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Delta DC-33 parallel thickness issue11/20
I have recently purchased a used Delta/Invicta DC-33 planer (model 22660) and am having problems getting a consistent planing thickness across the entire knife. I"m not talking about a huge amount, but .010 across an 8" board is enough to be a problem, and thats what i've got.
First off, the blades should be parallel with the head. Then start checking table to blade clearance from the table. It can be as simple as a block of material on one side, bring the table up until it just touches the blade (machine off of course) slide it over to the other side to check how parallel you are.
Ken, thanks for this.
First, use the Delta 3 leg gauge to set your knives in the head. This will put them all in the right place, correct projections, etc.If you don't have the gauge, you can get a dial indicator mount that will straddle the knife and help you set it correctly.
Secondly, you need to indicate from the bed to the knife. Jigging to go up and over, etc is a path to insanity. Again, a dial indicator with base can do this just fine. This is a direct measurement and will help out immensely if you do the first thing correctly.
Third, when setting the posts and chain, take out all the lash in the chain and then in the threads of the height adjusters.
Fourth, when setting the thickness on these types of machines, it is important to always come up on the dimension. That is, to go from 3/4" to 11/16", you need to go below 11/16" and then crank up to 11/16". This is similar to tuning a stringed instrument, if you are familiar with that.
If you do not learn to set the height correctly each and every time you will easily see about .010 or more variations. The considerable weight of the machine head is on those posts/sprockets/chain, and the head is designed to be set only on the up tension, not the down. If cranking down, the weight is unbalanced and not on the threads as it is designed to be.
If you need to hold such close dimensions, I suggest looking at a better planer, with moving bed on 4 posts, and using a digital readout. I have an older Powermatic 18" with and Accurate Co readout on it that gets lots of use and routinely holds within about .002 or .003 between sharpenings.
By the way, I also set the thickness on the "up" on this machine also - again with the threads..... As well as the shapers, the molder, the mortiser, the tenoner.....
OK Andrew, I just threw that out there with my planer in mind which is a Rockwell wedge bed where the table moves up & down. Looking at the diagram ( http://www.ereplacementparts.com/images/delta/22-660_TYPE_2.pdf ) on the DC-33 I can see where you're limited to the sprocket tooth spacing since the sprocket is keyed on the lifting screw ( parts 22, 26, 29). My thoughts and I can't tell exactly by the diagram, is how is the bearing (#24) seated? If it's sitting in the base then determine the difference in height one side to the other and possibly shim the bearings to raise it up?? Again just guessing looking at the diagram.
Andrew - I will add that when I had that planer, it worked well once I learned how to keep it accurate. However, the feedworks started to get noisy, and I found the gears were severely worn. I sat down to order parts only to find out that Delta no longer made parts for the machine, and if it went down, it was likely down for good. A machine shop could make the 3 gears it needed, but it would be 3 weeks and unknown expense - one hypoid gear was bronze. This would have made life extremely difficult, and even if I made it through that, anything else could fail, and I'd be back at the mercy of unknowns.
That is when I found my beloved Powermatic. I did get $32.00 at the recycling center for the Delta......
This is the best indicator for jointer knives and all planer adjustments. The button tip is far superior to the stock tip. For setting planer knives it straddles the. Easily sets feed rolls, bed rolls, adjusting the head to the table. I can set a four knife 20" jointer in a leisurely 20 minutes within .0005. I had to chuckle when I saw your jig.
Thanks everyone- Rick, David, Ken, for weighing in on this. Reading all of your comments has been really helpful.
I've been setting machinery professionally for over 35 years. You always go down not up when doing this. If you go up then you are introducing backlash which will easily introduce 0.010 to 0.015" error. Always set the knives to the head. Not quite sure of your procedure but when I see the gauges you made I cringe in disbelief. The gauge I posted is the ultimate planer jointer gauge but I get impression you don't get it.
Well i guess there is some disagreement on the "up to" - vs - "down to" for a finished dimension planing operation. I just hope we're all talking about the same type of planer.. dc-33 (rc-33 would be the same) where the weight of the moving component (head, gearing, motor, etc) is not a balanced or symmetrical assembly.
It's never up, it's always down because thats how you use the planer to thickness the wood. Set the knives to the head. You need to focus on setting the head itself to the table. Undo the chain for the posts and zero the head to the table then hook up the chain. You are bound to have some backlash such a .005". Other table systems such a wedge beds can be more accurate but in woodworking .005 is more than acceptable. On my Oliver 16" jointer the manufacturer allowed .010" for flatness of the tables. Mine was .015" so I had it ground and got it within .005". Powermatic allowed .015" for flatness of the 66 Table saw.
I've worked on more machines in 30 something years than you can imagine. I did warranty service on Delta and SCMI. Also did work on every other brand from old iron like Crescent, Northfield, etc and Modern imports and the adjustment procedures are all the same steps in a certain sequence.
The gauge was purchased 30 years ago for $250 and is designed to straddle heads 4" or bigger. I have made one with 2" channel for straddling smaller heads that cost me some scrap and drilling and tapping. Your jigs would be useless to any professional machine set up person...
My first planer was a 1919 Fay & Eagan with babbitt bearings. It had almost 1/32" of wear in the center of the table. Not knowing anything else, or being able to afford a jig, I always indicated up from the table to the knives when setting them.
Those who say this is wrong, why? Shaper heads used to be set this way before corrugations held the knives in rigid angular alignment. If you needed a small taper, you set the knife at a small angle. Why not adjust the angle according to the angle of the table?
Andrew R, I wonder if you have play in the castings around the bearings. Ball bearings themselves are generally much much tighter than that. How about putting an indicator under the head and levering on different things to try to determine what is moving?
All my planers have jacked the bed into the knives, so I never lowered the table for a final pass. The screws were always tightened with successive passes, so backlash was never an issue like it would be on, say, the jointer. If your screws are jacking the head, then it will be every time.
Just thinking about this machine's mechanical design VS traditional raise the bed machines. Gravity and the force of the knives on a raise the bed machine are always working in the same direction, Down. On the move the head machines, gravity is working to hold the head down, but the force of the knives is working to push it up. There will always be some slack in any mechanical system of the adjustment type you have. Seems like 2 things could occur. 1. when a board is run to one side, the force of the knives pushing the head up will be greater on that side. 2. if there is a difference in "slack" between the two sides it will make the problem worse. This will make it nearly impossible to correct the differences. Even if you manage to get the knives set dead-on to the head the problem of a less than ideal design won't be overcome. Anyone understand where I'm coming from? I had also thought that this design may increase the ripple on the board but the amount of head bounce during each move to the next knife cut would be very small. By the way, in calculating the effective knife cuts per inch of board you have to assume a one knife finish cut. Not the 3 or 4 knives in the head.
You are talking about the cutterhead being out about 1/64"over its width. Can you shim the bearings? Can you shim the table against its jacking nuts? Keep in mind you are talking a pretty fine tolerance for woodworking. Yes, the machine should hold it, but do you really truly need it?
I'd be more concerned if there was that much play than if the head was out of parallel. Look at another issue— when you made the auxiliary table, how beefy was it? Planers compress with a good bit of force. Are you absolutely sure the shimmed table didn't yield? even 1" plywood could compress .010" at the 8" mark, if it was only supported at the edges.
Try putting your indicator on the auxiliary table, then stand on it. Does it move? The planer no doubt presses with several times that much force.
Rick L- My gauges are useless and they make you cringe. Got it. Thanks so much.
Much as it surprised me, when I tried a paten made the same way it didn't work at all. Just too much compression from the planer, it flattened the platen out.
Three possibilities: is your bed flat? Try working a feeler gauge under a straightedge, laid in different positions on the bed. It would throw off your indicator readings, especially if you use the long arm in your picture.
Is the cutterhead a cylinder or does it taper? It would be weird, but possible.
More likely: have you checked out the bed rollers for evenness and roundness? They are often made so they can be shimmed or jacked with screws. Seems obvious enough that you'd have done it, but you don't mention it.
Tracking down the issue with the geometry will tell you how to compensate. It can be frustrating, but keep at it. Have you checked the amount of projection of the knives? When you indicate them and the head, is the jump the same on both sides?
Another possibility is that the knives are dull on one side or are so badly sharpened that they cut differently at different places.
If the cutterhead is parallel to the table like you say, the saddle type gauge described above might well be your best bet. Amazon has them for about $60.
First off I think your gauges are first rate and 30 years of setting machines up evidently doesn't get you thirty years of class.
I would say it's fair to assume when you have a moving head and a fixed table, slop is going to be there. You are lowering the head as you reduce thickness so backlash in the screws is an issue and not sure it can be completely overcome. Not to mention this machine is used.
I helped a friend setup a 20" grizzly planer (piece of crap) once of similar design. The instructions basically walked you through the entire process of systematically leveling and dialing in the head and table because of course the factory doesn't do that for you. You can download those manuals online and might help.
Also my gears wore out and I used the ones from a Grizzly and it works perfectly. Since Delta doesn't make them what choice do you have? LOL Machine does feed a little slower but now the finish is nicer too!