First ever print

[ahp 0]

Hey,

 

For my first print I was wondering what the optimal position for my object(small box) would be? Right now it is oriented on it's bottom but there are some problems with the handle of the box and the two stoppers on the side which would need support. Cura also indicates that the letters and number need support but these protrude only 2mm(at max). Do these elements need support? I can also position it on the back of the box instead of the bottom but then it will need alot of support (I suppose) in order for the front panel to print good. What would you advise?

 

Printing on an aquintance's MakerBot Replicator 2 (which as far as i know only takes PLA(?))

 

box dimensions:

51(width) x 34(height) x 64.2(depth)

 

Some images of the box & .stl attached

 

Thanks, a.

3DP_Brause-1.5-test.stl

[gr5 2,024]

stick with pla, yes.  Much easier than other filaments.

 

You could print it on it's back (last pic) except for those "stoppers".

 

I'd probably print it in the first photo orientation.  The front handle will be fine.  45 degree angles are fine and then you have bridging which prints reasonably okay.  Although I'd fix the stoppers by adding a 45 degree angle at the bottom of them.

 

Also I would have the text only stick out by 0.5mm and it should be okay.

 

I try to avoid support and I don't think you need any support for either of those 2 orientations if you fix the stoppers in cad and shrink the text to 0.5mm extrusion.

 

[ahp 0]

Thanks for the advise!

[geert_2 556]

 

For best quality of the text, I would print it on its back, thus the text facing up. But I would design custom supports, so that I would use far less material, and waste less time. Similar to this test with support bridges shown below, after an idea of user smartavionics if I remember well. I don't know if this feature is already integrated in newer versions of Cura? (I am using an older one.) If yes, try that first: it will probably give a much better undersurface. I have UM2 (non-plus) single nozzle printers, so I can print in one material only (this is PLA).

 

 

 

 

[ahp 0]

Interesting tips, thanks. It would be more important for the text to print good instead of the back of the front panel and "stoppers". I'll search for that feature or if you have info on how to create such support..most welcome :-)

[geert_2 556]

I modeled this test table in CAD in DesignSpark Mechanical (freeware, requires registration).

 

Dimensions in this test model:

- for reference: most plates are 1mm thick, text caps height is 3.5mm, text legs are 0.5mm wide

- horizontal gap between supports and model: 1mm

- tiny connection strands to keep support attached: 0.5mm wide (for nozzle of 0.4mm) x 0.2mm high (=2 layers of 0.1mm). These can easily be cut off, and cleaned.

- inverse staircase in supports: steps of 1mm. This staircase reduces the overhangs curling up, but does not eliminate it. But in my tests these stairs worked better than a 45° overhang slope.

- ribs on top of support: 0.5mm wide x 0.5mm high x 1mm horizontally separated.

- vertical gap between ribs and underside of model: depends on model, usually 0.2 to 0.4mm. Try what works best for you.

- supports extend sideways, bigger than the model: 0.5mm to 1mm. Making the support a bit bigger than the model improves the edges of the first layer of the model. Otherwise they sometimes sag and fall off the supports.

 

I think this was the STL-file of the model:

overhangtest11e.stl

 

Also, for bigger models or difficult to reach areas: make very sure you implement enough features to insert pliers, hooks, knifes, and other tools to remove the supports. So you don't get stuck with unreachable and unremovable supports. This make take quite a lot of planning in complex models. Here too: the supports took way more time to model and test, than the table itself.

 

[ahp 0]

On 3/1/2019 at 4:56 PM, geert_2 said:

I modeled this test table in CAD in DesignSpark Mechanical (freeware, requires registration).

 

Dimensions in this test model:

- for reference: most plates are 1mm thick, text caps height is 3.5mm, text legs are 0.5mm wide

- horizontal gap between supports and model: 1mm

- tiny connection strands to keep support attached: 0.5mm wide (for nozzle of 0.4mm) x 0.2mm high (=2 layers of 0.1mm). These can easily be cut off, and cleaned.

- inverse staircase in supports: steps of 1mm. This staircase reduces the overhangs curling up, but does not eliminate it. But in my tests these stairs worked better than a 45° overhang slope.

- ribs on top of support: 0.5mm wide x 0.5mm high x 1mm horizontally separated.

- vertical gap between ribs and underside of model: depends on model, usually 0.2 to 0.4mm. Try what works best for you.

- supports extend sideways, bigger than the model: 0.5mm to 1mm. Making the support a bit bigger than the model improves the edges of the first layer of the model. Otherwise they sometimes sag and fall off the supports.

 

I think this was the STL-file of the model:

overhangtest11e.stl 117.66 kB · 3 downloads

 

Also, for bigger models or difficult to reach areas: make very sure you implement enough features to insert pliers, hooks, knifes, and other tools to remove the supports. So you don't get stuck with unreachable and unremovable supports. This make take quite a lot of planning in complex models. Here too: the supports took way more time to model and test, than the table itself.

 

Hey Geert,

Thanks for these tips and the .stl. I'll try and construct something similar for my model. Cheers!

 

[ahp 0]

I tried constructing some support for the overhanging parts of my model. I'm thinking that I will remove the middle connecting arm of the outer supports (small supports under the "stoppers") before I print it (see purple arrows in the image). Any other suggestions or concerns you might notice?

 

Edit: Oh my...I scaled your model in netfabb in order to measure it without realising this also scales up the original distance and measurements of the support...the inner support is about 5x too big...argh

3DP_Brause-3-vert.stl

Edited March 5, 2019 by ahp
addition

[geert_2 556]

Yes, I was going to say it looked too big indeed... :-)

 

But in my model, the connection strands are not plates, but just sort of tiny "hairs": they are 0.5mm wide (=a bit more than nozzle-width), 0.2mm high (=2 layers of 0.1mm), and 1mm long (=the distance of the gap).

 

Before you print the whole box, try the concept on a small test piece first, to find the best dimensions for your materials and printer.

 

The concept is clearer in this pic, where only the outer supports are shown. For reference: the upside-down stairs and the table plates are all 1mm. For small models, these tiny strands provides enough strength, and they are easy to cut.

 

[ahp 0]

yeah 🙂

 

Thanks for the specific measurements and clarification. I'll make testprints first.

[ahp 0]

I am in the proces of constructing the supports. I measured from the model you supplied that the supports are .7mm apart. I made a mistake which caused the distance between 2 rows of supports to be .8mm. Does this matter or is this still ok?

[geert_2 556]

On 3/9/2019 at 3:35 PM, ahp said:

I am in the proces of constructing the supports. I measured from the model you supplied that the supports are .7mm apart. I made a mistake which caused the distance between 2 rows of supports to be .8mm. Does this matter or is this still ok?

Do you mean the ribs on top of the supports? I usually design them on a 0.5mm grid, so they are usually 0.5mm wide (a bit wider than my 0.4mm nozzle), and 1.0mm separated from each other. But this is not critical, and occasionally they may differ in my designs.

 

The vertical gap between the support-ribs and the bottom of the real model usually is 0.2mm to 0.3mm. The idea is to get the supports as close as possible to the real model for best accuracy, but without fusing them. So, dimensions may depend on the material you use, printing temp and speed, amound of fan (more fan = more cooling = less fusing). I would suggest that you make several small test pieces with slightly different dimensions, and then select the one that works best for your situation. It may require some trial and error...

 

[ahp 0]

On 3/11/2019 at 2:32 PM, geert_2 said:

Do you mean the ribs on top of the supports? I usually design them on a 0.5mm grid, so they are usually 0.5mm wide (a bit wider than my 0.4mm nozzle), and 1.0mm separated from each other. But this is not critical, and occasionally they may differ in my designs.

 

The vertical gap between the support-ribs and the bottom of the real model usually is 0.2mm to 0.3mm. The idea is to get the supports as close as possible to the real model for best accuracy, but without fusing them. So, dimensions may depend on the material you use, printing temp and speed, amound of fan (more fan = more cooling = less fusing). I would suggest that you make several small test pieces with slightly different dimensions, and then select the one that works best for your situation. It may require some trial and error...

 

Hey geert, thanks for the extensive info..i'll give those variables a try as soon as i find some time..Cheers

[Reverse_Engineer 0]

I don't know if you've printed it yet but another possibility would be to split the model into two parts and then glue or screw it together.That way you could  print the face on its back and you'd only need supports under the two tabs on the front panel and along the slot on the stepper bracket. I'd split it along the red face on underside of the fascia in your model shown in your pic.

Edited March 14, 2019 by Reverse_Engineer

[geert_2 556]

14 hours ago, Reverse_Engineer said:

I don't know if you've printed it yet but another possibility would be to split the model into two parts and then glue or screw it together.That way you could  print the face on its back and you'd only need supports under the two tabs on the front panel and along the slot on the stepper bracket. I'd split it along the red face on underside of the fascia in your model shown in your pic.

 

Yes, this is also a good idea, provided that the material can be glued well (PLA, ABS). Not for nylon or PP, or PE.

 

In that case I would design alignment features into the model, so that both parts can easily be mated up. For example by cutting it along this blue line. Add a ~0.2mm tolerance gap (this depends on printer accuracy, material flow, temp,..., so you may have to experiment).

 

 

[ahp 0]

On 3/14/2019 at 4:00 AM, Reverse_Engineer said:

...and along the slot on the stepper bracket...

What part do you mean by this ?

 

On 3/14/2019 at 6:20 PM, geert_2 said:

Yes, this is also a good idea, provided that the material can be glued well (PLA, ABS). Not for nylon or PP, or PE.

What glue would be best to use to glue the two parts together? (this will be printed with PLA).

 

On 3/6/2019 at 12:59 PM, geert_2 said:

But in my model, the connection strands are not plates, but just sort of tiny "hairs": they are 0.5mm wide (=a bit more than nozzle-width), 0.2mm high (=2 layers of 0.1mm), and 1mm long (=the distance of the gap).

Are the dimensions drawn in the attached picture correct?

[geert_2 556]

The "0.1mm" should be "1.0mm", to bridge the gap of 1mm between walls and support. Also see the STL-file above, and the picture, where most other major dimensions are 1.0mm also (the width of all plates, and the stair-cases).

 

This is what works for me, but of course, you may want to adapt it to your situation. Different materials, models, and printing circumstances may require different parameters. Before printing big models, I would recommend you design a few small test models with lots of variations, and print these with your typical setup, so you can see what works best for you.

 

For bonding PLA, I use standard Loctite cyanoacrylate glue, after sanding the surface a little bit.

 

[ahp 0]

Ok, will do that. Thanks for the advice !