LDF spoil board

[signman315]

Hey folks, I'm looking for a source of LDF somewhere near Cooperstown NY. I'll be using it for the spoil board on our recently purchased CNC router. I've found some at Atlantic plywood in Farmingdale, NY but that's a 5 hour drive from me and noboby wants to ship a single sheet of LDF. Looking for something closer, or that's willing to ship a single sheet. Thanks for your insight!

 

[Devon19515]

We use Rugby woodproducts in Atlanta. Not sure if they have a branch in NY but we used to get our local Cabinet guy to order a sheet when he had a delivery coming and would p/u from his shop.

 

[signman315]

Thanks checking them out now, they are only 3.5 hours away so much better than 5. Left their NJ sales rep a voicemail and waiting for his call back. Thanks again!

 

[signman315]

yup spoil board on vacuum table for CNC router....I used to use the Gerber Sabre 408 with 1/2" PVC, but had a file that came with the machine that pockets and drills the holes in the PVC to line up with the holes in the aluminum router table. But on newer machines the way to go is use the LDF and it's porous enough to allow strong suction through the wood without any pocketing/drilling. I doubted this until I saw it in action at ISA a couple years ago, it really works well and holds the material strongly in place. Which is why the less dense LDF is ideal vs something like MDF, the MDF is more dense and doesn't allow as strong vacuum to hold things in place. The MDF I can find anywhere, the LDF I can't seem to find as easily, or more importantly as close to home.

 

[signman315]

Yeah I'm pumped to try it out with the LDF, the example I saw at ISA you couldn't nudge the material unless tapping it with a hammer, no joke. Granted they probably had the strongest vacuum possible, but still seems like a great solution. I also like the idea of the spoil board being wood, I'm going to pre drill holes into it and print a hole pattern on my media (PVC for example) then I'll put studs in the spoil board that line up with the printed dots on the PVC/media...the end result is kind of like a registration mark system where you line up the dots with the pins on the table and don't need camera registration, I used to do something similar with the sabre 408 and it was faster and just as accurate as a camera registration system....but gotta get my hands on this elusive LDF first lol!

 

[signman315]

yup shrinkage is an issue, especially in the cold (sorry inappropriate joke there that I couldn't resist, watched too many episodes of Seinfeld!)....

But in seriousness, I probably wouldn't try it with a vinyl on ACM combo for the very reason you explained, but it's ideal for direct print to PVC/styrene and then to cutting after that. Direct print to rigid substrates won't allow for any warping of the print. If vinyl on ACM I'll usually plotter cut the vinyl, router cut the ACM and manually line up and apply the vinyl to the ACM, usually adding an outline/inline to the vinyl cut shape depending on if it's a full bleed finished product or not.

Also update on the LDF....so I've found it a few places, closest in NJ about 4 hours away from me. But after talking to a bunch of different people some suggest regular MDF instead of the lower density LDF....some say the LDF has better vacuum because of its low density, others say MDF holds tighter vacuum because of it's higher density....so since I can't get a straight answer from anybody I'm going to try it with MDF since I can grab a sheet of that from Lowe's quick/cheap. I'll try that and if I'm not getting the vacuum hold down I desire then I'll drive my sorry rear down to NJ and get a sheet of the LDF....I'll post back once I have results in case it helps anybody!

 

[bowtievega]

We have been running 1/4" mdf sheets on our vacuum table since about 2004. Normal mdf works great. Tried some ldf once but the stuff we got wasn't as flat across the entire sheet as the mdf. We use 1/4" on top of our 3/4" deck on our table so we can switch out cutting surfaces quickly. Also cut alot of aluminum with a mister so we don't have to worry about contamination on our printed products when cutting. That cutting fluid makes alot of fish eyes when you clear printed panels lol.

 

[MoultrieMade]

But after talking to a bunch of different people some suggest regular MDF instead of the lower density LDF....some say the LDF has better vacuum because of its low density, others say MDF holds tighter vacuum because of it's higher density....so since I can't get a straight answer from anybody I'm going to try it with MDF since I can grab a sheet of that from Lowe's quick/cheap. I'll try that and if I'm not getting the vacuum hold down I desire then I'll drive my sorry rear down to NJ and get a sheet of the LDF....I'll post back once I have results in case it helps anybody!

I've used both LDF and MDF and I found that any difference is minimal. With either, be sure to skim cut the bottom side to remove the smooth/pressed surface before flipping it over and attaching permanently. I've been doing some experimenting with this lately, I tend to think that your conflicting "some say"s above are both correct. A thinner or lower-density spoil board will give you better nominal hold-down force; however, a denser/thicker board will be less sensitive to leaks as you cut out your parts and expose more areas of the board. I keep scraps of coro or other cheap, light, air-tight material around to cover up the unused areas of the spoilboard, and I apply glue or some other sealant around the edges. I'm using a 5x8 table with a 15HP vacuum that pulls about -140 inH2O max, fwiw.

As for sourcing the LDF, I'll echo Devon19515 and say talk to your local cabinet guys. Even if you're in a rural area, they probably have a distributor delivering high-end plywood every week or so, and they might let you piggy-back on one of their orders.

 

[signman315]

You folks are great, thanks a ton for all of this info, it's really helpful! Your assessment on LDF vs MDF is right in line with what I was hearing from various sources and with what opinions I'm beginning to form for myself. Since the LDF is a harder find I'm going to go with the MDF, seal the profile edges and see if I'm happy with it. I was originally thinking of going with roughly 3/4" thickness....what's your recommendation for thickness for best vacuum? Do you think 3/4" is too thick, would you recommend I go down to 1/2" or 1/4"? Thanks again for the insight!

 

[MoultrieMade]

I was originally thinking of going with roughly 3/4" thickness....what's your recommendation for thickness for best vacuum? Do you think 3/4" is too thick, would you recommend I go down to 1/2" or 1/4"? Thanks again for the insight!

3/4" should be fine, assuming you've got a reasonably strong vacuum. I've always used 3/4" in the past, and replaced it when it got down to 3/8-1/2 or so. As it gets thinner, the exposed areas become more leaky and it's harder to maintain a good seal.

Just this past weekend, I decided to try doing two layers of 3/4" MDF (with a careful gluing strategy that avoids creating a seal between the layers). This is what confirmed my thoughts above about the high/low density trade-offs. The overall performance was disappointing - some small parts that I routinely cut would not stay put, even with tabs. However, removing parts or leaving areas exposed had much less effect on the overall vacuum pressure, according to my gauge.

This 1-1/2" setup works fine for most of our jobs - say, anything larger than 8x8" or so. But the next time I have to do some tiny letters, etc., I'll probably mill it down to about 1" first.

 

[MoultrieMade]

So what does a sheet of LDF even cost? No counting delivery or other wildcard factors, just 4'x8'x.25" or whatever thickness is optimum.
I saw somewhere yesterday that Multicam Canada stocks and sells the stuff...

My last purchase was $29/ea for 4x8x3/4 "ULDF". This was from Hood Distribution out of Jacksonville. Delivery was free, but they have a minimum order of about $400 I think. I'm about 200 miles from them, but they have a truck here every week serving the local cabinet shops.

 

[johnnysigns]

We scrapped the PVC bed on our Gerber 408 and glued down high density MDF to the aluminum vac plenums. We ditched the pocketing, but just run the hole program for the 1/8" vac holes through the high density MDF. With the denser MDF we still run an LDF spoilboard on top when we need to. We don't do any wet cutting so no need for a plastic table bed for our needs. Both types of MDF we use we generally get from Harbor Sales as they deliver. It's more costly per sheet, but I'm not mad about as it's usually next day delivery. When the permanent bed gets low, we just glue on a new sheet of high density on top and run the drill program. We got tired of the PVC bed Gerber recommends because the adhesive they use would allow cutting chips under the PVC and render the vac useless. The biggest downside to the permanent MDF bed is it's more susceptible to swelling with humidity changes, but we find the high density stuff holds really well overall. Clearing swarf and cutting chips off the bed with an air compressor w/out a drying system on it will make that much worse. Nothing that a milling cycle can't clean up in 30 mins.

 

[Ardor Creative]

What size table do you have? I've only used MDF for spoil boards. I have a 4x8 table and the sheets from home depot and lowes have worked out fine for me

 

[fixtureman]

I use 3/4 Trupan LDF I get it from Allegheny plywood They have a place in Pittsburgh I payed about $30 a sheet

 

[rossmosh]

Harbor Sales sells it. Not sure if you're in their shipping area.

 

[Zendavor Signs]

We get LDF from a local lumber yard. It takes a week or so for them to get it in. We found a big difference in suction with the LDF vs MDF.