Help me improve my jig for machininig hockey pucks

[MogulTx]

I agree that there are too many bolts here... they have WAY more power than needed to hold those. I also like what some people have suggested- like Brady's suggestion for clamping them into a Vee. I like that one because it makes sure there are no protrusions into the "safe Z" volume. And what I think of when I look at this is: I would want a quantity that is a sufficient number so that you get a good long machining cycle out of your set up. And secondly, I like Brady's individual-puck hold downs, all-in-a-row idea because you can go in and set up for maybe two or three or four machining zones/areas. When the one area is done and the spindle moves to the next area, you can go in and remove and replace the parts that have already been machined with new stock. And when your machine gets to the end of all the zones or the cycle, you can have it programmed to automatically go back to the beginning and do the next sets(s). If someone is "tending" the machine, they can simply install and remove pucks in a succession without ever having the spindle turn off, go home and then have to turn on and go back to the first machining zone to begin all over again. Over thousands of parts- it will wind up being a significant time and wear and tear savings. Significant labor savings....

Don't get me wrong: I LIKE your set up. But you are using a lot of bolts, that are of a large size. And if you are going to be looking at making this process faster and more cost effective- I would be looking for ways to accomplish the task without having to un-bolt that many bolts, and then rebolt them. And make sure all the T-Nuts are still in place and make sure sawdust or rubber chips aren't keeping the assembly from going together properly, etc.... And make sure the MDF has not gotten soft from being pulled by all those bolts and then loosened, and tightened and loosened.... Brady's set up would save lots of time in the repetition of the processes required....

Best of Luck with it.

Monty Ma Gill

[PatSabre12]

First off thank you to everyone who replied

@coryatjohn - I drop in a stainless steel plate and make the pucks into a bottle opener. I actually ended up adding a row of bolts on the outside edges because those pucks kept moving during cutting. It may be because I'm using a custom bit that starts at 1/2" and tapers down to 1/4" (that's how I get the taper).

@myxpykalin - Thanks for putting that drawing together. I think I might have to get rid of the MDF all together as it flexes quite a bit and if I hold down on the edges I'll end up with flex in the areas that aren't directly next to the aluminum. It might work if I use the aluminum angle with a few of the bolt holes I currently have in there.

@Brian - That's a pretty cool idea. I'd have to check to see if I could use that solution with the Desktop as I only have a bout 2-1/2" of play in the z direction. I can definitely see how that's super time saving on a larger machine.

@Brady - Another cool idea. I never though of using cams like that. And thanks for throwing the illustration together. I could see something like this working really well if I use some smaller cams, it would be awesome to throw all the pucks on, pull a few levers to actuate the cams in place then start machining. What were you cutting so many hockey pucks for?

@geometree - Stop by any time, I'd be happy to show you around. Do you have a recommendation on the size of vacuum pump I would need? Do you think something like this would work (the first pump listed)? I attached some pictures to this post. Would a vacuum jig like this work?

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[Brady Watson]

@Brady - Another cool idea. I never though of using cams like that. And thanks for throwing the illustration together. I could see something like this working really well if I use some smaller cams, it would be awesome to throw all the pucks on, pull a few levers to actuate the cams in place then start machining. What were you cutting so many hockey pucks for?

The parts were wood discs that the customer sent in a box from time to time. Not hockey pucks.

Cams are super simple and work fantastically for this application.

You can use vacuum for this as well. A Gast or Welch pump is what I'd recommend, although a Harbor Freight one would work too. Gasketing is a must for these pumps. You *may* be able to sneak by with a Lighthouse vac et al or Fein Turbo III. You want 'open vacuum air' to touch the backside of the puck. No ultralight MDF bleeder board - or it won't work. See BradyVac II on SB main site.

-B

[PatSabre12]

Did you take a look at the pictures in my most recent posts. I'm not sure if I posted them correctly. Here they are again. Do you think this type of vacuum setup would work, with the 'hollow' area underneath the pucks, is that what you mean by 'open vacuum air'?

[geometree]

Basically that's what I had in mind, but MDF wont work. You would need to use a material that is nonporous for your table (azek,corian,phenolic sheet,hdpe,possibly melamine?) and direct all of the vacuum to that area right under the puck, it needs to be absolutely air tight all around. With a high vacuum pump you could run a tube to each individual pocket. Here's a link with lots of good info on vacuum clamping. http://www.joewoodworker.com/veneeri...umclamping.htm

[PatSabre12]

Ok, if I understand your post and the link you sent me I'll have to lay out a little network of piping underneath my jig. Something like this? Let me know if I'm on the right track thinking about this.

One thing I'm worried about is this is a lot more piping than what was shown on the Joe Woodworker site. Do you think I'd be able to make up for any losses by maybe having to vacuum inlets? One in each corner?