Set bottom layer as with Raft in Cura

[aripod 0]

Hello,

 

I am printing a box with a large surface with transparent PLA from ultimaker. By letting cura chose the default parameters, I am getting some warping or the material is not sticking properly to the heated bed. One thing that I did was to increase the temperature of the bed from 60 to 65 and this helped a bit. Next, I thought a Raft would help and indeed its first layer was flawless. Although, I actually don't need a Raft but the configuration of its first layer. How can I configure cura so it prints the first layer (thinkness, speed, temperature) like it did for the Raft?

 

Thanks for the help.

[geert_2 558]

Although this is not an answer to your question, it might also improve the situation: the cause of warping might also be because of the way you clean your glass plate, the bonding method you use (or lack of), the distance between nozzle and bed, and the environmental situation (air moisture, temp).

 

Since I started using the "salt method" for bonding, I don't have Ultimaker PLA warping anymore. I use their nice "Pearl" color; I don't know about other colors.

 

The "salt method" = first clean the glass with whatever means you want, e.g. isopropyl alcohol, acetone,... (but no soaps or oils). Then clean with pure warm tap water only. Then wipe the glass plate with a tissue moistened with salt water. Or put a few drops of salt water on the glass and wipe them dry with the tissue. Very gently (!!!) keep wiping until this dries in a thin almost invisible mist of salt stuck to the glass. Especially in moist weather this gives me a much improved bonding when the glass is hot (60°C). When cold, there is no bonding at all, so the models come off by themself after finishing and cooling down. The ease of applying and ease of model removal makes this method attractive for me.

 

This works very well for low and flat models. My models are usually 12 to 15 cm long and 100% filled. But I don't recommend it for narrow and high models (e.g. lantern poles) or models with huge overhangs, because the salt can not absorb much shocks when the nozzle bangs into edges of a model (overhangs tend to curl up).

 

An original model (bottom), perfectly flat after printing. And one that sat in a laboratory oven (top) at an elevated temperature of 70°C for a couple of hours, to see how it would react and warp due to its internal molded-in stresses, as a result of the 3D-printing process.

 

Other people are very successfully using other bonding methods: hairspray, dilluted wood glue, glue stick (some wipe it with water afterwards), 3D-LAC, and other means. Each method may have its advantages and disadvantages.

 

So it might be worth sorting out the basic cause of the warping and remedy that, instead of trying to find a workaround.