Hitachi plunge router collet slipping
I also have the Hitachi plunge router, model MV12, purchased about four years ago. It has failed several times to securely hold bits, usually 1/4″ diameter. The problem is most acute with dovetail bits, but it has also failed to hold straight fluted bits. I have tried several things to fix it:
1. Brute force
2. Alignment of open slots in collet and adapter to reduce torque required to close collet.
3. Replacement of collet. (major battle with Hitachi service)
4. Cleaning and dry lubrication of internal collet surfaces, except for the one that grabs the shank.
Today, I still use the router in my router table, but I used primarily 1/2″ shank bits, avoid bits that produce axial force (dovetail, spiral down cut), take very light cuts, and watch it like a hawk. My opinion is that the collet design is just too stiff, especially when used with an adaptor for 1/4″ shanks. Any others have trouble with this router? Any ideas on a fix?
thanks, Tom.
Replies
Collets like everything else wear out. I've replaced collets. $15 for a new one is cheap insurance when one considers the possibilities.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Thanks for your response. The original collet failed early in its life, and the replacement was no better. Neither had enough use for wear to be a factor.
Best regards, Tom.
Lets take this a step further. What kind of router bits are you using ? Have you "miked" shanks ? Others have said use the reducer inserts, I say they are a poor excuse for the "real thing", The tolerences, alloy and tempering are never going to approach that of a top of the line collet. A bit spinning @ 23000 is nothing to take chances with. Is the slipping happening with ALL 1/4" bits or a few ? Personally I prefer the DeWalt style collet, where the collet is split in eight segments, so that four segments grip the upper part of the shank and four grip the bottom part of the shank. It is also a double locking collet.Work Safe, Count to 10 when your done for the day !!
Bruce S.
Bruce,
Thanks again for your interest in this problem. I haven't measured the shank diameters recently, but that is a good suggestion. I think you are "spot on" with your comment about collet inserts. I have tried two with no success. As to router bit brands, I use a wide variety of brands. I have experienced the most problem with dovetail bits, because, I believe, the cutting forces want to pull the bit out of the collet.
After reading all of the posts and ideas, I think a good action plan is:
1. Measure shank diameters. Replace those that are undersize.
2. Find a better collet insert, one with more slots for flexibility when tightening the collet.
3. Use 1/2" shanks whenever possible.
4. Disassemble the collet, clean and inspect, and apply dry lubricant to the surfaces that must slip during the tightening operation. (but not the bit grabbing surfaces)
5. As stated before, take light cuts and watch it like a hawk.
Thanks again, Tom.
I don't own a Hitachi router, so I can't help you there. But it does sound like they are using a poorly designed collet. Years ago, I found the brass collet brushes linked below, and I use them religiously on all my routers. Note also, they offer a free pamphlet on collet care.http://www.woodhaven.com/SearchResult.aspx?KeyWords=collet%20brushesBTW, my router collection includes PC, Bosch, and Milwaukee -- and I have never once had problems with bits slipping in any of the collets. And that's over a span of 25 years or so.********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
The Hitachi M12V2 that I just got (but am sending back because of plunge shaft sticking) has a separate collet and nut for 1/4" bits, so it looks like they've decided to go that way (they still list a sleeve for 3/8", but who uses those anyway?)
The part # for the 1/4" chuck is 323-293. It's the same design as the 1/2", just smaller.
Don
Don,
Thanks for the info. I will check to see if it is compatible with my old machine.
Tom.
If you are using a 1/2 inch collet with a conversion sleeve to 1/4" it is not a good way to go: now the bigger collet has to squeeze quite a thick tube that is only with one split-it will have to be tightened like hell-not good. You need a dedicated 1/4 inch collet with the multi-splits so that tighttening pressure is evenly distributed.
It makes sense-the bigger the router the better the collet must be....
Philip,
Thanks for your reply. I agree with your assessment. That would rule out use of this Hitachi router with anything but 1/2" bits. I will probably continue to use it with the caveats listed in my first post.
Best regards, Tom.
Tom, that leads me to another point:I think routers are becomin6E Andg so huge now that some function is actually being lost. Example: I needed to rout out some small irregularly shaped areas on an old "talking machine " cabinet (Cheney Gramophone) to insert patches of veneer where it had been damaged- very easy to do with a smallish router freehand but difficult to do with a big one. I have two Elu routers: the MoF 96E and the 177E which is 1/2 inchPhilip Marcou
Philip,
I agree. The router I most often use is an old Stanley, 1/3 hp, that I bought about 40 years ago. It is very easy to use one handed.
Tom.
Philip,
I also have some smaller routers from...long ago..., made by Rockwell. I can use them one handed and they do the trick. The larger machines I also use, but only when it isn't prudent to use the small guys.
I have also had a 1/4 inch router bit spin out of the collet. I thanked God that it went the other way and not into me, and then purchased a new bit and a complete collet system from the manufacturer of the router, in this case Rockwell. The problem did not reappear. JL
Tom-I have owned Hitachi plunge routers for at least 35 years.
I have had the problem of which you speak.
1. Most 1/4" shank bits are less than 1/4" diameter.
2. Once you spin a 1/4" bit in a 1/4" collet insert, that insert will not hold well thereafter. Replace it.
3. Buy some new ones, there are universal 1/4" inserts that work well.
4. You may consider purchasing a new collet as well as the insert(s), especially if you have had the router a long time and have used it a lot.
5. When you use the insert, make sure the through slot (the one that goes from top to bottom of the insert) is lined up with the slot in the 1/2". That way the collet will tighten tighter around the 1/4" shop. This suggestion was given to me many years ago by the Hitachi technical people.
6. Regularly clean the main collet thoroughly. I do not recommend lubricating the inside.
I try never to buy a 1/4" shank bit, unless I can't find the cutter I want with a 1/2" shank.
I own 2 Hitachi plunger routers (TR12 and M12V). I haven't had this problem for quite some time now. I also own three other routers and I still prefer the Hitachi routers and they are the most heavily used.
I think this should help.
Billy B.
Billy B.,
Thanks for your thorough reply. I am glad to find someone else who has experienced the same problem. You have filled in some missing pieces for me. I am still using the original collet insert, so that looks like a good thing to change. The other ideas are helpful as well.
Best regards, Tom.
Tom--I remembered where got one of my 1/4" adapter inserts. I bought it from Woodcraft. I've used it for about 4 years now and it still serves me well. Also, I religiously line up the slots when I used the 1/4 shank bits.
Billy B.
Billy B.,
Thanks. I will check it out on my next visit.
Tom.
Billy,
Re your point #1- I wander if you have some metric bits there, which are 6mm diameter shank. I think you may be mistaken in saying that all 1/4 inch shank bits are undersize- I measured 1/4 inch bits and found that the diameter varied between 6.34 and 6.36mm which is of no consequence.
Re your point #5: this certainly helps the grip of this type of collet, but there will be run out whiuch can affect the cut quality.
I do wander why Hitachi, who make good stuff, elected to put that type of collet rather than the multi slit type which exerts even and reliable pressure.Philip Marcou
Philip--I said "Most" 1/4" shank bits are less than 1/4". I did not say "all".
At the time I encountered the problem, about 4 years ago, I was teaching a router seminar and had a new 1/4" spiral bit climb through a board. That was a first for me. Later after having the same problem back in my shop, I called somewhere to Hitachi and was told I needed to get another insert and to check the dia. of the shank. Sure enough, it was significantly undersize.
Then I visited two stores in Tyler that sold top of the line router bits as well as Home Depot and Lowes (both sold cheaper brands of router bits). Guess what. Except for the ones checked at the Tool Shed store, none of the 1/4' shank bits were a full 1/4" dia. And, several of those checked at each Lowes and Home Depot store were significantly under size. That was 4 years ago and I do not remember the dimensions. Also, some of the 1/4" shank bits I had in my shop were also undersize. Later, I ran across an article in one of the WW magazines that commented about the shanks of 1/4 shank bits being less than 1/4" dia.
As to my #5 point, please explain to me how lining up the through slot in the adapter insert with the through slot in the router collet could cause runout. I might also point out that I have read about this precaution in at least two WW magazine articles. And, if this causes any runout with my two Hitachi routers, I have not seen any indication of that.
Since, I threw away the inserts I was using 4 years ago, bought new ones and started using the practice mentioned above, I have not had a repeat of slippage.
Respectfully,
Billy B.
Yes , I mis -read that one. I would not want to run a bit with a shank diameter of less than 6.25mm in a 1/4 inch shank, as those multi split collets are not meant to close down to very much less than 6.35mm. They certainly do not grip a 6mm shank properly.
Re point #5 : adapting from 1/2" to 1/4" via a sleeve adaptor having only one slit means that the walls of that sleeve are thick and require much force from the big collet. If you line up the slots there is a tendency for an oval shape to occur which will make the bit run out of true.That is the reason for having multi slit collets-they exert force more evenly because they are more flexible.
Looking at your findings I do wonder if some bit manufactures did not decide to come up with an average size between 6mm and 6.35 mm so that these would fit either 6mm or 1/4" collets (not well).
For my Elu 96E I have three collets-6mm, 1/4", and 3/8", whilst the 177E has a 12mm and a 12.7(1/2")....so that I can accommodate most sizes-I think there is a 9mm shank size out there too.
It would be fine if there were just two sizes- 3/8" and 1/2".
Philip Marcou
Philip Marcou
Edited 1/26/2007 11:18 pm by philip
Phillip--Thanks for your reply.
First, let me state that my reply to Tom was simply to help him solve the problem that he had. It was not to get into a debate as to which routers are the best. I learned a long time ago that most defend their choice "to their dying day". It doesn't matter what the brand.
Regarding your statement about having to tighten the collet tighter than normal to hold the insert and bit does not agree with my experiences. I have not found that to be true. I deliberately avoid over-tightening, not any tighter than with my other routers.
I do not buy your theory that lining up the slit in the insert/adapter with the slit in the collet causes a distortion in the insert/adapter and thus results in run-out. Take a closer look at the insert/adapters. I have three different brands. They each have two grooves machined into the outer diameter. I am sure the primary purpose of these grooves is to balance the inserts. They remove approximately (may be exact as far as I know) the weight or amount of that of the slit. And, in my opinion (this is not scientific fact) these grooves will add to the flexibility of the insert. I have never found any evidence of runout using the insert/adapter. I don't know anyone else that has been able to prove your theory.
It matters little whether I am right or whether you are right. Because, if Tom follows my suggestions, it should solve the problem he stated. The fact that such steps have worked for me without fail for the past 4 years attest to that. And, Tom--you do not have to exert extra force in tightening the collet.
I will have nothing more to say about this matter. Best wishes to all.
Billy B.
I meant to reply to ALL...I own and use several router's including the Hitachi M12V. I don't use quarter inch shank bits in this router, I have smaller dedicated routers for those size shanks, so I can not comment on the smaller router bit's slipping, however I have not had trouble with the 1/2 shank collet slipping in the M12V. In fact the M12 is my favorite router. More importantly, I spent many years working as a machinist and collet tool holders were very common in the machines I worked with. I was taught that over tightening a collet ruined the collet and could cause the collet to distort and fatigue leading to slipping or catastrophic failure. Over tightening was considered a poor practice and discouraged. Not suggesting they shouldn't be tight. Just don't Hulk out on them. Clean dry surfaces are critical in proper collet usage. So is full length surface contact. If you are following proper procedure and having problems with slippage, then there's a problem with undersize shanks (already mentioned), damaged collet, or bad taper in the spindle. Hope this helps.Jeff
Edited 1/27/2007 9:17 pm by jeff100
Hitachi plunge router collet slipping
Thankyou thankyou thankyou Billy B.
I am waiting on a new collet and a 1/4" adapter right now because of the same problem/s listed on this forum.
I really hope this solves the problem. The "walking" 1/4" bit sucks when you are trying to do something precise.
Happy woodworking, and happy routing.
Roger
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