Shark HD3 Z-axis problems

Discussion/questions about software used with your CNC Shark and programming issues

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Re: Shark HD3 Z-axis problems

Post by dgarvin »

Thanks for all of the responses!

I'll be investigating this further in the next few days with all the suggestions. I have found how to view the virtual zero adjusted file and I suspect I can use the ctrl-c/ctrl-v copy and paste to stuff it into a text file.

Are there any free g-code simulators out there that will allow me to visualize the virtual-zero adjusted file?

"The right tool can be used for just about anything" - Red Green

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Re: Shark HD3 Z-axis problems

Post by dgarvin »

So, just to update what happened...

I did a ton of experiments with using virtual zero, not using virtual zero, manually jogging the spindle around, tramming a spoil board, manually editing the g-code and found absolutely nothing. Everything on the system is working properly: no play in the bearings, all connections are tight with no wiggle, router is (well, almost is) vertical, and there are no chips or other anomalies on the X/Y/Z worms.

I created several tap files to surface an entire board, cut various pockets, and measured the errors in lots of different cases. No problems. I never got around to messing with the post-processor because I wasn't finding issues with the g-code that was coming out.

I finally went and reloaded the same project, with the same board, under the same conditions, with the same tap file, and performed another virtual-zero procedure. I pulled up the adjusted code and reviewed all of the z-height settings and did the manual calculation on several points. Everything looked correct.

I said to myself "Screw it!" and ran the program.

What came out was the most perfectly cut sign I have ever made. No variations in z-height. No problems whatsoever. I spent several weeks chasing a problem that went away on it's own.

There is something in the code for the control panel coupled with the virtual zero that messes things up. I know this is going to pop up again but thanks to all the comments and suggestions here, I know where to go looking when it happens. Thanks again everyone!

"The right tool can be used for just about anything" - Red Green

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Re: Shark HD3 Z-axis problems

Post by Bob »

One more afterthought...If it has not already been checked, Is the Z screw drive coupler tight. Is the setscrew seated tight on the flat portion of the shaft? If not, there could be future unwanted movement.

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Re: Shark HD3 Z-axis problems

Post by jeb2cav »

Thanks for posting a followup. Too often the outcome never makes it here - so you never know. Bob's last comment is a good one as well. I have seen what I call 'free electrons' play a role over the years. In my case, I eliminated all of this with a UPS - primarily for power conditioning aspect vice battery backup.

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Re: Shark HD3 Z-axis problems

Post by Paco10 »

jeb2cav wrote:Hi Dave,

Some additional thoughts after entering the conversation at this point - from your very first picture - having a ~0.35" difference in pocket depth is frankly either a rogue virtual zero setup (somehow) or you have a mechanical issue of some sort (that may be hard to recognize). If you have any slop at all, you may want to try loosening the z axis coupler, getting it all 'tight', and then tightening it and trying again. I would frankly run with without a virtual zero workflow for a starting sense of the mechanical condition. Could be a burr along the spiral rod as well - or a hard bit of material on the lead screw.

On the G64 - the easiest thing to do would be to open the tap file using notepad (as discussed) and setting that to P0 - and running at a low tool path speed as well - until you are able to narrow this down.

To add to some of the discussion - there is an old pdf on the post processors, some of which is still applicable - ... f1922c.pdfrachat de credit meilleur taux - and if you go down to page 8 and 9, you can see the discussion on this setting. As pointed out, you can create your own custom post processor to use in generating the tap file.

I would take the file you ran for the picture in your first post, edit G64 to P0, run at a very slow IPM (either in the tap file or using the slider to slow the machine down) and go from there. Again, I can't imagine that your table is 0.35" 'off' over 3.5 inches. Bob's questions I suspect were based on similar thinking of a mechanical challenge of some sort.

As you stated, you may also be out of alignment between the gantry and the table as well. While that would aggravate this in a pocket, you should still have a similar depth of cut over 3.5".

You mention in a later post you were getting a ridge of about 0.006" between passes. That is within the G64 P0.01 setting.
Hi, can you explain the term "peak of around 0.006 between passes"? thank you

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Re: Shark HD3 Z-axis problems

Post by sharkcutup »


You may want to be sure all is well grounded too. Static has been a culprit in some of the mysterious unexplained happenings in the operation of some of these machines. I have had a couple of unexplained occurrences early in the setup and operation of my machine but have not had any of those weird/mysterious occurrences since I have checked to make sure all is well grounded including the vacuum system.

Just more food for thought!!!

Oh and yes Thank You for the update on your progress that is something that is one that does not usually get to hear about or see here (unfortunate but true).

Shark HD3 Pro Plus Extended Bed with Water-Cooled Spindle

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