By Phil Krol
I have been given the opportunity to review this machine by Proxxon, a German company with a facility in Luxemburg where the planer is made. Proxxon manufactures a variety of power tools with world wide distribution. Their North American Service and Distribution Center is Prox-Tech, Inc. in Hickory, North Carolina servicing the US, Canada and Mexico. As usual, click on pictures to view larger images.
The planer is packed in a factory carton with box art showing the machine, specifications and is protected from damage with molded Styrofoam ends. The planer is a compact cube measuring 11" long by 8 7/8" wide by 9 1/8" tall and weighs 17.6 pounds. There is a comprehensive illustrated operation manual with exploded drawings, an 8mm combination wrench and 2 sizes of Allen wrenches included.
Proxxon DH40 Microplaner
The planer chassis is constructed of die cast aluminum with ABS plastic covers which in no way compromises the structural integrity of the machine. There are 4 mounting lugs on the base that will allow bolting the machine to a larger base or table. However, I found the machine to have sufficient weight to stay in place and with the power feed, bolting down, while desirable, was not necessary. A 1/5 hp motor (150 Watts) drives the cutter head at 6,000 rpm with toothed pulleys and belts which also operate a train of reduction gears that drive the infeed and outfeed rollers. These rollers power feed the wood through the cutter head at just the right speed for optimum finish (15.75 feet per minute). The spring loaded infeed roller is knurled metal and the outfeed roller is rubber so as not to mar the finished wood. The photo shows a calibrated hand wheel that turns a set of gears that rotate 3 threaded rods that raise and lower the table. The table will accommodate wood stock up to 3 1/8" wide and 1 1/2" thick and can be planed down to 1/32".
The Cover Removed
The cutter head design is similar to those used on jointers with a notable difference. Replacing the knives on jointer heads is very labor intensive and generally requires a fixture to assure concentricity with the table and equal depth of cut with the pair of knives. The Proxxon cutter head is exposed by removing the top and side covers which are held in place with socket head screws. It has 2 partial dovetail grooves preventing the centrifugal forces throwing the cutter holders in the event the hold-down nuts were not tightened. There are 2 HSS (high speed steel) reversible cutters. These are inserted in the holders and when they become dull, are reversed for a fresh set of sharp cutting edges. The holders are preset for uniform depth and concentricity with the table at the factory and further adjustment is unnecessary, even when reversing or replacing the cutters. The 3 hex nuts are loosened by turning clockwise with the 8mm open end wrench. The cutter can then be lifted from the holder for reversal or replacement without changing the adjustment. The 3 hex head nuts are tightened by turning counter clockwise which turns them outward jamming them in the dovetail groove.
Should it become necessary to adjust the cutter holders, there are 2 set screws, 1 on each end of the holder. Loosening the 3 hex nuts frees the holder which can now be moved up and down by turning the set screws with the Allen wrench provided. I purposely put the cutters out of adjustment and went through the following process to determine just how precisely I could restore them. A 1" by 1" by 3" aluminum block was placed on the table just under the cutter from the outfeed end. Shining a light through the infeed end will help illuminate the cutter edge on the block and by observing the sliver of light between the edge and the block will facilitate adjustment. With the hand wheel, raise the table such that the block barely grazes the cutter edge. The head may be rotated by hand turning the exposed cutter head pulley. I found that a strip of paper placed between the block and blade edge acts as a feeler gage. The blade is precisely adjusted when the same amount of resistance is felt when pulling the paper strip feeler gauge at each end of the holder. This is a trial and error process and patience will yield the desired result. Now, without touching the handwheel, rotate the cutter head and do the same thing with the second blade being sure not to move the hand wheel. This will assure both cutters are set exactly the same. You are now finished and ready to start making wood shavings. The white reduction gears visible with the side cover removed are made from PM Powdered Metal. This technology involves compressing a metal powder alloy at very high pressure and high heat in a mold under Argon gas. The result is a very strong part with a long service life.
Infeed Slot
Using this machine to precisely dimension model lumber is a real pleasure. I tried running maple, pear and beech for hardwoods and a piece of pine for softwood. The finish left by the cutters on all the woods is smooth and free of scratch marks. This is because the wood is being shaved with sharp cutting edges rather than ground with abrasive as with a thickness sander. There is no pushing against the rotating cutter head. The wood is inserted through the infeed slot and the power feed rollers take over, moving the wood through the machine effortlessly. I used a dial caliper to measure both ends and sides of finished pieces to check for accuracy and they were within .001". Wood can change that much or more just from holding it. The chips or shavings are relatively heavy and fall into a neat pile in front of the machine. There is a heavy duty kickback mechanism just before the infeed roller that is very effective and once a piece of wood is inserted in the infeed slot, it is impossible to back it out.
The learning curve for efficient operation of this machine is very short. Anyone familiar with a full size wood shop planer knows how aggressive they can be. This micro planer is a pussycat and very safe to use yet effective in doing the job it was designed to do: mill model lumber to precise dimensions. The only tricky operation is adjusting the cutters. However, since they are preset at the factory they should stay in adjustment even when changing or reversing the blades so the need for doing this would be infrequent, if ever. The build quality and functionality is excellent. For anyone wanting to dimension model lumber, this machine would be a welcome addition to your shop.
The selling price for this machine will be $499 and replacement cutters are available at nominal cost. The toll free telephone number for Prox-Tech, Inc. is 1-877-776-9966 and their web address is: www.proxxon.com/us.