KWM Bushing Tool

[Tim Nelson]

Does anyone have experience using the German made KWM Bushing Tool ?

 

[bkerr]

What are you looking for?

 

[Tim Nelson]

I am looking for a good bushing machine that is easy to use and is accurate.
The KWM seems to cost a lot more than the others and I wanted to know what the pros and cons were.

 

[harold bain]

Hi, Tim, welcome to the message board. You may have a hard time finding any members who have worked with more than one make. I use a Bergeon, and having never used any other machine, can't say it's better or worse, but it works for me.

 

[al_taka]

I've used the kwm for several years and like its operation. But its pricey and only has a single purpose.

If I had to do it again I would consider a micro milling machine instead of a bushing machine. I would make a removable plate mount or buy a commercially available one. It would serve as a bushing machine, drill press and milling machine in a small working area. The x-y table would be nice for positioning.

Instead of investing lots of money in a hundred sizes of kwm or bergeon bushings, use Mark's inexpensive Brass Bushings assortment which covers most pivot sizes in 9 bergeon bushing sizes. The savings would be considerable.

 

[moe1942]

I have and usually use my Bergeon bushing tool but have the KWM hand bushing tool I started out with. I like the Bergeon better for its greater ease of use and accuracy but the KWM can perform the task equally well. KWM bushing are cheaper and easily found.

 

[bkerr]

I have both KWM and a Bergeon. The KWM buhing system allows for a smaller o.d. and this can sometimes be a benefit.
I will sometimes need the Bergeon for larger diameters.
I also have metal lates and wil make special bushings. I guess it all depends on how much you plan on using the tools, your budget and then what you get comfortable with.

The post about a micro mill is interesting. The key to all of these systems is keeping the hole centered and getting the right press fit.

Not all bushings are avaiable in the "systems" and you may find the need to make something specal. That is when having a metal lathe is nice too.

 

[Willie X]

Nelson,

I have had both.

The KWM's spindle is a little looser and the peculiar 'quick change' tools take a while to get used to. The tools don't fit tightly in the spindle. This adds wobble and they will sometimes fall out unexpectedly. You can still do good work, and do it faster, but it will take a lot of practice.

Note, A bushing tool does very little for you, other than keeping the hole perpendicular to the plate. The accuracy of placing the bushing hole where it needs to be depends on two things. First you need to determine exactly where the bushing hole is supposed to go. Second, your skill in fileing, broaching, or nibbling (with your bushing tool) the metal away to put the hole exactly where it is supposed to go.

Willie X

 

[Carl Spencer]

Willie X: Always look for that name in any discussion. You will see my new post at the top of the forum dealing with KWM bushing tool. Just bought a used one recently and did not like the clamp up-down adjust to start with. No way without measuring to tell if the plate is level or not. Bergeon machines do not have up-down clamp adjust. Made new spacers, approx. .378" thick to keep the clamps level with the center anvil. I had to learn the the hard way when the bushing bore was plenty big but the gear did turn freely. Several said the bushings were not in perpendicular but failed to say why until I figured out that one clamp was a little higher than the other. Works fine now. Will turn some smaller adapters to eliminate stacking. Don't want to get above the level plane. Carl in NC.

 

[binman]

I brought KWM bushing tool c/w base and the rule for measuring plus loads of bushes for £360 but still need to spend nearly £300 for all the parts to complete but even at £600 still half price or more than new,

 

[ncollar]

I do not understand if it is lazy or just too much money. A piece of brass and a nice set of drill bit and you can make one in seconds. For my money I'll keep it in my pocket.
Cheers

 

[Jerry Kieffer]

Does anyone have experience using the German made KWM Bushing Tool ?

Tim
My personal experience is as follows.

Between my personal purchases and the NAWCC school, I have worked with all of the Commercially available Bushing machines that I am aware of including KWM. Without exception, they all have the same issues. Plate positioning for center location requires skill and luck. Spindles and reamer mountings are a loose fit in most cases.
The loose fits (I am sure not intended) assure that the reamer can properly ream a tight fitting hole since they can find the path of least resistance. Another words they are not turned into a boring bar that enlarges a hole such as being held in a chuck with runout.
While the Bushings replaced in bushing machines have the proper friction fit, the location of the bushing has not always been in a predetermined location. Close most of the time, but not to a consistent standard I wish to put my name on.

In the beginning, I used hand methods that I found were even more inconsistent in both bushing fit and bushing location. While those who use these methods on a consistent basis (mostly file the opposite direction) have always told me that they never fail. But based on my experience and what I have seen over the years, this is not true. Or they tell me that a typical movement can absorb such errors.
The reason I bring this up, is that if you do any amount of repair, you will have to deal with what others have done. Of course an 8 day american movement can absorb some errors, but its an accumulation of errors that will decrease its running efficiency from when it was new. And now what do you do when you run into a movement that cannot absorb errors.

My personal goal when repairing a movement is to return it to original condition with properly placed bushings. A running movement that is more of a ticker is not except-able.

Again personally, My solution has been to use a small Milling machine for bushing.

(1) The calibrated slides allow me to very accurately and quickly predetermine reamer location.

(2) The accurate and stable/rigid spindle with collet mounted reamer assures position and bushing fit.

(3) The Milling machine offers a quick and efficient method of properly depthing poorly placed bushings

(4) The Milling machine provide the option of very quickly and accurately grinding a Verge that is critical to a solid running movement.

The above bushing description is only a small example of what the mill can do for about the same cost as a bushing machine that can only bush.
When you consider all of the other tools it can replace and its capabilities, it has to be one of the best values one can make in any kind of repair work.

The use of a Mill for bushing and depthing is covered in the NAWCC on line education program as well as Workshop WS-120

Jerry Kieffer