i have this file which i was using to cut out theses can holders and everything was going well until i ran out of that batch of wood and now seem to have a bit thicker wood i have tried the kerf offset and even bought a set of files which once cut on your laser give you the right size including kerf for slots…
the problem i am having is with the slots that are not horizontal or vertical they are at an angle i have tried everything i know but still failing to slot together…
just wondering if anyone has any ideas as i am confused.com
I think the image failed to be uploaded as I don’t see anything here.
The .lbrn file that you attached doesn’t have any kerf set. Also, keep in mind that you will need to have a separate layer for the inner kerfs vs outer kerfs.
Can you describe in what way the parts are not fitting together?
Also please confirm that your laser can otherwise cut dimensionally correct parts in both X and Y.
hi
the tabs and slot is too tight as if the slot is too small for the thickness of the wood as i said everything was going well until i change the batch of wood i was using.
the wood is coming out at 6.4mm to 6.7mm instead of what i had before was 6.1mm
when the slots are vertical i change the thickness and they fit together fine but if i change the angled slots does not work the same way.
hi thanks for the reply i just uploaded that as an example did not set any parameter’s so when i set a kerf offset you saying i have to have them on separate layers… how do i do that ???
When I run into such a problem, I calculate the percentage difference of the material thickness and use this value to change the whole drawing with. That is, I upscale or downscale everything. Of course, this is only possible if a change in total size is acceptable.
By the way, it is not possible for me to demonstrate on your file you have sent here that there is an “error” in the ratio.
The design is drawn up for 6mm thickness but my wood is coming out anywhere from 6.2 to 6.7 mm which is causing me problems when joining the peices together. I can send you the file but not sure if that will help… what is the way you upscale how do i work that out on the percentage… thanks for your help as it is driving me crazy i have tried most things but it seems to be the slots that are angled but i will send you the parts… ove if you dont mind lòoking for me.
So with the x and y i just draw a 100mm square cut it out and mearsure the cut version to see if it is 100mm i guess minus the kerf ???
I want to sort my wood into e.g. 6.3mm and 6.6mm.
If I have a drawing for 6.0mm, for 6.3mm enter 105 in the percentage field (the aspect ratio must be closed).
For 6.6mm it is 10% you have to increase your drawing by - 110 in the percentage field.
The selected kerf setting from your original 6mm is retained.
But like I said before, your whole subject gets 5 or 10 percent bigger. If it is not acceptable, the drawing must be redone.
Kerf setting does not have to be “constructed”, it is a value that is added and automatically distributed to two connected parts. I use e.g. with 0.075mm for a tight fit. (60 Watt co2 laser)
Based on your description it’s unclear to me if the issue is in the design or in the burn. The file may clear that up.
A 0.7 mm deviation is fairly sizable. More than what I would expect from just a problem with kerf.
Have you confirmed that the wood’s thickness actually measures 6 mm?
There are a couple of different dimensional tests really.
The more basic one doesn’t account for kerf. You’re just trying to see if your motors are accurately moving to the nominal dimensions specified. So as you say, measured without kerf. You can take the average of measured cutout and the hole that it was cut from.
Test of kerf offset. If you’ve adjusted for kerf, the actual final output should measure to the designed dimensions. So if you designed for 100x100 mm, the object should measure 100x100 mm. Similarly, if you design a hole to 10 mm diameter. The actual hole should measure 10 mm diameter.
In what way is the size changing? Can you take a screenshot of what you’re seeing?
If you’re talking about the Width Height components in the Numeric Edits Toolbar then it’s because LB is showing you the Width and Height of the shape in terms of the workspace. Meaning if you were to measure it on screen left to right, up and down. It’s not showing you the pre-rotated Width and Height.
You can use the Measurement tool to show you the individual segment lengths (as well as other measurements).
You’re saying you’re able to adjust for this for horizontal or vertical parts but not those at an angle. You haven’t confirmed but based on what you’re saying it sounds like you’re changing the design size to account for this rather than using kerf offset. This is fine but I just want to confirm your approach. If this is the behavior you’re getting, and assuming the design doesn’t have a fundamental problem then it could be a material property or possibly a mechanical issue that’s not getting you the right dimensions.
yes that is correct the material varies in thickness not the design like i said when i had the old batch of wood it was around 6mm to 6.2 so less the kerf it was working out ok sometimes i had to plus or minus the kerf depending on the thickness of the wood…
ok i have checked with the measuring tool and you are correct it is the correct size i was confused because when it is on an angal the height and width in the boxes in lightburn show different values and i thought it had changed the size my bad !!!
i have a kerf tool that i can slot the wood into and it is coming out at 6.375 mm so what percentage would i need to upscale to get it too work sorry i am rubbish at maths or can you explain the way you work it out so i can understand and learn something
to be honest i think my machine is pretty spot on for squareness but i will double check
