PSA: Harbor Freight Digital Caliper $16

Page 2 of 5  
I didn't understand what you meant by bed extension until I read it again. When I get off my butt and install my DRO, I'll push the up and down arrows to accomodate the sled. Or I'll adjust the planer so that it just touches the sled, and then zero out the display.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Have you considered attaching one of these to your planer?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category 581&item839370322&rd=1
I just received mine and will be attaching it to my Ridgid planer in a few weeks (I have a few other projects to finish first). I'll post after I install it.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Nope. Up until you posted the above, I didn't realize these existed. Thanks -- even better.

Please do so, I would be very interested in any photos and/or descriptions of how you mounted it.
Thanks -- definitely a better solution than jury-rigging a caliper

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<snip>

Patriarch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I've had the 6" and 4" calipers for several years and really like them. The 4" fits nicely in my pocket.
What's wrong with a vernier? They are difficult to read at an angle or in dim light. You can't zero them out when partially open to do a comparison reading. You can't switch to metric at the push of a button. And when taking dozens of readings, they take a long time. Comparing a digital caliper to a vernier is like comparing a calculator to slide rule.
I've also been very happy with HF's dial indictors (normally around $13 but frequently on sale for around $7). Dial indicators are very useful when you have more than one. Many tools (such as the TS Aligner Jr, and numerous height gauges used to set jointer/shaper blades) use outdated designs which assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only have one). But these tools could do a far better and quicker job if they were designed to use 2 or 3 indicators.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm not very well versed in the nuances of alignment and set up jigs for machinery, but I'm very intrigued by your line of thinking. Could you elaborate a little on how you would envision a multiple gauge to work, and why it would be better and quicker? Thanks.
JP ******************** Now you've got me thinking....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Consider the gauge used to set jointer blades. To see an example, search Woodcraft's web page for item 126979. It is essentially an iron square that holds one dial indicator above the blade. The design dates from a time when dial indicators were very expensive and so the gauge was designed to use only one indicator. You slide it back and forth repetitively, and wiggle the blade until you get the same reading at different positions.
Now consider a modern version that holds two dial indicators spaced about 4" apart. You set the square on the jointer's outfeed bed such that both indicator stems touch the bed. Move the arrows (ie. most dial indicators have 2 moveable arrows around the outside) to mark the readings (both indicators do not need to read the same). You've just zeroed out both indicators. Now slide the square so that the stems touch the blade, and adjust the blade so that the indicator needles touch the arrows (ie. the zero position that you previously established). You don't have to slide the gauge back and forth. And you only need minimal adjustment of the blade.
As for a table saw alignment tool like the TS Aligner Jr, first you slide it back and forth and adjust the bearings to take up slop in the miter gauge slot. Then you slide it back and forth along the blade (turning the blade at the same time). You have to do this because you only have one dial indicator.
Consider an improved version which has two indicators spaced about 8" apart which has been factory adjusted so that both indicators read the same. You put it in the miter gauge so that both indicators are touching the blade. Then you turn an eccentric bolt which locks the gauge in place. No more sliding back and forth. Now you turn the blade several revolutions by hand and watch both indicators as you turn. If the blade is warped, the needles are going to move a lot, and you want to stop at a point where the needles aren't moving very much (ie. you've moved the warp into the vertical axis). If the blade isn't warped, the needles won't move much and you can stop anywhere. Now get out the hammer and screwdriver and adjust the table so that both indicators read the same. If you don't want a factory adjusted gauge, you can use a machinist's square to zero out the indicators.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snip of multi-gauge discussion
Are there gauges that can be retrofitted for multiple dial indicators, or is this something that you'd need to create from scratch? Given the low cost of highly accurate (or is it precise?) gauges, I'm surprised their aren't a whole bunch of commercially available, multiple gauge alignment aides.
My gut tells me that I should first learn how to tune machinery using the most rudimentary jigs and devices, so the physics of the process become very clear. Then I can better evaluate whether a certain jig is timesaving and/or more accurate.
JP ***************************** Give yourself the best chance to do excellent work.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My whole point is that people who design the gauges are stuck with an outdated way of thinking that says "dial indicators are expensive so my design will only use one".
Gauges that are designed from the beginning assuming multiple cheap indicators won't work with just one. So you won't see gauges that can use one indicator, or optionally use more.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Not at all. Dial indicators were developed by, and are used extensively in the metalworking industry. The reason for using a single gage is the elimination of variables. The cost of indicators has never been a factor to them. They have always been relatively cheap. For someone using an indicator for alignment at home, two might seem easier. For me (machinist), setting two indicators to do a simple alignment (mill vise, or tablesaw blade) would increase the time to do the job.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Aligning a mill vise with two indicators would take longer because the jig used to do the alignment was designed for one indicator (ie. clamp the indicator in the chuck and sweep the fixed jaw). Imagine a jig that you clamp in the chuck/collet/holder that holds 3 indicators (all factory calibrated to read the same). The center indicator is centered with the shaft in the chuck/collet/holder. All you have to do square the jig against the table (ie. all 3 indicators read the same), clamp the spindle, then adjust the vise so that the two outside indicators read the same as the middle one. No more sweeping.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
How do you square the 3 dial jig in the chuck? One indicator in a locked chuck and all you have to do is a sweep to check. Does it take hours to establish that the jig is square? What jig does it take to make sure the 3 indicator jig is square or parallel or plumb or choose your word?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 16 Sep 2004 11:56:21 GMT, Jim Behning

he's using magic- "factory calibrated to read the same".
I don't think he's used indicators much.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
What you call magic, I call child's play.
The three indicators need to read the same to work. Adjusting them at the factory is child's play. Merely a setscrew that allows the indicator to slide back and forth.
If you want to do your own calibration, you merely need to use a machinists square. One leg against the indicator stems, another leg against the edge of the holder (that has been machined square).
I use indicators all the time. I don't handicap myself by doing things the traditional way.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
As I said before. Your setup introduces more variables and takes longer to do the job as you have to calibrate.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I agree it introduces more variables, but I don't think it will take longer than sweeping the vise back and forth.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Precision machining has been my job for almost 18 years. I have a pretty good idea what works and what doesn't.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I own I think 6 or 7 indicators. sometimes I set them up in multiples, but never more than one to measure the same thing, which is what it sounds like you are advocating. bloody waste of time, much like what this thread has become.
tell you what. take some pictures of your setup and post them to ABPW. 'till then, this thread is dead as far as I'm concerned.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
As I said, you square it against the table by getting all 3 indicators to read the same. To elaborate, you let all three stems touch the table, then turn the chuck so that the three read the same. When this happens, the jig is square to the table. Then clamp the spindle. It is a few seconds of work.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Turn the "chuck"? You must be joking.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.