(240,’2006-08-15 12:00:00′,’figNoggle’,’2007-02-11 22:34:47′,’david’,’Sieg X2 Mini-Mill Belt Drive Conversion – Part 2′,”,’After waiting over the weekend for some cutting tools from ENCO (metric drill bit set and some square HSS tool bits for cutting the 5mm keyway on the spindle pulley), we resumed mocking up this prototype belt drive conversion.

We wanted to make things interesting. How long would it take to work on these parts for the conversion while the drivetrain was disassembled? As it turns out, for roughing, it’s still quite fast. What took some time was cutting the keyway on the steel timing pulley for the spindle. After a few hours of machine work, you end up with something like this:

After quickly grinding down some multiple reliefs in the 3/16″ square tool bit, we got to work cutting the keyway in the timing pulley to the 8×12 lathe and eyeballed center after first placing the spindle collar on top of the pulley and scribing the location and depth of the keyway to be cut:

We could have purchased a $5 5mm bit from MSC Direct or other sources, but 3/16″ is close enough and would just require adjusting the height of the toolpost or some final skim passes to widen the keyway. Oh, the 3/16″ bits are just $0.49 each!

This took just over two hours to cut as we experimented with rotating the toolpost to increase the cutting relief angle of the bit. On smaller bits like this, deflection of the bit is common. One trick is to start with just a nub cut of less than 1/2″ or so to get things started. Then when you get close to the depth of cut, start extending the bit further for the full pass through. There will still be deflection, but it seems to work well. Also, when making cuts using a bit of the same width, the stock that isn’t ground with relief will rub against the keyway as the bit cuts through. The trick here is to rotate the toolpost so that only the cutting edges make contact with the keyway.

After many, many passes (CNC would be good here!), we end up with this:

Now it’s time to drill a hole for the spindle lock. Remember in the previous stage we mentioned orienting the hole vertically. With a 8mm drill bit, a hole was drilled in the timing pulley:

And here’s the pulley on the spindle:

Next we need to offset the motor plate from the top of the spindle head. We had some steel tubing with the right hole diameter for the 6Mx1 metric socket head cap screws. This took a few minutes to part in the 8×12:

And here’s the assembly:

Oops! Forgot to drill the hole for the spindle lock. Just for kicks, a 5/16″ 2 flute end mill at 300rpm was used to attempt to “drill” the hole. OK, this is perhaps one of the uglier pictures you’ll see:

It was a mess.The spindle on the drill press wobbled like crazy and ultimately a combination of the end mill and drill bit were used.

Now, the moment our ears have been waiting for…

TITLE: Click on the image to view the short video clip. Now that’s music to our ears.)

The motor was spinning at max (based on rating) of 000rpm and with a 1:2 ratio, the spindle maxed at 000rpm. It’s noticably quiter than before!

BTW, the gear assembly in the head was adjusted with the lever so that they weren’t engaged. The “proper” way to do this is to remove the assembly which requires removing the head to access the cavity where they reside. Doing so prevents any chance you hit the lever and crunch the gearbox.

Now off to endurance testing… Some modifications will of course be made to the design, but in essence this was a really simple build requiring only a lathe and drill press which means you could do this while your mill was apart. Considering the cost of parts was under $50 (actually closer to $30+) and required minimal machining, it makes for a fun weekend upgrade. We’ll be offering plans and possibly kits) of this in the near future. Stay tuned…’

Here’s Version 2 of the prototype!’,’

After waiting over the weekend for some cutting tools from ENCO (metric drill bit set and some square HSS tool bits for cutting the 5mm keyway on the spindle pulley), we resumed mocking up this prototype belt drive conversion.

We wanted to make things interesting. How long would it take to work on these parts for the conversion while the drivetrain was disassembled? As it turns out, for roughing, it’s still quite fast. What took some time was cutting the keyway on the steel timing pulley for the spindle. After a few hours of machine work, you end up with something like this:

After quickly grinding down some multiple reliefs in the 3/16” square tool bit, we got to work cutting the keyway in the timing pulley to the 8×12 lathe and eyeballed center after first placing the spindle collar on top of the pulley and scribing the location and depth of the keyway to be cut:

We could have purchased a $5 5mm bit from MSC Direct or other sources, but 3/16” is close enough and would just require adjusting the height of the toolpost or some final skim passes to widen the keyway. Oh, the 3/16” bits are just $0.49 each!

This took just over two hours to cut as we experimented with rotating the toolpost to increase the cutting relief angle of the bit. On smaller bits like this, deflection of the bit is common. One trick is to start with just a nub cut of less than 1/2” or so to get things started. Then when you get close to the depth of cut, start extending the bit further for the full pass through. There will still be deflection, but it seems to work well. Also, when making cuts using a bit of the same width, the stock that isn’t ground with relief will rub against the keyway as the bit cuts through. The trick here is to rotate the toolpost so that only the cutting edges make contact with the keyway.

After many, many passes (CNC would be good here!), we end up with this:

Now it’s time to drill a hole for the spindle lock. Remember in the previous stage we mentioned orienting the hole vertically. With a 8mm drill bit, a hole was drilled in the timing pulley:

And here’s the pulley on the spindle:

Next we need to offset the motor plate from the top of the spindle head. We had some steel tubing with the right hole diameter for the 6Mx1 metric socket head cap screws. This took a few minutes to part in the 8×12:

And here’s the assembly:

Oops! Forgot to drill the hole for the spindle lock. Just for kicks, a 5/16” 2 flute end mill at 300rpm was used to attempt to “drill” the hole. OK, this is perhaps one of the uglier pictures you’ll see:

It was a mess.The spindle on the drill press wobbled like crazy and ultimately a combination of the end mill and drill bit were used.

Now, the moment our ears have been waiting for…

TITLE: Click on the image to view the short video clip. Now that’s music to our ears.)

The motor was spinning at max (based on rating) of 000rpm and with a 1:2 ratio, the spindle maxed at 000rpm. It’s noticably quiter than before!

BTW, the gear assembly in the head was adjusted with the lever so that they weren’t engaged. The “proper” way to do this is to remove the assembly which requires removing the head to access the cavity where they reside. Doing so prevents any chance you hit the lever and crunch the gearbox.

Now off to endurance testing… Some modifications will of course be made to the design, but in essence this was a really simple build requiring only a lathe and drill press which means you could do this while your mill was apart. Considering the cost of parts was under $50 (actually closer to $30+) and required minimal machining, it makes for a fun weekend upgrade. We’ll be offering plans and possibly kits) of this in the near future. Stay tuned…’

Here’s Version 2 of the prototype!

‘,’After waiting over the weekend for some cutting tools from ENCO (metric drill bit set and some square HSS tool bits for cutting the 5mm keyway on the spindle pulley), we resumed mocking up this prototype belt drive conversion.

We wanted to make things interesting. How long would it take to work on these parts for the conversion while the drivetrain was disassembled? As it turns out, for roughing, it’s still quite fast. What took some time was cutting the keyway on the steel timing pulley for the spindle. After a few hours of machine work, you end up with something like this:

<','

After waiting over the weekend for some cutting tools from ENCO (metric drill bit set and some square HSS tool bits for cutting the 5mm keyway on the spindle pulley), we resumed mocking up this prototype belt drive conversion.

We wanted to make things interesting. How long would it take to work on these parts for the conversion while the drivetrain was disassembled? As it turns out, for roughing, it’s still quite fast. What took some time was cutting the keyway on the steel timing pulley for the spindle. After a few hours of machine work, you end up with something like this:

<

‘,”,’Sieg-X2-Mini-Mill’,”,0,”,0,4,1,1,’article’,”,”,’sieg-x2-mini-mill-belt-drive-conversion-part-2′,”,”,”,”,”,”,”,”,”,”,’82359f039b0a6e65b37fee456b456e66′,’2006-08-15′);

(239,’2006-08-10 12:00:00′,’figNoggle’,’2007-01-05 00:04:27′,’david’,’Sieg X2 Mini-Mill Belt Drive Conversion – Part 1′,”,’Finally the noise got to us. The gears amazingly have remained intact through some careful, though rough use with flycutters, 3/4″ end mills, cutting mild steel, aluminum and other strange things. It must be because we weren’t taking 1/2″ cuts at a time

That’s all fine, but when the mill is being used in CNC mode for hours at a time, the noise becomes unbearable. So while some other projects required re-tooling in the shop, we found this an opportune time to work on this belt drive conversion.

We had three basic design constraints: 1. can it be made using a lathe or mill itself prior to the conversion and 2. low-cost and 3. relatively easy to make.

Since turning v-belt pulleys takes some skill (especially if working with a smaller lathe like the 7×12 or even the 8×12), we wondered if we could use timing belt pulleys instead. There were already a few laying around in the shop, plus we like them better than v-pulleys.

The first step was to remove the gear cover.

Next, remove the intermediate gear (one of the commonly broken ones):

Next, using the two included spanner wrenches (they are sized differently so be sure to use the right one for the collar and the lock nut):

Now, remove the 5mm key and the collar and lock nut:

Now comes the fun part! We’re going to use a 1:2 gearing ratio which will give us a max speed of 000RPM based on the motor’s rated 000RPM. You may be wondering about being able to change speed ranges. We think for many milling operations using “regular” sized end mills and given the feed rates possible via manual and CNC on the mini-mill, simplicity of a single range should be fine.

We’ll need to drill and bore out the two shaft holes; the smaller for the 9mm motor shaft and 1.180″ for the spindle.

But first, remove the gear from the motor shaft (watch out for that flying circlip when you remove it!):

After drilling a 9MM hole into the smaller timing pulley (ours was mounted in the 8×12 lathe), you’ll also need to make a small spacer (which was also turned in the lathe) to offset the pulley from the motor shaft base. This also produces enough clearance:

Next, we’ll need to bore a hole to fit the spindle. It starts out with a 5/16″ hole:

After a few passes at 0.020″, we end up with a really nice fitting bored hole:

This really was much easier to do in the 8×12 than with the 7×10 mini-lathe.

Now the mock-up assembly:

Some of you astute conversion-ists may be wondering where the spindle lock will go? We’re going to simplify things here and drill a hole right into the pulley vertically! More on this conversion coming shortly… Stay tuned!

And here’s part 2 of the series.‘

‘,’

Finally the noise got to us. The gears amazingly have remained intact through some careful, though rough use with flycutters, 3/4” end mills, cutting mild steel, aluminum and other strange things. It must be because we weren’t taking 1/2” cuts at a time

That’s all fine, but when the mill is being used in CNC mode for hours at a time, the noise becomes unbearable. So while some other projects required re-tooling in the shop, we found this an opportune time to work on this belt drive conversion.

We had three basic design constraints: 1. can it be made using a lathe or mill itself prior to the conversion and 2. low-cost and 3. relatively easy to make.

Since turning v-belt pulleys takes some skill (especially if working with a smaller lathe like the 7×12 or even the 8×12), we wondered if we could use timing belt pulleys instead. There were already a few laying around in the shop, plus we like them better than v-pulleys.

The first step was to remove the gear cover.

Next, remove the intermediate gear (one of the commonly broken ones):

Next, using the two included spanner wrenches (they are sized differently so be sure to use the right one for the collar and the lock nut):

Now, remove the 5mm key and the collar and lock nut:

Now comes the fun part! We’re going to use a 1:2 gearing ratio which will give us a max speed of 000RPM based on the motor’s rated 000RPM. You may be wondering about being able to change speed ranges. We think for many milling operations using “regular” sized end mills and given the feed rates possible via manual and CNC on the mini-mill, simplicity of a single range should be fine.

We’ll need to drill and bore out the two shaft holes; the smaller for the 9mm motor shaft and 1.180” for the spindle.

But first, remove the gear from the motor shaft (watch out for that flying circlip when you remove it!):

After drilling a 9MM hole into the smaller timing pulley (ours was mounted in the 8×12 lathe), you’ll also need to make a small spacer (which was also turned in the lathe) to offset the pulley from the motor shaft base. This also produces enough clearance:

Next, we’ll need to bore a hole to fit the spindle. It starts out with a 5/16” hole:

After a few passes at 0.020”, we end up with a really nice fitting bored hole:

This really was much easier to do in the 8×12 than with the 7×10 mini-lathe.

Now the mock-up assembly:

Some of you astute conversion-ists may be wondering where the spindle lock will go? We’re going to simplify things here and drill a hole right into the pulley vertically! More on this conversion coming shortly… Stay tuned!

And here’s part 2 of the series.‘

‘,’Finally the noise got to us. The gears amazingly have remained intact through some careful, though rough use with flycutters, 3/4″ end mills, cutting mild steel, aluminum and other strange things. It must be because we weren’t taking 1/2″ cuts at a time

That’s all fine, but when the mill is being used in CNC mode for hours at a time, the noise becomes unbearable. So while some other projects required re-tooling in the shop, we found this an opportune time to work on this belt drive conversion.

We had three basic design constraints: 1. can it be made using a lathe or mill itself prior to the conversion and 2. low-cost and 3. relatively easy to make.

Since turning v-belt pulleys takes some skill (especially if working with a smaller lathe like the 7×12 or even the 8×12), we wondered if we could use timing belt pulleys instead. There were already a few laying around in the shop, plus we like them better than v-pulleys.

‘,’

Finally the noise got to us. The gears amazingly have remained intact through some careful, though rough use with flycutters, 3/4” end mills, cutting mild steel, aluminum and other strange things. It must be because we weren’t taking 1/2” cuts at a time

That’s all fine, but when the mill is being used in CNC mode for hours at a time, the noise becomes unbearable. So while some other projects required re-tooling in the shop, we found this an opportune time to work on this belt drive conversion.

We had three basic design constraints: 1. can it be made using a lathe or mill itself prior to the conversion and 2. low-cost and 3. relatively easy to make.

Since turning v-belt pulleys takes some skill (especially if working with a smaller lathe like the 7×12 or even the 8×12), we wondered if we could use timing belt pulleys instead. There were already a few laying around in the shop, plus we like them better than v-pulleys.

‘,”,’Sieg-X2-Mini-Mill’,”,0,”,0,4,1,1,’article’,”,”,’sieg-x2-mini-mill-belt-drive-conversion-part-1′,”,”,”,”,”,”,”,”,”,”,’b7ed1ec2f429f591adb35298b28ec8da’,’2006-08-10′);

(238,’2006-08-10 12:00:00′,’figNoggle’,’2006-12-20 08:03:41′,’david’,’Keling NEMA 34 Step Motors (AKA Steppers) and Gecko G202s Arrived!’,”,’The two NEMA34 frame step motors and Gecko G202s arrived! Initial impression was that the motors are HUGE compared to NEMA23 frame motors (like the ones on the X2 CNC mini-mill) and the drives are small.

The motors are model number KL34H295-43-8B with the following specs:

-990oz.in. holding torque

-4-phase can be wired in parallel, series and unipolar

The Gecko drives are model G202s and basically is the one without half/full step but has short circuit protection.

A power supply needs to be purchased as well. Here’s how we went about finding the “right” one…

According to G202 documentation, a minimum of 24VDC and maximum of 80VDC are the limits that the Gecko will take. Apparently, there’s a linear relationship between power supply voltage and the “high speed performance” of the motor. So “doubling the voltage also doubles the motor’s high speed power” according to Gecko. Since 24VDC switching power supplies can be had for $50 or so from any outlet including Jameco, we looked there first.

After seeing that 48VDC supplies weren’t all that expensive, we decided on that. But what about current supply? Again, the G202 doc says that 67% of the motor’s rated phase current is the maximum the power supply requirement. So, the motor’s numbers come down to this:

Parallel = 6.1A@100% / 4.087A@67%

Series = 3.05A@100% / 2.0435A@67%

Unipolar = 4.3A@100% / 2.881A@67%

This basically tells us that the common 0-2A power supplies would work except in the case of a parallel-wired stepper. So, now we’re off looking for something like a 48VDC 0-5A or similar power supply. Jameco sells MeanWell (what a name!) supplies; model number S-240-48 does the trick! A quick online search found only a few other places that had deals better than Jameco.’

‘,’

The two NEMA34 frame step motors and Gecko G202s arrived! Initial impression was that the motors are HUGE compared to NEMA23 frame motors (like the ones on the X2 CNC mini-mill) and the drives are small.

The motors are model number KL34H295-43-8B with the following specs:

-990oz.in. holding torque

-4-phase can be wired in parallel, series and unipolar

The Gecko drives are model G202s and basically is the one without half/full step but has short circuit protection.

A power supply needs to be purchased as well. Here’s how we went about finding the “right” one…

According to G202 documentation, a minimum of 24VDC and maximum of 80VDC are the limits that the Gecko will take. Apparently, there’s a linear relationship between power supply voltage and the “high speed performance” of the motor. So “doubling the voltage also doubles the motor’s high speed power” according to Gecko. Since 24VDC switching power supplies can be had for $50 or so from any outlet including Jameco, we looked there first.

After seeing that 48VDC supplies weren’t all that expensive, we decided on that. But what about current supply? Again, the G202 doc says that 67% of the motor’s rated phase current is the maximum the power supply requirement. So, the motor’s numbers come down to this:

Parallel = 6.1A@100% / 4.087A@67%

Series = 3.05A@100% / 2.0435A@67%

Unipolar = 4.3A@100% / 2.881A@67%

This basically tells us that the common 0-2A power supplies would work except in the case of a parallel-wired stepper. So, now we’re off looking for something like a 48VDC 0-5A or similar power supply. Jameco sells MeanWell (what a name!) supplies; model number S-240-48 does the trick! A quick online search found only a few other places that had deals better than Jameco.’

‘,”,”,”,’Home-Brewed-CNC-Vertical-Mill’,”,0,”,0,4,1,1,’article’,”,”,’keling-nema-34-step-motors-aka-steppers-and-gecko-g202s-arrived’,”,”,”,”,”,”,”,”,”,”,’3c18ba5d484bf3d4e5061771d5458e29′,’2006-08-10′);