I have change the cutting knives in my planer/ thicknesser after a re grind.
The manual for the machine tells me to place some flat planed hardwood on the outfeed table, then rotate the cutter block by hand,so that when the blade contacts the wood it is lifted and moved .040 – .080 inch.
How critical is this measurement? Does it change the cutting angle if it is not correct and blunt the knives quicker?
I suppose it will put pressure on the thicknessing pick up rollers if the blades are set too low?
Any better ways of setting the cutting knives up?
I would appreciate your thoughts
Mike
Replies
Are you maybe talking about a jointer instead of a planer?
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
I thought that at first, but then saw the mention of "pick-up rollers" so I think it must be a planer.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Mike, a planer in UK parlance (and many other parts of the english speaking world) is what is known as a jointer in the US. It planes faces and edges of wood flat and square to each other. Also in UK parlance a (US termed) planer is known as a thicknesser, so a combination machine as talked about here is known as a planer/thicknesser. Slainte.Richard Jones Furniture
Thankyou for all the comments. It makes this site worth visiting for all the help that is out there when a technical question pops up.
The Planer/ Thicknesser make is A Kity 439, the company is based in France on the boarder with Germany. They have been bought out recently by Scheppach a German company. It has an 8 inch width jointer and the thicknesser takes up to 10 inches.
There are no screws to adjust the blade as the blade sits on springs which you push down to the desired height and lock off with locking nuts. Although the machine hand book tells me to set the blades with hardwood flat on the outfeed table and rotate the cutter etc etc, there is also a separate iron setting gauge which I have just found in the manual, but comes as an additional option. ( It seems logical to purchase this item?)
I find that the blades seem to dull quicker when thicknessing softwoods, compared to hardwoods but in general the finish is of a good standard.
I would like to thank everyone for their advice and will try out the methods described.
Sorry it took a few days to come back to you all but I seem to have been sat in a pub or in church or stuffing my face with turkey dinners since the start of December.
I wish you all a Happy New Year and hope this year brings you a lot more knot free wood, joints that do not need shimming, a bandsaw that stops making the length you just cut too short, splinter free fingers, and lots off mugs of hot tea served by that French au pair you will decide to employ in your new year resolution list of things to do for 2006!!!!
HAPPY NEW YEAR!!!!
Might I suggest you include the make and model of your planer in this post...
Mike, there are more involved ways of setting the irons for planer/thicknessers, but the method described of picking up a piece of wood with each knife as the cutterblock is rotated and moving it towards the infeed table between about 1 mm and 2 mm+ sounds like it should be workable.
I have a slight hesitancy because you are talking of a combination machine where the cutting geometry needs also to be correct for the thicknessing element of the machine. If this is out by a significant amount it would require checking and setting the infeed roller, outfeed roller and the pressure bars to match, and you'd also certainly need to reset the rule a little to set thicknessing cuts. The anti-kick back fingers (if any are fitted) shouldn't need adjusting.
The setting really sought is that all the knives must protrude an equal and specific amount from the circular cutterblock so that they describe a manufacturers prescribed circumference within certain engineering tolerances, i.e. the radius or diameter of the described circumference is set to a known figure, plus or minus. This setting is usually made using a manufacturer supplied knife setting jig which registers off the circumference of the cutter block. You should have one, but if the machine is second-hand you may not have been supplied it by the previous owner.
However, all else being equal and if you've made no changes to the setting of the machine in any way and it worked fine before you replaced the knives then the manufacturers recommendations should be followed.
I have a slight wrinkle to the described method of setting the knives in this type of machine. Before doing anything, including removing the old knives isolate the machine from the power source. Then mark a 0.5 mm pencil line all across the face of a true piece of wood. Set the edge of the wood on the outfeed table and line up this 0.5 mm pencil line with the front edge of the table. The planer outfeed table must not be adjusted to anything other than its normal operating position as you make these marks. (It's too late for you to do this on this occasion as you've already replaced the knives.)
Rotate the cutter block by hand slowly so that a knife picks up the wood and moves it towards the infeed table. When the knife drops the wood mark where the front edge of the outfeed table intersects the edge of the wood. Now you can check the other knives and various positions across the width of the outfeed table to see how much variation there is in the 'carry.' Find the longest and shortest 'carry' and mark them. This gives you the old 'knife protrusion to outfeed table operating setting' which should be good for the new set of knives, assuming that is, that the old setting allowed your old machine to work properly.
I add yet another wrinkle because I then drop and lock the outfeed table about one extra millimetre so that I end up with a pencil marked 'very long carry' of the trued board. The old knives can now be removed and replaced with new ones one at a time. I find it easier to sneak up on the required new knife protrusion using the jack screws (if fitted) with this 'very long carry.' After the new knives are set to the pencilled 'very long carry' marks, the outfeed table then needs to be raised a little at a time until the wood is carried by the knives to the old 'knife protrusion to outfeed table operating setting.' There are other simple ways of establishing this final setting, but this will do for now.
In theory the surface of the outfeed table in use should be a line tangent to the circumference described by the cutters. In practice the table needs to be set just a bo'hair below this line and the 0.04"- 0.08" (1+mm to 2+mm) described by the manufacturer gives this setting.
To save all this bother you can buy tools that are claimed to hold the knives at the correct height in the cutter block prior to clamping them tight with the machine screws and wedges. Magnaset is one brand name that comes to mind, but there are sure to be others. I've never used any of these devices, but there are those out there that swear by them. Nor do I go to the bother of getting all nitpickingly engineering about the job using overly complex dial gauges and complicated rig-ups and the like. The lump of wood and a few pencil marks have always done it good enough for me, and the truth is you do get to know over time when settings are about right or if they're a mile out requiring some drastic remedial action. Slainte.
Richard Jones Furniture
Edited 12/29/2005 3:42 am by SgianDubh
I used to set jointer knives the way you describe. I now use another method that Mark posted on this forum a year or so ago. I remove the guard, remove one knife. Then install new knife with the jib screws only tight enough to just touch the knife.I place a piece of plate glass on the outfeed table extending past the cutterhead. No need to find top dead center. Then place a large bar type magnet on the glass. You can hear the knife click when it hits the glass. I sometimes have to turn the cutterhead a hair by hand so the entire bevel is flush on the glass. I do this by slightly moving the belt. Tighten the screws a little at a time, repeat for the other knives. I usually have to lower the outfeed table a .0001 or so.Takes me about 45 minutes for three knives. The first time I tried this I checked my knives with a dial indicator after installation.They were within a .0001 across the outfeed table, and all three knives were the same height. Used to take several hours and several more choice words.
mike
Wow, that's ingenious!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
It is ingenius,wish I could take the credit. I do not recall mark's screen name but he should take the credit. Mark posted this method about a year ago on this forum.I've changed knives four or five times in the past year, all without reverting to a few choice words.
Happy New Year
mike
"...all without reverting to a few choice words." Left you speechless, did it? (she laughs at her own joke). Cool, thanks for passing the technique along, as I missed it the first time.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Mike, sorry about the slow reply-- Hogmanay excesses and all that at this end have kept me occupied, ha, ha.
I'd forgotten all about the glass and magnet method you described. I do remember it being posted on Knots some time ago now, as you say. Obviously, as I'd forgotten all about it, it's pretty obvious I've also never tried it.
I guess next time I have to change knives in a machine with that kind of installation requirement I'll have to remember it and give it a whirl. Slainte.Richard Jones Furniture
Hi Richard,
I tried it last night and did not get the results I hoped for - seemed too good to be true.
But, then again, the jointer I have has the usual spring loaded knives and gib screws (no height adjustment screws.)
Over a 12" jointer width, at TDC, the knives were level with the outfeed table at one side and about 20 thou high on the other side. I couldn't get the blades to slide easily without them going too much - this could be a function of the jointer and not the technique.
I was using 6mm glass - it had a bit of flex that was causing this problem- I'd go to 10mm glass if you have it.
Best regards,
eddie
Edited 1/5/2006 3:45 am by eddiefromAustralia
Thanks for the report eddie. I'll keep an open mind. Most of the machines I've had to set the knives in have had jack screws, so the glass and magnet trick seems a bit of a non-starter on that type. Other machines used a jig of some sort that held the knives in the right place and are supplied with the machine. I've never had to fit knives to a machine with no means of setting them to the right protrusion above the cutterblock circumference.
Even on the machine we're using now it's a case of reversible disposable knives. Install and turn on. The knives are thrown out to their correct setting when the machine is turned on for the first time. I don't even fit them. We have staff that maintain the workshop and the machines-- I just use the kit when I need it. Slainte.Richard Jones Furniture
Mike, I've got a couple of questions for ya on this. (1) where do you get the bar-type magnet? and (2) you mention "I usually have to lower the outfeed table a .0001 or so." Can you explain this some?
Thanks! forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I got the magnet from Harbor Freight,don't buy much from them but this was a good purchase. The type I bought is about 4" long and is supposed to pick up 50 lbs. About $9.00 if I recall. The reason I drop the outfeed table is because the method I use brings the exactly even with the outfeed table. By lowering the outfeed table,you wind up with the factory setting .001 . I test first with a board, if everything is fine I leave the outfeed table alone. That's why I said I sometimes have to lower the outfeed table.Theorectically the cutters and the outfeed table should be the same, theory doesn't always work.I made a mistake with my first post, I said.0001, meant .001
mike
Ah, OK I've got one of those magnets I think -- it's not just a bar right? but 2 of them encased in steel I think.
And....the .001 I've heard folks here talk about. That's the .001 that will push the stock a smidge if you rotate the cutterhead by hand.
You can tell I've procrastinated on swapping out my knives. Between you and the member who exalted the Lee Valley jointer-knife honing jig, there's plenty of incentive to take 'em out and spiff 'em up.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
You're correct, there is two magnets in a steel case.Now go change them knives,send your old ones out for sharpening.
mike
When I bought the jointer, I arm-twisted the sales guy into tossing in 2 extra sets of blades. So, when I change out, I can sharpen my own! Might take a week or two to get it right, but that's OK.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Forest Girl, do you have a knife sharpener? I have sharpened planer and joiner knives in the past, but not as well as a sharpening service.I do not own a dedicated knife sharpener or I might try it again. The best way I found, besides sending them out was on a tablesaw.I had an old saw that I mounted a white friable wheel on the arbor. I made a jig that slides perpendicular to the stone for a hollow grind. I used a power feed to move the jig, the powerfeed gave me a slow but consistent lateral movement. The amount I ground was determined by how high I raised the stone.
I got sharp cutters, but not the proffesional grind I get when sending them out. The quality of the professional cut was a good deal better than my home method.I have 5 sets of knives now, I send three out at a time. I keep one sharp set in a drawer while the cutters are being sharpened.
If you need plane iron cutters for your machine, Grizzly cutters are my choice. They are inexpensive but last longer than the Freud and Jet I used before.
mike
Wow, that's a creative way to go about it! I'm going to try the Veritas Jointer Blade Sharpener (seen here) for basic resharpening. But I'm sure I'll have to send them out periodically. One of our members here (sorry, name?) reports using the Veritas holder and getting great results with it.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Biulding on Mike4244 idea of placing a piece of plate glass on the planer outfeed table to set the hieght of planer Knives. I have the following sugestions and would like to hear what other woodworkers think
(1)After setting the knives as described my Mike, alignment could be further tweekd by spaying a fine film of furniture polish on the underside of the glass to create an opaque film Then in small incruments adjust the hieght of the knives , rotate knives by hand after each adjustment until the knives just break through the suface of the film when viewed from above
(1) If the knives need to be set slighly above the hieght of the outfeed table select pieces of paper of suitable thickness, measure the thickness of the paper with calipers Then place the paper under the glass on the out feed table This would then facilite further micro adjustments if step one is then repeated
Mike
After trying a lot of methods including dial guages and a variety of setting guages I use the same method Richard just described because I find it quicker, simpler & no less accurate. My advice is print off his guide & follow it step by step. When you have done it once you will find it is really very simple & it works. You will probably also change knives when they need to be sharpened instead of hanging on just one more job:-)
Don
Mike, what is the make of your machine?
Richard has described the old trusted and true method, which can be very accurate if you are patient. I just add that it helps to use a hardwood, of some weight-something about 600mm long by 150mm height by 50mm thick.
If your machine has jacking screws the job is made a lot easier, as you can creep up on the required projection .
My machines do not have jacking screws, and I have not been in a position to try out these Magnasets etc. I made something to do the job-but it only suits my machine which has virtually nospace to retrieve the blade if it has gone down too far, when the swearing used to start.
I also hope that the top tables of your machine are co-planar with the lower table.
Hi Mike,
I can't add to what Richard and Don have to say - it's the easiest way to adjust a jointer with an adjustable outfeed table.
I use a lower-end SCM combination machine (MiniMax) and the over and under part of the machine has a non-adjustable outfeed table. I find this exact brand of blade setting jigs indispensable as I have to get the blades accurate to the outfeed table within a thou or two. Without these, setting the blades was d*mn near impossible. This picture gives the principle of the unit.
http://www.ds-messwerkzeuge.de/main/bild_gesamt/barkomat.html
Error with these is within the thousandth of an inch - more than accurate enough.
But, setting the bl00dy things takes forever initially as there's no fine adjustment and setting is through trial and error.
As well, check with a straightedge that the outfeed table is parallel to the planer/jointer knife head **once only when you set up the jointer initially** and that the infeed table is parallel to the outfeed table.
I wouldn't get too hung up on parallelism, however, at the end of the day, the test cuts are the measurements that really matter.
Cheers,
eddie
Edited 12/29/2005 4:16 am by eddiefromAustralia
This forum post is now archived. Commenting has been disabled