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How to Find and Distill Community Knowledge

I’m new to open source and community projects like Maslow. There is so much great information in these forums that it is a bit overwhelming. I enjoy spending time reading through threads to answer questions that I have. I don’t want to reinvent the wheel and it isn’t practical to read every relevant thread, which may have 100s of comments.

Is there a way for the community to vote on, or capture the latest/greatest designs and best practices? For example, sled/linkage design. There has been trial/learning among the community since this thing started and I’m not sure which design is the “best”.

I would appreciate any insight or thoughts on this.

Thanks!
Jesse

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Well, @jwolter can help with the voting part :slight_smile:

The wiki (and the forum wiki) can be used for “best practices” and such. I try to curate the forum wiki and if someone has good information, I’d be happy to help make it into a wiki post.

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there are 3 linkage designs 1. top mount, 2 45 degree linkage and 3 ring
the ring design isn’t made anymore and it’s not economical to get one laser cut so that leaves the two pantograph linkage kits.

they are both fairly easy to make but the 45 degree one is especially easy and more tolerant of slight measuring mistakes. you take 8 metal bars and make a hole on each end 9" apart, then you use spacers/washers and bolts to connect to the sled. The most important thing is that all 8 bars are the same distance apart, so it’s not that they have to be 9" apart, they could all be 9.25" apart, as long as it is the same.

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Other desireable features when designing a sled:

  1. An 18" diameter (approximately, some have 16" for example) sled so that it “bridges” any pockets you have cut.
  2. A surface that glides smoothly over the work piece. Lots of people are using plastics, like HDPE for that. Others are using polished wood.
  3. Two L-shaped brackets to hold thet z-axis motor over the height adjustment lead screw if you are following the original kit. Others have used pre-built assemblies to raise and lower the router motor.
  4. A router that can be raised or lowered in a repeatable fashion. Some folks have used CNC spindles for this.
  5. A mount point for the chains that will cause the sled to naturally tilt pretty much parallel to the work surface.

Someone else will have to summarize the community’s experience with sled weight.

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Where might I find sheets of HDPE (or UHMW)?

You don’t say where you are, so this only applies in the US.

Amazon, eBay, your local plastic shop (bargain bins are my favorite when we hit the big city), or do a Google (or your favorite search engine) search, “uhmw sheet near me” for example

I’m not sure how thick a sheet you’re looking for, but I’ve used these as a sole on a 1/2" plywood sled:

UHMW

HDPE

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Thanks @blurfl and @mooselake
I was looking on amazon and didn’t see anything that was large enough but noticed I fat fingered the filter…I tried deleting the message but it doesn’t go away for 24 hrs! I still didn’t see an 1/8" sheet…my “google foo” is off today… :man_facepalming:

@blurfl, I like the idea of getting a very thin sheet…thanks for the links :pray:

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the sled weight should be ~20 pounds (10Kg), there is room for error, but we are
close to the limit of the motors in the top center, so if you make it too heavy
(and we know 30 pounds is too heavy), you can no longer cut along the top
properly

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I agree. I made the top mount metal kit, but it is far more sensitive to errors
(so I have it laser cut)

If you are making a linkage yourself, make the 45 kit.

the spacing between the holes doesn’t even need to be the same, as long as you
are consistant.

I’ll try to do a diagram of the things that are critical to be the same.

David Lang

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here are some diagrams

note that when I say something isn’t critical, that’s only saying it’s not critical for accuracy, you may not be able to fit the parts around the router (especially through the whole range of travel)

first the parts, showing different lengths and spacing on the 3-hole arms. Lenths, spacing, thickness, etc is not critical

Critical ITEMS
the 4 main arms must be exactly the same length (hole to hole)
the 3-hole arms must have the holes exactly in line with each other


to drill the holes in the sled, take each of the 3-hole arms, put the center hole on the router bit (helps if the hole is the same size as a bit you have), rotate the arm and drill through the sled to match the arm.
the holes must match exactly, but the angle isn’t critical for accuracy

finally assemble the linkage

The final critical item is connecting the chains to the center hole of the 3-hole arms, whatever mount you use needs to be exactly the same length on each side from the chain to the hole

the original maslow with the L brackets is not very accurate, but it is very precise (i.e. very repeatable). So if you move the workpiece from side to side under the router, you can have it drill the holes to match exactly (and if you do it in the exact center, the holes will be perfectly aligned vertically).

So you can have it drill the holes for all the arms, and drill a center hole into your backer board.
Then cut out the arms (with whatever saw is handy)
Then drill a hole in the center of the sled and put a bolt/dowel through that hole and the center hole on your backer board.
You can now drill the other two holes for one arm, rotate the sled and drill the two holes for the other arm.

make some spacers to let the arms go past each other, and stand-offs to space the arms out from the sled and you can assemble a working linkage kit.

now, all of this is much more of a hassle than just buying a laser cut kit (either the 45 kit or the top mount kit), but if you are going to DIY a kit, there is not much you really have to be precise on.

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are you sure these drawings are correct? You seems to have taken the parts for the top linkage kit and used them to make a 45 degree kit? the 45 degree kit uses 6 (or 8) arm segments which are all the same length. with center to center holes being 9" apart. the linkages are not even centered on the last drawing, I dont’ see how that could possibly work?

This is a top linkage kit. These drawings are not “final assembly” drawings, rather shown as taken apart to illustrate the different parts. Search the forums for metal pantograph and take a look at some of the pictures.

I think it might work, if one was careful to use each arm with the holes it marked, and in the same orientation as when marked. The central hole in each arm will always point toward the center of the one in the middle of the circle. I think that the sled circle in the second drawing is rotated about 120 degrees CCW from the first drawing.

my note of 8x was wrong, that’s 4x of that part.

My point is that the holes do not have to be evenly spaced to make it
work, so even if you have a maslow that is horribly inaccuracte, you could use
it to make a linkage set that looks bad, but will actually work and the result
will be accurate.

David Lang

yes exactly, sorry for the rotation of the parts between the two. I’ll try to go
back and fix that if it will help clarify things.

If you were making the parts on an inaccurate maslow, the two 3-hole parts would
be the same, but I was trying to show how extreme the errors could be and still
work, as long as the holes are drilled to match the arms and the four connecting
arms match.

David Lang

Discovered that knowledge distillation is an AI thing, then stumbled across this alternative description. Know it’s OT…

Sorry for the late reply :wink: . The best design is not determined since Oct 2018 till date.

As for the search, i’d like to share a experiance from a more visual perspective and including one of the biggest data-miners. -> Giggle!

The first Forum was a disaster on ‘search’, this Forum is better but has also flaws that seem to be related to AS (artificial stupidity) because of wrong programmed algorithms. I’m sure the intend was AI.

Copy this in the “search engine of your choice” ->forums.maslowcnc.com<- , go to images, add a blank plus the word you are looking for and you will beat AS/AI.

Pics:
Search ->forums.maslowcnc.com frame<-


Search ->forums.maslowcnc.com sled<-

Search ->forums.maslowcnc.com sprocket<-

I pick what looks like what i’m searching for and was able to find long lost posts that i needed this way.

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Thanks, Gero!

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