broke my 1/8 cutting bit...thinking about my replacement options

[Digitalwoodshop]

Something to do with the hardness and the Collet inability to crimp tight enought.....


AL

[Jeff_Birt]

Pressing the adapter sleeves off and re-using them is not a good idea. You will introduce a LOT of run out (wobble) in the bit. When adapter bushing like this are pressed on at the factory a special fixture is used to hold the bushings squarely in place and to guide the bit as it is pressed into the bushing. This is the only way to do an accurate job.

[Digitalwoodshop]

Pressing the adapter sleeves off and re-using them is not a good idea. You will introduce a LOT of run out (wobble) in the bit. When adapter bushing like this are pressed on at the factory a special fixture is used to hold the bushings squarely in place and to guide the bit as it is pressed into the bushing. This is the only way to do an accurate job.

Plus 1 on that too... Tapping one on could introduce runout...

AL

[PCW]

Something that may work for reassembly is... freezing the bit in the freezer then warm the bushing up in pan of oil. When assembled back together the bit should drop right in bushing then let cool. We use to do this in the shop with bearings and bushings.

[bergerud]

Pressing the adapter sleeves off and re-using them is not a good idea. You will introduce a LOT of run out (wobble) in the bit. When adapter bushing like this are pressed on at the factory a special fixture is used to hold the bushings squarely in place and to guide the bit as it is pressed into the bushing. This is the only way to do an accurate job.

I disagree that pressing the adapters on and off will cause any significant run out. There is a run out from the loose fit of the adapter into the CT which dwarfs any bit to adapter run out. A friend of mine has a CT and I do not know if they are all like his but, I can see the bit wobble. Remember how nicely the carving bits fit into the QC adapters? It was a nice close fit. Does your CT adapter fit as snugly into your CT? I believe this loose fit along with the clamping from the side is the real source of run out.

Sorry to rant but the whole run out thing is a sore point with me. I changed a long time ago to the ER collet system.

(My advice to CT users would be to rotate your bit once in a while so the bit wears evenly.)

[henry1]

I have to agree with PCW that will work and trust me I have been there, way ago pcw

[Jeff_Birt]

I disagree that pressing the adapters on and off will cause any significant run out.

Everyone is free to do what you want with your own machine but I am quite certain that what I said is correct. I don't want to make a big deal out of it but saving a few $ by trying to reuse the bushings way wind up cost more money in the long run as the bits will wear out faster and the wear on your spindle will be increased. Again, everyone is free to do what pleases them I just want to make sure that the pros and cons of trying to reuse the bushings are known so everyone can make an informed decision.

I talked with a tool manufacturer who spent several thousand dollars developing the fixture that let them press the bits into the bushings with minimal run-out. They had to do this to keep the run-out low enough to have a usable bit. I am also very confident in this manufacturers ability to measure run out very accurately as I built part of the laser micrometer system they use.

[mtylerfl]

I disagree that pressing the adapters on and off will cause any significant run out. There is a run out from the loose fit of the adapter into the CT which dwarfs any bit to adapter run out. A friend of mine has a CT and I do not know if they are all like his but, I can see the bit wobble. Remember how nicely the carving bits fit into the QC adapters? It was a nice close fit. Does your CT adapter fit as snugly into your CT? I believe this loose fit along with the clamping from the side is the real source of run out.

Sorry to rant but the whole run out thing is a sore point with me. I changed a long time ago to the ER collet system.

(My advice to CT users would be to rotate your bit once in a while so the bit wears evenly.)

Now you have me very curious...I have never noticed any wobble using the CT...and, there is no loose fit either. In fact, it is snug as all get out. So, I'm really not sure what's up with your friend's CT...doesn't sound right to me. (There should be no wobble or looseness of fit in the CT.)

I do enjoy the ER collet system on my ShopBot machine. I recall you had posted about the modification some time ago. Do you have a link to that info?

[bergerud]

Now you have me very curious...I have never noticed any wobble using the CT...and, there is no loose fit either. In fact, it is snug as all get out. So, I'm really not sure what's up with your friend's CT...doesn't sound right to me. (There should be no wobble or looseness of fit in the CT.)

Interesting that your adapter fits snugly in your CT. Maybe there is a variation in CTs and/or adapter diameters. Now I am going have to go back to my friends machine and remeasure things. I do recall that the adapter diameter was slightly less than 1/2" whereas the bore of the CT , I think, was 1/2". Maybe you could measure your adapter diameter. Because of the side dog clamping design, any difference in diameter would result in a run out of the same magnitude. (Even if the fit were snug, the compression and distortion of the adapter and CT during tightening would cause run outs greater than any adapter to bit run out.)

[CNC Carver]

I ordered from lowes and was able to specify carve tight chuck. LHR called to confirm before they shipped order for Lowes. Price was much better from Lowes shipped to store for free.

Well, that is part of the reason I decided to ask them, better for LHR if Lowes carries your stuff or at least has more of your line available for order and better for me as a customer because it is easier access to the product. Maybe if enough of us ask our local store it will percolate up the chain?

I did notice that the carving bit they list has the picture of the old type, If I order one from them which version do I get?

dave