Osprey Calibration and repeatability testing

Leo Voisine

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East Freeetown, Massachusetts
This weekend I finally got back to setting up the Osprey. I had a couple of retirement projects to do before I could get this done.

I got the step per inch calibrated to with .0005 - .0010 over 48" on the "X" & "Y" axis and within the same tolerance over 10" on the "Z" axis.

The repeatability and reliability test was within .0005 on all 3 axis's

This is far above my expectations for a Chinese built machine.
I was expecting about .002 - .005
Not complaining.
I am impressed.


 
Thanks for the video Leo, fascinating how you did it. I always wondered about how repeatable these machines were. Would be interesting to see if one of the guys with the smaller units could do a test and see how theirs goes in terms of repeatability accuracy. Thanks for showing how its done.

What holds those T Tracks in place in the center. ?

One would have thought that the manufacturer would have at least got that rubber flat.

Are you going to live with that as your surface or put a waste board across the whole thing? Only thing then is how do you hold things down.

I guess waste boards are for guys like me that are always making mistakes. :rofl:
 
Thanks for the video Leo, fascinating how you did it. I always wondered about how repeatable these machines were. Would be interesting to see if one of the guys with the smaller units could do a test and see how theirs goes in terms of repeatability accuracy. Thanks for showing how its done.

What holds those T Tracks in place in the center. ?

One would have thought that the manufacturer would have at least got that rubber flat.

Are you going to live with that as your surface or put a waste board across the whole thing? Only thing then is how do you hold things down.

I guess waste boards are for guys like me that are always making mistakes. :rofl:


Rob, I knew you would be interested in the results.

The setup for the repeatability was a tiny bit tricky. I write my own G-Code, so I could get it done the way I did it. I just thought it was a cool setup, it could have been done simpler.

I don't think my other two machines would share the same results.

As to the quality of the fit and finish (the table not being flat), I have no issue with that. For the price difference I planned on some inefficiencies. The workmanship of the Chinese leaves a little bit less than desired. The machine is solid and the components are fantastic. The welds are cosmetically unappealing, as is the paint job. Those things can be fixed. I expected all of that. When they assembled the machine they didn't do a good job tapping holes. I have re-tapped several already. I re-machined a few components, re-drilled some holes and realigned. When they assembled parts they drilled for the tap through both components but no clearance hole in the mating part. They tapped through both components, and of course that is improper. I have fixed a lot of that, including the "T" channels. Not disappointed at all with the machine. It just keeps getting better. The bones are just as they should be. Everything is just as I expect. I have heard from many Chinese machine owners before buying, so, I was ready for all of this.

The proof of the pudding is in the eating. The repeatability is fantastic. I am just loving this machine.

As to the spoil board - yes I need a spoil board. I will have one every time I need one. I just don't need one all the time and the one I need will just be scraps as I need it. There will not be a permanently mounted spoil board. I will take advantage of the "T" slots, even when I do use a spoil board.
 
Hmmm, I have 2 dial indicators laying around. I'll pick up another one and see if I can do something similar. Should be fun to see what the results are.
 
Cool Brent it would fun to see what you get.

My guess as to repeatability in a lighter machine would be the same but be influenced by what is being cut , how much its expected to take off in each pass and how fast its been pushed to do it.



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I know for sure I've got some slop in mine. Also have some flex in the X axis, so I try to run some light final passes to clean things up. I should do the test to see how much screw slop I have and add that into mach3. Thanks for the video/walk through Leo.
 
When I looked at the specs on the HiWin rails I was really impressed. I kinda thought the rack and pinion drives would be a bit of an issue, but so far, I have not seen any evidence of that.

I just finished two retirement gifts for guys at work. At one point I was cutting corian with a 1mm (.039") end mill at 15-18 IPM. The machine is as smooth as silk. That tiny end mill would not take any sort of jiggling around.
 
WOW am I understanding you correctly you saying the diameter of the bit is 1mm. I am utterly amazed. I cannot comprehend how that bit cuts yet does not break. And on top of it u saying in Corian not basswood. Lol.

Can you help me out in understanding how a bit that size stands up to any lateral pressure. Is it spindle speed???

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WOW am I understanding you correctly you saying the diameter of the bit is 1mm. I am utterly amazed. I cannot comprehend how that bit cuts yet does not break. And on top of it u saying in Corian not basswood. Lol.

Can you help me out in understanding how a bit that size stands up to any lateral pressure. Is it spindle speed???

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I have gone down to 1/64 bits (.015"). I do break those. Maybe this machine will handle it better.

Corian actually cuts very nicely. It's all about chipload. I am cutting at .020 deep, that is half the diameter of the cutter and at about 15 IPM. I watch the chips and when I see chips, not dust - that's the place to be. I have been running this spindle at 10,000 to 12,000 RPM. It is soooo quiet and smooth. Basswood would be more difficult to cut.

I cut 440C stainless steel with a 1/16 end mill. Somehow a 1mm in Corian doesn't seem so bad.

I actually burried the 1mm cutter down to about .093 deep - .02 depth at a time. I walked away and came back when it was finished.

I have a video's and pics. I need to put the vid n pics together and edit them into a movie, then I can post them. I should be able to catch up with some of that this week.
 
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