Random banding issue. Layers don't line up perfectly.

[pjfossee]

Any tips on getting my prints to stick better now that I can't use my bed for the whole print? Or possibly a better replacement for the relay? Or a fix for the bed? I'm researching it now but figured I'd ask. Thanks.

[moyesusa]

I quit using 70C for my bed temp with PLA due to adhesion issues.

Currently using 50C and hairspray with pretty good results.

-moyes

[printbus]

A cold bed and 3M blue painters tape cleaned with alcohol provides me with great PLA adhesion. I've broken multiple prints and pieces of glass with this approach. If I have a delicate part or a very large print, I'll cut back on the alcohol swabbing so that wax on the tape limits the adhesion.

Make sure your clips are close to the bed corners. The farther they are from the corners, the less degree that the glass is mechanically tied to the bed mounts in the corners.

It's not the mechanical relay that is the problem here. The root issue is that the (glass + heat bed) flexes as heat is turned on and off. A mechanical relay requires the heat to be turned on and off fairly slow, leading to the flex being detectable in some prints. Swapping out the mechanical relay with a Solid State Relay (SSR) allows you to then migrate to PID, a smarter control method built into Marlin that turns heat on and off far faster. The faster cycling both provides a more stable temperature and won't lead to as much noticeable flex. It takes the combination to reap the benefits. Just swapping out the relay alone won't solve the problem.

For more info, you can search the MakerFarm subforum for Solid State Relay. Here's one recent thread - 3dprintboard.com/showthread.php?15818-How-I-fixed-Z-banding-on-my-12-quot-i3v-AL-Y-bed-and-solid-state-heat-bed-relay-PID

[Chadd]

Looks like bed warping issues to me, try a print with blue tape and the heat bed off and see if it looks better.

If it does you need to get an aluminum bed if you haven't already and get a solid state relay and setup PID control on your heat bed. There is a thread somewhere in the forums that I did when I setup PID on my heatbed that has some info on how to do it.


"EDIT" I somehow replied to a cached version of this thread before you realized it was your bed as I mention above"

[Chadd]

Here is what I did to fix my bed warping and Z banding.


http://3dprintboard.com/showthread.p...ighlight=fixed

[clough42]

I've never succeeded with a hot bed and PLA. I've had my best success with blue tape and a cold bed. Cleaning the tape with alcohol or acetone caused the print to bond permanently to the tape. It worked great for me just on the tape, skin oil and all.

James

[Chadd]

I've never succeeded with a hot bed and PLA. I've had my best success with blue tape and a cold bed. Cleaning the tape with alcohol or acetone caused the print to bond permanently to the tape. It worked great for me just on the tape, skin oil and all.

James

On the makerfarm for PLA I use glue stick and keep the bed at around 60°C and have good adhesion, on the Daughters Da'vinci JR without a heated bed I use blue painters tape and as you mention if I clean it with alcohol the parts can't be removed from the tape without pulling the tape off the bed surface.

What I don't like about the painters tape is the rough texture of the printed surface that was in contact with the tape. The other issue with tape is that sometimes the part will still warp and pull the tape away from the glass print surface even though the PLA is still stuck to the tape.

For me glue stick and heat seems to work the best

[pjfossee]

Thanks for all the replies. I'll definetly be moving to blue painters tape for the time being it looks like. And Chadd, it was actually your thread that gave me the answer. Thanks! I'll be ordering a solid state relay soon. If I have these issues with PLA and a heated bed can I assume I will have them with ABS as well? If so hopefully a SSR will solve that. I'll probably build am enclosure while I'm at it.

[Chadd]

Thanks for all the replies. I'll definetly be moving to blue painters tape for the time being it looks like. And Chadd, it was actually your thread that gave me the answer. Thanks! I'll be ordering a solid state relay soon. If I have these issues with PLA and a heated bed can I assume I will have them with ABS as well? If so hopefully a SSR will solve that. I'll probably build am enclosure while I'm at it.

The higher the bed temp the worse the warping will be because the heat bed has to kick on and off so much, so yes you will likely have more issues with ABS than PLA. But both will look like crap until you get the bed warping taken care of.

Once you get it fixed the difference is literally unbelievable, it not only fixes appearance but also will fix things like layer delamination, first layer issues, nozzle dragging, strings, etc etc..

[tonybuckley]

I've never succeeded with a hot bed and PLA. I've had my best success with blue tape and a cold bed. Cleaning the tape with alcohol or acetone caused the print to bond permanently to the tape. It worked great for me just on the tape, skin oil and all.

James

I have always used hot bed (70C) with PLA and its been brilliant. But with the hair spray tip. You are the pro however :-). The hair spray wears off after a couple of prints so needs to be reapplied. It works amazingly well.