Replies

1. 
   DougF | Apr 20, 2005 05:29pm | #1

   JR,

   Can't answer your question since you've provided no information about how you intend to use the machine.  What I can give you is my experience with a 5hp 25" dual-drum sander.  It is a love-hate relationship:

   They do not eliminate finish sanding.  For close to finish work you need to feed the boards at an angle to the drum, reverse the angle and then feed straight through for a total of 3 passes.  This reduces the machining marks even using the best roll paper.  Of course this is the same method you would use for flattening a board using a belt sander.  You still need to clean up with your planes, scrapers, ROS or hand-sanding

   They are not as good as your planer until the width of the boards exceed your planer's capacity.

   Paper is expensive and you can ruin a roll in a heartbeat if your roll paper if the take-up tensioner is worn, the roll stretches or if you run a board with glue line, knots or pitch pocket straight through rather than at an angle.  The residue from the glue or pitch quickly builds up on the surface of the paper and burns the wood.  Thus, you always start feeding at an angle to diffuse the build-up.  Using a crepe bar frequently helps minimize the problem.

   If you buy your roll paper in bulk, which is much cheaper than pre-cut rolls, you have to very carefully measure and cut each piece.  There is no margin of error except to cut too long.  The whole process can take 10-1 5 minutes to remove, measure, cut, install, adjust, run in and readjust.

   My machine takes some attention to keep the feed belt in alignment.  In-feed belt tracking requires periodic adjustment during long sanding sessions.

   Keeping the bed perfectly referenced to the drums can be a bit of a challenge.

   You need a really good DC.

   They take up a lot of floor space.

   Okay, those are the downside points.  On the upside:

    To flatten slabs, they are quicker, cleaner and easier than a good 4 x 24 belt sander. 

   They provide better thickness control than belt sanding although I've been told that a sanding frame can help address this issue.

   For highly-figured woods subject to planer tear-out, they can't be beat, at least up to point of the finish scraping or planing.

   They are quieter than a planer or belt sander.

   Mine is a production model and I got a good deal on it.  Were I doing it again, I would not buy a stationary sander unless the majority of my work involved a lot of solid wood slab-sided cabinetry and/or frame and panel doors and I was doing it for a living.  In retrospect I would have been better off putting the money into a 4 x 24 belt sander with a frame and L-N hand planes.  For the occasional need, I would use a local cabinet shop and run it through their wide-belt machine. 

   Bottom line, it still gets back to the problem you are trying to address with this piece of equipment.  If you need the capability of a stationary sander, then I think you  would be better served with a wide-belt sander over drum sanders.  If you decide on a drum sander, I would one that does not cushion the roll paper since that will tend  to distort the edges of the material and not always flatten hard, high spots on boards.  This includes the H & L backed systems. 

   For what it is worth, this is my story and I'm sticking to it :)

   Doug

    

    

    

    

1. 
   rosasco | May 10, 2005 08:01pm | #2

   Doug, thanks for the thorough reply !I do want to get a stationary thickness sander. Of most importance is to be able to dial in
   a thickness on a very well calibrated tool and have it produce stock with according precision.A millimeter is about as course a graduation as I would want to deal with. Ideally, within
   a few tenths of a millimeter, but I think the ultimate target of 1/2 a millimeter would work
   great.One thing that I have a hard time with is buying tools that have only English units. They
   are much more difficult to work with mathematically.

1. 
   DougF | May 10, 2005 10:55pm | #3

   Unless you you go on the upper-end of production machines, the measurements are trial and error.  The measurements change based on the paper grit.  I use a scrap the same dimension of my finished stock and try it until I get what I need.  To much and you can burn the material, particularly the high sugar woods such as maple and cherry.  I would not trust a scale on these machine except to get me in hand grenade proximity to my target thickness. 

   Doug  

1. 
   rosasco | May 11, 2005 01:19am | #4

   Doug, you're information was confirmed with the several phone calls
   I had made earlier today. I was hoping to dial in a thickness with high
   precision. The majority of machines capable of this require three phase
   and the cheapest I found, the General International 15" open ended
   (which requires a 75 PSI airline feed to operate) was $6000.The guys I spoke to at Performax were very little help. I was duly
   unimpressed with their understanding of their own machine and
   willingness to learn more about it to provide me the answers I was
   looking for.

1. 
   DougF | May 12, 2005 04:50pm | #5

   If you really want to know about PerforMax products, talk to Dave in Technical Services.  He has worked with these machines since forever and is a wealth of information as well as being a nice guy: 800 274.6846 ext 1322.