3ddave

hi ultiarjam, I did also wonder about the properties of the material, the pla that came with the machine was new and I never had this problem, but the problem always occurred with 4 different rolls of differing colours of abs that I bought at the same time from someone selling it cheaply and I wasn't sure if it was cheap because it was old or deteriorated due to its age and was no longer fit for purpose. I will be experimenting now in light of the answers I have received. I do not have any data for the rolls that I have and I do not know yet how to accurately measure softening rates but with the parameters you have given me then I guess a thermometer in a pan of water may be an option. dave

hi gr5, thank you for your very comprehensive and informative reply it has given me a much better understanding of the principles involved. I did notice that the problem occurred more on the cooling fan side of the print and also on the side of a very cold draught as I am operating in a cold draughty and unheated garage and as you say the problem occurred more on angular surfaces with thin sidewalls. I think that you have also hit on the bonding between layers as being a possible cause. I also had another issue and posted a question (oversize prints) in one of the other topics, this was due to large a setting on the x and y steps / mm, so I would also be suffering from weak horizontal bonding as well poor vertical bonding. you have given me the best possible answer on this problem and how to reduce it just has the contributer on the other topic and would like to thank you again and this site/forum for expanding my knowledge and understanding in the world of 3d printing. dave

hi Robert, success! when I 1st put the new settings in the machine they kept getting overwritten by cura when I sent the print to the machine, but following your lead and a lot of experimentation I managed to add some programing to the start of the g code and now my prints are true to scale and I have gained a lot more experience thanks again dave

hi Robert, sample part size that I drew on sketchup. not sure of the printer manufacturer its a marlin, rep rap, ultimaker clone, I use cura 15.04 and get the same results with both abs and pla set to their recommended temps. the model size should be 24 x 39 x 7.5 but comes out at 28 x 44 x 7.5. I think it has ramps hardware, I bought the printer 2nd hand and have no information with it.

hi Robert, sample part size that I drew on sketchup. not sure of the printer manufacturer its a marlin, rep rap, ultimaker clone, I use cura 15.04 and get the same results with both abs and pla set to their recommended temps.

hi, when I do prints using abs they have a tendency to de-laminate and split in a curving fashion, they are also very easy to break apart between layers. is there anything I can do to reduce this? thanks dave

hi, when I make a print the overall size is approximately 10% larger on the x and y dimentions to those shown when I scale the print, the z size is just about right. is there any way that I can rectify this to give a more accurate print. thanks dave