Spiral Heads on Old Equipment

Re-tooling an old, heavy piece of iron with a new helical cutterhead can be the ideal value solution for some shops. August 18, 2009

I'm looking for someone who has used a spiral cutterhead on a planer. Is the spiral head worth the expense? Does it do a better job? Brands? Powermatic 15HH vs. Grizzly G1021X2?

I have always bought named brands thinking I was getting quality. Delta has shattered that belief for me. I bought their top model 8" jointer a year ago. The outfeed bed was warped the last 6" over a 1/32" and the infeed was dished out in the center. That was followed up by them sending another set of beds that were just as bad. Three times was the charm. Finally good beds and 3 days of a Delta tech replacing them. The machine is the biggest disappointment.

A month later my friend bought the Grizzly match of my Delta. It was identical. Only thing different is the color and the knobs, and his was flat. Why am I paying twice as much - a name? It's not only Delta. My other friend is a diehard Powermatic fan. He purchased their top 8" jointer as well. The beds ended up being twisted. Are all these machines coming off the same factory line and just getting different paint, names, and price tags? It's very sad to be a craftsman these days and not have quality equipment anymore.

Forum Responses
(Solid Wood Machining Forum)
From contributor J:
What kind of work/volume are you doing? If you're doing more than several hundred bd. ft. of material a year, none of the machines you're looking at will be worthwhile. If you're working smaller batches, you may be able to get by.

Here's my experience with newer machinery. In the last 8 years I've bought a new Powermatic 24" DD sander, model 27 5 hp shaper, 21 spindle line boring machine, Bridgewood 20" spiral head planer, and almost new (2 year old) Delta 20" bandsaw, 3hp shaper, 1 hp powerfeeder.

The Bridgewood was the first to go. It was their heaviest 20" and sold for about $3800, but wasn't up to the task of heavy planing for my small shop. Within a year I upgraded to a 50 year old SCM 20" planer that's so much better built they're not comparable. Next to go was the Delta shaper, as it had a slight vibration I couldn't get rid of and the motor ran really hot even when doing light cuts. The Powermatic is better, but it too will eventually be replaced with an SCMI or equivalent. The Delta Bandsaw is adequate for my needs as I don't use it much, but for someone who used it daily, I think it would be a disappointment. I think the drum sander is very well built for its price and is the only new machine I've bought that I feel like I got my money's worth. Everything else I listed with the exception of the powerfeed will eventually get upgraded to true industrial equipment.

All this to say quality depends on your perspective. Some guys buy these machines and are perfectly happy with them. Myself, I find I'm better off buying industrial machines used that I couldn't afford new. I'm also not a big fan of Grizzly. I think they're great for hobbyists, but if you're making a living with your tools, maybe not so much. I bought a couple of their machines years back and if you ever take one apart to fix it, you see where the money gets saved. Cheap bearings, undersized drive shafts, lesser quality cast iron, and cheaper motors to name a few. Not to mention the resale comparatively speaking is usually dismal. And on one of the machines I had, although it looked similar to a name brand, the way they cast a certain part was so poorly done I still don't know how it lasted a year before I did manage to break it.

Lastly, whether or not the spiral is worth the cost depends on what you're doing with it. It may well be worth it for a small shop, as it's easier than changing knives and they last a very long time. Having said that, I get as good or better finish with my SCM planer when the blades are sharp, so I don't really miss it.

From contributor R:
I agree with the idea that your uses and volume should help you guide your purchases. I have used spiral heads in both planers and jointers and they do make a huge difference. You can literally joint against the grain and get a clean cut. It also reduces the cutting pressure dramatically. The stock simply moves easier across the head.

Most industrial equipment can be easily retrofitted with spiral heads. A client just ordered a Byrd Shellix for his 16" Invicta jointer. Maybe your best bet is to buy high end equipment used, and use the money you save to equip them with spiral heads.

From the original questioner:
Thanks for the input. You both have good logic. I am a professional. I make my living designing and building my own line of home furnishings and sculpture. I've been doing this for 12 years on the side and am now going into it full time. So some of my equipment is entry level, like the little 12.5" Delta planer that has died. I work with odd materials that are tough to plane. That is why I have interest in the spiral heads. I've only heard rumors of these spiral cutter heads and it is usually bad. People have said that they don't leave smooth cuts, and that they leave lots of fine lines in the wood surface, as if a knife had a nick. Have either of you come across this?

I could easily run a hundred board feet in a week to a month and definitely a year. So you can upgrade any planer with a spiral head? I'm looking at a 20" SCMI. The only thing that disinterests me is the regular knives.

Contributor J, you feel that the years of intense use and unknown abuse to industrial machinery don't compromise the integrity of the machine? Compared to buying a brand new Powermatic?

From contributor M:
I run a Byrd Shelix in a SAC planer that is comparable to an SCMI and all this bologna about them not leaving smooth cuts is just not true. I've had too many woodworkers into my shop that have seen it run and they all leave believers. They almost eliminate all tearout, require less horsepower, and are easier on your dust collection, as it creates a uniform stream of chips. I can't speak about the clones that are put on some of the Chinese machines. You will see small lines on the boards, but with a straight knife cutterhead you see scallops. Every board needs to sanded anyway, no matter what kind of machine it comes out of, so I don't see what the big deal is when it comes to the so-called lines you see in the board. The benefits far outweigh that. Now keep in mind that I'm talking about a 125 mm diameter cutterhead, not one of the small diameter ones they put in the light duty machines. That makes a big difference. I think that's why, contributor J, your SCMI cuts better than your old Bridgewood. Put a Byrd Shelix in that SCMI and it will cut even better.

From contributor J:
My Bridgewood had the offshore copy of the Shelix and it still left a very clean cut. No matter what comes out of my planer, it's going to get machined, then hand sanded, so even if you have lines left over, they're not an issue.

If you check out the Shelix website you'll find that they carry, or can fabricate, a head for just about any machine out there. The question is, do you want to spend the money for it? The head for my machine is several thousand dollars, which is much more than I paid for the machine. And as I said earlier, I have a knife grinder on my planer, so there's not much incentive to spend all that extra money on a new cutterhead.

I also don't get why so many guys are afraid of the straight knife planers all of a sudden? They've been in use for well over a century and worked fine until just a few years ago when the spiral insert heads came along. Sure the smaller, cheaper planers are a pain, but if it's a heavy duty, well-made machine, properly set up it should do a fine job.

Lastly, I don't want to be misinterpreted - years of abuse can and will certainly take their toll on any machine. My SCM was bought from a local retiring furniture maker with a small shop who bought the machine new when he was starting out. It had plenty of use on it, but I don't believe it had been abused. On the other hand you can see machines coming out of bigger shops that have been beat hard and are probably not worth much. You have to be able to see the machine run and make sure everything is in working condition. Ideally you would want to take someone with a very good knowledge of woodworking equipment with you to look it over. I've been lucky so far, as my knowledge is limited but I've been in the right place at the right time on some great deals.

Consider this also - when you're comparing a new Powermatic to a used SCM, you're comparing a $2-3k machine to a $10k+ machine. In my case, if I had bought it and still had to spend the cost of a new Powermatic to restore it, I would still be ahead of the game. But again, this is my view and may not be the best fit for you.

From the original questioner:
Unfortunately, there are not any good used planers coming up for sale locally that I can go over and check out firsthand. I have found 2 SCMI 20" planers (S-50) for sale on these used machine websites, neither of them close enough to go look at. One of them has a knife grinder.

It sounds like you really like that option. How long does it take to sharpen the knives? You don't have to remove them, right? Does it sharpen them as well as sending them out to Dinosaw?

Contributor M, thanks for your info. That's what I wanted to hear. I know you get four cutting sides to each cutter. Do the corners get worn away that you can only use the opposite side rather than the next side? How many cutters does your head have? How often do you have to replace the cutter with all new ones (after using all sides)? I know that it depends on how much you plane, but do you feel it's as cost effective, having them over straight knives?

For 9 years I've changed big jointer and planer knives in old machinery. I don't know about you guys, but it's a pain in the butt. I'm tired of doing it. It's very time consuming getting them lined up perfectly. I could never have a shop assistant do that task, either, because they were never careful or skilled enough.

I work with some funky laminated and recycled composite woods that have grain directions going every way. I run them through the planer. They do okay with fresh knives, but I wear out knives fast. It sounds like I either need the Byrd or a knife grinder.

Has anyone purchased machinery from any of these used industrial machinery auction websites? I have found four planers listed online - some dealer, some private sealers. None close to Rochester, NY where I live. Who do you trust - the dealer who is out to make a buck, but a legal business, or the private sealer, who you don't know?

From contributor J:
I find I have to sharpen the knives about every 6 months or so depending on how much use they get. At a leisurely pace it takes about an hour to remove, clean off, and re-set all the knives. Then grind them, wax the tables and get back to work. You have to loosen the knives to sharpen them as they will be coming out of the head just a tiny bit. Otherwise you would change the cutting height of the knives. It's not like changing knives on a regular planer, though - you have a knife gauge that you hold over the head which holds your knives in place. It doesn't matter if they're perfectly aligned, since you'll be grinding them after. And they'll leave a better cut than any sharpener could, since they are ground to the exact same height - something nearly impossible to do without grinding on the head.

As for the machines you listed, I'm not sure I have any worthwhile advice. I would definitely recommend the knife grinder if you don't go with spiral head, as it will already be set up and you won't have to find one and install it yourself. Unfortunately your timing is off, as several months back a local dealer had a Northfield #7 with grinder that was in very good condition.

What I would recommend is calling Ben Rock before you commit to anything. He's a dealer I just bought a machine from and probably the most down to earth, helpful guy I've talked to about machinery. He's located in Illinois but has very good shipping rates if he does happen to have something you can use. My only other recommendation is to not rush into anything if you don't have to. I find patience is the best tool in finding good deals on used equipment.

From contributor L:
I replaced the quiet head of my Powermatic 24 with a Shelix two years ago and love it. I am just 20-30 minutes east of you in Ontario if you would like to see for yourself what the Shelix can do.

From the original questioner:
The knife grinder sounds really good. I think I'll give your guy a call. I've already been looking for 3 weeks, before getting turned on to WOODWEB. My planer died about 2 months ago. I've been getting by using a friend's, but he is moving out of my building. So I really need to get a machine to get working again.

I found an SCMI (S-52) 20" in Osgood IN. I talked to the guy and he says the machine is tip top. He's had 4 years and believes he's the second owner of the machine. He's reluctant to sell because he likes it so much, but he just upgraded to a 36" Bus. The only thing that he sees wear on is that pressure roller on the far left side. Its serration, he said, is worn down in one spot. He said it was like that when he got it - looks as if something got jammed in there. He said it does not affect the performance of the machine. He never noticed it until he was changing the knives one day.

Besides that, it seems to me a great value for that machine and it's only a 9 hour drive. My gut is telling me to check this one out. I'm not sure of all the differences between the S-50 and the S-52, and then there's a S-520. I tried Googling them all, but am not finding very much info.

I also found one on eBay that is closer. Except the description of wear, seams really odd. In the 12 years I've been doing woodworking, I have never heard of this - the points of wear are where two front dust bellows have opened up, and electrical connection box at lower front corner is loose. I'm not sure what that means but it sounds as if they didn't keep up maintenance on the machine.

From contributor J:
Sounds like you may be onto a good machine! I don't know the differences between the SCM models, just that the one I own is a S-50 with L'invinceable on the front. Not sure when they dropped the L'invinceable part, but I've been told mine is from the late 60's. It has a single central support post for the table, whereas later ones seem to go to multiple posts. Other than that I don't have much info and what I did find I got by scouring sites like Ex-factory. Having the knife grinder will be a good thing. It will get you up and running quickly until you decide if you want to spend the money on a spiral insert head.

From the original questioner:
Thank you so much for Ben Rock's info - he is a really good guy and he knows his stuff. He gave me an hour and half of his time discussing what planers are good and what planers to stay away from.

Today I went to contributor L's shop and he showed off his Powermatic 24" (1950's) upgraded with a Byrd Shelix head. I was very impressed. First off, the head is a beautiful piece of machining. Plenty of cutting edges. He said he bought the head 3 years ago and has yet to rotate the cutters. He's only had to replace and rotate a couple cutters due to a nick. He runs a good size 2 man cabinet shop (1800sqft).

So he fired up the planer and put a piece of hickory through it. All you could hear was the motor and a real slight hum. Almost as if you stuck a piece of paper in a fan. I think my cordless drill is louder. That's the first time I've had a conversation with someone while planing a board.

The board came out looking as if it came out any other planer. Except in spots where the grain went the opposite direction, there was barely any tear out. No little pin striped lines. He showed me a hard rock maple board that he planed before I got there. Most of us would've burned this board. It was full of knots, and gnarly grain. Except it was, again, nearly tear-free. Now let me remind you these edges are 3 years old. I think they are ready to be rotated soon. With that said, they still put out incredible results and I bet with fresh edges it would give perfect results.

How many times do you think you would have to change and sharpen the knives in your planer in a three year time frame? When it does come time, contributor L has no worry about letting a shop assistant rotate the knives for him. It's brainless and impossible to screw up. No adjusting and trying to get the knives perfect.

The only thing you have to worry about is if you are one of those guys that likes to take off heavy passes. You do have to go lighter on passes due to the shallow cutting edge. If you do take too much in one pass you risk jamming the board into the head, which could break the cutter free. Cutting depth depends on the size of the cutters. The Byrd Shelix has made a believer out of me. I hope this review will help anyone who has wondered about this new style of cutter heads.

From contributor J:
Yup, sounds about right. Not to beat a dead horse, but I'll just throw out a couple observations.

You do have to have someone with a brain to rotate the cutters, as they need to be torqued correctly or can be snapped. Remember, carbide is much more brittle than HSS.

And if you have the budget for the spiral, by all means get it. But if it's a choice between buying a top quality planer, or a not so great planer with a spiral, I'd go with the better planer. In all honesty I think you will be surprised at how much better a good machine cuts as compared to the light duty machines. And you can always upgrade the head at a later time.

Last, in 3 years I expect I'll sharpen my blades about 5-6 times, running all hardwoods. But if you added up all the time it will take (about 1/2 hour per sharpening, not including cleaning and waxing, which you'll still have regardless of cutter head), I don't think it will be much more than the time it will take to rotate all those little cutters once. Certainly not enough time to make it a factor for me.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor B:
I purchased a used Powermatic 60 long bed 8" jointer four years ago and have successfully made mounds of saw dust with the three straight knife blades. I am currently working through quarter sawn oak, old barn wood, having to resaw the 4x6 timbers to get my flooring planks. This is the first time Iíve worked with old wood and the jointer does a great job, but does leave a 1/32 wide raised "pipe" near one edge. It will clean off with the Dewalt planer using straight knife blades.

Both do a great job in a one man non-production shop. Iím retiring next year and if furniture and children's rocky horses begin to sell, I might trade up for used industrial machines. For now I get satisfactory performance from the standard straight blades. I hope you have great success with your wood machines.