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Printing a large surfboard fin  

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MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

I forgot to mention how the mystery bend in the distal slat occurred, although there was no visible detachment from the printbed, and no visible warping of the bed:

The PEI sheet got sucked up into the centre of the pads on the ends of the print. Above 110C, according to Prusa instructions I read somewhere, the glue under the PEI can liquefy.

The baffling thing is that there is no palpable hump in the PEI sheet where the larger of the 2 two concave area shown in the photos had been, but the smaller one has left a convexity. It will probably settle down over time.

Postato : 28/12/2016 6:53 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

MkMik

In order to get maximum strength, you need to increase layer height and extrusion width.

Try printing with 0.25mm layer height and 0.5mm width. But print slower (max 60mm/s) due to the larger melt volume. The only downside with be the slightly rougher finish of the taller layers. If you can live with that, your fin should be stronger.

Peter

Thank you very much!

I was actually considering to increase the layer height, but not because of better strength, but to save time. I was watching some more videos and reading about Polymaker PC-Max (and PC-Plus) today, and one of the endearing qualities is that they can be sanded nicely. So, surface finish is of minor importance, and if it increases strength and prints faster at the same time, then extreme layer height and extrusion width it shall be!

I have a set of nozzles lying around, I thought I'd want them in a hurry one day, all sizes I could find in hardened steel. Among them is a 0.5mm and a 0.8mm nozzle.

Do you think I should use a bigger nozzle and maximise extrusion width and height?

Now that you mention it, it seems obvious, particularly considering that I pointed out above that the failure mode of 3D printed objects is usually inter-layer separation. It's the weak point, so fatter layers mean less layer boundaries to potentially separate. In other words, increased strength. 😀

Is there any disadvantage to going to 0.35mm Fast setting (Prusa Slic3r)? It has 0.45mm default extrusion width and 0.43mm for solid top infill.

Do I understand it correctly that increasing the extrusion width to 0.5mm will increase the amount of material extruded, make the object potentially more water tight, but cause a rougher surface and a bit of over-size?

Postato : 04/01/2017 10:53 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Printing a large surfboard fin

You really should not go above 80% of nozzle diameter for layer height.

Changing the extrusion width will not produce over-sized models; the slicer will adjust positioning and increase the flow accordingly.

I was printing well before I even saw the PR defaults and therefore I have never used them (and never will...). what I do is to change my settings based on a small understanding of how it works and the model I am printing.

What we are trying to achieve is a perfectly rectangular cross section of extrusion which binds perfectly with the extruded material on all 4 sides. This is never quite going to happen, but by making the right adjustments, it is possible to get close.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Postato : 04/01/2017 11:10 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

You really should not go above 80% of nozzle diameter for layer height.

Changing the extrusion width will not produce over-sized models; the slicer will adjust positioning and increase the flow accordingly.

I was printing well before I even saw the PR defaults and therefore I have never used them (and never will...). what I do is to change my settings based on a small understanding of how it works and the model I am printing.

What we are trying to achieve is a perfectly rectangular cross section of extrusion which binds perfectly with the extruded material on all 4 sides. This is never quite going to happen, but by making the right adjustments, it is possible to get close.

Peter

Thanks!

Can this be assessed to some degree by looking at the proposed slicing in preview, or do I need to print it to see the results?

If I set the layer height to 0.8 * 0.4mm = 0.32mm as you suggest as the maximum for the standard 0.4mm nozzle, is that then the sweet spot for maximum strength?

Postato : 04/01/2017 11:20 am
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Printing a large surfboard fin

Personally I would say not, but that is more "experience" than calculation.

Problem with taller and wider is that the hot filament is less controlled and may not fully fill all the gaps. I don't think I would push much past 0.25, maybe try a test print at 0.3 layers and see

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Postato : 04/01/2017 11:28 am
simon.p
(@simon-p)
Trusted Member
Re: Printing a large surfboard fin

maybe relevant http://thrinter.com/high-z-resolution-3d-printing/

Postato : 07/01/2017 11:20 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

maybe relevant http://thrinter.com/high-z-resolution-3d-printing/

Cheers, an interesting read.

Note that he is printing in PLA, with a fin that has one totally flat side, and is comparatively small.

The single fins I try to print have convex surfaces on both sides and are several times larger, that's what makes it so tricky.

Postato : 07/01/2017 11:36 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

I have continued to mess around with attempts to print this fin.

Vague plans to use a heated chamber continue to ferment in the back of my head: http://shop.prusa3d.com/forum/viewtopic.php?f=14&t=2936

However, I have tried a different approach recently, and that is to print using PLA to create an accurate outer shell for the fin without the warping problems, but use other methods to add the mechanical strength required.

The photos below show a hollow PLA fin after printing with the trailing edge down on a support structure. It has hollow spaces for insertion of high tensile strength steel bolts.
Second photo shows the fin after insertion of bolts, ball spring plungers and filling with epoxy resin.

Somehow this fin ended up with 7 solid layers in the forward tips, that's why I filled the resin from the tip. Not recommended.

Postato : 25/03/2017 3:26 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

Now I'm printing a slightly modified fin with much more modified support structure. I hope it will still be stable enough to prevent wobbling when the upper layers are being printed.

Main difference is that the H-beams have been replaced by crosses, and the cross layers perpendicular to the fin's trailing edge ave been shortened so that they do not cross into the fins area. It is not fun trying to sand back PLA, I decided after a while to re-print because I made some other changes anyway, instead of sanding thoroughly. The PLA fin can only be sanded under water, or at least when very wet. It is therefore very important to print the fin so that as little sanding as possible is required.

I have also removed the short forward steel bolt hole, so that the resin-space in the front part of the tab will be much better connected to the rest of the resin fill.

First picture shows the old support structure and fin (which needs too much sanding);
second picture shows the hopefully improved support structure;
third picture shows print in progress.

Postato : 25/03/2017 3:50 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

Here is the OpenScad code, file locations for STL imports need to be amended for use on a different computer.

I have not tidied it up, lots of old stuff left in it from previous tinkering.....

$fn=25;

// Wanderfalke-2-1-W_UTFB_1-6-4-8-0-2.scad restarted 2017-03-19 to adapt for PLA printing.
// Changes made: Make rod holes a little larger to ease insertion and reduce risk of splitting: r1 +r2 increased from 2.5mm to 2.6mm; larger hole for bolt head left unchanged.

rotate([0,0,78.75]) // Rotate for alternative diagonal position on print bed
rotate([0,0,-39.5]) // Rotate union of it all so it fits on print table diagonally in Slic3r

union(){ // union of it all

union(){ // union of H-beams and base plates
// H-Beam with double base plate

translate([-140,0,0])
union(){
//linear_extrude(13){
//square(size=[10,0.8], center = true);
//translate([-5,-5,0])
//square(size=[0.8,10]);
//translate([4.2,-5,0])
//square(size=[0.8,10]);}
// Double base plate
translate([0,0,2])
cube([10,0.8,4],center=true);
translate([0,0,0.5])
cube([0.8,10,1],center=true);

union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-118,0,0])
union(){
//linear_extrude(35){
//square(size=[10,0.8], center = true);
//translate([-5,-5,0])
//square(size=[0.8,10]);
//translate([4.2,-5,0])
//square(size=[0.8,10]);}

translate([0,0,10])
cube([10,0.8,20],center=true);
translate([0,0,7.25])
cube([0.8,10,14.5],center=true);

// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-90,0,0])
union(){
translate([0,0,25])
cube([10,0.8,50],center=true);
translate([0,0,20.2])
cube([0.8,10,40.4],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-60,0,0])
union(){
translate([0,0,36])
cube([10,0.8,72],center=true);
translate([0,0,33.5])
cube([0.8,10,67],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-40,0,0])
union(){
translate([0,0,41])
cube([10,0.8,82],center=true);
translate([0,0,39.7])
cube([0.8,10,79.4],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-26,0,0])
union(){
translate([0,0,41])
cube([10,0.8,82],center=true);
translate([0,0,39.7])
cube([0.8,10,79.4],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([-6,0,0])
union(){
translate([0,0,37])
cube([10,0.8,74],center=true);
translate([0,0,34.5])
cube([0.8,10,69],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([24,0,0])
union(){
translate([0,0,25])
cube([10,0.8,50],center=true);
translate([0,0,22.8])
cube([0.8,10,45.6],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([52,0,0])
union(){
translate([0,0,14])
cube([10,0.8,28],center=true);
translate([0,0,12])
cube([0.8,10,24],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([65,0,0])
union(){
translate([0,0,10])
cube([10,0.8,20],center=true);
translate([0,0,7.9])
cube([0.8,10,15.8],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([77,0,0])
union(){
translate([0,0,6.25])
cube([10,0.8,12.5],center=true);
translate([0,0,4.875])
cube([0.8,10,9.75],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-Beam with double base plate
translate([88,0,0])
union(){
translate([0,0,4])
cube([10,0.8,8],center=true);
translate([0,0,3])
cube([0.8,10,6],center=true);
// Double base plate
union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-H-Beam with double base plate
translate([99,0,0])
union(){
//linear_extrude(6){
//square(size=[10,0.8], center = true);
//translate([0,3,0])
// square(size=[10,0.8], center = true);
//translate([0,-3,0])
// square(size=[10,0.8], center = true);
//translate([-5,-5,0])
//square(size=[0.8,10]);
//translate([4.2,-5,0])
//square(size=[0.8,10]);}

translate([0,0,1.9])
cube([10,0.8,3.8],center=true);
translate([0,3,1.9])
cube([10,0.8,3.8],center=true);
translate([0,-3,1.9])
cube([10,0.8,3.8],center=true);

translate([0,0,1.25])
cube([0.8,10,2.5],center=true);

union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}

// H-H-Beam with double base plate
translate([110,0,0])
union(){
//linear_extrude(3){
//square(size=[10,0.8], center = true);
//translate([0,3,0])
// square(size=[10,0.8], center = true);
//translate([0,-3,0])
// square(size=[10,0.8], center = true);
//translate([-5,-5,0])
//square(size=[0.8,10]);
//translate([4.2,-5,0])
//square(size=[0.8,10]);}

translate([0,0,1])
cube([10,0.8,2],center=true);
translate([0,3,1])
cube([10,0.8,2],center=true);
translate([0,-3,1])
cube([10,0.8,2],center=true);
translate([0,0,0.45])
cube([0.8,10,0.9],center=true);

union(){
linear_extrude(height=0.4){
scale([0.9,1.5,0])
circle(7.5);}
linear_extrude(height=0.2){
scale([0.9,1.5,0])
circle(10);}}}
}

//union(){ // union of sacrificial first tongue for reusable enclosure to be printed with the fin:

//difference(){ // Making the sacrificial tongue.

//scale([159,34,0.3]) // scale([159,34,0.05]) for 5mm high tongue
//linear_extrude([0,0,0.5])
//circle(1);

//scale([157,32,0.3]) // scale([159,34,0.05]) for 5mm high tongue
//linear_extrude([0,0,0.5])
//circle(1);}}

//difference(){ // Closed bottom plate same size as tongue. Differencing outer diameter of tongue from itself with 0.2mm z difference:

//scale([159,34,0.05])
//linear_extrude([0,0,0.5])
//circle(1);

//translate([0,0,0.2]) // lift otherwise identical scaled circle by 0.2mm to make thin base
//scale([159,34,0.05])
//linear_extrude([0,0,0.5])
//circle(1);

//scale([139,14,0.05]) // smaller inner scaled circle
//linear_extrude([0,0,0.5])
//circle(1);// Removing center of closed bottom to convert it into a "inverted brim"

//} // End of differencing bottom plate.

translate([112,0,125.4]) // move fin and UTFB into position on supports
rotate([0,-80.5,0]) // rotate fin and UTFB so trailing edge extreme points are level.
rotate([90,0,0]) // rotate fin and UTFB

difference(){ // Differencing threaded rods from fin and UTFB. Includes entire rest of code.
union(){ // Union of fin and plug and UTFB to allow differencing of threaded rod holes. Goes to end of UTFB and includes differencing of BSP and pin holes.

resize([0,240,0], auto=true) // resizes finFoil fin file to 240mm height.
import("/INSERT-CORRECT_LOCATION_HERE/Wanderfalke_2_1_4_5_v1.1.1-highres.stl"); // importing the finFoil fin file

color("blue") // makes base plate blue in preview
translate([-41.25,-2,0]) // translates base plate
cube([77,4,9.2], center=true); // Disable this base plate when printing fin without UTFB. The base plate purpose is to get rid of gaps between rounded UTFB tab edges and bottom of plug.

translate([-121,-22, -4.5]) // Moves the UTFB. Change translate values to move it in place for different fin base lengths. For Wanderfalke_1-9 use translate([-116.385,-22, -4.5])

rotate([0,0,90]) // rotates the UTFB

union(){ // Union of UTFB to allow importing the entire UTFB-tab into another OpenScad file

difference(){ // To remove the BSP holes by 'differencing' the UTFB-Mould from it:

rotate([90,0,0]){ // To rotate the UTFB; It was required to allow 2D printing of outline in an earlier development step:

union(){ // union of UTFB to allow rotating

color("green",0.5){ // This makes the fin base green in Preview:

minkowski(){ // Minkowski sum three times to round the base edges:
minkowski(){
minkowski(){

linear_extrude (height = 152.9, centre = false, twist = 0) // Linear Extrude length of the fin base is reduced to compensate for elongation due to Minkowski sum. Actual length after Minkowski was 150mm in initial UTFB versions (height=146); reduced to 135mm (height = 131) in Wanderfalke_1-9-cored_UTFB_2-3.scad. For Wanderfalke_2-1 use height = 148 (first versions had 146 but that makes front of base float above print bed)

polygon(points=[[0,3.1],[0,6.9],[1.5,7.1],[19,7.1],[19,2.9],[1.5,2.9]]); // Polygon points brought closer together to compensate for enlargement due to Minkowski sum. Without Minkowski sum use the actual intended size. // 9.2mm wide fin base with small taper at bottom to ease entry into the fin box. // Use these dimensions instead for 9.2mm fin base without taper: polygon(points=[[0,2.9],[0,7.1],[19,7.1],[19,2.9]]);

cylinder(r=1,h=1); } // 3 cylinders, each rotated differently, to round off the fin base edges with the Minkowski Sum function:

rotate([0,90,0])
cylinder(r=1,h=1); }

rotate([90,0,0])
cylinder(r=1,h=1); }

} // defines end of GREEN color for base:
} // end of union to be rotated
} // end of rotate base

// Cylinders for ball spring plungers etc to be differenced:
translate([7,-6,9.1])
cylinder(h = 20, r = 2.5, center = true); // Hole for aft pin

translate([7,-17,9.1]) // Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true); // First forward BSP:
translate([7,-17,9.1]) // Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true); // First forward BSP outer wide part:

translate([9,-37,9.1])// Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true); // 2nd BSP:
translate([9,-37,0])// Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true);// 2nd BSP outer wide part

translate([11,-57,9.1])// Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true);// 3rd
translate([11,-57,9.1])// Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true);// 3rd wide part

//translate([13,-66,9.1])// Move cylinder cutout for BSP
//cylinder(h = 20, r = 4.1, center = true);// 4th

//translate([13,-83,9.1])// Move cylinder cutout for BSP
//cylinder(h = 20, r = 4.1, center = true);// 5th

translate([11,-90,9.1])// Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true);// 6th
translate([11,-90,0])// Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true);// 6th wide part

translate([9,-110,9.1])// Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true);// 7th
translate([9,-110,9.1])// Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true);// 7th wide part

translate([7,-130,9.1])// Move cylinder cutout for BSP
cylinder(h = 20, r = 4.1, center = true);// 8th
translate([7,-130,0])// Move cylinder cutout for BSP
cylinder(h = 1.25, r = 4.35, center = true);// 8th wide part

translate([7,-143,9.1])
cylinder(h = 20, r = 2.5, center = true);// Front pin hole.

} // End of differencing BSP holes from the UTFB.
} // End of union of UTFB to allow importing the entire UTFB-tab into another OpenScad file
} // End of union of fin and plug and UTFB to allow differencing of threaded rod holes. Goes to end of UTFB and includes differencing of BSP and pin holes.
// End of UTFB tab
translate([0,0,0]) // Moves the union of threaded rod holes. Change the Z value to "4" to temporarily move rod holes out of fin for editing
union(){ // Threaded rods holes and internal stabilisers
// Using high tensile steel screws M5 various lengths, with heads 8.4mm diam x 5mm deep
// Available lengths (including 5mm head, then add 3mm to each to make head disappear): 135mm (5); 105mm (3 only); 95mm (7); 85mm (5); 75mm (1); 65mm (4); 45mm (5); 35mm (5); 25mm (5)

color ("red"){ // making holes red in preview for easier editing

//translate([-21,-25,0])
//rotate([-90,0,0])
//union(){ // Union of bolt hole 1 (forward):
// cylinder(h =48, r1 = 2.45, r2 = 2.45, center = true/false);
// cylinder(h = 8, r1 = 3.9, r = 4.2, center = true/false);}

translate([-42.5,-25,0])
rotate([0,0,-17])
rotate([-90,0,0])
union(){// Bolt hole 2:

cylinder(h =138, r1 = 2.45, r2 = 2.45, center = true/false);
cylinder(h = 8, r1 = 3.9, r = 4.2, center = true/false);}

translate([-51.75,-25,0])
rotate([0,0,-17])
rotate([-90,0,0])
union(){// Bolt hole 3:
cylinder(h = 138, r1 = 2.45, r2 = 2.45, center = true/false);
cylinder(h = 8, r1 = 3.9, r = 4.2, center = true/false);}

translate([-61,-25,0])
rotate([0,0,-17])
rotate([-90,0,0])
union(){// Bolt hole 4:
cylinder(h = 138, r1 = 2.45, r = 2.45, center = true/false);
cylinder(h = 8, r1 = 3.9, r = 4.2, center = true/false);}

translate([-77,-25,0])
rotate([0,0,-17])
rotate([-90,0,0])
union(){// Bolt hole 5 (aft):
cylinder(h = 68, r1 = 2.45, r = 2.45, center = true/false);
cylinder(h = 8, r1 = 3.9, r = 4.2, center = true/false);}

color ("purple"){ // Internal stabilisers to stop fin walls without infill from warping

//translate([15,0,0])
//union(){

//translate([0,140,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,160,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//}

translate([-5,0,0])
union(){

//translate([0,120,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,140,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
translate([-5,155,0])
cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,180,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

translate([-25,0,0])
union(){

//translate([0,120,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,140,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,160,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
translate([-10,180,0])
cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,200,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

translate([-45,0,0])
union(){

//translate([0,100,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,120,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,140,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,160,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,180,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,200,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

translate([-65,0,0])
union(){

//translate([0,60,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([10,80,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,180,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
translate([0,200,0])
cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

translate([-85,0,0])
union(){

//translate([0,20,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([10,40,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,200,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
//translate([0,220,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

translate([-105,0,0])
union(){

//translate([0,200,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);
translate([0,213,0])
cylinder(h=20, r1=0.1, r2=0.1, center=true);
}

//translate([-125,220,0])
//cylinder(h=20, r1=0.1, r2=0.1, center=true);

} // End purple color internal stabilisers instead of infill
// End purple internal stabilisers to stop fin walls without infill from warping
}// End red color
} // End of union of threaded rods holes
} // End of differencing threaded rods from fin and UTFB
} // End union of it all

Postato : 25/03/2017 4:05 am
erick.v
(@erick-v)
Estimable Member
Re: Printing a large surfboard fin

Good progress and very interesting read. I hope this is possible. I love to see real world applications to this technology.

Have you tried the .8mm nozzle? in all of my research, I have found claims that a bigger nozzle should give you more strength because there is more surface area and fewer gaps between extrusion lines and make the items essentially more solid.

I would try the .8mm nozzle with a .4mm layer height especially since you already have the nozzles in your collection. I saw somewhere that some people have used the .8mm nozzle to print at .1mm layer height but they are using some insane settings. Here is where I first saw it at the 12-minute mark. for your case

Postato : 25/03/2017 5:36 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

Good progress and very interesting read. I hope this is possible. I love to see real world applications to this technology.

Have you tried the .8mm nozzle? in all of my research, I have found claims that a bigger nozzle should give you more strength because there is more surface area and fewer gaps between extrusion lines and make the items essentially more solid.

I would try the .8mm nozzle with a .4mm layer height especially since you already have the nozzles in your collection. I saw somewhere that some people have used the .8mm nozzle to print at .1mm layer height but they are using some insane settings. Here is where I first saw it at the 12-minute mark. for your case

Thanks Erik, I also have the 40W heater installed in the hotend now, so using the 0.8mm nozzle should not be as much of a problem.

But, right now I'm trying to just print a nice outer shell, then fill it with the necessary mechanical strength items, namely 6mm threaded stainless steel rods x2, SS rods 5mm x2, and epoxy resin. All my attempts to print with Polymaker PC-Max or polycarbonate have failed so far, and PLA will be too weak with any nozzle size.

Postato : 29/03/2017 6:45 pm
LocalFiend
(@localfiend)
Active Member
Re: Printing a large surfboard fin

You might also consider buying some slightly longer acme screws and rods to make the Z-axis taller. Might be much less work to modify the printer than try to print something on it's side.

Postato : 29/03/2017 10:15 pm
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

You might also consider buying some slightly longer acme screws and rods to make the Z-axis taller. Might be much less work to modify the printer than try to print something on it's side.

Maybe, but I think the black metal frame would also have to be replaced by something larger. And I would have to learn some programming and what not....If I tackle that, then only as part of a very significant redesign with heat resistant components, so I can print polycarbonate in a well heated chamber.

For now I'm having fun learning to use the simpler tools in OpenScad, and there are advantages to the sideway-printing of the fin: The main forces (when surfing) run parallel with the print layers if the fin is printed standing upright. The way I print it at the moment, there is about a 45deg angle between the print layers and the main surfing forces trying to snap the fin off horizontally at the base, and trying to snap the tip of the fin off vertically.

Postato : 29/03/2017 10:41 pm
LocalFiend
(@localfiend)
Active Member
Re: Printing a large surfboard fin

[quote="MrMik"
Maybe, but I think the black metal frame would also have to be replaced by something larger. And I would have to learn some programming and what not....If I tackle that, then only as part of a very significant redesign with heat resistant components, so I can print polycarbonate in a well heated chamber.

For now I'm having fun learning to use the simpler tools in OpenScad, and there are advantages to the sideway-printing of the fin: The main forces (when surfing) run parallel with the print layers if the fin is printed standing upright. The way I print it at the moment, there is about a 45deg angle between the print layers and the main surfing forces trying to snap the fin off horizontally at the base, and trying to snap the tip of the fin off vertically.[/quote]

I think you could just bolt on another piece of sheet aluminum or steel. No need to completely replace it. Also, I don't think that there would be any programming involved. Just need to change the Z axis dimension in your slicer. Not sure if anything would need to be changed on the printer firmware but I'm thinking not.

Also, strength wouldn't be an issue if you're just going to fill the fin with resin or something anyway.

Postato : 31/03/2017 10:00 pm
richard.l
(@richard-l)
Utenti Moderator
Re: Printing a large surfboard fin

I think you could just bolt on another piece of sheet aluminum or steel. No need to completely replace it. Also, I don't think that there would be any programming involved. Just need to change the Z axis dimension in your slicer. Not sure if anything would need to be changed on the printer firmware but I'm thinking not.

Also, strength wouldn't be an issue if you're just going to fill the fin with resin or something anyway.

You would need to edit the firmware as well. It is limited in firmware at 210mm.

Postato : 01/04/2017 5:17 am
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

Finally some fins ready for real world testing!

Postato : 09/04/2017 10:48 am
erick.v
(@erick-v)
Estimable Member
Re: Printing a large surfboard fin

Those look fantastic! Did you fill them up with resin? if so what resin did you use?

Postato : 10/04/2017 11:17 pm
MrMik
(@mrmik)
Honorable Member
Topic starter answered:
Re: Printing a large surfboard fin

Thanks Eric,

yes they are filled with West Epoxy (93ml part 105 plus 31ml part 207). Probably not the best epoxy, it gets soft with heat, like the PLA, so a hot car might destroy the fins.
However, some proof of concept has been achieved, I have surfed the bumpy leading edge fin and it did not bend, crack, fall out of the box or cause any other trouble.

Postato : 11/04/2017 10:43 pm
erick.v
(@erick-v)
Estimable Member
Re: Printing a large surfboard fin

How did they "FEEL"?

Postato : 12/04/2017 12:19 am
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