OF1400 - Guide Bushings and what exactly is the problem and solution

[DeformedTree]

[member=68063]DeformedTree[/member]  I’ve bought a bunch of expensive tools and I can’t think of a single one that arrived perfect in respect to alignment. Most are close enough that I can live with the slight discrepancy. I the case of a router the slight misconcentricity can be used to adjust a dado on the fly by referencing difference parts of the base.
When something really must be tweaked to be useful the presence of adjusting screws is way more useful than the lack. Hit or miss is not adjusting. It’s just gambling.

I agree. I deal with precise instruments and "adjusting screws" are not just a good thing, they are critical. Machines get damaged, parts wear out, parts get replaced. You need a way to tune thing up.

To be clear, I'm not talking lab instruments, items that need to be sent out for yearly calibration, that is a completely different world and situation.

Far as parts getting damaged, yes, that can happen, and modern manufacturing and quality control means you can swap out a replacement part and it's still hits the original specs.  Far as parts wearing out, parts that wear out mean either further bad design, or the whole item has got to end of life were all of it has worn out at the same time.  A company is suppose to select a life of something and design the parts to hit that, all of them.  Less than target is a fail, and designing some of the parts to last way longer than the rest of it is a waste.  If the design accepts some of the parts are service parts to hit a total life expectancy, replacement of those parts will not cause a need for adjustments.

If tools come not adjusted right, that is a fail on the manufacture. There being an adjustment shouldn't be met with "oh good" it should be met with scorn.  If people accept this as good, then the manufactures have no reason to do better and they lower the bar on themselves. 

This problem unfolded with cameras a few years ago. Manufactures found they could have software adjust for bad lens assembles by having the camera calibrate itself to each lens.  It was sold as a great thing, in fact it's not and just gave camera makers a path to not hold lenses to the higher tolerances they used to.  The other end is manufacturing such as automotive. You will struggle to find items that have adjustment in a car anymore as they learned it's much cheaper and better quality to design the parts right, hold tolerances on the manufacturing side, and then anyone can bolt it together and it works every time.  More upfront cost, but end cost are far less and the end product is much better.

An adjustment is just something that is going to get out of adjustment. In a lot of cases you will not have the tools or fixtures to get something back into adjustment.  Look at a saw like a TS55, it didn't need to be so bad and trying to square it up is almost impossible because so many different moving parts. Now you have a saw that a user won't ever want to tilt for fear of getting it back square again.

There are places where there has to be adjustments as there is no practical way to get the tolerances tight enough, but the bulk of things when it comes to tools are not this.  In this case, it it came down to just adjusting the speed the machine the housing, or improving the tooling fixture for it, or a different cutter, or finishing it up with a grinding stone or a reamer (one more step on the same machine) they could have just fixed it.  If the router was some cheap thing from harbor freight, I can see it having adjustments to make up for very poor design/cost cutting. But if I'm spending festool money I expect them to have it come out of the box dead on and stay there.

 

[Kanuka]

By your logic every mill Bridgeport ships is of unacceptable quality by virtue of the fact that the purchaser is expected to set it up to the tolerances they require. Needless to say, no one at Bridgeport is consulting you for quality control.

I have absolutely nothing good to say about the 1400 as I sold mine off a long time ago but you are spouting nonsense. Field adjustable parts are a very good thing.

 

[Lincoln]

I don't use bushings very often, but I noticed the issue when I made a full height template for routing butt hinges into internal doors/jambs. I routed the door, then removed the template, fixed it to the jamb and routed. When I offered up the door, the hinges on the door didn't line up with the housings in the jamb - quickly realised that I had to orient the router the exact same way for all the cutouts. I'm sure the movement that [member=44099]Cheese[/member] has shown above also contributed.

 

[DeformedTree]

By your logic every mill Bridgeport ships is of unacceptable quality by virtue of the fact that the purchaser is expected to set it up to the tolerances they require. Needless to say, no one at Bridgeport is consulting you for quality control.

I have absolutely nothing good to say about the 1400 as I sold mine off a long time ago but you are spouting nonsense. Field adjustable parts are a very good thing.

I have no idea what you are talking about "set it up the the tolerance they require".  It has a tolerance that it is, when they sell it to you they tell you what it can hold.  And in the case of a Bridgeport mill, very good.  It's an example of how things should be.  They don't ship it with a warped bed, dye and a chisel and tell the buyer to flatten the bed themselves.

 

[Cheese]

I don't use bushings very often, but I noticed the issue when I made a full height template for routing butt hinges into internal doors/jambs. I routed the door, then removed the template, fixed it to the jamb and routed. When I offered up the door, the hinges on the door didn't line up with the housings in the jamb - quickly realised that I had to orient the router the exact same way for all the cutouts. I'm sure the movement that [member=44099]Cheese[/member] has shown above also contributed.

Lincoln has this observation correct.  [thumbs up]  Because the actual amount of template movement is different in the X and Y axis, it's imperative that you orient the router in the exact same position every time in order to minimize the router cutter out-of-round variances.

I bored 2 holes with the Woodpeckers template and noted a wonky hole. I then assumed it was my technique and I tried a different method. Long story short, after boring 20 wonky holes and trying to change my method 10 times, I came to the conclusion that there was something amiss with the 1400 and at that time I reached for the Starretts. That's when I decided to measure.

 

[DeformedTree]

That's when I decided to measure.

Trouble maker, all that can do is bring facts to the situation.

 

[Svar]

I have no idea what you are talking about "set it up the the tolerance they require".  It has a tolerance that it is, when they sell it to you they tell you what it can hold. 

Can't speak for the OP, however it means, among many other things, that you need to tram the mill to desired specs after set up and then once in a while. There are literally adjustment screws that position the quill perpendicular to the table.

On the topic: my ideal router would have bushings around guide posts that you could tighten. This is to eliminate lateral play when plunging. Just another factor in poor concentricity between spindle and base (looking at Woodpeckers MFT template that [member=44099]Cheese[/member] posted).
Credit where credit is due, Festool routers are superb in this regard (minimum to no lateral play around guide posts).

 

[Bob D.]

"Credit where credit is due, Festool routers are superb in this regard (minimum to no lateral play around guide posts)."

So who makes the sloppy baseplate inserts, HF ?

 

[Cheese]

On the topic: my ideal router would have bushings around guide posts that you could tighten. This is to eliminate lateral play when plunging.

Well interestingly enough, that's exactly what UJK employed in their original drill guide. They placed small nylon set screws, on 3 sides,  in the aluminum yoke that travels up & down to tighten the bushing against the guide.

[attachimg=1]

 

[Michael Kellough]

[member=44099]Cheese[/member]  the bushing was synthetic and bendable?

 

[Svar]

On the topic: my ideal router would have bushings around guide posts that you could tighten. This is to eliminate lateral play when plunging.

Well interestingly enough, that's exactly what UJK employed in their original drill guide. They placed small nylon set screws, on 3 sides,  in the aluminum yoke that travels up & down to tighten the bushing against the guide.

I was thinking of shaft clamp collar design. I.e. the bushing is split.

 

[Cheese]

[member=44099]Cheese[/member]  the bushing was synthetic and bendable?

No Michael, the yoke is aluminum with 2 guide holes, for guide rods, bored through the yoke. Then 3 nylon setscrews are placed on 2 sides of the bored hole to take up any slop.

Here's the best shot I have. Setscrew at the top & bottom of the yoke and a setscrew at the front of the yoke.

[attachimg=1]

 

[Michael Kellough]

This is what mislead me “to tighten the bushing against the guide”.

The same thing could be done to any of the cheap ubiquitous guides.