the air.
http://reprap.org/wiki/PLA#Moisture_Issues

This may be your issue. I use ABS almost exclusively myself so I have limited experience with PLA.

Hello,
The PLA spool has been hanging on the printer since I assembled and tested it for the first time. (About a week ago) Didn't know it had special storage requirements. I have a new roll of ABS I might try.

That being said, can anyone suggest storage alternatives for PLA.

Does ABS require special storage?

Thanks for your reply.

[Wolfie]

PLA more than ABS. Nylon is very hydroscopic as well. For a week, meh, may not be your issue. Unless its humid where you are, doubt a week would affect it serious enough to notice i the prints.

The following is from a post I made on another forum....

As for storage, here are some of the containers I worked through:
Open Storage: Bad. Simply leaving it laying about. Collects dust. Collects moisture.
Storage Bins: Fair. Yes, fair! Unless you get reasonably expensive ones they are NOT air tight! If you are buying ones from Walmart for $5, you are wasting money.
Plastic bags: Decent. While they do work, are prone to failure (holes, failed to seal). Ends of filament tend to poke through them (well, obviously not NinjaFlex ) Their downfall is that each and every bag must be sealed tight and must have a desiccant pack in it. They are the cheapest solution
Plastic Buckets: Excellent. They seal air tight. They are reasonably priced. One desiccant pack per bucket. They are convenient in that they easily stack. Downfall is PITA lids, but thats fixable for a little more money!

My choice...5gal buckets.

Home Depot buckets are $2.50. The expensive part is convenience, the screw lid. You can get black ones for $7.25 at Home Depot too. If black is not your thing...
http://www.ebay.com/itm/GAMMA-SEAL-SCRE ... 1094497687

So, basic bucket and lid combo is $9.75 plus tax.

Desiccant packs are stupid EXPENSIVE most places. Yes. I said expensive! From Uline, 10g sized bags in a 600 pack container (6000g or roughly 13#) costs $130. That works out to $10 per pound! Off Amazon, 20 1g packages are $5.50 which works out to $124 per pound. Cheapest I could find at Grainger was 1.7# refill bags for $35 ea working out to $20 per pound. In-Freaking-Sane!

How about I let you in on how to score the exact same desiccant material, silica gel, for a mere $1.05 per pound? Here you go: http://www.walmart.com/ip/Mimi-Litter-C ... s/12018928 and if you can't find that one, then here it is for $1.81 per pound: http://www.walmart.com/ip/Fresh-Step-Cr ... s/10313505 Yep. Cat litter. But don't go and get just any cat litter, you have to make sure its pure silica gel and contains no clay (clumping agent).

I learned that secret from a guy at the gun range for use in gun safes a couple years ago. I get the huge coffee filters from a local restaurant supply store and make up 2 cup pouches for the gun safes and I throw in the pouches (instructions below) in individual gun cases.

For our need here, you need this: http://www.walmart.com/ip/FILTER-DRIP-C ... K/32559272 or if your work gets a coffee service, yall probably have stacks of them laying around the break room. See if you can score a few for free. I did. Our boxes of coffee come in 100 coffee packs. Yet there are 250 coffee filters in each box. Hot dogs and buns take two.

And you will need a stapler or hot glue gun. I use the stapler as its less mess and cheaper. And I don't have to worry about the staples in the oven when I recharge them. Brain says the hot glue is ok at the 180f recharge temp but I don't want it opening up in the oven. Gut says go with staples.

So for a 5gal bucket (1155in3), I go with 1/2 cup. I am ok with putting 2x what I need in a 5 gallon bucket since 8 pounds of it only ran me $15.

You are going to make a pita bread type pouch. Take two coffee filters, lay one on top of the other flat on the counter/table. Fold a little of an edge over and staple, only need 1/8" fold. Rotate, fold, staple. Keep doing that until you only got a couple inches left. Measure out 1/4c of cat litter and pour in your coffee filter pouch. Measure and add another 1/4c and add it. Doing 1/2c at once, I can't manage without spilling it. YMMV. Finish stapling it closed. You will probably use about a dozen staples on the large 12c coffee filters.

Repeat about 100 times until you have used up the cat litter. No, really. Go ahead and make up a bunch of pouches while you got your stuff out. Also, make up some pirogi pouches too (single filter folded in half with just 1/4c). And make up a few 1/8c. And make up some smaller ones by cutting the filters up into rectangles and putting a tablespoon in each.

Once you got them all made up, heat your oven up to 150-180F. Spread the packs out on cookie sheets or aluminum foil. Bake overnight with the door cracked open slightly to let moisture out. Next morning shut the oven off and allow to cool to the point you can handle them. You can also use a dehydrator if you have one and the packs fit in it.

Grab your cooking scale and weigh each packet in grams. Take that figure and multiply it by 1.3. Using a sharpie, write that figure on the packet somewhere. Each will weigh slightly different unless you were extremely fastidious as to measuring the cat litter and counting staples. I was not.

Why? Knowing when to recharge it! Silica gel can absorb up to 40% its weight in water. So I cut it off at 30% as its effectiveness declines after that. So multiplying the weight times 1.3 (or 130%) gives you a target weight to recharge at. That way you don't have to do the math later, you did it now Simply check them once a month or so and if they weigh more than their target weight, time to recharge.

Remember all those extras? Seal them up in ziplock bags or if you have a foodsaver, vacuum pack em. When you need them they will be made and ready. Those half sized ones are good for boxes and pistol cases. The tiny ones I had you make with a tablespoon, those are perfect for spools in ziplock bags. Or if you got a filament spool thats not very happy with its moisture content and you are not in a hurry for it, you can throw one of the 1/4c bags and the spool in a ziplock bag for a week.

Any leftover cat litter, yea, I know you didn't process all 8# did you? Load gallon ziplock bags to about 75% full, seal. Drop that into another gallon bag and seal. Throw all those (mine equated to about 3 leftovers) back in the resealable cat litter bag (Fresh Step bag) and seal it back up. Leave a cup or so scraps in the bottom of the cat litter bag to clean up moisture in the bag before it gets to the ziplock bags.

The 8# bag will be enough for about 36 of the larger packets. Give or take. Just about $0.40 per packet. Even if you go overboard and put 2 in a bucket, you are still under a buck per bucket!