insert cutterheads

[jim mills]

Have a vast collection of brazed shaper cutters, but thinking about investing in a insert cutterhead. Mostly to save money on "one off" stuff. My instinct says stay away from the aluminum heads. I've been looking at CG Schmidt corrugated heads. Any advice is appreciated.

[Peter Quinn]

Schmidt is a fine choice, as is WKW (Wisconsin knife works) , I'm sure there are others, mine is an old DML refurb. I use aluminum euro block heads like the profile pro series from amana but you are limited to 5/8" depth of cut, most grinders I've called steer you away from having custom knives ground in the 4mm stock. Just more cost effective to go corrugated back.

[jim mills]

Ah, the 5'8" max is definitely a concern. I figured the corrugated knives would be more expensive. The stock ones sure are. I'm sure I'll get differing opinions on this question, but what about hand feeding without limiters on the schmidt or eq. heads?
Another question: Can I buy say a 4" tall head & run any height knife in it, or do I need a specific head for each knife height?

[Mel Fulks]

The aluminum corg heads I've used were out of balance and could not be used at high speed. Worked in shops that had
cheap ,probably Chinese ,steel heads and they were fine. I think they probably have the biggest share of the commercial
shop market.

[Mel Fulks]

Just noticed your other question . Even though the mfg say don't use small knives with large heads you can do it with narrow "blanks" to even the knife pressure and secure long gibs, IF they are exactly the same thickness as the cutting knives. IMO mfg warning to not do it is based on liability prudence and not safety. The problem with just having a 4 inch
head is that if you need to have knives toward the top ,say to be close to a bearing you might not be able to drop the head
down far enough.

[Mark Wooden]

Get a good, machined steel head. High speed steel knives produce a much better cut in solid stock and is less expensive than quality carbide. Call Bobby at Woodworkers Tool Works and he'll set you up.
You can use any knife that is the same size as the head or smaller than the head. But you will need fillers when the knives are approaching 1/2 the head height- i.e. a 2-1/2" high knife in a 4" tall head. The grinding shop will have filler blanks in any size you need .

[jim mills]

Dealing with the "blanks" seems a bit fiddly, and the cost of the heads is really not that bad.

[Tony Joyce]

what about hand feeding without limiters on the schmidt or eq. heads?

Another question: Can I buy say a 4" tall head & run any height knife in it, or do I need a specific head for each knife height?

1- If you're talking about this type head, yes you can hand feed. 290716(http://www.cggschmidt.com/catalog.html) page 30
They will work the same as any other shaper head in that respect.

2- The knife should not extend past the end of the head more than twice the thickness of the knife.

"Dealing with the "blanks" seems a bit fiddly"
Ask the person that grinds your knives to always square(flush) the knife to one end of the head. Each time you put them in square(flush) them to the same end. Square all sets to the same end every time makes it very repeatable and fast.

Tony

[jim mills]

Yep, that's the head Tony, 'cept it says " 1 1/2" depth of cut with 3/8" thick steel.

[David Kumm]

I'll second Bobby at Woodworkerstoolworks. I'm also assuming you are running a big shaper to use a 4" steel head? Dave

[Mel Fulks]

It's only fiddly if you are an employee and someone has misplaced them. Two other quick points: even when material is
being hand fed it should have a spring hold down, and the cut depth of two times knife thickness is IMO another liability thing,
never seen it observed in commercial shops.

[jim mills]

Yep, big shaper Dave. Again, good point on the "fillers". I will give some thought to how tall a head I would need. Most likely I would never do anything wide like crown, etc. Just easier to sub that out. Seems a 2" tall head might be all I need 99% of the time.

[Tony Joyce]

"1 1/2" depth of cut with 3/8" thick steel. "
That can vary some using good judgment and a light cut.

The twice the thickness of the steel comment made by me above, was referring to the extension of the steel past the end of the head unsupported.

Tony

[Mel Fulks]

Tony, I have misinterpreted that spec for years. Good thing I ignored it! Thanks for clarification.

[Rick Lizek]

http://www.oellasawandtool.com/categories/Shaper-Cutters/Lockedge-shaper-collars/
You should look into the lock edge shaper heads. Very versatile and you can get them with a ball bearing pattern base for doing copy work. Do not confuse this head with the old style version that didn't have the locking screw feature.

[Peter Quinn]

We run knives smaller than the head all the time, in fact a 2 1/2" knife spins fine without fillers in a 4" head as long as you catch the middle two jib screws to lock the knife in, stand it off with a spacer so the knives are up an even amount. They will tell you not to in the rule book but it works fine. That said I do that when I have to, not because I want to, and always try to match the knife more closely to the head. A 3" head is more useful to me than a 4", at 4" I want a molder not a shaper except for very large millwork items. I use a 2" the most, I think mine at home is actually 60MM which is a bit over 2"? Does 95% of what I have ever needed.

Run them freehand? It works, for larger knives I like to be further away, for quality of cut its really hard to beat the feeder, its quicker to set up IME than all the hold downs you would need to get the same performance anyway. I guess its a personal safety issue. Should the worst ever happen and hands hit cutter, a 2Z insert head sans limiters is going to suck your hands in and rip them off period. A limiter head will take some but not all, slaps them away so I'm told. Same reason those old iron jointers are a hazard with the old heads, a kick back turns tragic quick. So set it up right, guard your hands, don't feed small parts and questionable stock fill of knots and odd grain, sure. Not allowed in Europe or Canada, or most of the rest of the civilized first world.....but this is America, and we are free to be almost as reckless as we choose at present. Don't tell but I've done it on short moldings. Often though I'm running longer stock in architectural moldings than I can't reasonably had feed anyway, so the point becomes moot.

The aluminum euro block heads are a good value for what they do, I would not bother getting a corrugated head in aluminum, not much savings.

[Tony Joyce]

Mel,
No, not necessarily misinterpreted. It is recommended by most knowledgeable people that profile depths are no more than twice the thickness of the steel. It is generally only ignored by experienced people with a hands on knowledge of cutter steel and materials being cut, amount being cut, etc. I was addressing the question by Jim about knife length(amount past the ends of the head). One of the best sources of good information about cutters and knives are the people experienced at doing the grinding of profiled knives. What little experience I have comes from grinding my own knives for my moulder and shaper heads. Even though I've done it for several years I would not presume myself to be an expert or expect anyone to view my words as gospel.

Tony

[Tony Joyce]

http://www.oellasawandtool.com/categories/Shaper-Cutters/Lockedge-shaper-collars/
You should look into the lock edge shaper heads. Very versatile and you can get them with a ball bearing pattern base for doing copy work. Do not confuse this head with the old style version that didn't have the locking screw feature.

Just my observations, but lock edge shaper heads are falling out of favor in most newer commercial shops. Corrugated and pinned heads are gaining favor because of safety and ease of setup. Corrugated and pinned knives are much easier to find ready made and I would add for the most part cheaper. Even though lock edge is safer than its predecessor it still can fail unless carefully setup. That being said any system can fail from operator error.

Tony

[jim mills]

So Peter, if using a 2" cutter in a 4" tall head, what do you do with the outer two gib screws? Just curious. I'm leaning towards a 2" head anyway.

Tony, not that I ever would, because i usually buy a brazed cutter set for a kitchen project, but what you are saying rules out the possibility of using a stile/rail cutter in an insert head? An I correct?

[Mel Fulks]

For the little difference between 2" knife and 4" head I just put a little tension on the screws not being used .

[Mel Fulks]

For some jobs ,especially where a small head is needed I think the slotted shaper cutters are still necessary. Yes, some are
scared of them, some don't know how to use them, liability issues keep the one company that still makes them from giving
Instruction. Modern shaper books have less info on them than the old thin book that was put out by delta. Some employers will let anyone do any type of work and expect good employees to use faulty and mis matched steel. I worked
for a company once that had over 500 knives that had been so abused that I took them home ,sorted them first by matching the steel, then by profile. Over 200 knives were too short, if matched in profile some had mismatched steel or
had been ground on edge to alter size. I made as much sense out of them as possible and threw away 200 knives that were worthless. I have been asked ,at times, by management to change a profile so that they won't have to buy more
steel. I absolutely refuse to do it.

[Tony Joyce]

So Peter, if using a 2" cutter in a 4" tall head, what do you do with the outer two gib screws? Just curious. I'm leaning towards a 2" head anyway.

Tony, not that I ever would, because i usually buy a brazed cutter set for a kitchen project, but what you are saying rules out the possibility of using a stile/rail cutter in an insert head? An I correct?

Jim,
I'm assuming you are referring to corrugated knives or heads. Insert knives and heads being entirely different are ideal for cope & stick patterns.

Depth of cut wise most cope and stick patterns are 5/8" or less. The problem with cope and stick patterns in corrugated heads has to do with vertical alignment of the two knives. This can be good or bad depending on how you look at it. If the cope cutters(knives) are not aligned up perfectly the tongue will be thinner. Conversely the groove will be wider with misalignment of the cutters. It's just simpler to use brazed cutters or insert heads for this application.

I used corrugated cutters on my moulder for T&G paneling and Flooring, because being able to offset the cutters gave me the ability to sharpen my own cutters and not worry about tongue and groove widths because I could tap one knife or the other to get a thinner tongue or wider groove. Of course this was mostly out of necessity because I could not afford brazed cutters or insert heads back when I started out. I've since changed to inserted heads for paneling and flooring and would not go back now. I still use brazed for cope & stick, because lets face it they last forever.

Tony

[Mel Fulks]

Peter, I guess we have all run some stuff free hand, but that doesn't make it a good idea. The thing that I find interesting is the way new stuff affects our outlook. When I was young all commercial shops around here had spring hold downs. Only some had electric feeders, a few had both. Once feeders became standard equipment in commercial shops the spring hold
downs started to disappear and the idea of running by hand came in. There are some shaper mfgs that offer proprietary
hold downs but as far back as 20 years ago I couldn't find any company still making the old beefy type. I have talked to
guys who have been dealing in used machines for decades and never even seen one. One shop made is better than nothing.

[Peter Quinn]

For the little difference between 2" knife and 4" head I just put a little tension on the screws not being used .


This exactly. I snug um up but don't crank down hard enough to start distorting the gibs. I suppose you could just remove them, one head I use they are peened so they can't back out fully. Stile/rail cutters work fine in corrugated and pinned heads, I'm using them presently extensively at work, have made all the interior passage doors in my house with them. You have to have a real good grinder match them and set them up accurately, any height error is basically doubled so grooves get larger and tongues smaller which leads to sloppy fit. Very precise set up required. I;ve gone as far as to measure the knife height with a dial indicator on magnetic base.

On the depth thing Wisconson Knife works list profile depth/projection should not exceed 3X the knives thickness, other factors apply, if in doubt feel free to call their engineering department. They been at it since 1920's, seems experienced enough to me. So feel free to call their engineering department if your instincts tell you you are on the wrong side of the bleeding edge. I trust the tooling outfitter we use at work, they generally match the knife thickness to the profile, suggest changes to drawings when they feel it necessary, and have flat out refused to grind certain profiles as a single knife due to excessive projection. This infuriates architects who like to draw big omnibus moldings for reasons I can't understand that are nearly impossible to source wood for anyway and dangerous to run. Perhaps they think it more efficient to have the carpenters nail down one monster back band than a composite? Or maybe they have suffered sight lines opening up due to wood movement, bad install? Not every knife you can draw is actually safe to spin is the point, their are limits, the 3X rule is basic, if most of a 3" knife is 3X the knives thickness in projection with fine/thin points it may technically fall in the 3X range yet still be unsafe, and you may be able to exceed the 3X max depth if most if the profile is much less. Being more of a wood guy than a machinist or mechanical engineer I've come to trust the tolling experts, and their experts.

[Tony Joyce]

For some jobs ,especially where a small head is needed I think the slotted shaper cutters are still necessary. Yes, some are
scared of them, some don't know how to use them, liability issues keep the one company that still makes them from giving
Instruction. Modern shaper books have less info on them than the old thin book that was put out by delta. Some employers will let anyone do any type of work and expect good employees to use faulty and mis matched steel. I worked
for a company once that had over 500 knives that had been so abused that I took them home ,sorted them first by matching the steel, then by profile. Over 200 knives were too short, if matched in profile some had mismatched steel or
had been ground on edge to alter size. I made as much sense out of them as possible and threw away 200 knives that were worthless. I have been asked ,at times, by management to change a profile so that they won't have to buy more
steel. I absolutely refuse to do it.

While I agree with most of what you say, I would say I can do any pattern with a corrugated head you can do with a lock-edge shaper head. The small Schmidt shaper head is only 2-3/4" dia., just saying.

Now I will agree most companies that still have the lock-edge heads and knives are very reluctant to change. I have a good friend that runs a cabinet shop, that still insist his people use slick knives. Most will say it's too expensive to change. As a small business owner I would argue it's too expensive not to change from a safety standpoint. One personal injury claim would fully fund newer safer heads. If you're just starting out why go down that road? Also let me say I have and have run lock-edge and slick edge knives in the past. But I absolutely would not today and would walk out of any place that did. I don't even want to be around where they are run. I have seen and heard of too many accidents caused by them.

Please note my remarks are just "my opinion" based on my experiences only, no one else's. For your consideration or amusement!

Tony

[Tony Joyce]

Not every knife you can draw is actually safe to spin is the point, their are limits, the 3X rule is basic, if most of a 3" knife is 3X the knives thickness in projection with fine/thin points it may technically fall in the 3X range yet still be unsafe, and you may be able to exceed the 3X max depth if most if the profile is much less.

Well put.

Tony

[jim mills]

Great info Guys, really appreciate it!

[Mel Fulks]

I've got a 2" diameter set of collars!,non ball bearing. We all have to decide what we will and won't use. Clearly the old collars are on their way out, and the amount of work done with special stair fittings and such is greatly reduced. For those
heavily invested in the old system they need to listen to trusted operators as to what has worn out or been compromised.
One tip I have not found in any of the modern books: it is up to operator to check existing knives to make sure they came
from the same bar of steel. Before tightening with wrench the nut should be tightened with fingers ,then you try to move
both knives. If either of them move DO NOT PROCEED WITH WRENCH. Find out what is wrong and fix it. That type of
info is well understood by mfg, for liability reasons they are being advised to not advise.

[Max Neu]

You can get the biggest head your shaper will accept, and have multiple profiles ground on your knives.I have some done that way on my 4" corrugated Weinig head.