Thread: Scalloping Marks Left by all Helical Spiral Head Cutters?

0.5 mm is too shallow. I routinely take 3mm with straight knives because I don’t want to waste cutter mileage taking whispers off, and I don’t want to be there all day.

Oh by the way…

I have a friend with a very high dollar Felder AD951 with the SilentPower helical head. He hates the tiny scallops and has decided to trade for a machine with a Tersa straight knife head.

I am still running straight knives despite the noise mostly because my work has been in timber known for easy milling. That may change, and if it does I will likely modify my machines with aftermarket heads.

Originally Posted by EagerBeaver71

I'm questioning whether I should actually take mine back now having seen them on yours Camelot. I've gathered so much information now, I realise they all do it and there's no way of preventing scalloping with a helical spiral designed head, it is what it is as they say!. It seems to be a small trade off from not having any tear out I guess.

If you can sand them out without much effort then yours is no worse than mine, I get a much better finish with the Sherwood on difficult timber and it is less noisy than my SCM traditional 4 blade, but if I have a production run where I need to put pieces through of slightly different thicknesses, then the sectional feed of the SCM allows me to do this, which is a feature that is missing on these less expensive thicknessers.

Ran some more tests today on the thicknesser and discovered that when making a pass over 0.5mm I get less noticeable scalloping, 1.0mm and above even less!. So in fairness to Timbecon they were right in suggesting my passes are too shallow.

I have to hold my hands up and admit I am very much a beginner with this lot and feel I've been abit unfair in judging Timbecon based on my own personal experiences with Warrant Assessments from another company. This is why I asked for peoples experiences with the process.

Having got the following response from Timbecon I feel much more confident in the Warranty Assessment, so I'd like to thank them for easing my concerns.

Here's their response:

"Thicknessers will leave different marks depending on a range of factors. Straight blade thicknessers are renowned for their 'chatter' marks which are normally quite easy to see to the naked eye, while helical thicknessers may leave scalloping which is generally only noticeable under fluorescent light. The majority of people would agree that the finish from a helical thicknesser is much preferred to that of a straight blade. Having used around a dozen different models myself, I am definitely in that boat.

At the end of the day, thicknessers are dimensioning machines that take a bit of understanding. I was taught the fundamentals of woodworking machinery at TAFE but still had to learn a lot of machining techniques from experience. There are heaps of factors that will change the results that you are able to achieve, a lot of which you too will learn from experience.

I hope you have fun learning the ins and outs, and any quirks you may not have known about."

So to conclude I'll be keeping this fantastic little machine and am very happy to have a renewed confidence in purchasing further equipment from Timbecon in the future.

Regarding material taken off per pass, the same apples to some extent to straight blade thicknessers. When sneaking up on a final dimension, I always like to leave the final "pass to size" with at least 1mm of material removal. Anything less than that gives very inconsistent results, especially as the blades wear a bit.

Some years ago I contemplated converting my JET JPT310 combo to a helical head, but the cost of a Shelix wasn't far off the cost of a JET 16/32 drum sander. I haven't regretted the decision to go down the drum sander path; it can handle anything (even burl), and makes a good companion to a jointer/thicknesser to just remove blade chatter marks, roller marks, etc.

Glad you got your issues sorted, and enjoy making lots of timber into smaller bits of timber !

Originally Posted by Mr Brush

t your issues sorted, and enjoy making lots of timber into smaller bits of timber !

Thanks Basil!

Originally Posted by Mr Brush

Regarding material taken off per pass, the same apples to some extent to straight blade thicknessers. When sneaking up on a final dimension, I always like to leave the final "pass to size" with at least 1mm of material removal. Anything less than that gives very inconsistent results, especially as the blades wear a bit.

I must admit I have always taken that approach, however this Sherwood unit and some straight blade thicknessers can be pushed to limits that most users would find difficult to accept. Taking very light passes with very acceptable results is possible with the helical head - with care and with limitations on stock size dimensions, particularly length. The feed rollers "clamping pressure" is "less" with light passes, less so than a more generous cut.

As I enjoy playing about making inlay banding patterns (thanks to PowderPost) I require plenty of thin strips of timber, some of which I may take down to 0.8 mm or even 0.6mm using the Sherwood thicknesser and a Jet 10-20 drum sander. With care and an understanding of each wood species and how they perform / react to each machining process it is possible to thickness some species down to 2 mm or even less directly on the thicknesser. That saves a lot of time on the drum sander! The key words some species, not all!

A word of warning though - particular species do not have the rigidity to resist the machining forces and once they reach a thickness threshold are like throwing a hand grenade into the thicknesser. Be Warned!

The other point I would make is that a thicknesser is not a jointer. The stock being fed through a thicknesser should (must?) have one clean reasonably smooth, flat, straight face as the "reference face" although there are means to use a bed board sled with wedges, shims, etc to emulate that face. Twists, warps, etc on the face opposite the thicknesser head will directly affect the quality of the machined face.

IMHO the Sherwood helical cutter head is unrivaled in its ability to produce thin stock.

As stated, the quality of the result is highly dependent upon, the stock, its dimensions, grain & its direction, cutter sharpness, operator knowledge and skill etc. But doesn't that apply to almost all tasks when working with wood!

Originally Posted by EagerBeaver71

I have to hold my hands up and admit I am very much a beginner with this lot and feel I've been abit unfair in judging Timbecon based on my own personal experiences with Warrant Assessments from another company. This is why I asked for peoples experiences with the process.

Don’t be too hard on yourself - you’re not the only one who has learnt from this thread, I certainly have and I’m sure there are others too.

Originally Posted by Colin62

Don’t be too hard on yourself - you’re not the only one who has learnt from this thread, I certainly have and I’m sure there are others too.

too Eager ?

Originally Posted by EagerBeaver71

Thats a lovely piece of timber right there, the grain is beautiful!, wonder what it is @Auscab. Yes I can see the scalloping, they do sand out pretty easily though.

I caught up with the guy at my local Woodworking Guild who suggested I buy the piece for a few Xmas presents I am working on, he says it's Emu Apple

Emu Apple

Hi all, I'm new to this forum - which I discovered when researching scalloping.
I recently bought the Sherwood Deluxe helical 13" thicknesser and found the scalloping issue a little intriguing to say the least. From all the hype it sounded like these machines would produce mirror finishes on whatever you put through.

Originally Posted by Flemming

From all the hype it sounded like these machines would produce mirror finishes on whatever you put through.

Hi, I'm not sure any thicknesser will produce a completely mirror finish. You would have to introduce a drum sander for that I think. Since purchasing mine I've not found the scalloping an issue as they're sanded out pretty easily.

Originally Posted by EagerBeaver71

Hi, I'm not sure any thicknesser will produce a completely mirror finish. You would have to introduce a drum sander for that I think. Since purchasing mine I've not found the scalloping an issue as they're sanded out pretty easily.

I was in touch with Timbecon and was told they had never seen this issue before and had to refer it to their technician. I said I thought it was the fact that the blades are radiused to 150mm. They then offered to send me some carbide blades to see if that made any difference - I asked if these were straight or radiused and was told straight. After some delay they arrived and were clearly radiused and made not the slightest difference.
Then the guy I was dealing with left and the next one I dealt with told me that it is a known issue and only happens on some woods and depends on the depth of cut. Deep cuts supposedly reduce the issue. There's quite some gap between "an issue they have never seen before" to it being a known issue etc. blah blah. As a consequence I have lost quite a lot of confidence in them. As for the nonsense that deeper cuts or the wood makes a difference is rubbish in my experience. I tried variations of cuts on pine, Tassie Oak and Redgum. All had scalloping.
Fortunately I came across your post and a few others out there in web-world and that has allowed me to move on and accept that this particular machine does not produce a scallop free surface but it is easily sanded, scraped or handplaned out - something that would need doing regardless.
So thank you for your original post and follow-up additions (and to all those that contributed along the way). Your post actually helped me come to terms with the issue.
I bought some straight 15mm carbide blades (from somewhere else) but I don't think they will fit because the head itself has a radiused seat for each blade. If I ever do try them I'll update it here.

Originally Posted by Flemming

I was in touch with Timbecon and was told they had never seen this issue before and had to refer it to their technician. I said I thought it was the fact that the blades are radiused to 150mm. They then offered to send me some carbide blades to see if that made any difference - I asked if these were straight or radiused and was told straight. After some delay they arrived and were clearly radiused and made not the slightest difference.
Then the guy I was dealing with left and the next one I dealt with told me that it is a known issue and only happens on some woods and depends on the depth of cut. Deep cuts supposedly reduce the issue. There's quite some gap between "an issue they have never seen before" to it being a known issue etc. blah blah. As a consequence I have lost quite a lot of confidence in them. As for the nonsense that deeper cuts or the wood makes a difference is rubbish in my experience. I tried variations of cuts on pine, Tassie Oak and Redgum. All had scalloping.
Fortunately I came across your post and a few others out there in web-world and that has allowed me to move on and accept that this particular machine does not produce a scallop free surface but it is easily sanded, scraped or handplaned out - something that would need doing regardless.
So thank you for your original post and follow-up additions (and to all those that contributed along the way). Your post actually helped me come to terms with the issue.
I bought some straight 15mm carbide blades (from somewhere else) but I don't think they will fit because the head itself has a radiused seat for each blade. If I ever do try them I'll update it here.

Hi,

Glad my post helped. When dealing with Timbecon or Carbatec for that matter its luck of the draw who you get to talk to and how clued up on their products they are. I think some re-training is order somewhere. As for the scalloping, anyone who say's their exact same machine and head doesn't produce the problem needs new glasses, they all do it.

Regards,

Sam.