Thickness Planer recommendations please

Hello,

I'm looking for a planer. But I want to plane pvc foam (divinicel) and end grain balsa for composite sandwich work. Any recommendations on a model old or new?

Now also I am wanting to design a jig that will allow me to plane the pieces so that the thickness is variable, going for example, from 3/4" at one end to about 1/2" at the other over a 40" length or so, or even 1/2" to 3/16" over the length of the piece. Maybe even as thin as 1/16" at one end.

So I thought it might be best to ask wood workers that use thickness planers all the time. I asked on a composites forum but no one was thickness planning their cores.

I sort of have a thought that maybe the jig should incorporate a vacuum to hold the foam down. I'm not sure if the lightness of the foam/balsa would be a problem in planning or if the planer itself can hold light pieces down.

Any ideas?

Thanks!

Reply to
Grant
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Only one.It probably won't work

Thickness planers have infeed and out feed rollers on either side of the cutting blades, at approximately the same level of the blades, and push down on the work to push/pull it past the blades. I doubt foam would survive the experience.and balsa would be iffy.

Possibly, with some major reengineering and hand feeding you might get something to work but I doubt it.

Reply to
Mike G

One option may be to use a router on a fixture that holds the foam/balsa on an angle and has the router gliding over it. One of the recent WWing mags just did an article on such a fixture. Maybe someone here can dig it up?? But since you say the pieces could be up to 40" long, that would be a lot of routing. Going down to 1/16" may be a problem with a planer. If you go with a planer, you can still use the same type of sled.

Another possibility could be a thickness sander. You wouldn't need a vacuum, s> Hello,

Reply to
Mark L.

thickness planers are not a good choice for end grain anything.

thickness planers are designed to make things a constant thickness. to plane a taper you'll have to fasten the work to a tapered sled

could be a reason for that.

you'll have to hold the foam to the sled somehow. if you're making a lot of parts vacuum might be a good approach. for one offs use a light tack glue.

thickness planers have feed rollers that hold the work down. some of them apply a lot of force, and may crush your foam, depending on it's density.

a thickness sander will probably be a better choice.

Reply to
bridger

Ok, may I should look into a thickness sander from the repies I got here. Any recommendations. Peices will not be that wide. Thanks!

Reply to
Grant

Your right , a wide belt drum sander could be a possibility with thin enough passes so the drum actually has a chance to sand the piece and not crush it.

However, you would still need a vacuum of some sort to remove the sanded off material and keep it from floating around the shop.

Reply to
Mike G

Grant...

A planer is probably the wrong tool for the job.

If you want to do the job yourself, then you'll probably end up building a wedge-shaped fixture to hold the foam and guide a router with a wide, flat bit.

You may want to build a vacuum hold down incorporating your shop vac. A second shop vac can be used for dust collection while you cut.

If you just want to get the job done (and not necessarily DIY), then visit local sign shops and ask about CNC routing.

Reply to
Morris Dovey

One of the reasons I was thinking planner and not sander was that I know that surfboard shapers use a handheld planer to shape surfboards. The foam and balsa that I want to change the thickness on is a bit harder though. Surfboard foam is about 3lb density.

Another thing that I want to do it change the thickness of the core so that the center is thinner than the two ends.

One reason that other composite manufacturers are not doing this is that my idea and what I am making is unique and my own. I don't know of anyone else doing what I want to do.

Reply to
Grant

"Morris Dovey" wrote > then visit local sign shops and ask about CNC routing.

Yes, I know about CNC foam routing services. This is how I have had it done to test out my ideas. I want to reduce the cost, do it myself, and have more control of variable thickness on the fly. I cannot afford to by a CNC machine myself. But yes the CNC machining works.

Reply to
Grant

Grant...

Yep, I have a ShopBot PRT-96 which would work well. If you do much of this kind of work, you might consider buying a used ShopBot - I've seen 'em go for as little as $2K.

You can "borrow" from the typical CNC machine design, though, and build a fixture that provides wooden rails on either side of your workpiece, with a router carriage whose ends rest on these rails; and manually move the router back and forth on the carriage. You'll need to manually move the carriage; but that shouldn't be a big deal.

The rails could be curved to provide a longitudinal profile; and the carriage might be curved to provide a lateral profile.

A piece of MDF fixed between the rails with routed channels and a proper-sized opening could provide a stable support and allow you to use a ShopVac to hold work in place.

If you already have the ShopVac and router, you should be able to build the "almost CNC machine" for about $50 and a /reasonable/ investment of time and effort.

Reply to
Morris Dovey

the folks who make foam cores for laminated aircraft parts cut the foam *very* accurately with a hot wire, and they make complex parts.....

Reply to
bridger

so does manual routing. get a router and set up some guide tooling and dust collection and have at it.....

Reply to
bridger

there are some plans floating around on the web for build it yourself thickness planers. it'll cost you a motor, some bearings and belts and wood scraps and time.

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for about $800 you can buy a performax 16/32. they now make a smaller, benchtop model that should be less money. the limit may be how thick a piece it will handle.

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Reply to
bridger

Why not cut the taper on a bandsaw in a resawing type of operation?

Tim

Reply to
Tim

Same with foam parts for serious, turbine powered, giant scale r/c models.

I'd think the hot wire would, be awesome for surfboard parts.

Barry

Reply to
B a r r y

Just don't hot-wire the wrong kind of foam.

Reply to
J. Clarke

Two choices, Delta or Performax.

Not the only choices but they are units that would seem to fit your needs at a reasonable price. The other choices would be much larger and probably over kill.

These units use a wide abrasive belt on the table to move stock under the sanding drum and !MAY! allow the use of some sort of jig to allow you to vary the thickness. Off hand I can't think of how but you have a better shot then with a planer.

I wouldn't hold out much hope though if I were you. The units are designed to take something with a flat bottom and sand the top parallel too the bottom surface and make it smooth.

They are not really meant to remove stock and thickness it, but rather to provide a near finish quality surface. They do not perform this function especially fast either.

Try to force too thick a piece of wood stock through and they stall. In the case of foam I would guess that the sanding drum would just crush it.

The only real way I could see it actually working for you would be if you were making multiple passes and manually lowering and raising the sanding drum as the piece passed under it.

But, who knows maybe you could get it to work somehow. About the only way I can think of doing it efficiently would be designing, building, and reengineering the unit to be computer controlled.

Reply to
Mike G

I think you have the right idea but the wrong tool, a planer would tend to tear out your material and leave a rough unusable end product. A sander would be a much better choice especially on made like a planer, and with a solid not soft roller. Check out Grizzly, they have some sander made to the same general order as a planer with a solid roller for about the same price as a planer. These would work much better on soft material such as foam and balsa and would give you an idea as what to look for in other machines. JMO

Reply to
Sweet Sawdust

Yes, the hot wire only works on Polystyrene foam, not PVC, SAN, or Balsa

Reply to
Grant

Yes, I've thought of this too. Because what I want to do is put the stock in a jig that just holds it at an angle. A homemade routing fixture would work. It would sure be quicker than sending it off to a cnc shop. What would be the bit I could use?

Reply to
Grant

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