[mountaindew]

Ray also mentions he uses mostly g54 as his offset for a given part position. This is a great method and much simpler to setup in all cam system software on the market. The only difference is you have a G-code file for each side / position. It also allows easy post code edit to position the part where you want and any offset number. Also that frees up g55-g59 to use on different sides of the same part. Then you can line up the material in fixtures across the table and run the same file over and over just putting raw stock in fixture at left and remove complete finished parts off the right side. Steve mentions this in his posts. Always wanted to use this method because most of my 1100 table goes un-used

Using a consistent ucs located at the bottom of material works very well and or with sprutcam its no problem using any fixed position on the vise, fixture, pin or some other magic point in space . Only time Rays method has bit me was about 0.125 oversize stock combined with high feeds and speeds with a marginally tight PDB oops leads to pullout and or material pull out and the big red button I run 5-6 parts watching material fly before I had a problem.

Anyway Sorry I can't help more. Without a Hamier probe or a similar electronic device. I would not get anything done. I have a rack of tts height guages, edge finders 2 of each type and style all to find ucs positions. I try to keep extra Hamier probes in stock for the vary reason to avoid having to use them. Still they are required to pick up thin material edges or mini pallet screw down parts and hole centers.

[mnicholas77]

Maybe I'm misunderstanding something. I use G54 already for any one particular part position, i.e. Set G54 At top of stock with the part .020" below stock surface and then machine down to top of part. Then OP2 gets a new G54 located at a feature of the part to pick up the part again on part bottom once flipped for decking and other bottom side features. I usually use carvesmart jaws with talon grip like feature built in for OP1 and then place part on parallels for OP2. I reference top of parallels for Z zero, then travel up the part thickness and re zero.

Are you saying to keep my OP2 WCS zero point on the bottom of the part instead of raising it up the part thickness and resetting zero to part thickness? I'll give that a try but with instruments capable of reading down to tenths, why should it matter? If that's enough to create such wild part thickness variations, then there's a problem bigger than just where I choose to stick my WCS.

Ray also mentions he uses mostly g54 as his offset for a given part position. This is a great method and much simpler to setup in all cam system software on the market. The only difference is you have a G-code file for each side / position. It also allows easy post code edit to position the part where you want and any offset number. Also that frees up g55-g59 to use on different sides of the same part. Then you can line up the material in fixtures across the table and run the same file over and over just putting raw stock in fixture at left and remove complete finished parts off the right side. Steve mentions this in his posts. Always wanted to use this method because most of my 1100 table goes un-used

Using a consistent ucs located at the bottom of material works very well and or with sprutcam its no problem using any fixed position on the vise, fixture, pin or some other magic point in space . Only time Rays method has bit me was about 0.125 oversize stock combined with high feeds and speeds with a marginally tight PDB oops leads to pullout and or material pull out and the big red button I run 5-6 parts watching material fly before I had a problem.

Anyway Sorry I can't help more. Without a Hamier probe or a similar electronic device. I would not get anything done. I have a rack of tts height guages, edge finders 2 of each type and style all to find ucs positions. I try to keep extra Hamier probes in stock for the vary reason to avoid having to use them. Still they are required to pick up thin material edges or mini pallet screw down parts and hole centers.

[C*H*U*D]

Are you saying to keep my OP2 WCS zero point on the bottom of the part instead of raising it up the part thickness and resetting zero to part thickness?

I assumed that's what you were already doing...measure once and keeping the Z zero there. Have you checked your Z for lost motion? If you are setting the Z once, then moving up and resetting again, lost motion in the Z could be your .003" - .0035" problem.

[SCzEngrgGroup]

Ray also mentions he uses mostly g54 as his offset for a given part position. This is a great method and much simpler to setup in all cam system software on the market. The only difference is you have a G-code file for each side / position.

Not so. I have a single g-code file, no matter how many fixtures/setups the part requires, and whether I use only G54, or several different fixtures (G54-G59). Every CAM I've ever used has allowed me to do this in a single g-code file. In particular, HSMXpress/HSMWorks/FusionCAM makes it truly trivial.

Regards,
Ray L.

[mountaindew]

Reducing the number of fixture offsets is one way to minimize errors, and most parts, even when machined on all sides, can be made using a single fixture offset.

Regards,
Ray L.

Not so. I have a single g-code file, no matter how many fixtures/setups the part requires, and whether I use only G54, or several different fixtures (G54-G59). Every CAM I've ever used has allowed me to do this in a single g-code file. In particular, HSMXpress/HSMWorks/FusionCAM makes it truly trivial.

Regards,
Ray L.

Understood, using one offset to machine a 4 sided part in my opinion would not be any less error proof then using 4 offsets. Only difference is in cam setup and my software would not deal with this well unless I split that program up and then combined into one file before running on machine. The simulation I rely on to keep me from breaking precision tools is all I have for us non pro cnc users and it works best as shown above for me anyway.