From what I see you are trying to drill some straight holes in a cylindrical length of aluminum with a drill press. You are assuming the angle of the drill press is at 90 degrees with the table. This may not be a correct assumption. If the alignment of the drill press is not exactly 90 degrees you will drill a hole that leads whatever your drill press is out. (this happens if your cylinder is square with the table) What is the name of your drill press? I am only asking this if your drill press came from China. If you buy stuff from China you should not expect too much so you will not be disappointed when it shows up poorly made. Do you have a dial test indicator? Since I do not believe you are working on space shuttle parts you can buy a cheap dial test indicator at http://littlemachineshop.com/products/product_view.php?ProductID=1249. (Sorry, I have used here before but that part of my small mind has left me so you must copy and paste.) It only costs $30. You will also need an indicator holder which can be found at http://littlemachineshop.com/products/product_view.php?ProductID=1251.
This will cost you another $10. You must sweep the table which means you set the indicator with the indicator holder to measure a 6 inch circle while it is touching the table. ( I use a Blake co-ax test indicator that keeps the face of the indicator facing toward me but if you do not want to spend $350 for it you must stick your head behind where you are reading to check the reading at the back side of your sweep) If your reading is more than .002 or .003 you have a cheap drill press. Take no fear, this can also be realigned or at least adjusted for with shims under the cylinder holder. I see you are making up a template and gluing it to the end of your cylindrical piece and using a wiggler to find the center. This can be more precisely accomplished with the test indicator and the indicator holder. The last thing you may need is a vee block to hold your cylindrical piece square with the table. One from China that will hold most of your cylindrical parts can be found at Travers Tool Company http://www.travers.com/product.asp?r=s&n=||UserSearch1%3Dvee+blocks&eaprodid=56977-57-109-145 for $35. I believe this part will hold your cylinder square with the table. Do you see how easily I spend your money? I am a precision machinist who has worked with tolerances of +.0002 -.0000 all my life and expect the machines I use to be precise. (Or at least reparable to hold tolerances)
From what I see you are trying to drill some straight holes in a cylindrical length of aluminum with a drill press. You are assuming the angle of the drill press is at 90 degrees with the table. This may not be a correct assumption. If the alignment of the drill press is not exactly 90 degrees you will drill a hole that leads whatever your drill press is out. (this happens if your cylinder is square with the table)
From what I see, you are assuming that I am ignorant, but since you are the new kid on the block, I will cut you a little slack and offer a little advice. Within this forum, there are some very intelligent and creative people, and believe me, just when you think you have all the answers, you will soon discover that you don't, as I have discovered many times. My suggestion would be to get a real feel for this forum and it's members, before going wild with postings. I realize you are just trying to help, but take it easy my friend.
I you read this entire thread, you will find that my method of making couplings involves aligning the outter dimensions with the inner hole, so the alignment of the table is actually an invalid point.
If you believe that my post has any way or all said or implied that you are ignorant please forgive me it was not intentional. I wholeheartedly believe you are 3 or 4 times smarter than I am. Look at your posts, I just have a BS2 and have a lot of trouble programming it. (most of the time I need help) I have read many of your posts and especially this post which I thought I could help but I am a precision machinist who can not understand why you would take a perfectly round cylinder, drill a hole on an angle and then cut the periphery to match the hole. Do you realize that the top and bottom faces are no longer square with the sides? I'm sorry but I believe square on square is the proper way to go. By the way, kid is no way to call me because I will be 65 in October.
As I am sure you are well aware, making shaft couplings on a lathe and making shaft couplings on a drill press, is like comparing apples to oranges. This thread discusses the making of couplings with a drill press, and it is very difficult to create an accurate coupling on a drill press. For the sake of discussion, I will address the issues you have brought up.
who can not understand why you would take a perfectly round cylinder, drill a hole on an angle and then cut the periphery to match the hole.
When making couplings, I would never intentionally drill the inner hole at an angle.
In my opinion, drilling a deep hole on a drill press, exactly centered, without any drill bit walking, is darn near impossible.
There are die marks on the stock finish of extruded aluminum from the extrusion process, therefore it is not a perfectly round cylinder. To remove these die marks, the workpiece must be turned. To make a nice coupling with a nice finish, from a "perfectly" round cylinder, on a drill press, a person would have to create their couplings from precision shafting, and drill their hole exactly centered, without any drill bit walk.
Do you realize that the top and bottom faces are no longer square with the sides?
This thread clearly discusses that the top and bottom faces are squared to the sides.
By the way, kid is no way to call me because I will be 65 in October.
No. 1: Never intentionally only counts if your drill press is set up at exactly 90 degrees from the table and this does not happen exactly even with expensive drill presses.
No. 2: You are technically correct on this one, if the lands and angles are even it detracts from this condition but it still walks because of play in bushings.
No. 3: Correct again, even with a high precision ground surface tolerances in the bearings, roughness in the ways or varying in the grit size will affect this reading.
If the top and bottom are square and the hole is on an angle other than 90 degrees from the table (caused by construction of the drill press) they will not be perpendicular to sides created by copying the hole.
Thanks for not calling me a kid, I had a younger looking face back then and could not buy beer (they did not have photo drivers licenses) till I was 26 years old.
In most instances, I normally do not drill anything thicker than 1/4", and unless I am drilling for mating surfaces, the alignment is not always that critical. However, if I am doing highly critical work, then I do my best to align everything possible to the best of my abilities. There are many times when I purposely drill at an angle, and when I am done, I just rotate the table back to the 0 degree and slap the pin back in, without squaring everything. The alignment pin is way off due to factory machining, but I use it just to keep the table more stable. As for the other direction, the weight of the milling vise makes the table sag a little, so shimming is necessary. As time goes by, the weight of the milling vise will make it sag a little more. So when necessary, I true the milling vise to the spindle instead of the table.
Just to give you an example, at this point in time, I am grinding the ends of lead screws, which is highly critical, but in this instance, there is a jig within the milling vise, and this jig must be aligned to the spindle. As previously stated, here is the result:
RESULTS: Within a 1/2" span, there is less than a 0.00025" difference in the diameter, which should equate to less than a 0.0025" runout from center at a 10" span, but more particularly, in my case, 7.125" (lead screw length) X 0.00025" (runout per inch from center) = less than 0.00178125" runout for my lead screws ( EDIT: Theoretically speaking). I believe that should be good enough, considering the sleeve bearings on my pillow blocks have 0.002" clearance.
I just finished machining my lead screws a few minutes ago, and I believe they should be okay and hopefully within my scope of tolerances. However, the set screw flats did not turn out nearly as well as I was hoping. My first mistake was that I relied on the grinding jig to firmly hold the screws for milling, and secondly, I cut them way too deep, but I think they should work well.
If anyone ever buys a milling vise, such as the one that I rely on so heavily, performing an accurate cut on the Z axis is very difficult, because it is very hard to obtain an accurate measurement. I once developed a method to get within 0.004", but since that time, I forgot just exactly how I was able to do that.
My order for the 5MM drill bits showed up yesterday, so the project for the day is to modify one of these to make my new set of couplings to match the lead screws, and hopefully I will be able to finish my linear actuators in a day or two. And of course, hopefully the majority of my runout will be eliminated.
I discovered a minor setback yesterday, while grinding my new 5MM step bit. To get a good grind on the drill bit with sufficient depth, I had to grind it to a smaller diameter than I had originally intended for the coupling end of the lead screws. Basically this means that I will have to regrind the coupling end of each lead screw to match the drill bit diameter. I do not believe this will be a huge setback, but it is still a setback. I will post the final diameters of the modified bit and lead screws sometime later today.
Anyhow, if a bit is being modifed, I am a firm believer that a landing should exist around the full circumference of the drill bit, with the exception of the grooves created by the fluting. However, I could be wrong about this, and it may just be necessary for a landing at the edge of the fluting. Keep this in mind if the diameters of the motor shaft and lead screws are in close proximity of each other.
Thanks for the consideration and the link, but my project is a million miles away from something like that. The project that I am working on, would consist of three items similar to this: http://www.velmex.com/images/motordriven/ma15/ma1500.jpg
I modified my procedure for grinding the drill bits, and it seems to work very well. The new procedure is as follows:
True the outter diameter of a 3/4" dia. X 3/4" grinding point to be parallel with the centerline of the drill press spindle.
Drill a 7/8" deep hole in some soft 1" aluminum bar stock with the machine screw drill bit that you intend to modify. Remove the bit from the drill press and insert the shank into the hole you just drill.
Attach a knob with a through hole to the drill bit and let it rest against the aluminum bar stock. Since I was modifying a 5MM bit, I simply used an approximate 1-1/4 diameter spur gear with 5MM shaft hole for this purpose.
Install the grinding point in the drill press.
Adjust the drill press table height, so that the bottom of the grinding point will grind the drill bit to the desired depth.
Start the drill press and slowly move the bit into the point, while rotating the drill bit with the knob, and grind the bit to the desired uniform diameter.
This method works much better than my previous method.
I just finished boring my new couplings with my newly modified drill bit. After boring them, I did a test fit on the lead screws and motors, and I must say that everything is fitting very snug, perhaps a bit to snug on the motors. Without pushing the couplings all the way onto the motor shaft or securing any set screws (because they have not been drilled yet), I eyed the runout of the lead screws while rotating the motor shaft, and the runout is very minimal. I would imagine that the runout will even get smaller when everything is fully assembled and the set screws are tightened. I do believe this set of couplings and lead screws should provide a fairly high degree of precision without putting unnecessary strain on lead screws, lead nuts, motor bearings, or the pillow block bearings.
The next course of action is to drill out the couplings for the set screws and turn the couplings down to desired outside diameter. After that is complete, I should once again be able to start moving forward on my PCB Drilling And Laser Direct Imaging Machine. As mentioned, this process would have been much quicker with the proper machinery, but for those folks that don't have access to a lathe, some fairly accurate machining can be completed with nothing more than a drill press, a milling vise, and a few miscellaneous tools.
I will post a photo of the finished shaft couplings, lead screws, and pillow blocks within the next several days.
During assembly, I discovered that the runout on the newly finished set of couplings and lead screws was worse than I anticipated. This could have been due to the very snug fits, which basically had to be forced into place and probably removed some necessary material for alignment. I should state for the record that a couple of the sets probably would have satisfied many people and would have made my assemblies operable at this point, but I am still not satisfied, so I am changing my strategy once again and making a new set.
For my new strategy, I will be doing a couple of things different. My new goal is to eliminate potential problems. Since I am unsure of the accuracy of the holes made in the couplings with the ground drill bits, I have decided to eliminate that part of the procedure. In order to eliminate the need for a step bit when making the new couplings, I will have to match the coupling end of the lead screw to the motor shaft size, and in order to have a nice shaft end for the coupling, without having any thread groove remnants, I have decided to increase the size of the lead screw from 1/4 to 5/16. By increasing the size of the lead screw to 5/16, I can machine the coupling end of the lead screw down to 5MM to match the motor shaft. So in other words, by matching the lead screw end to the motor, I can eliminate the potential error that may be caused by a double sized bore in the coupling. Additionally, considering the very snug fits of the couplings that I previously encountered, I have decided to increase the bore size by a couple thousandths, and drill out a new set of couplings with a #8 bit.
I believe this will be my 5TH batch of couplings and lead screws (maybe 6TH), and believe me, it is starting to get very tiresome. However, as I am sure that many of you already know, I am a very stubborn man, and I hate to admit defeat.
As it turns out, the #8 drill bit provided a bit too much clearance. Out of curiousity, I used an "unmodified" 5MM bit, which produced a hole with a pretty nice fit. I think Phil mentioned in another thread, that the fluting of a drill bit is of a smaller diameter than the cutting head, which I briefly forgot and overlooked. This is what was creating the very snug fit on my motor shafts. So now I will be drilling the new couplers with an unmodified 5MM bit, instead of a #8.
As you may have guessed, with so many attempts resulting in unsatisfactory outcomes, my ambition started to run low. However, I finally got around to making a new set of couplings with an unmodified 5MM drill bit and the couplings turned out to look quite nice. Furthermore, just this morning, I machined down one of the new 5/16 lead screws to have a 5MM end with my homemade jig. I have not yet machined a flat on this end for the set screws, but in it's current condition, without set screws, this lead screw has very little runout. If I had to guess (since my dial indicator was swindled), I would estimate the runout to be somewhere in ballpark of 0.001-0.003" for a 7-1/8" run. I also have not yet put the bearing sleeve on this leadscrew, but I do believe this leadscrew and coupling set is a definite keeper. And I must say, considering this entire assembly was constructed with nothing more than a drill press and some miscellaneous tools, I am really quite impressed with the new result. I am hoping the remaining two screws and couplings turn out to be just as nice as the first.
It is noteworthy to mention that if anyone decides to attempt a similar process, but will be making lead screws and couplings for NEMA 23 motors, instead of NEMA 17 motors, the lead screw will have to be upgraded to 3/8", because the 5/16 screws must be machined down to a diameter of at least 0.235" to remove all remants of the threads.
Looking back now, I wish I had initially designed my machine for 5/16 lead screws instead of 1/4. I do believe that oversight cost me a lot of time, labor, and ambition. Anyhow, now that I have finally achieved such a nice result, my ambition is starting to quickly return, and hopefully, I should soon have three smooth running linear actuators to build my new machine.
Here is another tidbit worth mentioning. To accomodate the 5/16 lead screws in the homemade jig, I had to create a couple 1/16" spacers. So this jig can now machine the ends of both 1/4" and 5/16" screws.
Comments
From what I see you are trying to drill some straight holes in a cylindrical length of aluminum with a drill press. You are assuming the angle of the drill press is at 90 degrees with the table. This may not be a correct assumption. If the alignment of the drill press is not exactly 90 degrees you will drill a hole that leads whatever your drill press is out. (this happens if your cylinder is square with the table) What is the name of your drill press? I am only asking this if your drill press came from China. If you buy stuff from China you should not expect too much so you will not be disappointed when it shows up poorly made. Do you have a dial test indicator? Since I do not believe you are working on space shuttle parts you can buy a cheap dial test indicator at http://littlemachineshop.com/products/product_view.php?ProductID=1249. (Sorry, I have used here before but that part of my small mind has left me so you must copy and paste.) It only costs $30. You will also need an indicator holder which can be found at http://littlemachineshop.com/products/product_view.php?ProductID=1251.
This will cost you another $10. You must sweep the table which means you set the indicator with the indicator holder to measure a 6 inch circle while it is touching the table. ( I use a Blake co-ax test indicator that keeps the face of the indicator facing toward me but if you do not want to spend $350 for it you must stick your head behind where you are reading to check the reading at the back side of your sweep) If your reading is more than .002 or .003 you have a cheap drill press. Take no fear, this can also be realigned or at least adjusted for with shims under the cylinder holder. I see you are making up a template and gluing it to the end of your cylindrical piece and using a wiggler to find the center. This can be more precisely accomplished with the test indicator and the indicator holder. The last thing you may need is a vee block to hold your cylindrical piece square with the table. One from China that will hold most of your cylindrical parts can be found at Travers Tool Company http://www.travers.com/product.asp?r=s&n=||UserSearch1%3Dvee+blocks&eaprodid=56977-57-109-145 for $35. I believe this part will hold your cylinder square with the table. Do you see how easily I spend your money? I am a precision machinist who has worked with tolerances of +.0002 -.0000 all my life and expect the machines I use to be precise. (Or at least reparable to hold tolerances)
From what I see, you are assuming that I am ignorant, but since you are the new kid on the block, I will cut you a little slack and offer a little advice. Within this forum, there are some very intelligent and creative people, and believe me, just when you think you have all the answers, you will soon discover that you don't, as I have discovered many times. My suggestion would be to get a real feel for this forum and it's members, before going wild with postings. I realize you are just trying to help, but take it easy my friend.
I you read this entire thread, you will find that my method of making couplings involves aligning the outter dimensions with the inner hole, so the alignment of the table is actually an invalid point.
Before assuming anything about me, you should probably read several of my threads. Here is just one to get you started:
http://forums.parallax.com/showthread.php?129612-My-Current-Prop-Based-CNC-Photos
Bruce
If you believe that my post has any way or all said or implied that you are ignorant please forgive me it was not intentional. I wholeheartedly believe you are 3 or 4 times smarter than I am. Look at your posts, I just have a BS2 and have a lot of trouble programming it. (most of the time I need help) I have read many of your posts and especially this post which I thought I could help but I am a precision machinist who can not understand why you would take a perfectly round cylinder, drill a hole on an angle and then cut the periphery to match the hole. Do you realize that the top and bottom faces are no longer square with the sides? I'm sorry but I believe square on square is the proper way to go. By the way, kid is no way to call me because I will be 65 in October.
As I am sure you are well aware, making shaft couplings on a lathe and making shaft couplings on a drill press, is like comparing apples to oranges. This thread discusses the making of couplings with a drill press, and it is very difficult to create an accurate coupling on a drill press. For the sake of discussion, I will address the issues you have brought up.
No. 1: Never intentionally only counts if your drill press is set up at exactly 90 degrees from the table and this does not happen exactly even with expensive drill presses.
No. 2: You are technically correct on this one, if the lands and angles are even it detracts from this condition but it still walks because of play in bushings.
No. 3: Correct again, even with a high precision ground surface tolerances in the bearings, roughness in the ways or varying in the grit size will affect this reading.
If the top and bottom are square and the hole is on an angle other than 90 degrees from the table (caused by construction of the drill press) they will not be perpendicular to sides created by copying the hole.
Thanks for not calling me a kid, I had a younger looking face back then and could not buy beer (they did not have photo drivers licenses) till I was 26 years old.
In response to your last reply:
In most instances, I normally do not drill anything thicker than 1/4", and unless I am drilling for mating surfaces, the alignment is not always that critical. However, if I am doing highly critical work, then I do my best to align everything possible to the best of my abilities. There are many times when I purposely drill at an angle, and when I am done, I just rotate the table back to the 0 degree and slap the pin back in, without squaring everything. The alignment pin is way off due to factory machining, but I use it just to keep the table more stable. As for the other direction, the weight of the milling vise makes the table sag a little, so shimming is necessary. As time goes by, the weight of the milling vise will make it sag a little more. So when necessary, I true the milling vise to the spindle instead of the table.
Just to give you an example, at this point in time, I am grinding the ends of lead screws, which is highly critical, but in this instance, there is a jig within the milling vise, and this jig must be aligned to the spindle. As previously stated, here is the result:
Bruce
I just finished machining my lead screws a few minutes ago, and I believe they should be okay and hopefully within my scope of tolerances. However, the set screw flats did not turn out nearly as well as I was hoping. My first mistake was that I relied on the grinding jig to firmly hold the screws for milling, and secondly, I cut them way too deep, but I think they should work well.
If anyone ever buys a milling vise, such as the one that I rely on so heavily, performing an accurate cut on the Z axis is very difficult, because it is very hard to obtain an accurate measurement. I once developed a method to get within 0.004", but since that time, I forgot just exactly how I was able to do that.
My order for the 5MM drill bits showed up yesterday, so the project for the day is to modify one of these to make my new set of couplings to match the lead screws, and hopefully I will be able to finish my linear actuators in a day or two. And of course, hopefully the majority of my runout will be eliminated.
Bruce
I serendipitously came across this last night and thought it was interesting in efforts to alleviate "shaft to shaft alignment" issues.
http://www.youtube.com/watch?v=_iIsibuIs08
It's called a Schmidt Coupling. Anyway, just thought I would pass it along.
It never ceases to amaze me, the things that people come up with. Thanks for sharing, it is a pretty cool contraption.
Bruce
I discovered a minor setback yesterday, while grinding my new 5MM step bit. To get a good grind on the drill bit with sufficient depth, I had to grind it to a smaller diameter than I had originally intended for the coupling end of the lead screws. Basically this means that I will have to regrind the coupling end of each lead screw to match the drill bit diameter. I do not believe this will be a huge setback, but it is still a setback. I will post the final diameters of the modified bit and lead screws sometime later today.
Anyhow, if a bit is being modifed, I am a firm believer that a landing should exist around the full circumference of the drill bit, with the exception of the grooves created by the fluting. However, I could be wrong about this, and it may just be necessary for a landing at the edge of the fluting. Keep this in mind if the diameters of the motor shaft and lead screws are in close proximity of each other.
Bruce
Here is a guy doing the same thing kinda. He is making a trac hoe with out hydalics. Best just a drill press. I hope it helps.
http://www.scale4x4rc.org/forums/showthread.php?t=66312
Evan
Thanks for the consideration and the link, but my project is a million miles away from something like that. The project that I am working on, would consist of three items similar to this: http://www.velmex.com/images/motordriven/ma15/ma1500.jpg
Bruce
I modified my procedure for grinding the drill bits, and it seems to work very well. The new procedure is as follows:
- True the outter diameter of a 3/4" dia. X 3/4" grinding point to be parallel with the centerline of the drill press spindle.
- Drill a 7/8" deep hole in some soft 1" aluminum bar stock with the machine screw drill bit that you intend to modify. Remove the bit from the drill press and insert the shank into the hole you just drill.
- Attach a knob with a through hole to the drill bit and let it rest against the aluminum bar stock. Since I was modifying a 5MM bit, I simply used an approximate 1-1/4 diameter spur gear with 5MM shaft hole for this purpose.
- Install the grinding point in the drill press.
- Adjust the drill press table height, so that the bottom of the grinding point will grind the drill bit to the desired depth.
- Start the drill press and slowly move the bit into the point, while rotating the drill bit with the knob, and grind the bit to the desired uniform diameter.
This method works much better than my previous method.Bruce
I just finished boring my new couplings with my newly modified drill bit. After boring them, I did a test fit on the lead screws and motors, and I must say that everything is fitting very snug, perhaps a bit to snug on the motors. Without pushing the couplings all the way onto the motor shaft or securing any set screws (because they have not been drilled yet), I eyed the runout of the lead screws while rotating the motor shaft, and the runout is very minimal. I would imagine that the runout will even get smaller when everything is fully assembled and the set screws are tightened. I do believe this set of couplings and lead screws should provide a fairly high degree of precision without putting unnecessary strain on lead screws, lead nuts, motor bearings, or the pillow block bearings.
The next course of action is to drill out the couplings for the set screws and turn the couplings down to desired outside diameter. After that is complete, I should once again be able to start moving forward on my PCB Drilling And Laser Direct Imaging Machine. As mentioned, this process would have been much quicker with the proper machinery, but for those folks that don't have access to a lathe, some fairly accurate machining can be completed with nothing more than a drill press, a milling vise, and a few miscellaneous tools.
I will post a photo of the finished shaft couplings, lead screws, and pillow blocks within the next several days.
Bruce
I was WRONG.
During assembly, I discovered that the runout on the newly finished set of couplings and lead screws was worse than I anticipated. This could have been due to the very snug fits, which basically had to be forced into place and probably removed some necessary material for alignment. I should state for the record that a couple of the sets probably would have satisfied many people and would have made my assemblies operable at this point, but I am still not satisfied, so I am changing my strategy once again and making a new set.
For my new strategy, I will be doing a couple of things different. My new goal is to eliminate potential problems. Since I am unsure of the accuracy of the holes made in the couplings with the ground drill bits, I have decided to eliminate that part of the procedure. In order to eliminate the need for a step bit when making the new couplings, I will have to match the coupling end of the lead screw to the motor shaft size, and in order to have a nice shaft end for the coupling, without having any thread groove remnants, I have decided to increase the size of the lead screw from 1/4 to 5/16. By increasing the size of the lead screw to 5/16, I can machine the coupling end of the lead screw down to 5MM to match the motor shaft. So in other words, by matching the lead screw end to the motor, I can eliminate the potential error that may be caused by a double sized bore in the coupling. Additionally, considering the very snug fits of the couplings that I previously encountered, I have decided to increase the bore size by a couple thousandths, and drill out a new set of couplings with a #8 bit.
I believe this will be my 5TH batch of couplings and lead screws (maybe 6TH), and believe me, it is starting to get very tiresome. However, as I am sure that many of you already know, I am a very stubborn man, and I hate to admit defeat.
Bruce
Bruce
To Those That May Be Interested
As you may have guessed, with so many attempts resulting in unsatisfactory outcomes, my ambition started to run low. However, I finally got around to making a new set of couplings with an unmodified 5MM drill bit and the couplings turned out to look quite nice. Furthermore, just this morning, I machined down one of the new 5/16 lead screws to have a 5MM end with my homemade jig. I have not yet machined a flat on this end for the set screws, but in it's current condition, without set screws, this lead screw has very little runout. If I had to guess (since my dial indicator was swindled), I would estimate the runout to be somewhere in ballpark of 0.001-0.003" for a 7-1/8" run. I also have not yet put the bearing sleeve on this leadscrew, but I do believe this leadscrew and coupling set is a definite keeper. And I must say, considering this entire assembly was constructed with nothing more than a drill press and some miscellaneous tools, I am really quite impressed with the new result. I am hoping the remaining two screws and couplings turn out to be just as nice as the first.
It is noteworthy to mention that if anyone decides to attempt a similar process, but will be making lead screws and couplings for NEMA 23 motors, instead of NEMA 17 motors, the lead screw will have to be upgraded to 3/8", because the 5/16 screws must be machined down to a diameter of at least 0.235" to remove all remants of the threads.
Looking back now, I wish I had initially designed my machine for 5/16 lead screws instead of 1/4. I do believe that oversight cost me a lot of time, labor, and ambition. Anyhow, now that I have finally achieved such a nice result, my ambition is starting to quickly return, and hopefully, I should soon have three smooth running linear actuators to build my new machine.
Here is another tidbit worth mentioning. To accomodate the 5/16 lead screws in the homemade jig, I had to create a couple 1/16" spacers. So this jig can now machine the ends of both 1/4" and 5/16" screws.
Bruce