The smallest hole I think is 3/16th inch I’ll recheck my drawing’s measurements tonight… I wish I had saved off an untouched version.
I’m good, we’ve talked 
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Amazing work you are doing!
Just wondering, why don’t you mount the camera directly on the shaft? Then it would be aligned perfectly with how the bit would cut.
Two problems. 1. The bushing would have to be rather long with a slot in it so you can pull the cable off to the side (hard to describe). 2. I think the bigger problem is the camera would be really close to the work surface once you do all that. The registration squares would have to be very small and I’m already concerned about how accurate the 1/2-inch squares are.
In another thread when I was working on this earlier this year, I came up with some ideas but they never really worked well. So I just started using the block of wood @marm sent me and the set up seems to work. I just need to make sure it’s more accurate I think (or at least verify how accurate it is).
How about if we have someone near you with a 4 x 8’ CNC carve up a 3/4" sheet of black melamine? Could put any and all markings on it that you want. squares everywhere, or line where you want them.
I talked to one of my local CNC shops, and $65 to 85/hr is what they charge in this area (Columbus OH). He thought a $100 bill could get this done for you, you provide the material. He said he makes his registrations sheets out of coated masonite.
Then you won’t have paper tearing on you. And it would be a smooth surface for the sled to ride on.
What do you think? I’ll foot the CNC charges for you.
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Well thanks for the offer, it’s very generous. But one main thing I’m trying to keep in focus is to make this accessible to everyone and not everyone has a local CNC machine shop nearby (I don’t even know what’s available around me… I’m sure someone has one). Anyway, we’ll find out just how well the laminated sheets work soon enough 
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I wasn’t thinking everybody would need one. I thought you would perhaps need something like that for the development that you are doing. If you change your mind just let me know.
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Got it. Thanks again… Let’s see how the sheets work.
Hey! Sorry I’ve been sort of off-grid for the last few months! (life has been quite crazy) I’ve dropped in from time to time but not enough to really keep 100% caught up. But I really like this idea and where you are going with it!
Perhaps I can help with laser cutting! I just saw this thread today, sorry I didn’t pipe up sooner!
I can cut up to 600x1000mm.
I can technically cut up to 1/2" thick plywood but edge fidelity goes down slightly with larger cuts (it’s difficult to explain but the first surface is accurate). (I even cut 3/4" once as a test) Generally when I’m trying to do something extremely precise I will use either 3mm or 5mm birch plywood (5mm is usually 7 ply) or sometimes acrylic sheet. MDF works but I dislike cutting it (it’s very slow because it’s full of glue/binders).
Yes the kerf is a variable but it’s also very measurable and calculable. It depends on the focal length of the focusing lens and the material being cut and the speed and power of the cut. But once you set all those things you can do a couple cuts and measure it easily. Generally speaking I allow .014" total for kerf (I offset a cut line by .007" or .1778mm)
Anyway, I know you already ordered some parts but if you need anything else I can probably donate the material and the laser time if you’re willing to chip in on shipping
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PTB - missed you! Welcome back.
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Thanks! I missed this place!!
Sort of overwhelming trying to catch up on all the happenings but I’ll get there in a week or two! ha!
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Good point on the mouse and now that you mention it, I do seem to recall that they do some interpolation, they do realize they are occasionally going to miss steps. The cameras certainly are inexpensive enough, I got one on eBay for looking at the bracing and tops of acoustic guitars and it set me back all of about $10 if that,… Measuring position over a long span and in what can be a harsh environment is not easy. I have a sawmill that has about 28" of vertical motion for the head and I would love to have a DRO on it. I have an LVDT and conditioner that will do up to a foot or a bit more, and that is big for an LVDT. I am pondering a string pot, or the same idea but with an optical encoder wheel. I also want to make a mount for a line laser that will mount on the crosshead and shine down the length of the log for setting the depth of the initial cut. I have way more projects than I have time. In the winter I will be much more into inside stuff so I may break down and 3D print the string whatever housing and the mount for the laser. I actually already have the laser though I am pretty sure I am going to need something hotter than the 5mw unit I have if I am going to be able to see it in the daylight and down a 8’ or longer log.
Keep up the good work, if you can get a nice auto cal that would be great.
One of my goals is to test out each type of linkage. I have two R22002 routers and am not terribly adverse to getting a third for testing (im sure can always sell it when done or give it to a friend who’s getting into woodworking as a present)… so I was looking at making three sleds but wanted to be certain that each is made as accurately as possible. I’d hate for sled be a little off center than the others and adversely affect the results. So I was looking for either a laser cut sled (but 3/4 inch is a lot for a laser cutter as you mentioned) or a laser cut template I could use to accurately drill holes for the linkage kits and router into a sled base. So far, my manual attempts, no matter how hard I’ve tried have been off a slight amount.
create the center hole first, then use that as the center to turn the outside
on.
It very well may be moving up and down.
some errors will cause Y to be high in one area, others may cause it to be low
in that same area, the different errors manifest in different ways, so the
interaction between the errors can be a wave, not a simple curve
I have no problem with cutting out the sled, it’s aligning the linkage kits to be perfect placed such that the center of the router bit is at the center of rotation
What’s causing these types of errors? Are you referring to errors in the control system (encoders/motors/etc) or external factors like friction?
Let’s do this in two stages
first get you whatever is needed to make this work (croudfunding the stuff as
needed)
Then figure out a cheap version that is easy for people to implement.
We are still trying to prove the idea produces meaningful results.
David Lang
I thought you were talking about cutting the camera holder
but for the sled
drill a small hole in the frame with the maslow (3/32 ideally, 1/4" can work)
drill a matching hole in the center of the sled and put them together.
move the maslow only up and down (not side to side) to drill additional holes.
IIRC, the router mounting holes are 4" on center, so move the router up 2" from
the center hole, drill a hole in the sled, rotate the sled, drill the next hole,
rotate the sled, drill the third hole.
for the wood kit, move the router up 4.5" from the center, rotate the sled 45
degrees from ‘vertical’, drill a hole, rotate 180 degrees, drill the next hole,
rotate 90 degrees, drill the third, rotate 180 degrees drill the fourth (you can
use an arm to validate these distances)
for the metal kit, you can use the j arm over a 3/32 pin and drill through two
holes to make sure the mounting is perfect.
the ring is a bit harder to center due to it’s odd mounts
then you cut out the center of the sled. move the router to 1.5" (minus bit
radius) drill down, and then rotate the sled under it until the center is cut
out.
you can do similar things to drill the holes for the brick mounts.
David Lang
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I was talking about the mechanical errors, motor spacing wrong, rotation radius
wrong, chain stretch, chain sag, etc
they won’t make much difference over a few inches, but over the width of the
machine, they will all interact in weird and wonderful ways