This part fell out of my ShopBot--can anyone identify it?

[hipstomp]

Hello everyone, I was cutting some walnut on my ShopBot Desktop, and after finishing was horrified to find this bolt sitting on top of my workpiece! It's a miracle the bit didn't run into it. Apparently it had fallen out of some part of the gantry or spindle assembly, I assume it has been working its way loose over the past year.

This isn't a bolt I previously owned that somehow made its way onto the bed. It's just under an inch long and is identical (see markings in photos) to the bolts used to connect the gantry verticals to the gantry crossbeam. (I've checked all of those and none are missing.) In other words, this bolt definitely came with the ShopBot, and definitely was not sitting atop my workpiece before the cut began.

I then went over the spindle assembly with a flashlight, but I cannot locate any hole that's missing a bolt.

Does anyone have any idea where this might go? Is there any mounting bolt you know of that's susceptible to spontaneously working its way loose? While I am in the middle of a project, it seems obvious I oughn't run the machine again until I figure this out.

Any info and suggestions appreciated!

thanks,

- Nick

[Roy Harding]

It LOOKS like the bolts holding the Z-Axis gantry onto the two side risers.

All the other bolts I can see on my desktop are not rounded over, and are corrugated around the periphery of the head.

If that location isn't making sense to you, let me know and I'll upload a couple of photos later today.

[Brady Watson]

Looks like one of the 4 router/spindle plate bolts. Now's a good time to go over the machine & re-torque bolts....

-B

[Roy Harding]

Maybe this will make my post clearer.

[hipstomp]

Hi Roy, thanks for responding, but those were the first I checked and it isn't one of those. Will keep investigating.

- Nick

[hipstomp]

Thanks Brady, I was not able to locate those bolts during my initial inspection but I'll go in and take a closer look. It makes sense that the bolt came from that region, as it was lying on top of the part after the cut.

- Nick

Looks like one of the 4 router/spindle plate bolts. Now's a good time to go over the machine & re-torque bolts....

-B

[hipstomp]

Mystery solved. By lowering the spindle and getting behind it with a dental mirror and a flashlight, I was able to locate a single threaded but unanswered hole. There was a telltale lack of dust around the hole in a slightly larger circle that corresponds with the diameter of the bolt head. Will get this thing back in there.

I'll include a photo of the location in case someone else with a Desktop experiences this problem and wants to know where to look.

Roy and Brady, thanks again for sounding off!

- Nick

[scottp55]

Funny, Yours fell off and I had to start my Z-mod twice as 2 of those bolts would NOT come out for Love or Money! Had to buy an impact driver with hex head to get 1 out and then the last one I had to swing the entire plate to get the leverage to break it free.
Kirk was doing his Z-mod today---going to have to ask him how tight his were.
Kevin at Shopbot says he usually has to use a small cheater pipe on a standard Allen key when they get Desktops in to repair or Mod.