Knurlingoperation

Minimal disruption from nicks in knives. With high-speed steel knives, if you nick one of your blades, you either have to remove the blades and sharpen the set or try to slide the knives so that the nicked portions of the blade no longer align. This presents either a cost factor, hassle, or both. With spiral cutter heads, you rotate and are back in business. Plus, since the inserts are made of carbide, the likelihood of getting nicks in the cutters goes way down in the first place.

Impact milling: In impact milling, the rotating milling tool is moved axially to the point of processing with a plunge cutting feed, stays there for an instant, and is then retracted to the starting position.

Groovingoperation

The synchronization gear can also be provided with a burnishing sector. This means that over the space of about 180 degrees, it is wider than the work piece and ground hollow in the direction of the flank lines. The result is that only those zones on the tooth flanks of the work piece are contacted, in which a secondary device can enter the tooth gap (Figure 3).

Both sides of the tooth must generally be deburred and chamfered. As such, the tool consists of two chamfering wheels. These are combined into a compact unit by the synchronization gear in the middle. During the production operation, the chamfering wheels do the shape-forming work to achieve the chamfers. Because rotary chamfering is a non-cutting operation, the squeezed material has the tendency to flow to the plane faces of the gear or in the tooth gaps.

Chamfering operationpdf

Setting knives can be frustrating. This can take a while and lead to inconsistent results in getting the knives consistently set to the perfect height. Of all the factors to consider with spiral cutter heads, this one appeals to me the most, as I am not a fan of swapping knives in a jointer.

Helical vs. Spiral. When looking into spiral cutter heads, you will hear the terms “spiral” and “helical” used nearly interchangeably, but there is a slight difference between these two designs. Both designs feature a machined steel head with small square cutters placed along the surface in a spiral pattern. The primary difference lies in the orientation of each cutter. Spiral cutter heads position each blade, so the active cutting edge is perpendicular to the jointer’s feed direction. This would be a similar cutting action to a hand plane, taking a cut straight into a piece of the wood grain.

Super easy cutter changes. Depending upon the design of a given cutter head, swapping out knives can be a cumbersome, time-consuming process. With spiral cutter heads, the process could not be much simpler. Remove one screw, rotate the cutter 90 degrees to a new edge, tighten it down, and resume jointing.

Chisel method: In this process, a specially formed chisel is used for chamfering. The spacing between the teeth is generally continuous in this case.

Easier dust collection. A minor benefit is that the smaller cutters on spiral cutter heads break the material into smaller pieces, so slightly less suction is required to extract the waste back to a central system.

Grinding with disk-shaped grinding wheels and/or milling with rotary cutters: These processes generally work with one or more swinging grinding/milling tools that use adjustable contact pressure to probe the edges of the teeth. The chamfering quality depends on these forces and the rotational speed selected for the work piece.

For special applications, the tool package can be modified. If the chamfering quality requirements are lower, it is sufficient to replace the synchronization gear with a spacer disk. This is particularly the case if shaving is to be done afterwards or if chamfering is carried out between two cuts during hobbing.

The chamfering and deburring of gears is often an undervalued process in gear production, but it has a great influence on the usage characteristics of the work piece. It is important to distinguish between the processes of chamfering and deburring, although in practice they are nearly always used together. In large-series production, rotary chamfering and deburring is the process most frequently used, because it is fast and cost-effective.

Joint MDF or plywood. If you ever have a requirement to join man-made materials such as MDF or plywood, you can do this with confidence using a carbide insert cutter head, while this is not recommended with traditional knives (although I will admit that I have jointed plywood with knives a time or two).

Milling with chamfer hobs: In this case there are two additional disk shaped tools mounted on the hob spindle. After the hobbing process, the chamfer tools are shifted into working position. The first side of the gear is chamfered with the first tool. Then the direction of tool rotation is changed, the position tool/work piece is adjusted again, and the second tool chamfers finally the other side of the gear.

If the costs are converted into cost per work piece produced, it is quickly apparent that the cost per work piece for chamfering with the described deburring process is low. However, it is equally obvious that the process can only be cost-effective when working with large unit volumes, that is, in series production.

Decisions, Decisions. Is a spiral cutter head right for you? Considering this upgrade, the following simple table might help you determine the trade-offs.

Speeds generally range from 100 to 150 rpm at the tool, and the processing itself takes only two to four seconds. The material pressed to the face by the chamfering process is then cut off in the last work step by chisels or deburring disks positioned by spring force. This compensates for the width tolerances of the work piece. The positioning itself can be done using a controlled axis or even hydraulically.

Helix cutter heads, on the other hand, operate more like a sheer or skew cut taken with a hand plane, as the cutters are positioned at an angle to the feed rate. Theoretically, this shearing action should provide a superior finish, as it does with a sheer cut on a hand plane. In practice, however, when applying a slow feed rate and a shallow cut, the surfaces produced on a figured stock by each style cutter head are nearly perfect to the naked eye, so it isn’t easy to substantiate a claim that one is better than the other without employing some level of magnification. And at that point, it becomes a science project rather than a meaningful measure of woodworking precision or productivity, which causes me to lose interest.

Roller deburring tools can be reconditioned about 3 times after use. Generally, the tool life when processing an automotive gear should be up to 10 million work piece teeth when using coolant. When dry processing, a tool life of about 2.5 million teeth can be expected.

Chamfering operationsteps

The deburring machines or units are relatively simple and consist of two parallel spindles whose center distance is reduced during processing. It does not matter whether the work piece or the tool is driven. The direction of revolution during the chamfer process is normally constant, but there are also solutions in which the direction is changed during the operation. It is also possible to have an electronic synchronization of the driven work piece and a driven chamfer tool. This has the advantage that the tool and the work piece can come faster into mesh and the risk of damaging the tooth tips during the plunge motion is greatly reduced.

The chamfering itself has two main tasks. A chamfered tooth is protected against damages during the handling of the work piece. This means the risk of nicks in the active flank is minimized. The other task of chamfering is to avoid the risk of over-carburizing the pointed front edge of the tooth during case hardening. This results in breakage under load.

And no tear out. You can pretty much forget about grain direction. This is a huge deal, and extremely important on figured woods. (At least with Shelix.)

Chamfering operationon Lathe Machine

Quieter. The spiral cutter heads operate much more quietly than knife-based cutter heads. Although I don’t own a sound level meter, I can’t quantify this, but the difference to my ears is pretty dramatic.

What is the purpose ofchamfering

What do you think? Are you using a spiral cutter head in your jointer? If so, let us know why you bought it and what you think of it in the comments section below. Questions? Please feel free to post those in the discussion forum so we can continue to add to the knowledge base that is growing there.

This upgrade is a no-brainer for professional woodworkers who use their jointer. Minimized downtime due to blade swaps, less sanding time on face jointed surfaces, and fewer sharpening expenses add to real savings and competitive advantage due to better productivity.

In addition, the cost of an integrated chamfer/deburr unit is significantly lower when compared to a stand-alone machine. This can be easily explained, because the control, the chip removal, the lubrication, and the power supply from the base machine are utilized. In addition, the automation between the two processes is far simpler.

The synchronization wheel ensures their exact guidance and this results in consistent chamfer form and quality. Since the synchronization gear is narrower than the work piece by twice the desired chamfer width, the flanks of the chamfering wheels will engage in those of the work piece during radial positioning. The synchronization gear also fills in the tooth gaps of the work piece, preventing material from penetrating the gap.

I have an old but beauty INCA over under 8.5" jointer/planner. In spite of having the gauges to set the knives this was pretty much a day long job. I bit the bullet and bought a SHELIX replacement head sold by BYRD Tools. Due to the age of my machine it was a custom order. It took some effort=time to install but in the end what a difference. I buy my lumber in the rough and the first job after installation was a Lacewood and Black Walnut box. It machined the figured wood with no problem or tear out. I was so impressed that i immediately ordered a head for my dewalt thickness planner. i am equally pleased here. Noised factor is greatly reduced as you are not turning a solid blade through the air. With the cutters the air can move with less effort between them resulting in less resistance and hence less noise. My only knock on the cutters is that they tend to snipe a bit more than blades. It is an easy solution on the thickness planer by passing a sacrificial piece behind your good wood. Not so easy on the jointer. I have checked my tables and they are aligned so right now i simply leave a little extra length to be trimmed at the miter station. In the end what sold me was the ease of changing the cutter heads especially when you get the inevitable nick in a nice new set of blades. Even if you are simply a weekend warrior the price is justifiable. Think of it this way . With 4 rotations per cutter, you may never have to buy another set of blades.

Manual chamfering and deburring with hand tools: This is a difficult and quite imprecise process primarily used for low-volume or large gears.

Can they be use on an old Craftsman joiner. Mine is about 30 years old and gets little use because of the pain of setting the knives.

ChamferingTool

Better surface on figured wood. This is the point that seems to get all the attention around the internet. From my standpoint, I have used a jointer with HSS knives for over a decade and have had good results when face jointing figured stock, provided my knives are sharp and set properly, the jointer is tuned, and I take light cuts with a slow feed rate. I don’t rely on a jointer for a finish-ready surface, so even with a spiral cutter head, I will continue to scrape or sand to a final surface. The results I have seen so far using a spiral cutter head on figured wood have been spectacular. I have face-jointed birds-eye maple, curly birch, quilted maple, and quarter-sawn white oak, all with great results.

The technology of rotary chamfering and deburring is primarily integrated in the tool itself. It is adapted to the specific processing task and is therefore work piece-specific in most cases. The diameter of the tools is generally between 150 and 200 mm. It is beneficial to choose a prime number as the tooth count. The range for the module that can be chamfered is about 0.8–5 mm. The rotary chamfer tools are made out of high-speed steel dedicated for cold forming operations. Especially for dry chamfering, it is recommended that the tools utilize state-of-the-art coating materials (Figure 2).

As with any machining process, the manufacturing of gears by hobbing or shaping results in burrs on the front edge. These burrs must be removed because they are hazardous to machines, tools, operators, or the process in general. This chamfer and deburring process should be carefully considered at the beginning of a new project for gear manufacturing.

Experience shows that a comma-shaped chamfer down into the root of the tooth is recommended when chamfering on both sides. However, a parallel chamfering shape can also be produced. Normally, the chamfering angle at the foot of the tooth is about 45 degrees. Measured from the flank, it should ideally not exceed 30 to 35 degrees. Here, up to module 5 mm, a chamfering width of less than 0.7 mm should be the goal. The size of the chamfer is thereby distance checked less than 90 degrees to the gear faces.

For instance, the hardened burrs can break off inside the gearbox and lead to failure of the gears and bearings. Residual burrs in the tooth gap after hardening are extremely sharp and will quickly destroy the grinding or honing tools during hard-fine finishing. The operators handling the work pieces run the risk of injuries caused by sharp and pointed edges of the burrs.

Unfortunately this isn’t always the case. Instead, the focus in many cases is mainly on hobbing or shaping, but it should be kept in mind that almost every gear needs to be chamfered and deburred (Figure 1).

These minimal but sharp secondary burrs are then rolled down by the burnishing sector. The remaining sector of the tool then handles the chamfering work. This variation is especially practical for subsequent hard finishing of the tooth flanks. If the secondary burrs are not removed, they will be extremely hard and sharp after hardening. To protect hard finishing tools such as grinding wheels or honing rings, it is essential to remove them.

I do a lot of work with Teak and as most folks know, teak is very destructive on sharp steel due to the silica in the wood. I traded in my jointer for a new jointer with a spiral head.... Worked so well that I also bought a new planer with a spiral cutter head. My large band saw even has carbide tips on the blade. Carbide is the only way to go in my opinion.

Rotary chamfering and deburring: In this process, a specially formed gear-shaped tool engages with the work piece. Their axes are parallel and there is only a radial plunge infeed. The desired chamfering is obtained after a few turns. The chamfer process itself is chip-free. The material removed from the plane sides is then cut off by deburring with a simple tool, such as turning tools or file discs.

My shaper and planer are older knife style. Where can I find out whether or not they are compatible for replacement with either the spiral or helix cutter heads? Is there a model chart of compatibility available?

All the processes listed have their particular areas of application. For large-series production, however, in addition to the shapes and qualities that can be produced, the determining factors include processing times, tool cycle times, and automation options. Rotary chamfering and deburring has therefore assumed the dominant role in the automotive and motorcycle industry, and we will now examine it in more detail.

I like the concept behind spiral and helical cutter heads, and I took the plunge and ordered one with my recent jointer purchase. As a hobbyist, I consider this a luxurious indulgence. I need to use a jointer more to justify the expense based on any cost savings I will incur down the road. But the surface quality, quieter operation, ease of blade change, etc., make it an attractive upgrade for any woodworker who can afford one without cutting into grocery money.

I just got my first planer and jointer. Both are Wen with spiral heads. I waited for an Amazon Prime day special and got BOTH, and an extra set of replacement blades for both, for a little over $700. Their 3 knife versions were about the same, and on Prime day it was actually LESS than both 3 blade versions would have been normally. I am really happy with both of them, although they are spiral heads, and not helical, and not carbide. Glad I waited for a sale, too!

Chamferingmachine

For all these reasons, gears must be chamfered and deburred. The chamfering and deburring process is often technically undervalued and does not receive the attention it deserves. However, ignoring the issue can lead to inevitable production downtimes.

In all cases, at least the sharp front edge should be provided with a chamfer. However, this is the exception, since generally both the sharp and the blunt edge must be chamfered. The corresponding design of the tool permits a variety of chamfering shapes to be obtained with a defined chamfering angle (Figure 5).

Nope, that’s certainly not your grandpa’s jointer cutter head. It’s called a spiral cutter head. It is a newer design that uses the concept of insert tooling rather than traditional straight knives installed in the cutter head. Small square carbide cutters are placed near one another along a machined spiral pattern in a steelhead. This same technology is also available for other tools, such as planers, shapers, and molders. Still, since the purchasing criteria may differ for these applications, I will focus on using spiral cutter heads in jointers for this article. Spiral cutter heads are considered an upgrade for a jointer and generally carry a premium of $300 to $1,700, depending upon the size of your cutter head. Many manufacturers now offer this as an option that can be factory installed in their jointers when initially purchased. They are also available as a retrofit that you can install yourself. They are superior to traditional knife-based cutter heads in nearly every respect. Whether it makes sense for an individual to purchase one depends on whether the incremental cost is worth it to that particular woodworker, given their specific requirements. To evaluate whether or not it is worth the money to you, here are some of the key benefits to consider:

Edge longevity. Spiral cutter heads utilize carbide steel inserts, while most knife-based cutter heads incorporate knives made of high-speed steel. Carbide normally holds an edge for at least three times as long as high-speed steel, much longer than that in many cases. This translates to less time between swapping out cutters. Plus, the insert cutters for spiral cutter heads normally have four cutting edges on each one, so if one gets dull, it can be rotated, and the jointer is immediately back in production. Depending upon the cost of sharpening and replacing knives in your area, it is unlikely that this longevity advantage alone will ever singlehandedly justify the cost of the spiral cutter upgrade. Still, it is a factor that can offset some of the price differentials, so it is worth consideration.

Rotary chamfering and deburring can be carried out either with individual machines or by units integrated into hobbing or shaving machines. In the past it was common to have a separate machine for hobbing or shaving and an additional stand-alone machine for chamfering and deburring. This has changed in recent years. Most of the modern machines are now equipped with an integrated chamfer/deburr unit, and for good reason. Because floor space is expensive, it is increasingly important to minimize the footprint of the equipment. An integrated chamfer unit does not need any additional floor space because it is fully integrated into the base machine (Figure 4).

I've been a hobbyist woodworker for 40+years. I just upgraded my planer ($1200) and jointer ($650) with helical cutter heads. Wish I had done it a decade ago. However, the price was always the deterrent. Every manufacturer that sells to "hobbyists" gouges them. ("Get as much money as you can as fast as you can" and "What the market will bear" are their mantras.) Any reasonable comparison with similar machine tooling removes any legitimate, (or honest), defense of the prices for this tooling. Nevertheless, if you are a professional, or you are someone for whom "money is no object", OR you are just old and retired and have decided that you 'deserve' the performance in spite of the gouging, GET one of these cutter heads. You WILL appreciate it. And if you're not happy with the performance of the new head, (ignoring the cost), you are doing something wrong.

The chamfering and deburring of gears is often an undervalued process in gear production. However, it has a great influence on the usage characteristics of the work piece.

I currently own one jointer and one thicknesser, both made by Invicta/Delta in Brazil about 30 years ago and still perform very well. I changed the cutterheads of both machines by also made in Brazil helical carbide cutterheads. I think all your remarks about these cutterheads absolutely true and I am very happy with them in spite of the cost. I am a weekend woodworker and really don't need superior machines but rewarding myself with these upgrades made me feel very good, fixing blades is in the past and I have more time to really enjoy woodworking.