Purchase the gas strut to avoid problems!

I’m posting this in the hopes that someone can avoid the massive problem I ran into this weekend.

Running a 65 mm spindle and in the first five minutes of using my new “$750.00” vacuum table the workpiece shifted and I needed to hit the E stop.

Big mistake !!!

Without power the z-axis dropped and drilled a hole straight through the vacuum table.

I stood there completely horrified at what just happened and I’m hoping someone will read this and avoid similar problems.

Best regards,

Michael

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That sucks… A good reason I want to get more experience before I get one of those. I understand its not just “experience” that would prevent this but the risk is much higher that I would ventilate it numerous different ways before I ran into this issue you presented.

By chance were you using a up or down cut bit?

The Emergency stop does not turn off the Spindle ? Not good.

It does turn it off on my S5Pro, however there is no electronic “brake” like some equipment does and the spindle takes time to spin down. So if the bit is in contact it will cut until it comes to rest.

The pause button will stop the gantry/axis from moving but my spindle continues to spin at the set speed for the selected toolpath.

If the spindle got turned off with the E-stop, I am surprised it had the mass to make it that far into the material.
I wasn’t expecting a “brake”, just have it turn off.

I will have to test this.

Having an up cut bit as this happened may have made this worse.

Sucked the bit into the material. Got it

Not my experience yet but others have posted a “up” cut bit can contribute to it. Lots of discussion on the 80MM spinal and gas struts with this being mentioned as an issue.

Fixed my post above. :zipper_mouth_face:

Not using a down cut bit.

The bit was in midair not touching material.

There is no break on the spindle so add gravity and things go south quick.

The bit wasn’t touching material.

Yes the ESTOP turns off the spindle but it takes a minute to stop spinning.

The bit wasn’t in the material, just gravity!

Thanks for clarifying that. Was the spindle moving in downward motion when you hit the e-stop? I have stopped mine several times this way while running some test and I don’t think my spindle lowered on its own?

No it wasn’t.
It seems like my system is right on the edge of what the z-axis can support without power.

When I park the machine and shut it down sometimes it stays up and sometimes it drops.

The point I was trying to make is that the gas strut is inexpensive, so a $40 safety net may be a worthwhile investment.

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If you have the 65mm spindle this is the first I have heard of it lowering on its own based on my short time here. I have read many discussion about the 80mm spindle having some issues and installing a strut.

I appreciate the information and will watch out for this.

I had random occurrences of my 65 mm spindle sinking into the waste board when the power was shut off on my Shapeoko 5 Pro 4x4.

I ordered the gas strut to protect my endmills and it worked fine for awhile. At some point though I noticed that when the spindle would retract on the first tool measurement, that it would slam into the top of the Z-axis assembly as if it was no longer honoring the proximity switches. This also caused missed steps in the z-axis heights during my carves.

I removed the gas strut and noticed that it did not smoothly compress and extend when actuated manually. C3D support sent me a replacement. I haven’t installed it yet but did notice that my spindle now descends into the waste board after EVERY power down. I hope that something wasn’t damaged by the faulty gas strut since this only occurred occasionally before.

Instead of installing the new gas strut, I just keep a piece of packing foam along the back edge to catch the spindle when it falls. It’s not ideal and I also don’t like how it back feeds electricity into the system as the spindle descends. Not sure if that could cause damage too. Still trying to decide if I want to try the new gas strut or not :slight_smile:

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I have a 65mm spindle and I always place a block of wood under it when I power off.
It sinks 30% of the time.

To have it drop after a E-stop, I would be in trouble.

To my mind, if one is hitting the E-stop, rather than pause, there is already trouble, and anything which happens because it is pressed should be less of an issue than if it were not pressed.

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Thanks Captain obvious.

First you say,

then you say

so, maybe you should have used the “PAUSE” feature? That would have prevented the descent into your expensive vac table.