Yes Aiph5u, I know it has been discussed here before and one can search for it, but I do not understand what is written in here about the coplanarity test.
So, based on what I’ve read, you do the following:
Get a couple pieces of fishing line ---- check
put weights on each end of the line — check
put one end over the top tube of a y axis rail — check
put the other end over the opposite corner on the other y axis rail — wait a minute…
Obviously, you can’t just rest these over the top of the tubes, because they’re tubes and they will slide away from the corner. The presumption is either that I’m going to have to put some tape to hold them in place (and use the x axis gantry for holding the other end in place), or I’m misunderstanding and doing this whole thing wrong.
Is what I’ve got in the pictures below an acceptable way to test this?
Once I’ve done the above, I have moved all four leveling knobs and can’t figure out a way to bring these two pieces of string together. I have to believe I’m doing something wrong, and it’s not that it’s so out of whack that the adjustments wont fix it…any thoughts?
Move your y-axis gantry to the middle, then move the x-axis the whole way to the right or left. The gantry bearing block in your picture looks like it’s touching the fishing line, which it can’t be doing.
Make sure the fishing lines are as tight as you can possibly get them. If either sags, you’re not really getting any useful information. If one line is pulling the other down, put that line under the other one.
I use the screws on the top of the aluminum extrusion that hold the tubes in place, the extrusions should be consistent enough for this to be an acceptable reference point.
I just did that and it looks pretty on the money, I even tried picking up on the corners of the QCW and couldn’t make it move much at all, and also swapped the top string around and not much difference. I went down this road (or rather I should say I had avoided going down this road until) because on my surfacing pass, I found that the back right corner of the WB didn’t have an edge to it even though the rest did, so I was thinking there might have been a twist in the setup, but maybe the boards themselves are not quite right and had a low spot back there. I’m gonna make another surface run a little deeper and see if it works itself out.
by the way, if you want to send me a signal from inside a post, put an “@” sign (the Ray Tomlinson sign) in front of my username, like this: @gilbee.
Three points in space are always in one plane (a table with three legs can not wobble). So if the fishing lines touch, you got to first reverse the fishing lines so that the other is on top, and adjust the fourth foot in height until the fishing lines just touch in both situations. Which foot that is does no matter. Professional gantry-type CNC machines have adjustment mechanisms to adjust this, and the Any Surface Leveling System that only works with QCW Frame is the first system that provides this that Onefinity offers for their machines. Unfortunately not for the bare machine, that is sold without millling motor and without a machine base (both has to be provided by the customer).
Note that this machine is welded out of 10 mm thick(!) rolled steel profiles and the frame is annealed for stress relief with temperatures of 550 – 650 °C in a gigantic annealing furnace like shown here and here – and still needs to be adjusted for coplanarity because it is still not stiff enough to not be twisted if the workshop floor is not even (it never is) and coplanarity is not adjusted.
Image: A workpiece has been annealed for stress relief in a big annealing furnace at the Glüherei Magdeburg.
If you manage that the four Y rails ends are in one plane (=machine is coplanar), this is the relevant part. It may be that your wasteboard is still not even. In this case you should remove material from the surface until all regions of the wasteboard are machined. On the other hand, if the machine’s Y rails ends are not in one plane, surfacing the wasteboard or the tabletop will not remove the twist.
Please forgive me that I did not provide a more detailed howto. I will do that with photos once I assemble the machine, I first have to move to another place before I can have the new workshop there.
@Aiph5u (a table with three legs can not wobble) You haven’t seen my tile flooring.
Was planning on using the unused bolt holes on the top ends of the Y rail brackets, will they be accurate enough?
Will have to watch that the loop on the string does not climb the bolt thread.
Thanks for all your contributions to this forum @Aiph5u !! You mentioned that it does not matter which foot to raise. In my case I have 1/8 “ gap between the fishing lines. Im debating to raise one foot so much. Maybe it would twist the Z travel? I’m just not sure what exactly to move other than one foot. Any suggestions?
I ended up using playing cards to shim the two feet that were attached to the lower string until they were high enough to touch the higher string (a total distance of 1/8”). Then I resurfaced and ended up nice and flat. I also replaced the smaller lag screws with some much beefier ones. I finished with a quick v-carve. I’m super excited for the possibilities. Thanks again to everyone who has been posting their experiences and advice.
