Freud 508…Did I do something wrong?
SBerruezo
| Posted in Power Tools and Machinery on
I picked up a Freud 508 dado set not long ago, threw it on the saw and made some rabbets. I bought it because I heard it gave flat-bottomed cuts with no bat ears, but i have some definite bat ears, and it seems like the chippers are maybe a wee bit smaller in diameter than the outer blades.
Now I admit, I’m more of a carpenter than a woodworker, but I’m a toolaholic and want the best tool and performance I can afford. I’m not sure if it’s possible to screw up using a dado set, but if so, it’s possible I did it, but I don’t know how.
So for all you woodworkers, is operator error possible, or did I buy a lemon of a dado set?
Thanks.
Replies
AFAIK the SD508 uses an ATB grind on the outside cutters for a clean edge...those are what causes the bat ears...it's nothing you did. Most stacked dado sets use a similar design, but there are some that use a flat top grind on the cutters and leave a truly flat bottom. The typically accepted downside of the FTG is increased tearout. AFAIK, the Infinity uses the FTG on their cutters, yet is still highly regarded.
Edit: I stand corrected about the Infinity cutters using an FTG teeth. They are indeed ATB.
"This performance is the result of our unique 6-tooth chipper design, 20deg. ATB grind with negative 5deg. hook, all premium materials and detailed craftsmanship. "
Edited 3/28/2007 6:38 am ET by Knotscott
I don't doubt Knotscot has provided you accurate information. However, I think you do have a lemon (and somehow don't feel that's a contradiction.)
I'm so pleased with Freud's SD208 that I don't understand what it is trying to provide with the expensive SD508.
Consider contacting Freud. Charles M. of Freud participates in this forum (33578.39 for example). I'll bet you a dime, Freud will not respond to your concern with "Well, that's the way it goes". That blade set should provide you a 'wow' experience.
IMO, jim
I doubt that you have an operator error problem. All stacked dado sets that I am aware of have bevel teeth on the outside saws to score the material and reduce chipping or splintering (unless they are custom ground). These bevel tips must be taller than the flat raker tips to be effective and the result is the bat ears in the corners. For Freud dado sets the bat ear should be less than 0.008" deep. I am sorry if you received incorrect information before you purchased.
If you will tell me what saw you are using I may have better insight into the overall flatness of the cut.
Freud America, Inc.
The Freud product that doesn't make "bat ears" is their Box Joint Cutter (SBOX08). Wonder if you got them confusicated??
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
One thing that hasn't been mentioned is a possible issue with your arbor. I have a Forrest stacked dado set that leaves a clean bottom when I use it on one of my saws, but not on the other. I have figured out that the one saw has an arbor that's just a hair undersized -- enough that it doesn't keep the saw plates on the same axis, leaving an uneven surface on the bottom of the dado. YMMV.
Mike Hennessy
Pittsburgh, PA
I wonder . . . does the "bad" saw happen to be a Delta contractor?
Hello,
I was just going thru the forum tonight and noticed this particular question which is exactly what I have been experiencing in the last couple of days with great frustration. I went years without a dado blade and just purchased the same blade (SD508) last week and have the same problems with bat ears!! Today was my second time using it to make some thru tendons and I actually had to set-up my router table to run the tendons thru to clean up the cheeks. I was going to purchase a cheaper dado set then decided at the last minute to spring for this set since it got the best ratings in FWW. I thought I was doing something wrong also and went looking for the manual that came w/the set.
I have a Grizzly contractors saw which is around 12 years old. Could it be the saw and not the blade??? I was going to post this question after I had more to time to investigate my problem but I'm not sure what else to do about it.
Thanks,
Frank
Might even slight arbor run out be a cause?I recently read a saw article regarding irregular dado blade cuts wherein the problem was found to be the arbor threads [that allowed the blade(s) to slip.] Thread fillers and sleeves have been used. No experience here.Talk to Freud?
What is it here that people aren't understanding?!??! A decent dado set is going to produce bat ears. To quote Charles' post above:
I think the OP (and those who follow) are confusing a flat groove with an earless groove. Stacked dados produce flat grooves (as opposed to a rounded groove such as you'd get with a wobble dado). The only stacked "dado" that doesn't produce bat-ears is one such as the Box Joint Cutter SBOX08 or its Johnny-come-lately Forrest equivalent. This cutter is made to cut with the grain therefore it does not need the bevel teeth required by a good dado set (which will be used to cut across the grain also). If you find a stacked dado set with no bevel tips, brace yourself for ugliness if you use it across the grain.
[sliding the soapbox under the bed]
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 3/28/2007 1:50 am by forestgirl
I think this might help clarify, if I can get the attachment in. The dado set should produce a flat bottom with a slight nick at the corners. Those are the "bat ears" made by the grind on the outside cutters. If I read Charles M correctly, they should be pretty small, i.e., 8/1000". That's a feature, not a bug. OTOH, if this is NOT the problem you are experiencing, then something has gone wrong.
You go girl. You beat me to it.
Paul
Dear FG,
YIKES!!John
This topic was discussed in messages 30111 from the perspective of good dado stacks. In message 30111.22 I posted some <crappy> pictures of bat ears that I believe are totally acceptable (the ears, not the photos). I used raking light to emphasize the scratches left by the outside beveled cutters. You have to read the post to make sense of the pictures.
http://forums.taunton.com/n/find/findRedir.asp?webtag=fw-knots&mg=016596EA-3994-464E-8EB7-9028F6083AB5
For the OP and others with concern about the ears, I would suggest assembling a small version of whatever--shelf piece into dado--using glue as planned, and finishing as planned. Then stand back three feet to analyze the visual effect of the ears. Probably, your eyes won't be drawn to the bat ears. If they are, perhaps there is something wrong with the stack, or it's mounted backwards on the arbor. :)
We're not working in metal, so we have to accomodate the fibrous nature of wood, and cross-grain scratching is part of the accomodation process.
This is post is not meant to offend anyone of any race, religion, creed, political or sexual orientation, gender, role, occupational group, or favorite wood, neander or normite, or advocate of brand names. If it does offend, then the poster denies posting it. Otherwise, I'm trying to be helpful.
Easy forestgirl, message received. The saw I'm running it on is just an older DW744. Apparently there was a misunderstanding of all the reviews I had read. However DESPITE the bat ears, I still don't have the flat bottom I was expecting from the reviews. The chippers seem to be a slightly smaller diameter than the outer blades, causing a raised section in the dado. Obviously, this is fairly easy to get rid of with some handwork.
Maybe this is true with all dados, I can't say...I've never owned a set before, and my use of them in the past has been milling stuff for more rough carpentry. I also acknowledge that my sorry excuse for a table saw could have some bearing on it, but I just can't swing for a cabinet saw at this point, but I can take my saw to the job and make my money there.
I don't believe the arbor is the problem for being too loose... If memory serves, I had to exert some fair pressure to get it on the arbor...Same with one of my other blades. (2 blades, both from the same company and purchased at the same time had different arbor holes...odd.)
Thank you all for the posts.
OK, if we're talking about a bottom that isn't flat (let alone as soft as....oh, wrong topic), then some technical help is in order. I would suggest you post to Charles by replying to his post above, and explain specifically what you're seeing in the shape of the dado.
I've not used the 508, I have a different Freud model, but the dados are very flat and smooth. Occasionally, I won't get the set mounted quite right, and the dado or rabbet won't be parallel to the surface. Haven't figured out exactly what it is I do to cause that problem, but it always goes away if I loosen, shuffle blades, and retighten, usually tighter than I normal tighten regular blades.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
A stacked dado set should leave the bottom of the dado dead flat. Mine (a very old set, manufacturer unknown), leaves a surface that looks as though it has been planed. In effect, it has been planed - by the middle cutters.
If yours leaves a surface that is anything less than perfectly flat, something's wrong. It's possible that the dado set was mis-ground somehow, leaving some of the cutters a different diameter than some of the others. I've had my dado set sharpened by Forrest, and they did it perfectly - and the result is the "shaved" bottom surface.
Though this doesn't apply in your case, some people get into trouble by having only the outside cutters sharpened on their dado sets - because those are the ones they use most. Then they set the dado up with a center cutter and find that the center cutter is cutting deeper than the outer cutters. That's a result of the inner cutters now being slightly larger in diameter than the outer ones, due to the outer cutters having lost some material due to the grinding process. And it sounds as though this is happening, to some degree, with yours.
So, I suspect your dado set is defective. It would be hard to envision a scenario where the saw itself could produce a dado with a non-flat bottom. I'd send it back, perhaps with a few samples of the defective cut. A brand new dado set should cut perfectly and yours is not.
Zolton
I don't discount the possibility of the dado set being ground incorrectly, but it is a very unusual occurrence. Is is possible for you to show a photo of the results and/or a measurement of the height of step between the outside saws and the chippers?
Charles M
Freud America, Inc.
Is the 508 the dial one? If it is I have one and have been very happy with the results. It does leave a very small score mark, but it is hardly noticeable. The dado itself had a very flat bottom with no telltale signs of blade overlap. Yes there are "bat ears" but at least on my dado set, they are very small.
The SD608 is the dial-a-dado, but it uses the same tooth configuration as the SD508 and SD506 AFAIK.
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