Hi Sean, I run a business called Bagpress and we specialise in vacuum pressing and associated technology. If you can give me a bit more information about what you are trying to achieve, I’m happy to offer my advice regardless of where you may end up purchasing the jig.

Cheers

Darren

@darrenking thanks for the response.  I have a Shop Sabre CNC machine and have been experimenting with different hold-down methods.  Some work and some are so so.  I am exploring using HDPE fixtures with a vacuum to do my hold down.  Im thinking mostly necks and bodies - electric - but could also venture into acoustic bridges and possibly acoustic necks as well.  I would do my necks in sections as I don't have the clearance to do a fully roughed-out neck. So would do the neck, the headstock, and the heel as 3 separate operations including the scarf joint, and then use registration pins to align and glue.

so I guess what I'm asking is for sources or advice on what I need to accomplish this.  what size pump, parts to use for connecting to HDPE fixture, etc.  I have watched your class on using veneers for acoustic sides and backs and am working on files to cut on CNC the forms etc. for laminating.  so will use the pump and tubing etc for both things.

so any advice or suggestions would be great.

Thanks

Sean

@seanwhcraig Hi Sean, I have an 8’ x 4’ CNC router with a 360 m3 per hour vacuum pump hooked up to the hold down table. However, when machining such relatively small components as guitar necks or head stocks I will always use a combination of registration pins and screws to hold the blank in place. 8500kg per m2 sounds like a lot, and it is when applied to 1m2 but a head stock blank may only measure 20cm x 10cm so the pressure being applied by a vacuum bed is really not enough to resist the forces being applied by the router cutter.

Electric bodies are a different matter as they have enough surface area to be satisfactorily held by a good vacuum pump alone. I would suggest that you need to consider a minimum of a 25m3 per hour pump and that the area around the work once be masked off to reduce air loss and subsequent reduction in clamping force.

You might also consider a combination of vacuum and screw fixing hold down. A baseboard could be vacuumed to your router bed and then the work blanks screw fixed to the board whilst being machined. I’ve done this many times and it works really well. If you look back at some of my early post from the beginning of 2019 there should be some photos showing this process.

Looking forward to seeing posts of your projects progress.

Regards

Darren

Posted by: @darrenking

I have an 8’ x 4’ CNC router

😋

Good to see you're still here @darrenking.

🙂