Grizzly 20 in Planer

[fRED mCnEILL]

I have just ordered the Grizzly 20 inch planer and hope to receive it in the next month or so(was backordered)

This planer has a 4 knife cutterhead and I have read threads indicating some have taken out two knives on these cutterheads.

I would like to try this and wonder if there is anyone with firsthand experience in only using two of the 4 knives.

Thanks

Fred Mc.

[Bob Winkler]

Hi Fred, welcome to Sawmill Creek!

I'm also considering this planer in the near future and would be very interested in what you think when it arrives. What other planers did you consider? The Yorkcraft 20" (from Wilke) is also on my short list. Any special reason for choosing the Grizz?

Bob

[Jim Becker]

Welcome to SMC, Fred.

The concept of removing two of the four knives was discussed here not long ago. Folks agreed that you "could" do it, but some indicated that it is likely a bad idea to leave the knife mounting positions "open"...flat stock of the same thickness and of similar weight to the knives should be inserted for balance and to insure that no flying parts result. Remember, the cutter assembly was designed for four knives, not two.

But frankly, what are you trying to gain? You get less quality in the cut, potentially more noise and only save a little money over time. Personally, I'd run with all the knives engaged.

[Bill Simmeth]

Along the same lines as Jim's advice, never leave one or more slots open in the cutterhead. This can cause the head to warp slightly, possibly loosening the grip of the remaining gibs (knife holders). At the very least, keep the gibs in place and torgue them as if a knife was present. If the bolts won't close the open gap, insert a metal filler of some sort. If you're really interested in running just two knives, it might be best to set two knives lower so that only two are routinely contacting your workpiece. That way the cutterhead would stay balanced and equally stressed.

PS... Welcome to the Creek!

[Shiraz Balolia]

I have just ordered the Grizzly 20 inch planer and hope to receive it in the next month or so(was backordered)

This planer has a 4 knife cutterhead and I have read threads indicating some have taken out two knives on these cutterheads.

I would like to try this and wonder if there is anyone with firsthand experience in only using two of the 4 knives.

Thanks

Fred Mc.

Fred - thank you for ordering the planer.

Please DO NOT run the machine with less knives in the cutterhead. If you happen to nick the knives with a stone or nail that was embedded in the wood, then simply shift the knives alternatively a 1/16 or 1/8" of an inch ie. shift one knife in one direction and the next one in the opposite direction. This will allow you to go longer between sharpenings and eliminate the "streak" in the wood caused by a nicked knife.

[Steve Clardy]

Purchased mine in 1998. Been a real good reliable machine.
Don't understand why someone would want to run only two knives in it.

[fRED mCnEILL]

"But frankly, what are you trying to gain? You get less quality in the cut, potentially more noise and only save a little money over time. Personally, I'd run with all the knives engaged".

Here is my reasoning.

In reading some prevoius posts I recall someone suggesting that you could run a 4 blade planer with only 2 blades because it would still be balanced. I currently have a 12 in Dewalt planer that I am quite satisfied with except that I want a larger planer. It only has two knives and when I compared the finish on a board with my neighbors 3 knife General 15 inch planer my finish was MUCH better. Mind you I had just put in new knives. That tells me that the number of knives doesn't necessarily mean better planing results. And if the results with 2 blades is as good as it is with 4 then why not only use two and keep the other two as spares. The additional noise is inconsequential. Setup would aso be easier. Perhaps in order to take heavy cuts you need the 4 blades.

Bob, I have a number of Grizzly machines and have been quite pleased with them. A friend just bought a 15 Griz planer a few weeks ago and likes it. In looking around I noticed there are a number of planers that appear to be identical and the only difference is in the paint job. I live in Canada and a local dealer carries the indentical machine under a different name . I think the Grizzly is finshed better and it is also cheaper. I also think that the after sales service ( if needed)with be better. I have NO confidence whatsover in my local dealer having ANY spare parts should I need then while I'm pretty sure Grizzly would have what I need. Of course I do have the border issue but I only live about an hour from Bellingham(Grizzly) so its not too much trouble to go there. And browsing the Grizzly showroom is such a rush.

Fred McNeill

[Curt Harms]

Hi Fred

Grizzly showrooms ARE a rush, aren't they? I live not too far from Muncy PA. Re your thoughts about blades, the Grizzly cutterhead turns at 5,000 RPM. I have a Delta lunchbox (2 knives) and it turns around 8,000RPM. The cuts per minute impact finish quality along with other factors. A Grizzly cutterhead should yield 20,000 cuts/minute(5000rpmx4 knives), my Delta should yield around 16,000 cuts/minute(8000rpm x 2knives). Removing 2 knives from the Grizzly would yield around 10,000 cuts/minute. Feed rate would determine cuts/inch. I certainly wouldn't remove knives.

Curt

[Jim Becker]

Fred, the cuts per inch on the portable unit is higher than the stationary machine in many cases which is why the finish can be so good with only two knives. Many of the stationary tools run at a lower cutter head RPM which is why they go to three and sometimes four knives. More knives at lower RPM restores the CPI to acceptable levels. The lower the CPI, the more "scalloping" on the surface. At any rate, you can try it both ways and see what works for you!