How about a fractional inch version of TouchDRO for woodworkers?

MikeInOr

MikeInOr

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The DRO's available for woodworking are very limited and have a pretty bad reputation for reliability not to mention overly expensive.

I would love a TouchDRO version that could handle fractions of inches and support the huge number of linear scales currently available to TouchDRO users. A table saw fence would be one use case. Length stops for a miter saw station or sliding table saw would be another use case. I would love to have one axis for my table saw fence and 2 more axis for length stops on the sliding table. In general, can 2 pickups be used on a single magnetic linear scale? To set zero on the furthest pickup a 1-2-3 block could be used as an offset from the blade.
 
MikeInOr said:
In general, can 2 pickups be used on a single magnetic linear scale?
Click to expand...
Indeed they can! The scales themselves are passive... They're just the divisions. The read head is where the magic happens.

I have 2 read heads on the Z-scale for my metal lathe. One for the carriage, and one for the tailstock. The latter is summed with the readout for my tailstock quill, so I can drill retract the entire tailstock to clear chips without losing my hole depth position.
 
I was in the custom wood woodworking business for over 20 years, I found it was much easier to simply work in decimal inches, or metric. A few of our machines had DROs, a couple could optionally display in fractions, however, I never liked using them that way. The problem is DRO will only display the closest fraction for the resolution it's set for. Say you have it set for 32nds and you are trying to to hit a a ¼" you cold be a 64th off +or - before it will read 9/23" or 7/32" Okay, you could set it to a finer resolution but then the math is more of a PITA to deal with unless you convert the fractions to decimals. Also, materials are not ever actually their nominal size, ¾" plywood is usually around .720" and can vary even on the same sheet. So IMHO it is just easier to use decimal inches in the first place.
I should add. I still used fractions for the finish dimensions, say a cabinet would finish a 24-½" wide, etc.
 
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Eddyde said:
I was in the custom wood woodworking business for over 20 years, I found it was much easier to simply work in decimal inches, or metric. A few of our machines had DROs, a couple could optionally display in fractions, however, I never liked using them that way. The problem is DRO will only display the closest fraction for the resolution it's set for. Say you have it set for 32nds and you are trying to to hit a a ¼" you cold be a 64th off +or - before it will read 9/23" or 7/32" Okay, you could set it to a finer resolution but then the math is more of a PITA to deal with unless you convert the fractions to decimals. Also, materials are not ever actually their nominal size, ¾" plywood is usually around .720" and can vary even on the same sheet. So IMHO it is just easier to use decimal inches in the first place.
I should add. I still used fractions for the finish dimensions, say a cabinet would finish a 24-½" wide, etc.
Click to expand...

The DRO I have on my planer I have set to display in 1/256". I don't actually measure anything in 1/256" but I know I am within 1/256" when I hit 1/4" which has worked well for me so far.

I have never tried a woodworking project measuring in decimal inches. I guess my mental block is all the scales on my machines and ESPECIALLY all my measuring tapes are in fractions. Do they even make a decimal inches measuring tape? Or do you just convert 1/16" increments to decimal when reading off a tape?

I know my fraction equivalents well enough to 1/8" and a fraction to decimal chart on the wall would be easy enough to print out. Most everything I do is my own design so there really isn't anything keeping my in the fraction world. Maybe I will try a cheap DRO with magnetic scale and see how it does for me.

In the other half of my shop I guess I machine in decimal inches but I weld in fractional inches... hmmm... I never actually though about it.

MidniteMachinist said:
Indeed they can! The scales themselves are passive... They're just the divisions. The read head is where the magic happens.

I have 2 read heads on the Z-scale for my metal lathe. One for the carriage, and one for the tailstock. The latter is summed with the readout for my tailstock quill, so I can drill retract the entire tailstock to clear chips without losing my hole depth position.
Click to expand...

Logically I figured multiple readouts per scale should not be a problem. Thank you for the confirmation. It sounds like your tail stock is always read in a position relative to where it starts? Versus absolute from a zero point on the scale?

To set multiple stops on the sliding table fence I would need to be able to zero both stops against the blade. If I could put a 1-2-3 block against the blade and then zero the furthest stop at 3" instead of 0" this would work. Hmmm.... the DRO on my mill will allow me to enter a relative point pretty easily. I haven't seen a woodworking specific DRO with this capability.



I would still love to see a fractional inch version of TouchDRO!

I guess if Carter was a better president this wouldn't be an issue because we would all be using metric. I always wondered how big a piece of drywall is in Europe? Or do they still use lath and plaster because they can't figure out how big a piece of drywall should be in metric?
 
Bought a digital height gauge to set blade height on the saw. Displays in fractions and decimal inches and millimetres. Thought the fraction scale would be great, BUT when your at say 27/128ths do you go up or down to get to 1/4. Its always on decimals now.

Greg
 
MikeInOr said:
I have never tried a woodworking project measuring in decimal inches. I guess my mental block is all the scales on my machines and ESPECIALLY all my measuring tapes are in fractions. Do they even make a decimal inches measuring tape? Or do you just convert 1/16" increments to decimal when reading off a tape?
Click to expand...
I used regular fractional tape measures, the overall dimensions I worked to wold usually be in fractions (Unless the job was specified in Metric).
Yes basically just think of ¼" as .250 and so forth when you are reading the DRO. I memorized the equivalents to 1/16" it's easily add or multiply .062. 031 to get 1/16ths or 32nds. Individual parts might be non fractional. Say some "¾" plywood averaged around .722" and I was cutting top & bottoms for a cabinet that had to finish at 24 ¼. 24.250"- 2x.722"= 22.806" That's what I'd set the DRO on the saw fence.

I might add, most of my work was making custom cabinets and millwork that would often need to fit to very tight specifications. Say if multiple cabinets had to fit a space even a small error on each piece could add up to trouble. For example, We (Business partner and crew) did a very large unit that basically was the wall between a bedroom and living room 27' long 10' high. The bedroom side was closets with full height doors and the living room side was panels with ¼" reveal between them. We assembled the entire unit in the shop before finishing, However, ones we installed it the paneled side was almost ¼" longer! this was a huge problem as it had to interface with other trades work, the doors to the bedroom were custom made stainless steel and glass so they could not be adjusted also the unit had to end precisely at a joint in the floor. We figured out the problem was the finish film thickness in the reveal joints was a little too heavy, and multiplied enough times... We had to de install all the panels and slightly tighten up the all reveals, fortunately, the architect didn't notice.

I think a successful fractional DRO should have at least (+) (-) indicators for when you are between the fractional divisions. That way you know when your are spot on. It could also perhaps have a "progress bar" type indication. You would see dots increase or decrease, before or after the fraction before it would change to the next division. The dots could be a set to a sub resolution, say 1/128' or 1/256" that way you could get high accuracy, make on the fly adjustments, etc.
 
i am a professional woodworker with many different DROs on different machines. the best bang for your buck are the ProScale ones- they just reliably work. call them and get one configured for whatever machine you want. im fairly certain the displays will show fractions, but i never use it. also you can get mulitple heads for a slider fence if you want. i now do the conversions in my head. its a ridiculous system, going to from 1/16" fractions, to decimal, to random decimal, plus/minus whatever but that is where i ended up.

i get the desire for the Touch DRO on a wood machine; i'd probably try it on a shaper - three axis on one screen would be cool. the nice modern machines have touch 3 (or more) axis screens with tool memories. sort of like a cnc but for a glorified router table. My primary shaper just has a DRO on the z and mitoyou scale on the Y. its not yet worth the cost increase for me for a more advanced machine. using multiple digital heads on a sliding saw fence also makes sense, and i've looked into it several times, but truth be told it would never pay off for me. i use a slider for things that i can easily get to within 1/64 (.0156") and rarely more accuracy is needed. plus i break down teh table for the floor space regularly, so i would be constantly recalibrating.

i havent used a TDRO, but want one on my new and neglected mill! from my wood perspective i'd really like to see the screens be way smaller than a tablet, like old original smartphone generation small. they must exist beyond the now ancient ipod touch, but is anyone used a tiny 'tablet' as the TDRO inteface?
 
I think it's best at this point in the history of the world to just use whatever is most suited to the job. For example, I got one of the Hemingway kits and the schematic was a mix of decimal inches, decimal millimeters and fractions. It was annoying but would have been a lot worse before the invention of the four function calculator.

I put the Wixey digital readouts on the table saw and planer...fractions are a nightmare to use. I tried it once and agree with all the negative comments about that here. I never tried it again.
 
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