Author Topic: Micro Adjust At The Cut Line  (Read 2850 times)

0 Members and 1 Guest are viewing this topic.

Offline Sean KS

  • Posts: 93
Micro Adjust At The Cut Line
« on: September 19, 2017, 01:57 AM »
I'm a fan of micro adjusters. My beef is that on miter gauges or cut of fences they are always positioned on the stop rather than near the cut. It forces you to walk back and forth, siting the cut, then walking over micro adjuster that is positioned on the other end of your work piece. Incra's rip fence is pretty cool in that often it's right next to your cut assuming you are doing a thin rip. You can click their micro adjuster while looking right down on your cut line. What I would love is if that micro adjuster could always be right next to the blade. I've thrown together a drawing of how I think it might work with some 80/20 gear, and a rack and spur gear set up, and of course JW Winco knobs.

The 80/20 forms the miter fence itself. The top extrusion slides along the bottom one using some bearings, one is a Double Keyed Linear Bearing Pad, the other is the Unibearing (by just using one side of the bearing on the back of the fence). The stop block can be macro adjusted anywhere on the extrusion, then locked in place. From there you can use the micro adjuster which turns the spur gear along the gear rack which is fixed to the mobile upper extrusion. Turn the adjuster knob, the whole top extrusion slides, which means the stop block moves with it.

« Last Edit: September 19, 2017, 02:02 AM by Sean KS »

Festool USA does not pre-approve the contents of this website nor endorse the application or use of any Festool product in any way other than in the manner described in the Festool Instruction Manual. To reduce the risk of serious injury and/or damage to your Festool product, always read, understand and follow all warnings and instructions in your Festool product's Instruction Manual. Although Festool strives for accuracy in the website material, the website may contain inaccuracies. Festool makes no representations about the accuracy, reliability, completeness or timeliness of the material on this website or about the results to be obtained from using the website. Festool and its affiliates cannot be responsible for improper postings or your reliance on the website's material. Your use of any material contained on this website is entirely at your own risk. The content contained on this site is provided for informational purposes only and does not constitute professional advice.


Offline Bob D.

  • Posts: 786
Re: Micro Adjust At The Cut Line
« Reply #1 on: September 19, 2017, 04:35 AM »
Nice, how much linear adjustment do you envision having, a few inches or just +/- an inch.
-----
It's a table saw, do you know where your fingers are?

Offline Sean KS

  • Posts: 93
Re: Micro Adjust At The Cut Line
« Reply #2 on: September 19, 2017, 05:23 AM »
Well I don't know? You only ever really need a +/- a tiny bit. Given that the the minimum length I can find some gear rack that'll fit in the extrusion is 24" I suppose it'll probably end up being 6" or so of travel? Guess I'll figure that out when I figure out how the gear rack is going to sit in the t-slot?

Offline ByrdieMan

  • Posts: 8
Re: Micro Adjust At The Cut Line
« Reply #3 on: September 20, 2017, 08:22 AM »
Nice work Sean. I'll be following this thread.

Offline Cheese

  • Posts: 4473
Re: Micro Adjust At The Cut Line
« Reply #4 on: September 20, 2017, 12:37 PM »
FWIW...McMaster Carr has some injection molded rack that they sell in 1 foot increments.

Offline Sean KS

  • Posts: 93
Re: Micro Adjust At The Cut Line
« Reply #5 on: September 20, 2017, 05:37 PM »
FWIW...McMaster Carr has some injection molded rack that they sell in 1 foot increments.

Dude $8 and I don't have to cut metal. Great looking out, thanks Cheese.

Offline Cheese

  • Posts: 4473
Re: Micro Adjust At The Cut Line
« Reply #6 on: September 21, 2017, 02:49 AM »
Actually, I was going to post that info a couple of days ago but I was unsure on how smoothly you wanted the rack/gear to run.

A metal rack is usually pretty smooth because it’s completely machined. Whereas, the injection molded rack, while having a nice smooth surface finish because of the molding process, the tooth geometries may be off a little bit not giving you the silky feel of a machined rack.

I’d suggest as a first round, using a plastic pinion with the plastic rack, but if that doesn’t have the feel you’re looking for, then I’d try swapping out the plastic pinion with a metal one.

Offline box185

  • Posts: 12
Re: Micro Adjust At The Cut Line
« Reply #7 on: March 18, 2018, 02:40 AM »
Well I don't know? You only ever really need a +/- a tiny bit. Given that the the minimum length I can find some gear rack that'll fit in the extrusion is 24" I suppose it'll probably end up being 6" or so of travel? Guess I'll figure that out when I figure out how the gear rack is going to sit in the t-slot?

I was working on the problem stated in your last sentence a few weeks ago. I wanted to have one of the six inch long Incra 1/32 inch racks installed in a piece of 40mm 8020 material. The only solution I could come up with was to fill the segment with a machinable epoxy, and then mill out the profile to fit the Incra rack. I've since moved on to another approach for my application, but I wanted to comment here because I had this exact same issue.

Offline Michael Kellough

  • Posts: 3299
Re: Micro Adjust At The Cut Line
« Reply #8 on: March 18, 2018, 08:22 PM »
Regarding the original post, fantastic illustrations but rack and pinion is the opposite of “micro” adjust. If you want to use rack then you need to replace the pinion with a screw installed parallel with the rack. A set screw with the same pitch as the rack might work but the usual approach is to forgo the rack and just use a screw in the stop block to offset the workpiece