ARGH! My router screwed up my project! Or, maybe there was something I did that I don’t know about. Here’s the story. I am building a hutch for my workbench, 5 feet tall, 8 feet wide, 2 feet deep. I was routing 3/8 in deep dadoes in the side pieces to receive the shelves. I had a 3/4 in bit chucked into my Craftsman router. I had my straightedge clamped tight. I had everything drawn out…man I was ready…or so I thought.
As I started routing the first dado, everything seemed fine. Then I noticed what seemed like more sawdust than normal, and my router depth collar seemed to be rotating loose. At the end, what was supposed to be a 3/8 in deep dado ended up being a 7/8 in deep canyon.
I cannot figure out what happened to cause this. My depth collar was locked as tight as I could get it, my bit was brand new. I don’t get it. I consider myself a beginner so I want to use this as a learning opportunity. Please let me know your thoughts.
Thanks–Erik
Replies
Vibration is not your friend. It will shake loose collars, collets and nuts holding guide settings.
Best solution I've found is masking tape to prevent the initial movement that starts the loosening of collars and nuts that eventually leads to big problems. As far as collets go, sharp bits and light cuts minmize vibration and reduces the chance of them letting go.
Sounds like your bit sliped out of the collet as the cut progressed. Things to consider: Is your collet absolutely clean and grease-free? Did you install the bit properly, i.e., not inserted all the way to the bottom prior to tightening? Is the collet firmly attached to the shaft? (I had one come loose once and it caused a lot of vibration that made it impossible to keep a depth setting.)
Mike Hennessy
Pittsburgh, PA
Mike, great questions. I guess the first newbie type question is, how deep should my bit be inserted into the collet? I've always been taught to put the bit shank into the collet as far as it will go and tighten it down, and that's what I did this time.
(s'cuze me Mike) "I've always been taught to put the bit shank into the collet as far as it will go and tighten it down, and that's what I did this time." Wrong! Heat will make the parts expand some, so after you find "full depth" by bottoming out the shank, you pull it back just a smidge to give it room to expand.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
You can also use a 1/2" O-ring (or 1/4", depending on the bit) on the shank to fit the bit into the collet. Measure the depth of the collet, and try to leave ~1/4" clearance between the end of the shank and the bottom of the collet. It can help when you are changing bits, especially on a table.Glaucon
If you don't think too good, then don't think too much...
FG, yer "scuzed.
Also, in addition to what FG said, if you bottom the bit before tightening it, it interferes with the collet's ability to tighten fully, since that requires the bit to be drawn a bit deeper as the threads tighten and the collet is forced down into the tapered opening.
Mike HennessyPittsburgh, PA
it has less to do with heat and expansion than it does with the mechanics of the way the collet works.
It is definately good practice to not "bottom out" your bits...
Your instructions received for tightening are incorrect. You do not want to bottom out the bit prior to tightening, as tightening tends to "want" to drive the bit slightly downward. Read the documentation that accompanies the router or bit. Consider yourself lucky. Once a spinning bit leaves the router, you're in a dangerous environment before you know it.
Unless you discover some obvious reason for the slippage, get a new collet.
David Ring
http://www.touchwood.co.il/?id=1&lang=e
I'd bet you are using a ¼" shank router bit. These are notorious for slipping in the collet. You need to take extra care in positioning them and tightening down. If the shank is bottomed out, the collet may not tighten all the way. You need to keep it up a little, this will also help against the bit getting stuck. Any bits that have spun in the collet will have abraded the walls and, perhaps, made them over size. A new collet may be in order but the shank is softer and will wear faster than a collet.
Your cut is a bit much. Normally ¼" x ¾" is typical for a dado. Heavier cuts put more strain on everything. I avoid ¼" shanks except in small size cutters. If you do use them in larger sizes, you have to keep your eyes and ears open. I've had plenty of them slip and didn't know it. I can't remember a ½" shank ever slipping or breaking off. Some routers won't accept ½" shanks. Go slow, take less of a cut, make sure the bit isn't bottomed out and tighten fully, check often.
Beat it to fit / Paint it to match
Consistent with some of the others, my bet is your problem is one of two reasons, whether you are using 1/4 or 1/2 inch.
1. You probably inserted the bit/shank all the way. That is wrong, as stated. The connection, or joint, between the shank and the cutter portion is usually just a touch wider than the shank itself. Therefore, easy to slip. Solution: Insert all the way -- then back off 1/8 to 1/4 inch. That way your collect is gripping the full shank.
2. Probably not, but your collet or collar could have a problem. Replace, then follow number one above.
If you have a 1/4 inch router, if you are going to do much woodworking or work that you care about, move as quickly as you can afford to a 1/2 inch router.
Alan - planesaw
Sorry, but it might be time to invest in a new router. After my long time affair with Makita, I've now switched to Hitachi, I don't know which is better, any one of the larger models, imports or domestics, like PC also would be good. A half inch collet with a good half inch bit would also help reduce vibrations. One more thing, the variable speed option is also a boon when working difficult bits or woods.
Gang, thanks to everyone one of you, I have learned something from each of your replies. I am using a 1/4 in collet. I didn't know about backing the shank up a bit after full insert, I will try that soon. I thought I might have been trying to take too much cut at once. I guess I could sneak up on the depth by taking 1/8 in cuts per pass.
But that brings up a new question: what is the proper depth for a dado? I had heard a dado is a third to a half the thickness of the board...but this feels like an assumption that needs to be challenged too.
there is nothing wrong with taking a 3/8" deep pass using a 3/4" bit if your router has sufficient balls to do so. If the router is struggling or if you detect a significant fluctuation in the rpm's under load then you should think about multiple passes.
there is also nothing wrong with using good 1/4" router bits for this type of task.
I don't know what craftsman router you have, and i haven't even looked at a craftsman router in quite some time, but the cheap ones they used to sell that were made almost entirely from plastic were definately not what you would call a quality tool. If the whole tool flexes when you twist it, you probably are not going to get the most accurate cuts on a consistent basis. Also if the plastic mechanics of the depth adjustment and lock do not lock up tight you are asking for problems before you even start.
Based on your statement that you bottomed out the bit before tightening the collet, my vote is also for collet slippage as the root of your problem. My second guess woud be for depth adjustment slippage in the router itself.
Generally I dado 5/16" on 3/4" stock.Two passes even with a Porter Cable 1 1/2hp router. Look at the shank where it meets the carbide,you will see that it is usually rounded.This prevents the bit from tightening.As others said ,push the bit down,pull up an 1/8". or use O rings.3/8" is too much at one time with your router ,in soft wood you can do it with two 3/16" passes.I do not think you can change collets in your router,I believe the craftsmen routers have the collet as part of the shaft,not removable.My first router is a craftsmen,has a split collet that cannot be removed.
mike
Boy this story brings back memories. Way back when I was new I also had such an experience. I was so frustrated that I threw my router onto the floor. Well that was really effective! Then I got to both figure out why the bit slipped (there were no internet forums then) AND I got to fix the router switch that broke when it hit the floor. Lucky me.
The good news is that I've always since really tightened the collet and keep my cool (just enough) to avoid breaking any more equipment.
I still have that router and use it regularly. It trembles a bit when I reach for it...... just enough to let me know the lesson wasn't totally wasted. I've never had a bit slip since.
I was so frustrated I threw my earmuffs...they shattered in spectacular fashion.
"My router screwed up my project.""I was so frustrated I threw my earmuffs.""I guess I could sneak up on the depth by taking 1/8 in cuts per pass."Well, we're supposed to be very politically correct here anymore and not say anything that could be considered "offensive." Tell you what, son, you should not let yourself back into the workshop until you acquire some discipline and respect for the working environment, before you REALLY hurt yourself.NOTHING, I repeat nothing that happens in a workshop, especially around power tools, is reason or justification for throwing ANYTHING. And the impuse to do so is a real warning that your temperment and impulsivity is the problem.It wasn't your router that screwed up your project. It was you. And your immediate reflex to blame something outside yourself, especially a tool, is another ominous indicatior.I am being completely serious, I, and many others who have taught this field would NOT let you work in our shop! Think about that. Throwing ANYTHING in a workshop is grounds for permanent banishment. There is no place for anything but stable, quiet, considered action around all tools, especially power tools. You DON'T throw a fit when something goes wrong.Taking 1/8" per pass with a 3/4" router bit is NOT sneaking up. It's prudent practice. A 3/4" bit is huge. And just because you can buy one with a 1/4" shaft does not mean that you can plow through wood full depth without understanding the forces involved.Your experience is a prime example of the danger in power tools being available to anyone, without the slightest training or experience in their use or opportunity to acquire respect for their danger from someone who is experienced, competent and understanding.I am not trying to put you down. Just the opposite. I wrote the above for your sake, not to make you feel bad in any way. You are very lucky you were not very seriously injured. You have no idea how close you came to tragedy. I strongly urge you to enroll in workshop courses that teach tool use and safety before you use a power tool again.Rich
settle down, Rich <G>.............................********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Rich,
Throwing stuff when things go south is standard procedure in my shop. I learned it from my dad, (who was the role model for the Darrin Mc Gavin character in "Christmas Story")so it must be ok. The trick is throwing something that will not break, at something that is easily replaceable. If you get the wrench that busted your knuckles clear thru the window, it gives you something to do (look the yard over for the wrench, and cut and glaze a new window) before returning to the procedure that caused the loss of temper. By the time I'm back in the shop, I'm usually whistling a merry tune. But then, maybe that's why I work alone...I admire your composure and self control.
Ray
Ray,
Thanks for this post. Your response to Rich14 has made me smile and calmed me down a bit. Before, I just wanted to throw something.Throwing tools is necessary to have tools that need fixing..... something to do on those slow days. I also work alone, except for the dog. He knows when to duck and he's quick. He also calms me down by letting me pet him. He's got the softest ears on the block.
Let me add to Mike's suggestions. Get some 400 W&D sand paper and sand the shaft of your router bit. Clean out the inside gripping portion of your collet.
If all fails, see if the collet on your router is replaceable. As I recall, the collet is integral with the motor shaft and can not be replaced separately. If that's the case, you may want be better off getting a new router.
On another forum, a brand of router sold by a major retail chain is often dis(cussed) for it's "self adjusting" bit depth feature. The traditional advice is to avoid this brand and buy a PC or other.
I have a Craftsman router about 15 years old and I have never been able to use my 3/4" dado bit with out the bit coming loose and doing just what happened to you. Solution, I purchased a Cable Porter 690 router and have had no problems using the same bit with no silpping out.
Well, I may be adding some controversy to this line of replies.
First, if you have calipers, check the diameter of the 1/4 shank. Many of the 1/4" shank bits are undersize on the shank. I have found some significantly undersize. You may need to buy another bit.
Second, if you bottomed out the shank before tightening, that could have caused the problem.
Third, you may need to try the dado in several passes at about 3/8" to 1/4" per pass.
Fourth, occasionally clean the collet thoroughly.
Fifth, if you were using a 1/4" insert in the 1/2" collet, buy another insert. Once you spin a bit in the insert, it likely will not hold good thereafter.
And last, buy yourself a good router book by Bill Hylton; Carol Reed, or a couple of the other more popular authors. You need to learn some of the finer points of using routers.
Best wishes,
Billy B.
I have 5 routers and the only problem I have had with the 3/4" dado bit is with the Sears router. It works fine with the others. I have 2, 3/4 dado bits and one shaft measures 0.251" and the other is 0.250". I never take more than 3/16 per pass and regardless how little stock you remove the bit eventually works loose in the Sears unit. The bit is installed properly I believe that they had a collet problem.
I clicked the "reply" to your reply message. But, I was thinking about helping Erik.
I don't doubt, at all, your having the slippage in your Craftsman. Erik says his is a Craftsman, but he does not give any further information as to the model, age and type collet (1/2' or 1/4" only), etc. I would think if you ever spun a bit shank in a collet, particularly a 1/4" only collet, you probably would have trouble with the collet holding from thereon. At least one factory technician told me this very same thing. The first solution, to my way of thinking, would to get a new collet. If still in warranty, contact Sears and take to them to repair or replace.
I tried to outline for Erik and others who may be interested, things to check in order to narrow down the source of the problem. One needs to keep in mind, a slipping bit problem is not unique to just Craftsman routers.
And, I do think it would be to Erik's benefit to get a good book on routers. I say that, because it is my impression, from reading his post and a reply, or two, that he is not a seasoned router user. Could be wrong.
Meant no embarrassment to him or you.
Have a great evening. Enjoy your woodworking.
Billy B.
To Billy, Rich, and everyone who has posted in reply:
First thanks for your comments...I have definitely learned some "mechanical" things about routers (setting the bit in the collet, things to watch out for, recommendations for a better router) and also some of the "softer" skills of woodworking that are clearly learned through patience and experience. As I said early on, although I had a bad experience on a project, let frustration take over and lost my cool, I view this whole thing as a learning experience. And I DO want to learn, otherwise I wouldn't be posting and looking around here.
I freely admit that I am a beginner, and even though I've had my sparse collection of tools for 6 years or so (router included) I have not had formal training, or even what I would call good steady practice in woodworking. That's due in large part to the fact I haven't had the shop space until now to really work safely and effectively (and then I go and blow up when trying to do something as seemingly simple as cutting dadoes...geesh).
That said, the specifics on my router: Craftsman model 315.175040, 1.5 HP, 25,000RPM, 1/4 in collet, and yes, there is a fair amount of plastic on it.
Several of you have mentioned getting a book on how to use a router, do you have any specific titles? Also, any workshops or training ideas would be great.
Again, thanks to each of you...I really do appreciate it.
Erik
Erik--Good! Most of us have had experiences similar to yours. I like your attitude about the future. You will do okay.
My favorite book on routers is "Router Magic" by Bill Hylton. The book "Router Joinery Workshop" by Carol Reed is another which I admire. This is a lady woodworker, and gives good concise information on most of the router work you will ever do. Pat Warner is another good author. I sometimes get the impression Pat's book contents are just a little beyond the beginners and/or medium skilled woodworkers. But, that's just my impression which does not mean much. Patrick Spealman (not sure of spelling) is a very skilled writer and craftsman. He writes good books on several subjects, router work is among his best.
The router and it's usage should become a key part of your shop and skills.
I started my interest in routers almost 40 years ago. I met Bob Rosendahl at a woodworking show in Pasadena, Texas. Over cold drinks and coffee at the concession stand, he gave me some good advice early on. I admired him and his work ever since. His router demonstrations and teaching in woodworking shows was in it's infancy. Believe it or not, his router insert plates and jigs were made of plywood then. He is a good teacher and believes in the "KISS" principal. He and his son Rick are good to watch in the "Router Workshop" programs.
I won't get into which brands of routers I think are best. I'll just say Porter Cable; DeWalt, Freud, Hitachi, Bosch and Craftsman are brands with which I have had experience. I currently own and use four of the above. If you should look for another router, give thought to how it will be used most of the time. Personally, look at them yourself, handle them and go by your instincts which will fit you best. And, I don't believe the most expensive is always the best quality or best choice for the individual. It's my philosophy that you should buy the one that is the best buy "dollar for dollar" and meets your needs as you seem them.
I wish you all the best. And, I particularly, wish you all the best and enjoyment in woodworking.
Billy B.
Edited 2/20/2007 11:31 pm ET by Billy B.
The big difference between a novice and a pro is that pros have a lot more time to make mistakes. Most of us have shared your experience once or twice including loosing it. None of us knew anything when we started and we are still working on it. Instead of pulverizing things, more experienced woodworkers start picking their brains for a fix to the goof. Some of us have a heavy bag in the corner when nothing is working right. When the stuffing starts falling out, you are a journeyman!Beat it to fit / Paint it to match
Being self-taught and making an effort to work safely (as you stated above) require reading! IMHO, you need a good book for each machine you're using, unless you're good enough at web searching to find all the safety info online. The router incident could have been alot worse than it was, considering how hard the 1/4" shaft bit was being pushed.
If I may endulge in some sexism here, staying comfortably ensconced in the "I don't need directions" male posture isn't in your best interest when it comes to operating power tools.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG,
Would a macho male who doesn't need directions, take advice from someone named "forestgirl" ? Sure hope the nurse in the ER is cute, tho...like the ones on Grey's Anatomy...
Hahaha couldn't resist a little sexism of my own.
Ray
LOL! Didn't realize I might be spitting into the wind. You old enough to know that Jim Croce song You Don't Mess Around with Jim??
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
epearso, I read all the replies to your thread and most of them are correct (especially using such a wide cutter having a quarter inch shaft
The solution? rip a few lengths of the same wood and glue the strips into the rabbets ,then, start over.
Also every router bit has a 'radiused' shoulder where the shaft extends into the cutter DON'T grip the collet onto this thicker area of the shaft. The reason for all machine tools to have a radius instead of a sharp transition from narrow to wider sections is to prevent a fracture that would occur, had not a radius been provided. Steinmetz. Also, 'deep six' that collet
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