@@ -12,9 +12,43 @@ Plastic is not the first place engineers usually go when designing this kind of
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@@ -12,9 +12,43 @@ Plastic is not the first place engineers usually go when designing this kind of
### 3d-print
### 3d-print
Carriage & final carriage
- 3x belt clampers
- simple beam joinery
- 15x T joins
- 14x simple joint
- 5 hours
### laser cut
### laser cut
Watch out for kurf offset parameters
That affects how tightly everything fits together. Currently set to (0.1mm per edge)
Before we go on to cut a bunch of stuff, we need to talk about some basics of setting up the laser cutter. Since everything here is meant to be semi-precise, we need to have our cutter and parameters up to par to ensure the machine will work as intended.
Machine adjustments:
- Make sure the laser cutter is cutting straight. This is the first point of failure and can cause parts to not fit quite right or not fit at all.
Design adjustments:
- Measure your material thicknesses. Variations in this can cause the current design to not work. Currently the setup is for thickness of thick sheet to be 6.75 mm and thin sheet to be 3.2mm (as measured on McMaster sourced Delrin used). On each part for the CAT, make sure to adjust the t_MAIN and t_SECOND variables to match your specific material. Note: even 0.1 mm is enough to mess up tightness of system. You will need to test this.
Kurf compensation:
- The laser does not cut a 0 thickness line. the laser itself has a certain cut thickness and that changes how the pieces will fit together. In each part, you an see variables for "squeeze_factor" or "kurf offset". Squeeze factor should be -2 * kurf offset. For the setup of the laser we are using (Trotec Speedy400), the kurf offset that works is 0.1mm. Note: You **will** need to adjust this to make it tight. Below, I have outlined a procedure to tune these parameters so that everything works nicely.
Setup for cutting delrin:
Cutting 1/8" Delrin is super easy. 3/16" is also relatively okay. Both of these are done well on a 50+W laser on a single pass
1/4" can start being a pain. You see quite a bit of melting and re-solidfying that causes parts to re-adhere and makes them hard to take out. After cutting quite a bit of 1/4" delrin, I have found that the best way is as follows:
Inside cuts: single pass with highest power (tune speed until it cuts nicely through)
Outside cuts: double pass with highest power (tune speed until it cuts nicely through) + single pass with highest power and 2x speed than previous cut. This will help get rid of the small bits that get stuck at bottom.
Even with this, you might need to get a razor or something to help take some parts out (especially large ones that might be out of focus in certain areas). To punch inside parts out, you can get a fancy tool, but I like to just use my keys or literally anything that won't break.
Note all values as follows include prep and taking out parts.
- carriage
- carriage
- Side plates x2
- Side plates x2
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@@ -23,9 +57,18 @@ That affects how tightly everything fits together. Currently set to (0.1mm per e
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@@ -23,9 +57,18 @@ That affects how tightly everything fits together. Currently set to (0.1mm per e
- each 8 mins
- each 8 mins
- Bottom face x1
- Bottom face x1
- Front facex1
- Front facex1
- Note here, the kurf offset is on the diag web not on the slots like usual
