QIDI Plus4 - 3D Printer

[XLR8]

Your parts are looking great!

I'm about to order filament and I'm looking for some advice.
Are we selecting PTEG over say ABS for its improved printability?
According to these graphs, ABS is stronger and more heat resistant than PTEG. Maybe it's all about the "pungent odors"??

I was considering using PLA for test prints but since it's priced the same as ABS and PTEG yet it has less strength and heat resistant, why would I ever consider buying PLA? My printer has an enclosure so not limited to printing PLA which doesn't require an enclosure.

[silvertriple]

Your parts are looking great!

I'm about to order filament and I'm looking for some advice.
Are we selecting PTEG over say ABS for its improved printability?
According to these graphs, ABS is stronger and more heat resistant than PTEG. Maybe it's all about the "pungent odors"??

filaments.jpg

I was considering using PLA for test prints but since it's priced the same as ABS and PTEG yet it has less strength and heat resistant, why would I ever consider buying PLA? My printer has an enclosure so not limited to printing PLA which doesn't require an enclosure.

PLA for dimensionnal testing is just perfect as it doesn't warp...
ABS is more heat resistant than PETG for sure... But strength is another story : depends what you want to do with it. ABS is prone to degrade with UV (not the case for PETG). I found PETG is a little bit more flexible than ABS, and once ABS is bent, the breaking point is not far... I tend to prefer PETG over ABS for RC because of the added flexibility and the better printability.

And overall, PETG gaves me very good results on the 44B Hilux, and even resisted quite a good number of high jumps (and it is not broken yet)...

[XLR8]

Your parts are looking great!

I'm about to order filament and I'm looking for some advice.
Are we selecting PTEG over say ABS for its improved printability?
According to these graphs, ABS is stronger and more heat resistant than PTEG. Maybe it's all about the "pungent odors"??

filaments.jpg

I was considering using PLA for test prints but since it's priced the same as ABS and PTEG yet it has less strength and heat resistant, why would I ever consider buying PLA? My printer has an enclosure so not limited to printing PLA which doesn't require an enclosure.

PLA for dimensionnal testing is just perfect as it doesn't warp...
ABS is more heat resistant than PETG for sure... But strength is another story : depends what you want to do with it. ABS is prone to degrade with UV (not the case for PETG). I found PETG is a little bit more flexible than ABS, and once ABS is bent, the breaking point is not far... I tend to prefer PETG over ABS for RC because of the added flexibility and the better printability.

And overall, PETG gaves me very good results on the 44B Hilux, and even resisted quite a good number of high jumps (and it is not broken yet)...

Thanks!!

I'm leaning toward ABS for printing bodies that will painted so UV exposure won't be a problem. How does PTEG sand and does it accept lacquer based primer and paint? Also, what is the best method to bond PTEG? Thanks for your reply.

[silvertriple]

Thanks!!

I'm leaning toward ABS for printing bodies that will painted so UV exposure won't be a problem. How does PTEG sand and does it accept lacquer based primer and paint? Also, what is the best method to bond PTEG? Thanks for your reply.

That's the biggest advantage of ABS : it's probably the easiest material to post process, either with sanding paper, either with vapor smoothing (Acetone)...

[GreenBar0n]

PETG is the second least toxic filament, after PLA, was the impression I was under after reading on it.

If I get a tent/vent, or print outdoors, I'd go with nylon filament. Thinking about PAHT-CF, or PA12-CF, as it is less prone to moisture absorption than ABS.

[Dadio]

Just going to throw in some confusion , I don't have much use for PETG or ABS , while PETG is more flexible it's also brittle under impact , ABS is not greatly stronger on impact but is by far better in post process however it's less dimensionally accurate as it contracts on cooling causing not only warped parts but often undersize parts .
I generally go with either PLA of nylon CF

[silvertriple]

PETG is the second least toxic filament, after PLA, was the impression I was under after reading on it.

If I get a tent/vent, or print outdoors, I'd go with nylon filament. Thinking about PAHT-CF, or PA12-CF, as it is less prone to moisture absorption than ABS.

ABS is not prone to moisture absorption, like ASA. All nylon composite material (PAHT-CF, PA12-CF, PA12) and polycarbonate are really the opposite : not ontly the absorb moisture, but they do it very quickly, and you won't be able to print properly if they are not perfectly dried before...

[GreenBar0n]

PETG is the second least toxic filament, after PLA, was the impression I was under after reading on it.

If I get a tent/vent, or print outdoors, I'd go with nylon filament. Thinking about PAHT-CF, or PA12-CF, as it is less prone to moisture absorption than ABS.

ABS is not prone to moisture absorption, like ASA. All nylon composite material (PAHT-CF, PA12-CF, PA12) and polycarbonate are really the opposite : not ontly the absorb moisture, but they do it very quickly, and you won't be able to print properly if they are not perfectly dried before...

I do see though that they advertise PAHT-CF, and PA12-CF, as being "low moisture sensitivity:
https://www.amazon.com/QIDI-TECHNOLOGY-Filament-Strength-Precision/dp/B09M8BMT2T

R QIDI TECHNOLOGY PA12-CF Nylon Filament 1.75 Black, Carbon Fiber Nylon Filament 1.75mm 1Kg Spool 3D Printer Filament, High Strength, High Precision, No Warpage, Low Moisture Sensitivity

[silvertriple]

What they compare to? Nylon is known to absorb moisture, filled material will absorb less in comparison....
But still, it will absorb moisture, and need to be perfectly dry to be printed correctly.
At the end, there is material characteristics, and commercial BS is to be avoided because it is purely marketing : marketing teams are really good to make illusions from partial facts just by turning sentences in a way that makes up something which is not true in reality...

[GreenBar0n]

I don't know what they are comparing their PA to, but that's a $100 roll of filament, if it had serious moisture issues someone should've complained in the comments about it by now. I'll try it out and see, at some point.

The humidity here is usually between 20% and 50%, I have acoustic guitars that require 40%, so I have to contend with that indoors.


Started printing in the Olive matte PLA, this stuff is soft and brittle, but prints really well.


Might have to make his legs out of the stronger non-matte PLA, the matte lower legs snapped off.

[silvertriple]

Reference image taken from Bambulab filament guide. Note the highlighted descrition for "seal with dessicant"


And this is not unique to Bambulab filament, this is inherent to the material used. Nylon, Polycarbonate for example are really moisture sensitive filament. Maybe carbon filled filament is less moisture sensitive than pure material, but it would still be moisture sensitive to a certain degree...

So ultimately, those materials need to be completely dried before printing and kept sealed with dessicant during printing.

[GreenBar0n]

Perhaps QIDI's carbon fiber PA12-CF is that element that resists the moisture, maybe the way the filament is processed has been improved, can't guess, but don't know for certain, I just don't believe they would entirely make that claim up.
https://www.amazon.com/dp/B09M8BMT2T


I have a set humidity here, 20-40% and the higher the better for acoustic instruments, those take priority, will have to figure it out when the time comes. Hoping the QIDI AMS said to be out in Q1, is a dryer/mixed abrasive filament unit.


Got 1 1/2 crash test dummies printed, and assembled.


Also got the screw kit for the Manx dune buggy, going to start building that next.

[GreenBar0n]

With the help of XLR8's CAD skills, we borrowed a CAD model of an early VW Bus from a gentleman by the name of Stan Ellis, over at TheSamba.com, thanks Stan! He'll never see this project, here, but I'll make sure to let him know over there when we're getting close.

XLR8 and I are attempting to 3D print a '50'-'55 Barndoor era VW Bus, from the ground up, and as close to scale as possible - extremely ambitious, we'll see if it turns out.

This current iteration is in 1:10 scale, but we have planned to go up to 1:6 scale, if all goes well.

This is in (3) pieces so far. Will need to strengthen the ladder frame chassis, maybe make it solid with a 25% infil for strength, in order to support the weight of the rest of the print.

First run at 1:10






The Olive Matte PLA is way too brittle, even for prototyping, the silver PLA is much better for this, but we'll settle on something stronger when the details are worked out.

Going to print the floor section in non-Matte PLA today.

Need to add belly pans to the bottom of the ladder frame, like a real Bus has, in order to make the frame more rigid.

[XLR8]

The test print look good!
Those belly plates will be easy to model, print and attach. Although the floor assembly print isn't meant to be structural, the plates should add some rigidity making it less brittle.

We can add a full aluminum pan to the top side of the frame assembly to give the bus a proper backbone. Thus, the front and rear frame subassemblies can be attached directly to the aluminum pan and create a rigid structure. The floor assembly print is only meant to accurately replicate the 1:1 bus; it's really not a structural element.

I'm very surprised to learn that PLA strength differs with color. Or, do you think it's the matte finish that's causing the print to be brittle?

[silvertriple]

The test print look good!
Those belly plates will be easy to model, print and attach. Although the floor assembly print isn't meant to be structural, the plates should add some rigidity making it less brittle.

We can add a full aluminum pan to the top side of the frame assembly to give the bus a proper backbone. Thus, the front and rear frame subassemblies can be attached directly to the aluminum pan and create a rigid structure. The floor assembly print is only meant to accurately replicate the 1:1 bus; it's really not a structural element.

I'm very surprised to learn that PLA strength differs with color. Or, do you think it's the matte finish that's causing the print to be brittle?

Any additive can change material properties regarding printing : ideal printing temperature and speed maybe affected, resulting in different layer adhesion. PLA+ is also having lower layer adhesion than PLA.
Some would even advise to do temperature tower, Flow calibration, Pressure advance calibration for each new roll of filament, even if it is same color/brand than the previous one used.