I am having trouble with the bit slipping in my router. It slides down (deeper) while I’m routing and I don’t notice it until the dammage is done. I am using a Porter-Cable 7529 plunge router. The chuck is held by a plunge pin while I tighten with a wrench. I tightened it as much as I could by hand. I was lowering the background around a planned carving in a pannel door when the bit suddenly went through the wood. Ruined!
I was using a 3/8″ diameter bit with a 1/4″ shank. The cut was 3/8″ deep. The router is about a 2 years old and has not seen much use. The bit is less than a year old, sharp and the shank is not dammaged. The wood is butternut. Is it possible that the chuck has been wiped and will no longer hold? Is there something that I’m doing worng?
Replies
Tex, it sounds like the collet is toast. You should be able to get a replacement from a good PC dealer. To be on the safe side, I'd change the collet nut too, give both a thorough clean prior to assembly just to me sure there's no manufacturing residue left in either.
Mike Wallace
Stay safe....Have fun
The bit and collet both have to be very clean. It doesn't take much built up burned sawdust to make a bit slip. Take the removable parts of the collet out. Clean them and the bit well. Don't use sandpaper or anything that would scratch. The smooth machined surface is best.
The nut should be tightened quite tightly.
1/4" shanks are notorious for slipping. If you are making a heavy or full depth cut, this can put the maximum stress on the chucks grip. Make sure there is no debris in the chuck taper. You are not the first person to have a bit come loose and ruin a job. When it happens to me, it is usually my fault. I'm pushing the small bit too much. If available, I buy 1/2" shank bits.
Beat it to fit / Paint it to match
1/4" bits usually have a fillet at the point where the shank meets the cutter. Make sure you aren't dropping the bit too far into the collet because when it's tightened on the fillet, it has no choice but to loosen. Next time you change bits, snug it up and pull it out about 1/8"-1/4" before tightening the nut. This applies if you have already checked for sawdust.
"I cut this piece four times and it's still too short."
"pull it out about 1/8"-1/4" before tightening the nut. " 1/4" seems like too much to me. Although, I now read on the Woodhaven site that more is OK, as long as 3/4" remains inside the collet. Actually, the page has a good description of parts and safety:http://www.woodhaven.com/FAQShow.aspx?ID=1748
Posted for "All"forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Tex, Before you go buying new parts, lets make sure that the problem is not you.
When you put the bit in, do you push it all of the way to the bottom before you tighten the collet? if you do, this may be the problem.
Always start out a little bit away from the bottom. The bit bottoming out before the collet is totally seated will prevent it from getting its maximum compression.
You have received some good advice so far -- especially about the bit bottoming out. I have a flock of PC routers, and have never once had a problem with the bit slipping. so if you follow the advice given in this thread, and you still have a problem, you need to invest in a new collet. BTW, Woodhaven also sells a nifty set of collet brushes (spiral shaped), that are intended to clean out the inside of a collet. If memory serves me correctly, they also have a free booklet on collet maintenance.
Thank all of you for the advice. Before going to a plunge router I made it a habbit to insert the bit to the bottom of the collet then withdraw it 1/8". That way I could drive the bit into the collet to break it loose if it became stuck. I have done this ever since.
This morning I examined the bit and router collet. The bit I was using is a Freud 3/8" X 1" streight. The 1/4" shank is 1-1/8" long and there is not a fillet at the sholder. The face of the shank has been wiped for a distance of 3/4" from its butt. There are scars around this portion of the shank which was in the collet. These scars are spiral indicating that the bit screwed itself out of the collet! The inside of the collet was clean and polished. There was no sawdust of other material in the collet socket to prevent it from obtaining a good grip on the bit.
I feel that both the bit and the collet are a loss and should be replaced. Unless the collet was previously wiped and had lost its grip, I'm at a loss to explain what happened and to assure that it does not happen again. When installing the bit, how tight is tight? I know I have read a warning somewhere about over-tightening. Also I lightly oil the sanks to prevent rust. Could this contribute to the problem?
Why not try it after wiping the oil off the shank and cleaning the collet? You can re-oil it when you're done. If you have a vernier caliper or micrometer, measure the shank, just for reference.
"I cut this piece four times and it's still too short."
I'm no expert, but it really sounds like part of the problem might have been pushing the bit too hard (esp. given the 1/4" shank). How much of what type of material were you taking off in one pass? forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I was making a 3/8" deep cut in soft butternut. There was no complaint from the operation until the last when the bit began to chatter. It was creeping out of the chuck at that point and dropped out of the chuck once it had chewed its way through 3/4" of butternut and into the top of my workbench. It didn't feel like I anything was wrong until the chatter started. There were not any burn marks on the sides of the cut. The depth of cut ramained at 3/8" until the last 6" or so of the run.
If just cleaning doesn't help, another idea I've seen in a metalworking context - haven't tried it myself - is to paint the bit shank and the interior of the collet with a little bit of rosin dissolved in alcohol. Non slip is why gymnasts use the stuff.
Edited 1/13/2005 2:40 pm ET by Uncle Dunc
I don't worry about over tightening router bits or shaper cutters. With 1/4" shank bits I crank them. The bit could be toast now that it has spun. Take an old useless bit and chuck it in the collet. See if you can pry it out. Most likely, the bit shank is softer than the collet and the collet was not damaged. Never use a lubricant on the bit shanks. After describing using oil and not over tightening, I think that was your problem. A heavy cut will pull even a well tightened bit. Don't over tighten table saw blades, but make sure anything that can go flying is secure.Beat it to fit / Paint it to match
Real good advise. Thanks a lot, I will take it to heart.
I used to have bits slip when using 1/4" bits in my half inch Hitachi plunge router. The solution was to line up the through slot in the 1/4" adapter with the through slot in the collet and then tighten the bit. Not sure this is your problem but it might be worth checking out before ordering new parts.
Chip
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