# Knobs/dials/cranks



## John J (Dec 29, 2007)

What do you call the knobs.dials, or cranks on a lathe that allow you to make adjustments in small increments?


I know there is a different name other than the ones I listed. 


I am looking for a after market upgrade to convert these adjusters to digital.


Anybody got any sources ?





JJ


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## cjsrch (May 29, 2010)

You mean to go CNC? or just digital readout? i think dial would be right


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## Semper Vaporo (Jan 2, 2008)

The thing-a-ma-bob I think you are refering to are called "Vernier dials"... maybe?

But for digital... MicroMark sold a set of Digital Readouts for their mini-Lathe (but will fit many of the similar brands of that lathe. It is still on their web site at:

http://www.micromark.com/SearchResu...mini+lathe

I bought a set, but I am not sure I recommend them... they were great when I installed them... REALLY handy and I am tempted to replace them since mine have broken...

BUT... The batteries run down in a week or so (whether the units are turned on or not) and they are a bear to replace without losing the tiny screws that keep the battery cover in place. Mine also have managed to get tiny bits of swarf inside between the LCD readout and the covers over them and I cannot fathom how it got there. I also think swarf has gotten into the detector mechanism of one of the units (the cross slide) and it has a long dead spot in each revolution of the handle, rendering it almost completely useless.


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## John J (Dec 29, 2007)

Vernier Dials/scales is the word I am looking for. 

Actually what I am want it for is a Radial Arm Saw. 

It's a project I am working on. Think Step and Repeat.


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## John J (Dec 29, 2007)

Posted By cjsrch on 11 Apr 2011 05:05 PM 
You mean to go CNC? or just digital readout? i think dial would be right


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## Semper Vaporo (Jan 2, 2008)

Posted By John J on 11 Apr 2011 07:52 PM 
Vernier Dials/scales is the word I am looking for. 

Actually what I am want it for is a Radial Arm Saw. 

It's a project I am working on. Think Step and Repeat. 

okay... then you want an X/Y table.

Like this from MicroMark:

http://www.micromark.com/MicroLux-X...,8009.html

I have one of these and it is very nice... BUT it does not move very far in either direction (X or Y) and setting it on a Radial Arm saw may be a bit dodgy since it is small and the usual radial arm saw is a billion times bigger and what you are working on is probably correspondingly bigger too... This one is nice for precision positioning to drill some holes in a small block or a step and repeat to cut fins from a 1x3 inch block of aluminium, but it would not be suitable to, say, cut shelf dado's every 10 inches in a 6 ft long board for the side of a cabinet.

So, you can get bigger X/Y tables as replacements for the minimill... Check out LittleMachineShop . com's assortment of repair parts:

http://www.littlemachineshop.com/pr...-888582885

Still this has a relatively short movement in either direction (Still not suitable to cut those shelf dados!).

Beyond such a machinist table for precision... I guess I wonder what you need the precision for and to what level of precision. If you are using a radial arm saw, I suppose you are working with large pieces of wood and I see no need for machinists precision in wood working (wood changes dimension with minor changes in temperature and humidity and those changes would fully negate any perceived precision of using such an expensive device as I have listed above).

How big are the steps you wanting to take and how many steps do you want to do before you have to remove the workpiece and reposition it?

I am assumming you are not just cutting same sized pieces from the end of a board (a simple stop block would suffice for that) but rather making dados or other saw cuts at regular intervals across a board (and there are simpler and cheaper methods of doing that). If you need randomly spaced (though precision) then I can't think of anything other than some sort of step mechanism that could be made from a long piece of threaded rod and some bearings, but you'd have to make the "dial" device to count turns and partial turns, based on the thread pitch to know the distance of a "step".


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## John J (Dec 29, 2007)

Here is what I am trying to accomplish. 

I have a old Rockwell Radial Arm Saw I got on E bay for 75 bucks. 

I want to add a Acme Screw to it with a Digital display for when I make siding. 

With the motor turned 90 degrees to the slide I can adjust the blade in and out. 

With a dado blade mounted to it. I can then acuratly admust the blade to the next cut by must turing a crank. 

I also have a wide feed belt off of a card sliter that will feed the work 

Some of this comes from Hauling junk home till you can figure out what to do with it. 

Some of the more Narrowl belts can be used as conveyor belts. 

JJ


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## Semper Vaporo (Jan 2, 2008)

Another bright idea popped into my head...









Rather than reading a dial on the crank adjustement, use a DRO (Digital Read Out). These are like a digital caliper in that they are a slider on a bar and the slider has a display that shows the position of the slider on the bar. They are resetable for zero at any location so you can measure precise steps.

You could mount one on the radial arm post in the back to measure the height of the post elevation adjustment, zero'd for the blade position at the table height.

Another could be mounted parallel to the arm with the post attached to the arm and the slider attached to the head that holds the motor (or vice versa) to measure the location of the blade along the arm, zero'd to the fence or any previous cut.

You don't have to buy a dedicated DRO, but could probably use a cheaper Digital Caliper and just drill holes in it to mount it to holes you drill in the Radial Arm saw post/arm/head. You probably want a 12-inch caliper which is a bit more expensive than the more common 6-inch ones (might not need more than 6 inches for the height, but will need longer for measuring along the arm).

There are many places to get these things on the web... LittleMachineShop sells quite high end stuff (Starrett, etc.) and MicroMark has some cheaper ones, both have dedicacted add-ons and simple calipers that you could re-purpose by drilling some holes.

Also, these things usually do not have backlash in them like a knob and gears/threaded rod do (such that you must always approach a setting/location by turning the knob/dial in the the same direction as the zero point was approached, every time) so adjustments are lots easier to do if you overshoot the desired position.


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## Semper Vaporo (Jan 2, 2008)

Some of these things DROs and calipers also display in inch fractions (1/8, 1/32, etc.). Most go to 64ths and I have seen some that will do 128ths (but are more expensive). 

LittleMachineShop has these: 

http://www.littlemachineshop.com/products/product_category.php?category=1516589126 

MicroMark has these: 

http://www.micromark.com/ProductSummary.aspx?DeptID=1001&map=web&page=2


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## Cougar Rock Rail (Jan 2, 2008)

Hi JJ, 

Sherline make these graduated handwheels...will they help? 

http://www.sherline.com/ezread.htm 

They also make a digital readout but I suspect it's more than you need. They have all sorts of handwheels with graduations...maybe email Craig. 

Keith


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## wchasr (Jan 2, 2008)

Lee Valley Tools has these: 
http://www.leevalley.com/US/wood/page.aspx?p=61612&cat=1,43513 

http://www.leevalley.com/US/wood/page.aspx?p=66892&cat=1,43513,49782 
& this 
http://www.leevalley.com/US/wood/page.aspx?p=67042&cat=1,43513,43553 

AND then to add to the cool tool to have category. 

http://www.leevalley.com/US/wood/page.aspx?p=64278&cat=1,43513 

Chas


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## denray (Jan 5, 2008)

John 
You may be complicating a simple process, mount a Acme thread on the carriage, a 5/8" x 8 threads per inch. That will give 1/8" per turn on the crank, 3/4" x 16 fine threads per inch will be 1/16" per crank. 
When you think about siding it does not need to be so precise. 
Dennis


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