Before anyone says it, YES, I know that a DC or 3-Phase motor can give me electronic speed control. I know that building that speed control is easy for some people. I'm using an AC motor because I have it and many people have AC motors sitting around. I'll probably upgrade to DC in the future.
I agree with your choice of motor. But second hand 3 phase motors are much cheaper (Ebay), because most people don't have 3 phase supplies, and cheap Chinese inverter/speed controllers are now very affordable off Ebay. This is the way to go for an upgrade later.
@@donaldasayers sir thanks for the lesson the how to make pully do you have a computation and size of wood for for deferential size of speed for low and high-speed thank you and have a nice weekend
The Rex Krueger definition of making a "cheap" tool: Making the most affordable, awesome, high quality tool that any beginner woodworker can make with limited tools. I love watching your videos, they have improved my woodworking so much! Thanks
I was a mechanic in the Army, and was deployed to Uzbekistan for one tour of duty (OEF) then Iraq (OIF). We had to get "creative" for most of our needs, building a literal city in the middle of the Uzbek National Air Force airfield for one! I had guys building the impossible- jigs for weapon repairs and multiple Hyster hydraulic failures. That was between 02-04. This particular video truly takes me back to those good old days! There was magic in those builds, and many crossed fingers when switches were flipped, lol! Thank you for what you do, and for reminding me that not all the war memories are bad! You have earned a new patreon member! ~Carla "Skully" B.
I’ve just started watching your channel and I wanted to express my appreciation for your approach and the way that you present your content. Being a child of the great depression, my grandfather took a very similar approach in his own workshop and so I grew up with a similar set of ideals. I enjoy your presentations for all of their facets but the approach coming from the garage/basement DIY’er strikes a chord reminiscent to my spending many hours ‘in the shop’ with Gramps. Thank you for bringing back a lot of good memories and kudos for the vast amounts of extremely useful and detailed information that you are sharing.
You make me smile as you remind me of my dad. We had scroll saws made out of sewing machine heads. Table saws made out of plywood and hand saw. Turned pulleys like you made. My dad didnt have a lot of money so he improvised to make the tools he needed for projects out of his workplace.
I don’t need to build a lathe from scratch because I inherited one from my grandfather. It was on a terrible angle iron base he made. I bought a new base at least a decade ago and have never been able to figure out how to mount the motor. This video has given me a few ideas I’m going to try. I’ve had the large for at least 20 years. It will be nice to get it running! Thanks Rex.
One big advantage of belts: They absorb pulses, better backpulses from the tool, when this gets in contakt with the material. So the bearings live longer and the whole machine runs more silent. And belts are easy and cheap (!) to replace. Bearings not. So a tablesaw with a belt runs way better then a direct coupled saw with AC-Universalmotor, where every pulse hammers into the bearings from the sawblade into the motor. This you will find typically in jobsitesaws. Hope, it was understandable, englisch is not my mothertongue. Cheerio from Germany.
Lex Luther , I mean Rex Krueger this pulley info really came in handy with my budget mini chopper build. I'd say it makes up for trying to blow up Superman
From the GET GO. #1: find an old treadmill someone wants gone for free and salvage the variable speed motor and the controller board. #2: Watch a few videos on how to wire it (often used for 2X72 belt grinders) and you will have a 2 HP variable speed Lathe motor!
It's coming along really well now, Rex. Fantastic range of speeds you will have. Very well thought out for sure. Looking forward to next week's instalment.
Hey Rex, one of the very best projects and explained awesomely. i have subscribed and will watch and most likely become a patron. i would not usually do that but your vids have changed my mind about becoming a patron. thanks again and keep up the awesome vids man.
Hi Rex, I want to have a go in making wood pulleys, for my high speed hand made knife belt sander/ grinder, but I am concerned with the sides of the pulleys snapping when pulley is in motion or if the heat from the v belt drive transfers to the wood pulley and heats the glue up and separates the pulley wheels, I wonder if long thin wood screws be placed through the pulleys to eliminate worries of heat transfer separation. Firstly are wood pulleys only safe for certain speeds, Have you ever had issue with pulley breaking or separating ? and using ply seams to be the wood to use but could we use a natural wood , and is soft wood or hard wood best from what you have learnt Also how long does a wooden pulley last on say a wood lathe, ? could it last like an aluminium pulley
Well don’t you just know that you start this series and I just bought an Excalibur from Rockler. Ain’t that how life is? But I give you a thumbs up just because I like your video presentations. Oh and yeah I’ll watch the whole series ‘cause I know I’ll learn something to apply to something else.
Okay Rex, this is not related to you current project but I felt your older videos needed some kudos points. I finally got my cheap plane and the iron did need some love. Not having all the fancy gizmo tools for sharpening I turned to your older videos and one other TH-camr as well, Colin Knecht of WoodWorkWeb. I used the techniques you modeled and Colin’s super easy sharpening jig and it could not have gone any smoother! It was awesome! So thank you so much! I love my new Chinese plane! Now because that went so well I decided to sharpen my wood chisels. I have the jig now so it should be easy right? NOT! I have to be honest, before discovering how to care for my tools I did misuse and dare I say abused my chisels. They were so bad that I had to start with 60 grit paper for shaping. It took me about 5 hours to shape and sharpen 4 chisels. However, theses things are works of art right now. I do not think chisels even come this sharp when you buy them new. They don’t take hair of my arm yet because I only had paper up to 600 grit. But as soon as I am at a real hardware store (not a big box store) I am gonna get some much finer grits. Just wanted to say thank you and validate you and your presence. You are a wonderful teacher.
Matthew, I'm really glad to hear you're making headway! I remember being a broke grad student and how i struggled to get even basic tools. Planes were such a frustration for me. It took me a year of on-and-off futzing to get my first plane to cut. But once you make a little progress, things start happening fast. I bet you did get your chisels sharper than they come from the store; they only come kinda sharp. The next thing is to keep your eyes peeled for some oil stones. Man-made or synthetic, they are a cheap and durable way to sharpen. Keep me posted on your progress. I love hearing about it!
... And a leather strop with a honing bar will get those chisels and plane irons taking the hairs off your arm in under 30 strokes of honing total. £15 from ebay.
Looks good and explains my question from the last video. I like the way you've used a cantilever mechanism and the motor weight to do all the belt tensioning; makes speed changes quick and easy.
Steve Crane Thanks! I like it too, but I'm not sure this setup is delivering enough tension. I might have to rig up a tension lever anyway. Oh well, it's a process.
@@jimwilliams2682 That totally might work. Wedges do deliver good tensioning. I think I might make an "over-center lever|" it's commonly used on old metal lathes.
Great series! Just curious if you chose your wheel diameters mathematically (ie with a specific target in mind) or aesthetically (went with what looked good). Thanks for sharing!
Mathematically! I'm an artist, but this is no time for aesthetics. I did use an online pulley diameter calculator, but I had target speeds in mind and I designed it to hit those speeds.
This is awesome! Do you have any plans to build any kind of housing for all the exposed pulleys and belts? It looks like a real hazard for catching any loose fitting clothing or dangly bits...or even chunks coming off the late.
Wood chips getting in there would be the biggest concern, since any trapped clothing would just come free after 3/4 a rotation (and hair, well..). I made myself a little magnetic chip guard out of a hardwood frame & wire mesh (5mm in this case) and it works remarkably well, doesn't weigh much, & looks quite cool too. I can highly recommend it for a cover.
No problem: The range pulleys are 8 inches and 3 inches. The double pulley on the motor is 2.5. The cone pulleys go 8, 7, 6, 5 inches. All these details will be in the final plans. Glad you enjoyed it!
Well, my current lathe has a low speed of 600 rpm, so 300 is a BIG improvement. Also the low speed is determined (largely) by the size of the low range pulley, which is already big. Any larger than that and I would have had to redesign the whole thing to accommodate some monster pulley. Good question!
Then we needed to get ready for a future podcast where you redesign your pulley system. Believe me, you will want to go slower. ;-) My last lathe, before my old (1998) Woodfast M910, was a Jet 1440 with a low speed of 450. That is way too fast for large, heavy or out of balance chunk. But, in the meantime, have fun.
Because this and whiskey = stumpy nubs... wait that's another channel. :-) Keep up the great work Rex. I was considering buying a lathe soon but this looks like much more fun and very satisfying at the end of the project. I really appreciate the way you make your videos funny and very informative. Oh and I was really looking forward to what project you were going to try on the lathe with 24" swing! :-)
Also in though i wonder if a dryer moter will work have an extra dryer that resently started squeeking and no heat but it still turns i wondrr if that will work
Your kidding right? I would give my right.. um knee for a couple of good motors. Where do you people get these things? All craigs list has is 3 phase 220. I keep my eye out, though ;)
I think this stuff all depends on where you live. I've lived in CT, FL, CA, and OH and all of those places have had cheap tools and materials. Since I've been doing youtube, I've learned that other parts of the country just don't have all the stuff floating around. I have 2 or three motors in my shop just waiting for projects. A buddy of mine is giving me 3 or 4 to save space. I know I'm lucky and all I can say is that I wish everyone else was, too.
Hi Rex! Turning these rabbets is a bit tricky because the sidewalls must be precise. I recommend the tiny little but great and free construction software named A9CAD to make a gauge for the aforementioned purpose like this: www.pic-upload.de/view-36648485/LehreKeilnut.jpg.html It's made for 10mm V-Belts according to german DIN2215. The software gives you dwg.-Files you can use for lasering the gauge from stainless steel or you print the shape and make your own gauge from a piece of plastik or hardwood. Hope it helps someone. Cheers!
Actually, YouYube has forced YOU to watch political ads. Ads are linked to the viewer, not the video. When I watch this video, I get ads for woodcraft. Still, thanks for watchintg.
@@glennfelpel9785 "RPM" stand for "Revolutions Per Minute", and is already plural. Adding an s on the end is as jarring as a dentist who talks about "teeths" instead of "teeth" would be.
@@alfredneumann4692 Yup, it's totally not technically correct. You're completely right. It's also kind of common to hear and that sort of thing slips out when you're talking off the cuff. I can't stand reading a script and little mess-ups are the price you pay for some spontaneity.
Before anyone says it, YES, I know that a DC or 3-Phase motor can give me electronic speed control. I know that building that speed control is easy for some people. I'm using an AC motor because I have it and many people have AC motors sitting around. I'll probably upgrade to DC in the future.
I agree with your choice of motor. But second hand 3 phase motors are much cheaper (Ebay), because most people don't have 3 phase supplies, and cheap Chinese inverter/speed controllers are now very affordable off Ebay. This is the way to go for an upgrade later.
Three phase isn't available everywhere.
Is it possible to make the polley with MDF?
@@donaldasayers sir thanks for the lesson the how to make pully do you have a computation and size of wood for for deferential size of speed for low and high-speed thank you and have a nice weekend
@@bricotico6498 I think the edges are too weak for it to work.
The Rex Krueger definition of making a "cheap" tool: Making the most affordable, awesome, high quality tool that any beginner woodworker can make with limited tools. I love watching your videos, they have improved my woodworking so much! Thanks
I was a mechanic in the Army, and was deployed to Uzbekistan for one tour of duty (OEF) then Iraq (OIF). We had to get "creative" for most of our needs, building a literal city in the middle of the Uzbek National Air Force airfield for one! I had guys building the impossible- jigs for weapon repairs and multiple Hyster hydraulic failures. That was between 02-04. This particular video truly takes me back to those good old days! There was magic in those builds, and many crossed fingers when switches were flipped, lol! Thank you for what you do, and for reminding me that not all the war memories are bad! You have earned a new patreon member!
~Carla "Skully" B.
Thank you for your service!!! I only with you could have had a TH-cam channel documenting that time. It would have been HUGE!!!
I’ve just started watching your channel and I wanted to express my appreciation for your approach and the way that you present your content. Being a child of the great depression, my grandfather took a very similar approach in his own workshop and so I grew up with a similar set of ideals. I enjoy your presentations for all of their facets but the approach coming from the garage/basement DIY’er strikes a chord reminiscent to my spending many hours ‘in the shop’ with Gramps. Thank you for bringing back a lot of good memories and kudos for the vast amounts of extremely useful and detailed information that you are sharing.
You make me smile as you remind me of my dad. We had scroll saws made out of sewing machine heads. Table saws made out of plywood and hand saw. Turned pulleys like you made. My dad didnt have a lot of money so he improvised to make the tools he needed for projects out of his workplace.
I don’t need to build a lathe from scratch because I inherited one from my grandfather. It was on a terrible angle iron base he made. I bought a new base at least a decade ago and have never been able to figure out how to mount the motor. This video has given me a few ideas I’m going to try. I’ve had the large for at least 20 years. It will be nice to get it running! Thanks Rex.
One big advantage of belts: They absorb pulses, better backpulses from the tool, when this gets in contakt with the material. So the bearings live longer and the whole machine runs more silent. And belts are easy and cheap (!) to replace. Bearings not. So a tablesaw with a belt runs way better then a direct coupled saw with AC-Universalmotor, where every pulse hammers into the bearings from the sawblade into the motor. This you will find typically in jobsitesaws. Hope, it was understandable, englisch is not my mothertongue.
Cheerio from Germany.
No, you were TOTALLY clear! Glad you approve of the design choices.
Your English is very good. Thanks for the information.
Also, no-one mentioned that using mechanical rpm reduction increases torque.
“Mmmmmmm....cheap” that’s good stuff right there.
Oh yes it is.
The comic book villain: Bargan-ario!
I love these videos of Alan Harper I’m glad after two and a half men he found something to do and I’m appreciating the work he’s doing
Thank you for the series of the videos on the lathe building!! They are very informative and helpful. Cheers!!
I freaking love your videos! Your sense of humor kills me, which is pretty rare for videos where I'm learning so much.
Thanks! I try to keep them from getting too dry.
Lex Luther , I mean Rex Krueger this pulley info really came in handy with my budget mini chopper build. I'd say it makes up for trying to blow up Superman
From the GET GO.
#1: find an old treadmill someone wants gone for free and salvage the variable speed motor and the controller board.
#2: Watch a few videos on how to wire it (often used for 2X72 belt grinders) and you will have a 2 HP variable speed Lathe motor!
It's coming along really well now, Rex. Fantastic range of speeds you will have. Very well thought out for sure. Looking forward to next week's instalment.
Cool! I'm already making next week's episode.
I like your low speed range. 500 rpm is a bit fast for a chainsawn bowl blank. I did chase my first lathe around the shop a few times...
I love this guy.
Hey Rex,
one of the very best projects and explained awesomely. i have subscribed and will watch and most likely become a patron. i would not usually do that but your vids have changed my mind about becoming a patron. thanks again and keep up the awesome vids man.
My pleasure! So glad you liked it!
Very Cool Sir an i think that pulley system is very interesting on how you made it Rex.
Love your idea for making pulleys.All the time I wasted searcing for expensive pulleys.......
Hi Rex,
I want to have a go in making wood pulleys, for my high speed hand made knife belt sander/ grinder, but I am concerned with the sides of the pulleys snapping when pulley is in motion or if the heat from the v belt drive transfers to the wood pulley and heats the glue up and separates the pulley wheels, I wonder if long thin wood screws be placed through the pulleys to eliminate worries of heat transfer separation.
Firstly are wood pulleys only safe for certain speeds, Have you ever had issue with pulley breaking or separating ? and using ply seams to be the wood to use but could we use a natural wood , and is soft wood or hard wood best from what you have learnt
Also how long does a wooden pulley last on say a wood lathe, ? could it last like an aluminium pulley
I think a wood pulley will be fine and last a long time. From my experience, use hardwood. Maple would be my choice.
Well don’t you just know that you start this series and I just bought an Excalibur from Rockler. Ain’t that how life is? But I give you a thumbs up just because I like your video presentations. Oh and yeah I’ll watch the whole series ‘cause I know I’ll learn something to apply to something else.
If you can afford a nice lathe, you might as well just buy it. This series is for the broke and the adventurous. Good luck with the new lathe.
Keep up the awesome work, Rex! Thanks for everything!
It's really my pleasure!
design and make a VFD using salvaged MOSFETs/IGBTs from a late 90s CRT television's tube board. easy.
Great video! Nice build with a great explanation of the mechanical workings.
Thanks! It took me some head-scratching and I wanted to save other people some of the trouble.
What’s the motor rpm and pulley sizes? Trying to figure out how to get similar rpm ranges with a 1725rpm motor and getting stumped.
good job brother just watched all 3 videos hope you plan on finishing it .
Of course! I didn't get this far to just stop. Next video monday...or tomorrow for Patrons. Thanks for watching!
Well that makes me feel safer about that design, it may not rip my face off. Great video rex! It even felt short for the amount i learnt today
Matías Klein You mean the variable speed makes you feel safer? I agree. I'll also add belt guards to the finished machine.
Okay Rex, this is not related to you current project but I felt your older videos needed some kudos points.
I finally got my cheap plane and the iron did need some love. Not having all the fancy gizmo tools for sharpening I turned to your older videos and one other TH-camr as well, Colin Knecht of WoodWorkWeb.
I used the techniques you modeled and Colin’s super easy sharpening jig and it could not have gone any smoother! It was awesome! So thank you so much! I love my new Chinese plane!
Now because that went so well I decided to sharpen my wood chisels. I have the jig now so it should be easy right?
NOT!
I have to be honest, before discovering how to care for my tools I did misuse and dare I say abused my chisels. They were so bad that I had to start with 60 grit paper for shaping. It took me about 5 hours to shape and sharpen 4 chisels. However, theses things are works of art right now. I do not think chisels even come this sharp when you buy them new. They don’t take hair of my arm yet because I only had paper up to 600 grit. But as soon as I am at a real hardware store (not a big box store) I am gonna get some much finer grits.
Just wanted to say thank you and validate you and your presence. You are a wonderful teacher.
Matthew, I'm really glad to hear you're making headway! I remember being a broke grad student and how i struggled to get even basic tools. Planes were such a frustration for me. It took me a year of on-and-off futzing to get my first plane to cut. But once you make a little progress, things start happening fast. I bet you did get your chisels sharper than they come from the store; they only come kinda sharp. The next thing is to keep your eyes peeled for some oil stones. Man-made or synthetic, they are a cheap and durable way to sharpen. Keep me posted on your progress. I love hearing about it!
... And a leather strop with a honing bar will get those chisels and plane irons taking the hairs off your arm in under 30 strokes of honing total. £15 from ebay.
I'm very fond of the strop, but what's a honing bar?
@@dibley1973 As Rex said, What's a Honing bar?
@@RexKruegerI just looked on EBay. I think its that steel bar that comes with your professional chef knives
Super cool
Very well done. Thank you for the video.
My pleasure!
Damn. I like that shirt
Looks good and explains my question from the last video. I like the way you've used a cantilever mechanism and the motor weight to do all the belt tensioning; makes speed changes quick and easy.
Steve Crane Thanks! I like it too, but I'm not sure this setup is delivering enough tension. I might have to rig up a tension lever anyway. Oh well, it's a process.
@@RexKrueger Would wedges work? That would be simple and cheap.
@@jimwilliams2682 That totally might work. Wedges do deliver good tensioning. I think I might make an "over-center lever|" it's commonly used on old metal lathes.
Maybe I missed it in the video but it's important to remember as you step speed up, your torque steps down.
You're the man
Thank you!
Great series! Just curious if you chose your wheel diameters mathematically (ie with a specific target in mind) or aesthetically (went with what looked good). Thanks for sharing!
Mathematically! I'm an artist, but this is no time for aesthetics. I did use an online pulley diameter calculator, but I had target speeds in mind and I designed it to hit those speeds.
Awesome!
This is awesome! Do you have any plans to build any kind of housing for all the exposed pulleys and belts? It looks like a real hazard for catching any loose fitting clothing or dangly bits...or even chunks coming off the late.
Wood chips getting in there would be the biggest concern, since any trapped clothing would just come free after 3/4 a rotation (and hair, well..). I made myself a little magnetic chip guard out of a hardwood frame & wire mesh (5mm in this case) and it works remarkably well, doesn't weigh much, & looks quite cool too. I can highly recommend it for a cover.
@@nightcatarts I do think there's some safety concern. A belt guard will be one of the finishing touches.
@@nightcatarts Hair wouldn't be a concern.... (Sorry Rex, I saw the opening, I had to take it....) :)
That's why I shave it. I could have a head of the most beautiful hair you ever saw, but I shave it for safety!
I enjoyed the video, and I'm following it. May I ask for the diameter of the pulleys ? Well done mate. Cheers.
No problem: The range pulleys are 8 inches and 3 inches. The double pulley on the motor is 2.5. The cone pulleys go 8, 7, 6, 5 inches. All these details will be in the final plans. Glad you enjoyed it!
Are those the same C clamps you found at the boot sale? See, you said you'd find a use for them someday
They are!
Since you were setting the ratios, why did you make the lowest speed so high? A lowest speeed of around 50-100 would have been much better.
Well, my current lathe has a low speed of 600 rpm, so 300 is a BIG improvement. Also the low speed is determined (largely) by the size of the low range pulley, which is already big. Any larger than that and I would have had to redesign the whole thing to accommodate some monster pulley. Good question!
Then we needed to get ready for a future podcast where you redesign your pulley system. Believe me, you will want to go slower. ;-) My last lathe, before my old (1998) Woodfast M910, was a Jet 1440 with a low speed of 450. That is way too fast for large, heavy or out of balance chunk. But, in the meantime, have fun.
What are you doing, step-pulley?
This needs a sanding cylinder attachment :)
But why not this and whiskey?
Because this and whiskey = stumpy nubs... wait that's another channel. :-) Keep up the great work Rex. I was considering buying a lathe soon but this looks like much more fun and very satisfying at the end of the project. I really appreciate the way you make your videos funny and very informative. Oh and I was really looking forward to what project you were going to try on the lathe with 24" swing! :-)
Hey Rex I know that Facebook isn't your big place to post things but I have some pics and posted there to your page!
I think I did good?
Recipe : use only one set of pulleys, of maximum ratio (1/10?) then add 80$ VFD on your motor, set up to 200hz. Enjoy. You will have MORE torque.
Do u just wanna sell the lathe im trying to get one just dont have everything to build it
@_ David _ prob would agree with u just finding everthing seems like a hastle
Also in though i wonder if a dryer moter will work have an extra dryer that resently started squeeking and no heat but it still turns i wondrr if that will work
Your kidding right? I would give my right.. um knee for a couple of good motors. Where do you people get these things? All craigs list has is 3 phase 220. I keep my eye out, though ;)
I'm loving this series by the way. You are doing one of my long time dreams!
I think this stuff all depends on where you live. I've lived in CT, FL, CA, and OH and all of those places have had cheap tools and materials. Since I've been doing youtube, I've learned that other parts of the country just don't have all the stuff floating around. I have 2 or three motors in my shop just waiting for projects. A buddy of mine is giving me 3 or 4 to save space. I know I'm lucky and all I can say is that I wish everyone else was, too.
@@RexKrueger That's it! I'm moving back to CT.
HOW !! ABOUT !! A !! CORD !! ON !! A !! SPINDLE ?? UNCLE !! FREDDIE !!
AAHHH !!! CCHHEEAAPP !!
Hi Rex! Turning these rabbets is a bit tricky because the sidewalls must be precise. I recommend the tiny little but great and free construction software named A9CAD to make a gauge for the aforementioned purpose like this: www.pic-upload.de/view-36648485/LehreKeilnut.jpg.html
It's made for 10mm V-Belts according to german DIN2215. The software gives you dwg.-Files you can use for lasering the gauge from stainless steel or you print the shape and make your own gauge from a piece of plastik or hardwood. Hope it helps someone. Cheers!
ATTENTION: THE link leads to a pop-up scam
Does this acutally work on Metal?
I'm a fucking Dumbass, I never thought about building my own Lathe out of wood'n'stuff + a Motor
Holy shit
Work on metal?
@@RexKrueger I meant, can this Lathe does "work on metal"/"work with metal"?
Sorry, Englisch isn't my native Language :(
He said, "Reasonable needs." hee hee hee.
Rex - That's a "Skookum Choocher"! ^5
Now THAT is some high praise!
"your workspace is probably filled with" and "inexpensive". Not at all. I wish I had spare electric motors lying around. :(
I have about six of them. Always looking for them mind you. They always appear at garage sales if you're looking. :)
I mean that any power tool you have almost certainly has one in it. I wasn't clear.
RPM is plural.. Revolutions per minute... Saying RPMs just sounds silly.
I'm really enjoying watching and learning from this project, however, I regret that TH-cam has forced you to air political ads.
Actually, YouYube has forced YOU to watch political ads. Ads are linked to the viewer, not the video. When I watch this video, I get ads for woodcraft. Still, thanks for watchintg.
Oh, now I understand.
@@grantparis5356,
Yeah ... so, it's TH-cam that is rubbing you against your natural grain.
(See what I did there?)
R.P.M. no S needed.
Mmmm, Macadamia nuts.
I love your content, but twitch a little every time you say "RPMs" instead of "RPM".
???
@@glennfelpel9785 "RPM" stand for "Revolutions Per Minute", and is already plural. Adding an s on the end is as jarring as a dentist who talks about "teeths" instead of "teeth" would be.
Wasn't it "Rotations Per Minute"?
@@alfredneumann4692 Yup, it's totally not technically correct. You're completely right. It's also kind of common to hear and that sort of thing slips out when you're talking off the cuff. I can't stand reading a script and little mess-ups are the price you pay for some spontaneity.
Common error even in college classrooms .
"RPMs" -- It's "rotations per minute" not "rotations per minutes"
I cannot believe you took the time to make that comment.
I gotta agree with the shirt.