Jeff
Registered User
If you have a bush that is off center, What is the best way to correct it?,and what is the better way to bush,with a hand bush or a bushing machine?
Jeff
Jeff
Dang! I'd love that setup, Jerry!Jeff
Great question to a more common problem than one would think, but seldom discussed on this board.
Personally I avoid this problem by bushing with a small Milling Machine. For those who are frugal, I think you would find a small mill less expensive and more efficient than the many tools it replaces including bushing machines.
In this case it is highly efficient in correcting manufacturing errors as mentioned by LaBounty or poor quality bushing work.
To correct such a problem I first remove the old bushing. Next the arbor/pinion/wheel are installed along with the previous or next wheel between the plates. The movement is then installed in a movement holder and mounted in the Mill as shown in the attached Photo. From this point a piece of bushing wire is installed in the spindle and dropped over the pivot of the incorrect bushing. This allows the pivot to be very precisely located within the bushing hole with the slides until correct depthing is achieved. When spinning the two wheels for correct depthing, you will be very surprised at how much difference a slight movement of the pivot will make on friction free operation.
Once depthing has been achieved the bushing wire is removed and the next larger size bushing reamer is installed in the Mill spindle. Then the lower plate is removed for reaming/boring a new bushing hole. The movement holder is designed to hold the top plate only and allow removal of the lower pate (See Attached Photo) Because the mill and movement holder are very rigid the reamer will bore the new bushing hole in the correct depthed locatation rather than ream the hole.
Personally I found this to be a fast, efficient and highly effective repair with a quality appearance.
Jerry Kieffer
Jerry, is that a small drill mill? Would you go into some detail. (size, cap, hp, brand ect.) I have two KWM's and one Bergeon but have thought about a bench top mill drill for the shop for some time.
Thanks
Wow, what a great idea! Although I don't have a "small" mill, I do have a micro (finger) feed quill attachment for my 8x36 mill. It is also equipped with a 3-axis DRO that has .0002" resolution scales. I don't foresee any problems using my machine with your procedure - do you?.......To correct such a problem I first remove the old bushing. Next the arbor/pinion/wheel are installed along with the previous or next wheel between the plates. The movement is then installed in a movement holder and mounted in the Mill as shown in the attached Photo. From this point a piece of bushing wire is installed in the spindle and dropped over the pivot of the incorrect bushing. This allows the pivot to be very precisely located within the bushing hole with the slides until correct depthing is achieved. When spinning the two wheels for correct depthing, you will be very surprised at how much difference a slight movement of the pivot will make on friction free operation.
Jerry Kieffer
Wow, what a great idea! Although I don't have a "small" mill, I do have a micro (finger) feed quill attachment for my 8x36 mill. It is also equipped with a 3-axis DRO that has .0002" resolution scales. I don't foresee any problems using my machine with your procedure - do you?
Highpower
Your large mill should work fine for this specific procedure on something the size of a typical American 8 day movement or larger.
However larger work holding options in larger equipment takes much longer to setup and caution must be observed not to damage small tooling.
Many other typical Horological milling procedures are better done on a smaller mill that is more sensitive to the small tooling required to do a quality job. While most anything can be done on larger equipment it becomes a matter of practicality and efficiency. Under industrial conditions it will be desirable to use heavy equipment setups to do one and specific part day in and day out. But not for general machining under Hobby or small shop conditions. My comments are based on my personal experiece with my larger machines. My largest mill is a Emco Maier F3 of very high quality and in new condition. (Attached Photo) While a great machine it simply is not practical to do a wide range of small work that comes up on a daily basis. But for large work it is of course the only way to go.
Jerry Kieffer
Jeff
Great question to a more common problem than one would think, but seldom discussed on this board.
Personally I avoid this problem by bushing with a small Milling Machine. For those who are frugal, I think you would find a small mill less expensive and more efficient than the many tools it replaces including bushing machines.
What kind of milling machine is this Jerry. Looks very nice. Does the "plate" holders go with it or did you make those?
Thanks
tick
Jeff
What kind of milling machine is this Jerry. Looks very nice. Does the "plate" holders go with it or did you make those?
Thanks
tick
Tick
As mentioned earlier in this thread the Mill shown with the movement holder is a Sherline standard model 5400. The 2.000"x 1.000"x 2.500" Movement Holder aluminum blocks can be easily be machined on this Mill.
Jerry Kieffer
Jerry, If you can hand bush and do ok, Why wouldn't a china made milling machine do a good job?, If that was all you are doing, just to rebush and some minor jobs. Surely they couldn't be that bad.
Is anyone using one?
Jeff
Jeff
I have owned several of the Chinese Mini Lathes/Mills since 1988 (Including HF) when they were first imported by Enco. (Photo of the last purchased/current version attached)
We each have our own standards and purpose/use when it comes to equipment. I will limit my comments to my personal experience with this equipment. All machines were purchased new. All were very course and crude with only one or two were in full operating condition out of the box.
This condition cannot be explained but must be compared side by side to tools of quality to be understood. Almost all ways were not parallel from the factory. This makes accurate Gibb adjustment over the full range of travel very difficult to impossible. On three examples I remachined/ground to correct this condition. On each example the castings warped in different directions upon completion of the machining/grinding. In the end each machine required the development of skills to minipulate it to do what it was intended to do before anything of value could be accomplished. (Can give examples) Available Chinese tooling and accessories were found to be to large and crude for typical horological work. (In my opinion of course) Personally I own these machines for a specific non critical appliction and they work fine for this since I understand their limitations. None that I have owned have ever been suitable for any kind of consistent quality machining.
A couple of things to consider when evaluating equipment. First the quality/capability of your tools will determine the skill levels you develope.
With todays Internet you can easily reseach what has been accomplished with a particular piece of equipment. This will indicate its capabilities.
To be fair to others who may have had a different experience, I will be more than happy to publicly demonstrate my experience with these or any other machine at the many shows I attend each year. I personally find demonstrations of all points of view to be highly productive and educational for all. Not to mention the fun to be had.
Jerry Kieffer
Jerry, If you can hand bush and do ok, Why wouldn't a china made milling machine do a good job?, If that was all you are doing, just to rebush and some minor jobs. Surely they couldn't be that bad.
Is anyone using one?
Jeff
Jerry,
I feel just a little under qualified to be chiming in here, and as I am a complete novice, I hope you will not be offended, but I will never learn unless I ask questions. Does your second photo show you reaming from the outside of the plate? I had been told that I should ream from the inside of the plate so that the taper on the hole would prevent the bush from pushing all the way through. Just asking. Apologies if this question is "out of line".
regards
Walesey
Walesey
This really is an old thread.
An example of this would be a common drill chuck in whatever it is mounted.
Easy there Jerry. I have a homemade mini mill that utilizes a high quality 1/4" drill chuck that I've lapped the jaws. It is now accurate to .0005 TIR. It's an older Supreme and the .003" runout wasn't that bad to begin with but after years of use the jaws had worn to a slight taper making repeatability impossible,lapping the jaws put it right back to new condition.(or maybe better)
A good Albrecht chuck comes from the factory advertised at .0015 and they're usually dead nuts or so I've read on the practical machinist forum. So don't be so quick to condemn them for inaccuracy. If you want accuracy,you won't get it from China these days. Just remember you get what you pay for. I don't use reamers in my setup,I use high quality drill bits and bore the hole .001" smaller than the OD of the bushing. They press in nice and tight.
Easy there Jerry. I have a homemade mini mill that utilizes a high quality 1/4" drill chuck that I've lapped the jaws. It is now accurate to .0005 TIR. It's an older Supreme and the .003" runout wasn't that bad to begin with but after years of use the jaws had worn to a slight taper making repeatability impossible,lapping the jaws put it right back to new condition.(or maybe better)
A good Albrecht chuck comes from the factory advertised at .0015 and they're usually dead nuts or so I've read on the practical machinist forum. So don't be so quick to condemn them for inaccuracy. If you want accuracy,you won't get it from China these days. Just remember you get what you pay for. I don't use reamers in my setup,I use high quality drill bits and bore the hole .001" smaller than the OD of the bushing. They press in nice and tight.
No,just a common jobber lenght twist drill. The trick is to start out with a very slow feed and high speed and let the drill cut instead of forcing it through,especially if the hole is oblong which it normally is hence the need for a bushing. Once the point of the drill is below the surface of the plate you can increase the feed and reduce the revs. I always drill in two steps. Initial hole is drilled at high speed and slow feed and the finished hole is drilled at low feed,low speed. My little mini mill uses a sewing machine motor and foot control so that makes it nice for speed changes and the drill column is from a discarded stereo microscope so feed can be controlled very nicely also using both hands on the knobs. I'll post some photos of my little contraption later this evening.Jay
I probably should have made my explanation more clear. The .003" runout before modification of your supreme chuck seems to be about what one will encounter in the typical common drill chuck. If the chuck in its original condition (.003" runout) was held rigid by whatever it is used in, then the reamer will bore a hole larger than intended for a proper friction fit.
I have several Albecht chucks that I would not hesitate to use for this application, however I do not consider them and other high quality chucks to be the common chucks one encounters on a regular basis as stated in the original comment.
How do you bore holes with a Drill unless your referring to something like a spotting drill?
Jerry Kieffer
Just standard jobber lenght drill bits. 118deg,chisel point,7deg relief angle. I use 135deg and various size ball mills to cut the oil sinks.You did not mention it, but for the benefit of others, I assume you adapted the bit to drill brass?
Here you go. This is what you can build if you have enough junk laying around. I haven't done any milling with it,so far I've only used the table for positioning. Everything is true and plumb and gives me the accurate results I'm striving for.
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A limerick just popped into my head that sums up this homemade stuff that I build,hopefully the mods will have enough sense of humor to not delete it;
Here you go. This is what you can build if you have enough junk laying around. I haven't done any milling with it,so far I've only used the table for positioning. Everything is true and plumb and gives me the accurate results I'm striving for.
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A limerick just popped into my head that sums up this homemade stuff that I build,hopefully the mods will have enough sense of humor to not delete it;
I would have used an Albrecht myself if I'd had one.Jay I really like what you come up with. Now I would have used a Albrecht chuck...but only because I have a few kicking around that need a home. Can't seem to find that Limerick .... where did it go?? Ah crap.. I am younger than 13...got it.
Thats funny when I complained about breast being on a profile picture I was told it was art. And a young person was viewing it on my computer. Oh it's only what you find unsuitable. And comments that are not suitable. I am not happy with this structure.
H/C
Hey David,I could help you with that dilemma,relieve you of your burden.Now I would have used a Albrecht chuck...but only because I have a few kicking around that need a home.
Awe come on H/C. I am sure we all understand some of the rules and regulations, I am not saying that we all like them..but they are what they are. And for sure all of us as contributors, can rise above the stuff we don't like, and just have fun with our hobby / passion / occupation.. and share. There is so much bad stuff going on in the world today, that some of these minor rules or whatever are indeed very very insignificant. And please accept this as my opinion, and don't take it any other way.
Awe come on H/C. I am sure we all understand some of the rules and regulations, I am not saying that we all like them..but they are what they are. And for sure all of us as contributors, can rise above the stuff we don't like, and just have fun with our hobby / passion / occupation.. and share. There is so much bad stuff going on in the world today, that some of these minor rules or whatever are indeed very very insignificant. And please accept this as my opinion, and don't take it any other way.