(237,’2006-08-04 12:00:00′,’figNoggle’,’2007-01-05 00:06:19′,’david’,’Broaching Keyways Using A Lathe’,”,’Thought this would be of interest to some of you who may want to make a keyway in a pulley or something like that. It had been asked in a few forums before and since there are only a few references online about how to do this, we thought we’d contribute!

This is for demonstration purposes only, so you may see a few details in this pictorial that are obviously not quite right. However, it should get the point across as to how to make those slots in pulleys using your 7×1 7×1 7×1 8×1 8×1 9×2 etc. mini-lathes.

We should first point out that there are such kits available for broaching keyways. They typically have a few long metal bars of various sizes and bushings that when inserted into the appropriately sized hole, provide just enough clearance to allow the metal bar to pass through and make cuts. The metal bars (picture coming soon) kind of look like what you’d get if you unwrapped the circumference of a circular saw blade. The teeth are different, but there are essentially a slightly sloped gradation of cutting teeth fixed to this bar.

In this pictorial, we’ll just show a one-off version which is no more than a typical (non-insert) lathe toolbit. This one happens to be a 3/8″ bit size:

What we’re going to do is make some reliefs in the bit. Here’s the marked-up bit end (it’s the opposite side of the actual cutting end). BTW, these metal-colored “Sharpie” permanent markers make great markers for darker colored metals where the typical black ones wouldn’t show through:

After a few minutes of rough grinding with some 6 8 100 grit stones, we came up with this: (yes, it’s rough and not that sharp)

Now we get to the interesting part. Perhaps many people broach workpieces in the lathe with the keyway to be broached in a vertical orientation. What this means is that for broaching/cutting, you’d have to adjust the height of the toolbit for each pass. If you have a turret-style non-QCTP (like those that come stock with many mini-lathes), this means shimming in interations until you reach your depth of the keyway. What a pain! Here’s an example:

After sliding the carriage back and forth for each iteration of cut, then re-adjust the toolbit height, repeat, etc.. you end up with something like this:

Again, this is for demonstration purposes only so we didn’t go all the way through or make a deep cut. One of the reasons is that the bit became dull quite quickly (and it didn’t help that it was dull to begin with!).

Now, the tip (if you will) here is that it’s somewhat easier (perhaps matter of opinion here) to adjust the depth of the keyway cuts by simply adjusting the depth of the cross feed! This means not only can you measure the depth of cuts with the handle indicators (or DRO :)), you only have to measure the height of the toolbit once! No successive shimming with non-QCTPs and no re-adjusting the heights of the toolbit period.

To do this, you simply rotate the toolbit and workpiece such that the keyway is now to be oriented horizontally:

That’s it! We think that this is a much simpler approach to one-off broaching of workpieces using the lathe.’

Here’s a demonstration of it.

‘,’

Thought this would be of interest to some of you who may want to make a keyway in a pulley or something like that. It had been asked in a few forums before and since there are only a few references online about how to do this, we thought we’d contribute!

This is for demonstration purposes only, so you may see a few details in this pictorial that are obviously not quite right. However, it should get the point across as to how to make those slots in pulleys using your 7×1 7×1 7×1 8×1 8×1 9×2 etc. mini-lathes.

We should first point out that there are such kits available for broaching keyways. They typically have a few long metal bars of various sizes and bushings that when inserted into the appropriately sized hole, provide just enough clearance to allow the metal bar to pass through and make cuts. The metal bars (picture coming soon) kind of look like what you’d get if you unwrapped the circumference of a circular saw blade. The teeth are different, but there are essentially a slightly sloped gradation of cutting teeth fixed to this bar.

In this pictorial, we’ll just show a one-off version which is no more than a typical (non-insert) lathe toolbit. This one happens to be a 3/8” bit size:

What we’re going to do is make some reliefs in the bit. Here’s the marked-up bit end (it’s the opposite side of the actual cutting end). BTW, these metal-colored “Sharpie” permanent markers make great markers for darker colored metals where the typical black ones wouldn’t show through:

After a few minutes of rough grinding with some 6 8 100 grit stones, we came up with this: (yes, it’s rough and not that sharp)

Now we get to the interesting part. Perhaps many people broach workpieces in the lathe with the keyway to be broached in a vertical orientation. What this means is that for broaching/cutting, you’d have to adjust the height of the toolbit for each pass. If you have a turret-style non-QCTP (like those that come stock with many mini-lathes), this means shimming in interations until you reach your depth of the keyway. What a pain! Here’s an example:

After sliding the carriage back and forth for each iteration of cut, then re-adjust the toolbit height, repeat, etc.. you end up with something like this:

Again, this is for demonstration purposes only so we didn’t go all the way through or make a deep cut. One of the reasons is that the bit became dull quite quickly (and it didn’t help that it was dull to begin with!).

Now, the tip (if you will) here is that it’s somewhat easier (perhaps matter of opinion here) to adjust the depth of the keyway cuts by simply adjusting the depth of the cross feed! This means not only can you measure the depth of cuts with the handle indicators (or DRO :)), you only have to measure the height of the toolbit once! No successive shimming with non-QCTPs and no re-adjusting the heights of the toolbit period.

To do this, you simply rotate the toolbit and workpiece such that the keyway is now to be oriented horizontally:

That’s it! We think that this is a much simpler approach to one-off broaching of workpieces using the lathe.’

Here’s a demonstration of it.

‘,’Thought this would be of interest to some of you who may want to make a keyway in a pulley or something like that. It had been asked in a few forums before and since there are only a few references online about how to do this, we thought we’d contribute!

This is for demonstration purposes only, so you may see a few details in this pictorial that are obviously not quite right. However, it should get the point across as to how to make those slots in pulleys using your 7×1 7×1 7×1 8×1 8×1 9×2 etc. mini-lathes.

‘,’

Thought this would be of interest to some of you who may want to make a keyway in a pulley or something like that. It had been asked in a few forums before and since there are only a few references online about how to do this, we thought we’d contribute!

This is for demonstration purposes only, so you may see a few details in this pictorial that are obviously not quite right. However, it should get the point across as to how to make those slots in pulleys using your 7×1 7×1 7×1 8×1 8×1 9×2 etc. mini-lathes.

‘,”,’8x128x14-Small-Lathe’,”,0,”,0,4,1,1,’article’,”,”,’broaching-keyways-using-a-lathe’,”,”,”,”,”,”,”,”,”,”,’5d48265c5ee0d360597d80a2c34159e5′,’2006-08-04′);

(236,’2006-08-03 12:00:00′,’figNoggle’,’2006-12-20 08:04:33′,’david’,’Quick and Simple Tailstock Locking Mechanism’,”,’Well, it’s been done before I’m sure. We’ve certainly seen many photos out there of people with wrenches somehow secured to the nut of the tailstock post.

All we’ve done here is used a cheap Harbor Freight (under $1?) low-profile ratcheting box wrench. It requires disassembly of the locking mechanism so that you can get your box wrench around the nut and re-inserted as an assembly since there’s not enough space to do so with the nut already on the post.

So, slide the tailstock off the bed and remove the bolt:

Now, insert nut into box wrench and re-thread onto post and you’re done!

The good news is that you’ll no longer need to fumble around for that wrench since it’s already there. Also, since it’s a ratcheting wrench, a simple flip of the lever will let you tighten or loosen. Bad news? Since it’s a ratcheting wrench, it requires enough torque to provide the required force to move the ratcheting mechanism. What this means is that there will be times where nut may be just loose enough that the ratcheting won’t work and you’ll be reduced to fumbling around yet again to tighten the nut just enough to get the wrench to do the work. Oh well. It sure beats the open wrench until we get a camlock installed. Stay tuned…’

‘,’

Well, it’s been done before I’m sure. We’ve certainly seen many photos out there of people with wrenches somehow secured to the nut of the tailstock post.

All we’ve done here is used a cheap Harbor Freight (under $1?) low-profile ratcheting box wrench. It requires disassembly of the locking mechanism so that you can get your box wrench around the nut and re-inserted as an assembly since there’s not enough space to do so with the nut already on the post.

So, slide the tailstock off the bed and remove the bolt:

Now, insert nut into box wrench and re-thread onto post and you’re done!

The good news is that you’ll no longer need to fumble around for that wrench since it’s already there. Also, since it’s a ratcheting wrench, a simple flip of the lever will let you tighten or loosen. Bad news? Since it’s a ratcheting wrench, it requires enough torque to provide the required force to move the ratcheting mechanism. What this means is that there will be times where nut may be just loose enough that the ratcheting won’t work and you’ll be reduced to fumbling around yet again to tighten the nut just enough to get the wrench to do the work. Oh well. It sure beats the open wrench until we get a camlock installed. Stay tuned…’

‘,”,”,”,’8x128x14-Small-Lathe’,”,0,”,0,4,1,1,’article’,”,”,’quick-and-simple-tailstock-locking-mechanism’,”,”,”,”,”,”,”,”,”,”,’46b3117297e5b63b8d8305bc7cc5092a’,’2006-08-03′);

(235,’2006-08-03 12:00:00′,’figNoggle’,’2007-01-29 08:26:06′,’david’,’8×12 CNC Project – Installing DRO Scales Part 2 – Shocking!’,”,’We noticed that the display was acting funny yesterday. After a few hours it just all of a sudden became dimly lit. It was on, but noticably dimmer to the point where the LCD display could be barely read.

After unplugging, replugging a few times, it seemed to have resolved itself and we were back to doing things with the 8×12.

Today, it appeared fine until we were going to put the DRO to use. Again, the problem arose. Thinking that maybe it was the cable, we swapped that out. No go. Then we tried both cables with the 6″ vertical scale thinking that it was the scale. At this point the culprit appeared to be the 18″ horizontal scale (the one shown in Part 1 of this journey).

After removing the scale and cleaning it up (at this time the unit was frozen at “0.000” and prior experience taught us that the scales when dirty can do strange things).

After the scale was cleaned with acetone, the battery was re-inserted and voila! The scale was no longer frozen.

At this point, the Shars display appeared to be the culprit. That is until the scale was being reinstalled and we noticed a small spark from the tip of the screw that mounts the bracket to the saddle. Aha! Now that’s something to look at…

So, after putting a voltmeter between the bracket and saddle, it read roughly 5VDC.

Now what?

Before we get there, here’s what we’ve been talking about all along. Here is the before and after of the display with the circuit completed and with the circuit interrupted:

Display with scale bracket disconnected from saddle or lathe unplugged or cable disconnected (basically the DRO display outputs can’t be simultaneously connected to power while the lathe is connected), the display is bright:

Now, with everything connected, the display dims:

Same as before, just with the entire assembly shown (this is a temporary mock-up, so please don’t mind the mess!):

And circuit completed:

So now that we’ve figured out there’s a small amount of juice here, what’s next?’

If you missed part 1 of this installation, here it is.

Here’s what the X-axis DRO scale mounted looks like.

‘,’

We noticed that the display was acting funny yesterday. After a few hours it just all of a sudden became dimly lit. It was on, but noticably dimmer to the point where the LCD display could be barely read.

After unplugging, replugging a few times, it seemed to have resolved itself and we were back to doing things with the 8×12.

Today, it appeared fine until we were going to put the DRO to use. Again, the problem arose. Thinking that maybe it was the cable, we swapped that out. No go. Then we tried both cables with the 6” vertical scale thinking that it was the scale. At this point the culprit appeared to be the 18” horizontal scale (the one shown in Part 1 of this journey).

After removing the scale and cleaning it up (at this time the unit was frozen at “0.000” and prior experience taught us that the scales when dirty can do strange things).

After the scale was cleaned with acetone, the battery was re-inserted and voila! The scale was no longer frozen.

At this point, the Shars display appeared to be the culprit. That is until the scale was being reinstalled and we noticed a small spark from the tip of the screw that mounts the bracket to the saddle. Aha! Now that’s something to look at…

So, after putting a voltmeter between the bracket and saddle, it read roughly 5VDC.

Now what?

Before we get there, here’s what we’ve been talking about all along. Here is the before and after of the display with the circuit completed and with the circuit interrupted:

Display with scale bracket disconnected from saddle or lathe unplugged or cable disconnected (basically the DRO display outputs can’t be simultaneously connected to power while the lathe is connected), the display is bright:

Now, with everything connected, the display dims:

Same as before, just with the entire assembly shown (this is a temporary mock-up, so please don’t mind the mess!):

And circuit completed:

So now that we’ve figured out there’s a small amount of juice here, what’s next?’

If you missed part 1 of this installation, here it is.

Here’s what the X-axis DRO scale mounted looks like.

‘,’We noticed that the display was acting funny yesterday. After a few hours it just all of a sudden became dimly lit. It was on, but noticably dimmer to the point where the LCD display could be barely read.

After unplugging, replugging a few times, it seemed to have resolved itself and we were back to doing things with the 8×12.

‘,’

We noticed that the display was acting funny yesterday. After a few hours it just all of a sudden became dimly lit. It was on, but noticably dimmer to the point where the LCD display could be barely read.

After unplugging, replugging a few times, it seemed to have resolved itself and we were back to doing things with the 8×12.

‘,”,’8x128x14-Small-Lathe’,”,0,”,0,4,1,1,’article’,”,”,’8×12-cnc-project-installing-dro-scales-part-2-shocking’,”,”,”,”,”,”,”,”,”,”,’73bac35bacfbf19b44f78c32b82018a5′,’2006-08-03′);