That is a rock solid machine you got there, we had 2 Thompsons in the Machine Repair shop on my first Navy ship. My neighbors are cat people. When they come out in the morning to go to work he always opens the hoods on both of their vehicles, checks the oil etc. while making sure there are no cats in the engine bay. I asked him about it. He grew up on a farm, every morning it was his job before school to check the oil levels and fuel of whatever equipment was going to be used that day and start them up and idle them to warm up. One day his dad asked him to start his Jeep for him so he did. There were 2 of their "barn cats" under the hood, and it scared him for life. Watching your shop cats hunting for vermin reminded me of that!
I never thought I'd live to see the day I'd spend my lunch hour watching a spirit level bubble wave around. Let's hear it for RUclips! And it's Friday I have boatbuilding, antique restoration and wheelwrighting to come!
Happy for you Keith! I have the same grinder for 20+ years and it's a rigid beast. My pointer for you would be to keep an eye on the coolant pump and hoses down there. Crappy design, if the carbon seals in the pump leak, coolant goes straight down into your hydraulic oil and will roach the hyd pump. Also, (perhaps stating the obvious?) there is an oil cup at the very top of the elevation screw to not forget about. I have the factory manual if you didn't get one, be glad to share.
My two grinders are 220/380 (English) [380 is power lighting ] My table moved up/down - head solid. Built like a tank. Liquid and dry-with vac that will suck 1/2" x 2" steel off the magnet when the magnet is off. I had one (got two) shipped from Southern CA production house. Hydro x&Y manual vertical. I cut the disks from plasma table and use up scraps into circles. I have some in AR400 which won't wear out. I like to keep the moisture off the leg. Concrete is water based 'solid'.
I agree with you Thompson made great machines . We had a Thompson automatic broach grinder at Goodyear Aerospace. A very nice and well built machine. I have run universal tool & cutter grinders for a long time that had ball bearing tables. If not properly leveled the tables will coast down hill and into your work. It doesn't take much out of level for it to do this. An old millright told me that the ways of a machine will not wear evenly if a machine is not leveled properly.
Nice addition, Keith. I have the same mag chuck on my Jones & Shipman 540P surface grinder. It has the auto hydraulic feed in it, with Z axis graduations of .00005 inch. I enjoy using it very much. I’m certain you will enjoy the Thompson as well.
Your Landis surface grinder sounds like the rack and pinion is bottoming out on its self and needs to have some shims or bearing surface for the table raised up
I have a slightly older version of that grinder, when you go to change the wheel that is on it you will find another spindle start switch behind the wheel, that switch is for small diameter wheels and engages the high speed mode of the grinder.
The plunger on the wheel guard cover is to engage the high speed function on the motor when using a smaller diameter wheel. I ran a similar model for about 43 years at the machine shop where i worked.
Omg, I ran one of these years ago. back in the 60's, along with a Chicago 6-12. We did some pretty close work with these machines, close as in .0001 tolerances. We built injection molds. CNC machines hadn't hit the small tool and die shops yet.
That's an awesome level. I think I saw some grit left over from the stoning of the chuck as you placed the level on it. Just a positive observation from an old toolmaker. I love your channel. I am trying to acquire an old B&S No.1 universal cylindrical grinder. It has a war production plate on it from WW2. It still works.
I remember back in 1974 a fella was running a Thompson with a 6 " wide wheel, the table travel was kind of aligned with a entry door from outside. That day just as a steel delivery man walked through that door, the Thompson grinder threw a 6" compound sine plate off the mag and it hit the wall just above the door! Scared the bejezzes out of the delivery driver.
This thing is a marvel of mechanical ingenuity! Really cool machine. I assume that these days it would be much more cost effective to put in some servo motors and let a computer control it. While there are advantages to that of course (and programming is my line of work), I miss some of these amazing old solutions.
While you did a very quick job of getting the grinder leveled I was still thinking just give the wrench to Adam Booth and tell him it's a 4 jaw chuck. Five seconds later it'd be level. Great channel and congrats on the new toy.
Many years ago, my high school had a very nice metal shop. Among the machines was a large lathe salvaged from a WW2 sub, and a vertical and horizontal milling machines. Cast into the base of these two was a plaque stating” War finish, DOD 1942” . Awesome machines, very accurate, to within 0.001 inch.
"This machine conforms to the order of the war production board." "The casting finishing and cosmetic treatment do not reflect the normal level of quality of the xyz machine company"
Very nice score Keith. Having been a tool and die maker, the one thing I would absolutely miss is having a variable magnetic chuck. They are so handy when you have a die that has a very small amount of twist to it. It does however become a game of chicken. LOL. How low do I dare turn the magnetism down to. For me the variable chuck is an absolute necessity. Great machine though Keith, I know you will love it.
Great buy! Used to run one of those. Awesome grinder. The one thing I had to becareful of was running the head cross slide in and out. On ours if you accidentally hit end of travel feeding it toward you the head would drop a thousandth or so.
Thanks for introducing us to your new machine. I believe the next step after leveling is to grind the chuck in perfectly true with the machine, then test grind some parts.
I got tired of recovering parts from under cabinets so I put a masonite barrier strip that seals to the floor. A couple of self drill screws and you're done. It comes off easily if you need to.
That's a nice machine. I'm sure many would love to have one of there own. ( I don't even have 220v so I would have to just sit and stare at it. lol) I enjoy your videos.
There should be some place where you can see part of the ways, at least on the table, to get an idea on the condition. We had to take table and spindle motor off of mine before the loader we used could handle the base. It turned into a pleasant surprise, I could see that the machine had little use (undetectable to my eye) on a scraping in. The man said he was told it had been reconditioned in 1993, and had seen hardly any use since then. Unlike yours, you can't see that any work like that had been done on it by the outside appearance. No new paint. I do need to go through the hydraulics (something I hates working on), components that will deteriorate over time whether the machine is in use or not. It also still has the original tube type power supply for the mag chuck. Surprisingly, it works ... but I'm keeping any eye open for a replacement
Looks great- one thought though, mounting the transformer below the coolant pump could be problematic if it were to ever leak. Might be wise to fashion some kind of deflector over it, just in case, to channel the coolant away. I imagine if it gets into/onto the transformer, it might be damaged.
Ran one nearly identical to this one. Would leave an absolute mirror, very level if i did my part. They always seem to grind more level with the head on the way in than the way out though! My 1-2-3 blocks were ground on that Thompson grinder.
I see Ginger has approved the leveling of the grinder. It's amazing how precision cats can be. Just ask them, they will tell you. Thanks for the video, and I'll see you at the Bar-Z. Jon
Would have been interesting to pull the chuck, clean up the table top, and level that, then clean up the chuck bottom and level the chuck. How much rust jacking is there under that chuck? Also might have been interesting to grab a corner of the machine with both hands and try to shake it a bit to see if vibration made it settle a bit on the foundation. After all, it vibrates and weight shifts during use.
Thats is the diamond tip on the dressing probe removing a tiny bit of material from the grinding wheel. The small glow is the heat of friction between the tip of the ultra hard diamond and the softer grinding wheel, consisting of abrasive media and a bonding resin.
Wow! That level is amazing. Finger weight movement. Question from a woodworker: is the goal level or is that just the easiest (relatively speaking), most precise way to achieve planar? I assume the problems with an unleveled machine are caused by tiny distortion in the massive frame. Love listening to detaching from “the old” and “the other” Landis grinder. Thanks for the video.
Keith, I'm not sure how to say this... but have you lost a fair bit of weight? If so good for you! Yours is one of the few channels that I watch without looking at the title because I know it will be great. It's a bit selfish but I want you to be around as long as possible and I know as someone who is working on it myself that dropping the pounds is hard work so thank-you.
Keith is being trained by the cat... Knock stuff on floor. He picks it up,over and over. Ha Ha Kitty Kalistentics for Keith. Toe touches and stretches. A one and a two
Nice machine indeed! And that leveling job - wow! But I wonder what does the level show if you move the table all the way to both sides? Now you know it't level in the center position? Wold that perhaps give an indication of how good the table ways are?
Keith, That Fell Level is amazing, My buddy came over to check my atlas 12" with one, I asked him was this really necessary for a lathe with .005 as the minimum from the factory? Not a precision machine.
That was probably the smoothest sponsor product placement on youTube. American Rotary is certainly getting their money's worth. On a different note, it seems you get the 440 V from 220 V, via the American Rotary transformer. The 220 V, if I listened correctly, comes from 110 V, via another American Rotary transformer. Is that true?
No, the shop is supplied with 220VAC single phase. There is an American Rotary Phase Converter to make three phases for the three phase machines, still at 220VAC. Then the new transformer for the Thompson grinder steps the 220VAC to 440VAC.
Thank you again Keith Don't forget, "He who has the most tools when he dies wins !!" I wonder, if you has something long to grind, could you not fit a small grinding attachment (like a tools post grinder) to the tool holder on your metal planer, especially if it had been trued up on the planer ? Thanks
Great video, Keith! I'm thinking out loud here, but I always wonder about the step-up transformers. It seems like we're getting something for nothing... but we all know there's no free lunch. So what are we giving up? I understand that the AC current on the primary side will induce a higher voltage across the secondary side, due to magnetism and the density of the coils. I guess the amount of current adjusts itself one way or another, but that's where my intuition stops. Anybody have a simple way of explaining this? What do we give up in order to double the voltage?
Transformers give off significant heat so a power draw change voltage. It's just accepted as a small loss. A transformer that size will generate ~ 500 watts of heat.
Watts (or power) is the same. Watts is volts times amps. If one is reduced the other is increased. If the voltage is doubled, the amperage is reduced by half. It will take twice the amps to run at 240 volts as compared to 480 volts. No free lunch, plus the losses in the transformer. For a single machine, it’s probably the easiest way to do it.
As mentioned, AC voltage can be changed without significant loss with a transformer. It's just the way electricity works - trading voltage for current (for a given power). The efficiency of transformers is very high, typically over 95%. The big difference is that higher currents have more power loss in a given size wire (wire resistance is determined by wire gauge). So a given motor will draw more current at lower voltage (to achieve the same power) and therefore the the windings will get hotter at lower VAC, which causes power loss. That is why power lines are running at like 100,000 VAC or higher, to reduce power loss of the transmission over long distances. It is then 'stepped down' at the last possible time.
That is a rock solid machine you got there, we had 2 Thompsons in the Machine Repair shop on my first Navy ship. My neighbors are cat people. When they come out in the morning to go to work he always opens the hoods on both of their vehicles, checks the oil etc. while making sure there are no cats in the engine bay. I asked him about it. He grew up on a farm, every morning it was his job before school to check the oil levels and fuel of whatever equipment was going to be used that day and start them up and idle them to warm up. One day his dad asked him to start his Jeep for him so he did. There were 2 of their "barn cats" under the hood, and it scared him for life. Watching your shop cats hunting for vermin reminded me of that!
I never thought I'd live to see the day I'd spend my lunch hour watching a spirit level bubble wave around. Let's hear it for RUclips! And it's Friday I have boatbuilding, antique restoration and wheelwrighting to come!
Keith I think you are happiest when you have a now toy to play with. Thanks for the vid.
Happy for you Keith! I have the same grinder for 20+ years and it's a rigid beast. My pointer for you would be to keep an eye on the coolant pump and hoses down there. Crappy design, if the carbon seals in the pump leak, coolant goes straight down into your hydraulic oil and will roach the hyd pump. Also, (perhaps stating the obvious?) there is an oil cup at the very top of the elevation screw to not forget about. I have the factory manual if you didn't get one, be glad to share.
When I leveled my machines I used a wireless bore scope aimed at the level and could watch it on my tablet while adjusting
I'm a retired toolmaker and I'm very impressed with your new surface grinder. That continues feed feature is a great way to get things really flat.
Time to start planning that shop expansion....Nice grinder !
My two grinders are 220/380 (English) [380 is power lighting ] My table moved up/down - head solid. Built like a tank. Liquid and dry-with vac that will suck 1/2" x 2" steel off the magnet when the magnet is off. I had one (got two) shipped from Southern CA production house. Hydro x&Y manual vertical. I cut the disks from plasma table and use up scraps into circles. I have some in AR400 which won't wear out. I like to keep the moisture off the leg. Concrete is water based 'solid'.
Inpector cat certifies the fact that the machine is perfectly leveled. =)
He's so beautifull and your dog (who sometimes makes a cameo) too.
Congratulations for your new surface grinder !
The dressing diamond mount and the self skimming coolant tank are awesome features. : )
I agree with you Thompson made great machines . We had a Thompson automatic broach grinder at Goodyear Aerospace. A very nice and well built machine.
I have run universal tool & cutter grinders for a long time that had ball bearing tables. If not properly leveled the tables will coast down hill and into your work.
It doesn't take much out of level for it to do this.
An old millright told me that the ways of a machine will not wear evenly if a machine is not leveled properly.
Nice addition, Keith. I have the same mag chuck on my Jones & Shipman 540P surface grinder. It has the auto hydraulic feed in it, with Z axis graduations of .00005 inch. I enjoy using it very much. I’m certain you will enjoy the Thompson as well.
Ran one similar to that model , in its home town of Springfield Ohio . It will get down to the nitty gritty little numbers !
Looks like a very usable machine. Thanks for letting us take a look.
Your Landis surface grinder sounds like the rack and pinion is bottoming out on its self and needs to have some shims or bearing surface for the table raised up
Talk about precision adjustments. Keith works his magic, then submits the new grinder to a CAT SCAN!
I have a slightly older version of that grinder, when you go to change the wheel that is on it you will find another spindle start switch behind the wheel, that switch is for small diameter wheels and engages the high speed mode of the grinder.
The plunger on the wheel guard cover is to engage the high speed function on the motor when using a smaller diameter wheel. I ran a similar model for about 43 years at the machine shop where i worked.
Hi Keith, Love this machine. What a great asset to your shop. Look forward to seeing this in full action.
Omg, I ran one of these years ago. back in the 60's, along with a Chicago 6-12. We did some pretty close work with these machines, close as in .0001 tolerances. We built injection molds. CNC machines hadn't hit the small tool and die shops yet.
That's an awesome level. I think I saw some grit left over from the stoning of the chuck as you placed the level on it. Just a positive observation from an old toolmaker. I love your channel. I am trying to acquire an old B&S No.1 universal cylindrical grinder. It has a war production plate on it from WW2. It still works.
Great find Keith.. Love your videos!!!
Hi Keith - I have been watching you for years - keep up sharing your knowledge and experience all is appreciated
I remember back in 1974 a fella was running a Thompson with a 6 " wide wheel, the table travel was kind of aligned with a entry door from outside. That day just as a steel delivery man walked through that door, the Thompson grinder threw a 6" compound sine plate off the mag and it hit the wall just above the door! Scared the bejezzes out of the delivery driver.
Wow. That's precise leveling
Awesome new machine can't wait to see some work done on it
Kitty! And a bonus kitty. Double feature. Always enjoy your videos, Keith. The machinery parts, too. :)
This thing is a marvel of mechanical ingenuity! Really cool machine. I assume that these days it would be much more cost effective to put in some servo motors and let a computer control it. While there are advantages to that of course (and programming is my line of work), I miss some of these amazing old solutions.
Great grinder! I do the same thing with my equipment for my pallet jack. Great when you want to do a deep clean.
THOMPSON always make great equipment.
While you did a very quick job of getting the grinder leveled I was still thinking just give the wrench to Adam Booth and tell him it's a 4 jaw chuck. Five seconds later it'd be level. Great channel and congrats on the new toy.
Many years ago, my high school had a very nice metal shop. Among the machines was a large lathe salvaged from a WW2 sub, and a vertical and horizontal milling machines. Cast into the base of these two was a plaque stating” War finish, DOD 1942” . Awesome machines, very accurate, to within 0.001 inch.
"This machine conforms to the order of the war production board."
"The casting finishing and cosmetic treatment do not reflect the normal level of quality of the xyz machine company"
As someone that has about 1/4 of a part of a garage for my entire shop space. I'm a bit jealous, I won't lie!
Thanks for the video Keith.
American craftsmanship at its finest
Wow - what a impressive machine! It looks to be in virtually brand-new condition too.
Congrats Keith!
got to love those precision levels. the act of putting a wrench on the bolt makes your bubble move
Nice looking piece of equipment you have there Keith.
Very nice score Keith. Having been a tool and die maker, the one thing I would absolutely miss is having a variable magnetic chuck. They are so handy when you have a die that has a very small amount of twist to it. It does however become a game of chicken. LOL. How low do I dare turn the magnetism down to. For me the variable chuck is an absolute necessity. Great machine though Keith, I know you will love it.
We have a big Thompson Surface grinder at work.
Its always good to have a cat scan of your work.
Great buy! Used to run one of those. Awesome grinder.
The one thing I had to becareful of was running the head cross slide in and out. On ours if you accidentally hit end of travel feeding it toward you the head would drop a thousandth or so.
Congrats on the new machine. Looks like a real nice addition.
Hello Keith, fantastic machine, i really enjoy your channel, keep the great content comming!
Learned something today. Thank you Keith! Aloha!
It looks like you found a nice grinder for your shop Keith.
The Ginger Inspector Inspected, and came away with the finding that were no treats on the grinder...
In the next video we will be grinding in a cat butt…
30:46 -- If you wonder where your cat / dog is, just turn on your video camera and it will appear in front of the lens.
GingerSpection passed?
Nice cats happy you saved them
Oh, the babies are growing up so fast.
I am envious of your workshop, both size and contents!
More toys for the big boys. How I miss those days.
Glad your grinder got a “cat” scan.
🤣
Love the cat, snooping around, checking everything out!
If he can borrow a dog, he can perform a lab test as well. 😁
Looks like you found a Cadillac. Congrats Mr Rucker.
Nice, I would have never guessed another surface grinder!
Thanks for introducing us to your new machine. I believe the next step after leveling is to grind the chuck in perfectly true with the machine, then test grind some parts.
Well, that was probably one of the most redundant comments ever.
Looks a nice machine. Let's hope it all works ok 👍👍
You could add a magnet in a strategic place to catch a lot of the very fine dust in the coolant tank..
Excellent video again. Cats, the only animal that will follow you from room to room just to ignore you.
I got tired of recovering parts from under cabinets so I put a masonite barrier strip that seals to the floor. A couple of self drill screws
and you're done. It comes off easily if you need to.
Congratulations on your new machine...
That's a nice machine. I'm sure many would love to have one of there own. ( I don't even have 220v so I would have to just sit and stare at it. lol) I enjoy your videos.
There should be some place where you can see part of the ways, at least on the table, to get an idea on the condition. We had to take table and spindle motor off of mine before the loader we used could handle the base. It turned into a pleasant surprise, I could see that the machine had little use (undetectable to my eye) on a scraping in. The man said he was told it had been reconditioned in 1993, and had seen hardly any use since then. Unlike yours, you can't see that any work like that had been done on it by the outside appearance. No new paint.
I do need to go through the hydraulics (something I hates working on), components that will deteriorate over time whether the machine is in use or not. It also still has the original tube type power supply for the mag chuck. Surprisingly, it works ... but I'm keeping any eye open for a replacement
I see one of your inspectors hard at work also nice grinder
Congrats on the new toy. Nice one... :)
That is a really nice grinder. Thanks for the video.
Awesome surface grinder. Thanks.
Looks great- one thought though, mounting the transformer below the coolant pump could be problematic if it were to ever leak. Might be wise to fashion some kind of deflector over it, just in case, to channel the coolant away. I imagine if it gets into/onto the transformer, it might be damaged.
Great machine to own, you’ll soon take to using it for all your jobs that’ll fit on the chuck, I’ve no doubt.
Ran one nearly identical to this one. Would leave an absolute mirror, very level if i did my part. They always seem to grind more level with the head on the way in than the way out though! My 1-2-3 blocks were ground on that Thompson grinder.
GREAT ADD-ON, GREAT JOB, GREAT VIDEO, SEE YOU ON THE NEXT VIDEO...
NICE PIECE OF MACHINERY
With age the toys just get bigger 👍
Your Thompson is fancier than my Thompson! It is a good grinder.
I see Ginger has approved the leveling of the grinder. It's amazing how precision cats can be. Just ask them, they will tell you. Thanks for the video, and I'll see you at the Bar-Z. Jon
Very interesting keith and thank you very much for sharing. I dread to think how much that level would cost now even if you could get one.
very interesting. that bubble level good to learn about; FI on the case =Feline Inspector you know its precise!
thats a pretty freaking awesome maschine
If you step up the voltage, you need enough amps. The watts stays about the same, but the voltage x the amps.
Would be interesting to displace the table left and right with the level on it.
Oh yeah, didn't think of that. If there were any 'warbles' in the ways that level would certainly find it. Good thinking Sir!
Art
Would have been interesting to pull the chuck, clean up the table top, and level that, then clean up the chuck bottom and level the chuck. How much rust jacking is there under that chuck?
Also might have been interesting to grab a corner of the machine with both hands and try to shake it a bit to see if vibration made it settle a bit on the foundation. After all, it vibrates and weight shifts during use.
Thank you for sharing. Nice machine.
Good morning from SE Louisiana 4 Jun 21.
What causes the glow when you make the first dressing pass, as at 10:16?
Thats is the diamond tip on the dressing probe removing a tiny bit of material from the grinding wheel. The small glow is the heat of friction between the tip of the ultra hard diamond and the softer grinding wheel, consisting of abrasive media and a bonding resin.
@@jenniferwhitewolf3784 Thanks, Jennifer.
Kitty!! Yet another reason to love your channel.
Definitely built like a tank!
Very nice machine, congratulations. Will you be adding a wing to the shop soon?
Art
Two speed, three phase spindle motor, love it! Consequent pole motor, I believe.
Dahlander motor we know them as in the UK. The old Colchester Bantam lathe used to use one.
Those levels are great but I think they could drive you a bit crazy in a very short time! It looks a lovely machine though and a great video. 👍🏼
Wow! That level is amazing. Finger weight movement. Question from a woodworker: is the goal level or is that just the easiest (relatively speaking), most precise way to achieve planar? I assume the problems with an unleveled machine are caused by tiny distortion in the massive frame. Love listening to detaching from “the old” and “the other” Landis grinder. Thanks for the video.
good machine keith
Keith, I'm not sure how to say this... but have you lost a fair bit of weight? If so good for you! Yours is one of the few channels that I watch without looking at the title because I know it will be great. It's a bit selfish but I want you to be around as long as possible and I know as someone who is working on it myself that dropping the pounds is hard work so thank-you.
Keith is being trained by the cat...
Knock stuff on floor.
He picks it up,over and over. Ha Ha
Kitty Kalistentics for Keith. Toe touches and stretches. A one and a two
Nice machine indeed! And that leveling job - wow! But I wonder what does the level show if you move the table all the way to both sides? Now you know it't level in the center position? Wold that perhaps give an indication of how good the table ways are?
Wish you had laid just one hand on a corner of the table after levelling. Wonder how much effect that would have :)
I am impressed, such a stout machine can't wait to see you do some grinding🤗🤗
Keith, That Fell Level is amazing, My buddy came over to check my atlas 12" with one, I asked him was this really necessary for a lathe with .005 as the minimum from the factory? Not a precision machine.
Good morning Keith
You said, "It will make you pull your hair out, " That seems to be working.
😂🤣
LOL He cannot stand to loose to much more . Even mine has thinned out. But then again I am three months shy of the big 70
That was probably the smoothest sponsor product placement on youTube. American Rotary is certainly getting their money's worth.
On a different note, it seems you get the 440 V from 220 V, via the American Rotary transformer. The 220 V, if I listened correctly, comes from 110 V, via another American Rotary transformer. Is that true?
No, the shop is supplied with 220VAC single phase. There is an American Rotary Phase Converter to make three phases for the three phase machines, still at 220VAC. Then the new transformer for the Thompson grinder steps the 220VAC to 440VAC.
@@ronaldhorne5106 thanks for that clarification!
Wow, what a beast!
Thank you again Keith
Don't forget, "He who has the most tools when he dies wins !!"
I wonder, if you has something long to grind, could you not fit a small grinding attachment (like a tools post grinder) to the tool holder on your metal planer, especially if it had been trued up on the planer ?
Thanks
Is the Thompson capable of doing fine finishing. Our is it mostly for rough grinding applications. Great getting new toys.RMM
Great video, Keith!
I'm thinking out loud here, but I always wonder about the step-up transformers.
It seems like we're getting something for nothing... but we all know there's no free lunch.
So what are we giving up?
I understand that the AC current on the primary side will induce a higher voltage across the secondary side, due to magnetism and the density of the coils.
I guess the amount of current adjusts itself one way or another, but that's where my intuition stops.
Anybody have a simple way of explaining this?
What do we give up in order to double the voltage?
Transformers give off significant heat so a power draw change voltage. It's just accepted as a small loss. A transformer that size will generate ~ 500 watts of heat.
Watts (or power) is the same. Watts is volts times amps. If one is reduced the other is increased. If the voltage is doubled, the amperage is reduced by half. It will take twice the amps to run at 240 volts as compared to 480 volts. No free lunch, plus the losses in the transformer. For a single machine, it’s probably the easiest way to do it.
As mentioned, AC voltage can be changed without significant loss with a transformer. It's just the way electricity works - trading voltage for current (for a given power). The efficiency of transformers is very high, typically over 95%. The big difference is that higher currents have more power loss in a given size wire (wire resistance is determined by wire gauge). So a given motor will draw more current at lower voltage (to achieve the same power) and therefore the the windings will get hotter at lower VAC, which causes power loss. That is why power lines are running at like 100,000 VAC or higher, to reduce power loss of the transmission over long distances. It is then 'stepped down' at the last possible time.