Even though i don't use acme rod, there's nothing stopping you from using it in your own projects. You can also use it instead of the standard stuff in the plans I produce. Whatever floats your boat!
A potential source: trailer jacks. I'm not talking new either. The innards are well greased (preserved), yet the tubes often rust out, or get bent. However, these are probably more abundant in coastal areas. Perhaps RV and moving rental stores.
I personally use ACME, because its more fit to purpose when handling traversal loads, due to the trapezoidal shape, they handle the load better, which leads to smoother traversal. That said, ACME rod is readily available where I live, if it weren't I'd probably just use standard threaded rod like you. Because although ACME is better on a technical level, nothing I build is so critical that it absolutely requires ACME to be good enough.
Perhaps I missed it but did you discuss the grade of the threaded rod? IME the home store stuff is grade 5 or perhaps lower and bends and galls easily. Grade 8 or higher from a fastener supplier is less prone to this type of failure.
I think it's always good when a RU-vid creator shows their mistakes or problems with their builds, we can all learn from it. Perfection is only in the editing.
TLDW: He did not use ACME threads because ACME thread rods may be specialty parts not available universally. Regular thread rods have worked fine before.
Good subject John, threaded rod and nuts come in a variety of material and classes of fit, as you demonstrated with the nut. Simple engineering for the diy''er is just go to a bigger size if you can't control the quality, also you are definitely on the right track if you apply habitual failure analysis whenever something fails. Enjoyed the video, looking forward to future instalments, cheers!
I watched the video all the way through (my table saw broke) and I agreed with your fix. Then I read the comments and laughed the entire time. I made my mistake long ago when I suggested putting the air compressor outside (I would do it but John won't). I now think a little longer before suggesting anything. 99% of the time it is what you have already done or intend o do. Great talk John.
All I can say is Thank You for your videos. The good and the bad. And I like the fact that you design your projects with simple things that are on the shelf.
I have some ideas for where to locally buy specialty parts like ACME thread, but it's still more expensive, the places are only open banker's hours, and when I don't know the vernacular of the specialty stores it can be awkward to trying explain what I want or need, especially when nothing is out on-display and it's all behind the counter or in the warehouse. Additionally sometimes these places want one to have an account in order to do business with them. There have been times I've gone to Graybar, or Grainger, or CSC/Wesco, but I'd rather go to Ace or Lowes because I have the luxury of digging through the available supplies myself. Sometimes I end up significantly revising my ideas while I'm browsing the available materials because material selection might itself provide for inspiration that I hadn't had when working it out on paper.
Thanks for the video! You probably already know this. But Princess auto sells threaded rods a lot cheaper than Home Depot or Rona. Rona is selling 1" threaded rod 36" long for $33. And Princess auto sells the same for $19. I bought it yesterday. I'm assuming Habor Freight in US would be equivalent to Princess auto in Canada.
I have to admit that I thought "Why not use an acme threaded rod" but I knew that you would have a reason, a history, etc for why you used regular threaded rod. The other thought I had was "Why not use a coupling nut". Good explanation of how you think about the amazing things you build. I for one appreciate the look into how you think about your designs. Cheers from Tokyo! Stu
Hi John, I live in the UK so I have very little knowledge of what is out there in the world; however, I used a scaffold coupling that has a very strong thread on it and a nut that goes with it. As scaffold is used all over the world I would assume (and yes I know the acromion for assume) that these items can be found without too much hassle. I have even used the nut and screw to make expectant die & tap sets to make wooden lengths. I have used your plans also and used the bar that use use without any problems.
I install gate openers, many brands of electronic actuator arms have 24” - 36” of acme threaded rod in them. I’ve thrown so many in the trash. Find a company who works on gates in your area and ask the guys who work there if they’ll set some aside for you. If you offer them lunch or beer, it’s pretty likely they’ll help you out. Also, I use 3/4” coupling nuts with 10” bolts and a lock nut to make adjustable positive stops on gates all the time. I weld the coupling nut to the gate and set the bolt to a depth that when closing or opening, the bolt head hits something solid and it makes the gate stop in perfect alignment. Those tapered couplers you were talking about I’ve never seen them anywhere near the threaded rod in the store, only in the plumbing dept and in the electrical dept for rigid pipe, but these are typically not shaped like a nut. (I cut these couplers in half all the time to weld onto a post over a hole I drilled so I can attach sealtite fittings to run wire for accessories.) Also, maybe I missed it but did you say on the plumbing/electrical couplers that one side is threaded the reverse direction of the other? The couplers on the shelf by the threaded rod will easily thread all the way through the rod. They work great for welding onto something, IMO. Thanks for the lesson on nuts, sir. I always enjoy your videos
That slot for the bearings, that you initially made linear ( then made it curved ) you could make linear again but longer. This way the stress on the thread would be spread to wider area of the rod. Then you could use smaller diameter knob ( to compensate the time needed to pick up the blade ). Sorry for imprefect english.
I saw another guy on YT that uses threaded rod with real square ACME threads and he doesnt buy them either. He takes them out of old automobile scissors jacks. Square threads work better than triangular threads for this stuff. It was the post-apocalyptic inventor.
Thanks John, when I watched your previous video (I don't know when either!), my first thought was ACME thread as well. My second thought was Johns pretty smart, I'm sure he thought about that and decided against it. And here you are, reading my mind... I'm glad you explained your logic, and I agree, Keep It Simple Stu*id!
I think part of the original problem could be that you didn't check for manufacturing variation when you bought your parts? If you grab any parts at random, there's a chance that the nut will be on the larger size of the acceptable tolerance, and the rod could be on the smaller side of the acceptable tolerance. Then you end up with less thread engagement and a sloppy fit- which you demonstrated.
Hi A good source for heavy duty threaded bar is your local scrap yard car jacks although they seem to be a lot shorter now. so try to get one from a 50s 60s or 70s model.
there was a time when getting stuff like acme rods and nuts was a PITA, but now with ebay and amazon its just as easy as going to the store. I scratch build a CNC about 8yrs ago, same acme rods and nut since it was built, still no slop and just as accurate all these years later.
I saw this video coming as soon as I read all the "You should have used an acme rod John." posts. Don't people read the comments to see if what they are going to post has already been posted? There were dozens of the acme posts.
But this way he's had the opportunity to create another video that has a lot of algorythm feeding interactions ( your post included ). This is how money on YT are being made.
coupling nuts are great epoxied into mounting blocks like tail stock, pillow block type assemblies, heavy duty -ish 'T' nuts for hold downs (well nuts slip).
I don't know what's available in Canada, but I was in my local Tractor Supply Store, and my Rural King Store (a US midwest regional chain) yesterday; and both had threaded rod up through 1"-8 and the coupling nuts located in the hardware section (in the racks with metal stock of all sizes and shapes of steel and aluminum) of each store. I know both had threaded rod in 3 ft lengths and the Rural King also had 6 ft lengths (I didn't look that close for 6 ft lengths at TSC. All are standard Inch series coarse threads, so regular hex nuts are also readily available. Maybe you don't have those type of stores in your area, but Tractor Supply is pretty common in the states and there are many small regional chains of 'farm' stores here in the US.
The kind of larger coupling nuts i've seen here in the US are the kind that is threaded all the way through but is then bonked with a punch in the middle, creating a stop. So you have to either run a tap all the way through or drill out the punched spot. Smaller sizes (3/8" and below i think) are true all-thread. I do see an appeal of double nuts though. Easier to get, ready to use, and more importantly can be used to adjust backlash of the thing they are used in by placing a washer in between, then very lightly lightening both nuts into it. Use plastic or rubber washer if you want some 'give' in case the threaded rod is not perfect. This double nut backlash adjustment is even used in some metal working machines.
If you want a lot of thread per inch , like fine indexing part on a jig, on a moderate size shaft. Lamp threaded steel tube out to 3ft is common in home depot etc. inexpensive
I built a vise and wanted acme rod - it was available in ten foot lengths! I ended up buying a cheap trailer jockey wheel which also had a cast acme nut. Perfect.
Great info on the use of coupling nuts, or the potential problems with their use. When you re worked the lift mechanism, you emphasized that application of grease. In your experience, does a dry lube hold up like a regular grease in similar applications? The lift/ tilt mechanism on my Delta TS needs cleaning and a relube several times a year, cause it gets gunked up with sawdust. Was curious if a dry lube keeps sawdust away better.
My 2c: 1) lubrication is important, but avoid oil that will make wood dust stick to the threads, wood dust can be very abrasive. 2) the advantage of a coupling nut is that the tread is consistent over the length of the nut. With two nuts it'll be hard to avoid one nut doing all the work until it's worn. My table saw also stripped out and I fixed it with (M10!) threaded rod and a coupling nut, it hasn't failed yet...
You'd think oil would be a problem. But in practice it really isn't. Steel is a lot harder than wood is. I've never found a dry lube that equals the performance of oil. I've gone through it all myself on my table saw. Just oil the rods. If it is good enough for chainsaws it is good enough for me. And yeah chainsaw bar oil is my lube of choice in those applications. I always have it.
@@1pcfred I'm not sure, but I think it can be a problem. I had sawn a lot of Azobe (red ironwood), which is notorious for containing crystallized minerals, and when the threads failed they were full of Azobe dust and very worn. I *think* the wood dust contributed to the wearing.
Regarding slop in the fit of your threads - there are different classes of threading, 1, 2, and 3, which is the loosest (easiest to assemble) to the tightest (and more precise, also more expensive), You typically see it at the end of the thread spec. E.g. 3/8-16 UNC 2A is a general purpose 3/8 inch male thread with 16 threads per inch (the nut would be 2B instead). If you want a tighter fit, see if your local hardware store carries 3A rod and 3B nuts.
Just to be devils advocate... placing an order on McMaster carr is pretty painless... seeing as going into public big box stores these days is a nightmare all by itself.
If one tends to think visually, catalogs like Grainger and McMaster-Carr aren't as intuitive, even if one has the dead-tree edition. I do a fair share of both, there have been times that the catalog-order solution requires more effort to conceptualize than I'm willing to invest. Other times I know that there isn't a locally-available solution or isn't one that can be achieved without going to expensive local specialty places, such that taking the time to work it out with catalogs and fitment/compatibility cross-references needed.
TWX1138 McMaster has great images of the things they sell! Look up acme threaded rod and you’ll find good stuff, cheap stuff, precision stuff, all with illustrated photos
No problem with threaded rod. I've got two table saws (brand name) and neither utilizes Acme threads. A solution would be to get get a higher grade steel in the rod which arguably may have to be ordered or in the least, visit a vendor that carries higher grade bolts/all-thread. Most store carry grade 5 and grade 8 bolts, possibly they also carry a couple of grades of rod.
If you discard the factory nut idea, and go with say using a piece of 1" steel, where you drill and tap it, your results will be a lot better. You have less backlash, and "wiggle". It gives you more thread contact, and transfers more force.
We are manufacturers of threaded rod and studs in high tensile. Must let us know if you got any requirement regarding it. We work non standard and custom made as well
I can't help but agree with your comments about using ready rod. Any specialized-thread rod is pretty much unobtanium in northern Alberta, and I've been using ordinary plain vanilla threaded rod with a pair of ordinary nuts to make a traverser for 40+ years (not knowing until recently that I was "doing it all wrong"). I just had this ridiculous idea that if it worked, gave repeatability, and didn't leave me broke it was a Good Thing. I used to have quite a stock of ready rod, bought back around 1980 when it was still made in Canada. I've finally used most of that up, and the current hardware-store stuff is definitely not as well made, and the quality of the steel is a question mark. Like you I've always gone "up one size" when I've built threaded rod into a machine for traversing, lifting or whatever. Lately I've been looking around for some better quality stuff, and there is a metal supply shop not too far away who will sell to the consumer in small quantities. I've had better luck with that. I've tried ordering "specialized" motion screws, couplings and so on via the "A" store, but some of what's arrived - particularly sliding rails - has been pure garbage, and I've sent it back. In some applications, I've used the "drawer slide" dodge, although sometimes I wait until Princess has it on sale half price. For some applications it works fine, and it's a lot more robust, less flexible, and less expensive. Anyhow, I appreciate your thoughts on making stuff using commonly available parts. Many thanks.
An inexpensive source of acme screws is an old scissor jack! FWIW I bought mine for $2.00 US at a yard sale. Really needed it as a jack but could have removed parts too. Good luck.
Maybe I'm overthinking it but if you use a couple of nuts backed up together you would need to make sure that they are the exact right distance from each other so that both sets of threads engage with the rod at the same time or you will just wear one out and the the other as it have not seen any real load until the first one wore out. If you use the coupler nuts, the right type as you mentioned, then the threads are always engaging at the same time as it's the same thread all the way through so I think that will last a lot longer than a couple of nuts or three as they may not line up the inner threads to the exact same pitch if that made sense?
Exercise barbell rods use acme threads and they're quite easily available. Finding a nut you'd need might be a bit more of a challenge and the size of the rod is rather large. There are plans out there using barbell rods for Moxon vises and they seem like a good choice.
You compare it to the router lift but as far as I can tell the table saw height adjustment isn't locked like the router lift. The router lift has external clamp which takes the load off the threaded rod.
We had this problem at work with a valve spring compressor. It uses 11/16ths all thread to compress the 4 springs. Probably somewhere in 600-800lb spring force. We switched it over to grade 8 all thread and never had a problem since...... but obviously not available at your local big box store.
11/16ths is an odd thread size. The last common thread in 1/16ths is 9/16ths. After that the sizes go up in 1/8ths. So after 9/16ths the next size is 5/8ths then comes 3/4s Which leaves 11/16ths out.
@@BudgetBuiltDiesel 7/16 is a SAE thread. Still not a popular size though. It sits between 3/8" and 1/2" which are both very popular. The common head size on 7/16" is 5/8s I have a bin of them next to me. I stock all sizes from 2-56 up to 1-8 I'd have had to get up for a 2-56 though. The 1/4-20 to 5/8-11 bins are within arms length. I didn't even have to stretch to get some 7/16-14 really.
@@BudgetBuiltDiesel let me check that out. The bin of nuts is right under the bolts. You're right! Probably the only person on the net that is right today. It is such a rare occurrence anymore that I'm shocked when it happens. There's usually two nut flat sizes for every thread. There's the regular size then an oversize. If I pulled the bin out I might have an oversize nut in it. I'm not getting up right now though. Sometimes I do store the oversized ones separately. But I wouldn't for 7/16-14 It is such a goofball thread I don't have much of that hardware at all.
The threaded rod you bought from one of the box stores was probably from China. My experience has been that products from China are not the best of quality. When I was younger, I worked in the mining industry. We used ready-rod for pulling huge pins from tight bosses. I’m talking about 30 ton hydraulic ram on a 1 inch coarse thread rod. It may have stretched but it never failed. In those circumstances it was a one time use item. We would scrap it after that. Canadian made ready-rod maybe more expensive, but it would have not failed.
Acme has higher efficiency than universal all thread thread. Which is why you are more likely to see acme thread in applications where movement is important. As I can recall acme is 40% efficient and all thread is 10% A ball screw is 90% efficient. That's the range.
Grab two nuts put them on your thread about 1/16th apart and tack weld them on 3 of the 6 sides, it will be very tight to start with... with a old chisel or screwdriver hammer the nuts between the unwelded facets to slightly spread to loosen... if it comes too loose a slight tap of a hammer on the threaded sides to tighten again.
All fantastic points! I wonder recon threading your own nut would be better as you get full cut threads instead of those flats on the inside of the nut, im not sure how the rod interfaces on the inside of the saw but if it was possible you could enclose the rod then then drill an oiling hole through the nut?
John, save yourself a lot of guessing and go with grade 8 threaded rod and nuts. They are rated at 33 rockwell on the "C" scale, that's fairly hard and wear resistant. For a comparison a hand file is around "48" on the "C" scale.
I would never use acme threads. Such threads always fail in unexpected ways and at the worst possible time. Acme produces most of the products Wile E. Coyote uses in his attempts to catch Roadrunner. Whether its a giant rubber band, rocket-powered roller skates, or (I'm sure) threads, Acme's products always boomerang and end up hurting Wile E. Coyote. (I'm not sure how Acme stays in business.)
Isn't a precision adjustment only important for the blade angle adjustment? It would seem like the blade high adjustment mechanism could be simple, like a circular saw. I guess if you're not making dadoes/box joints, no?
The number of things I see US and Canadian makers get by walking into their local big box store that I can only dream of finding in any store locally to me (UK) is really frustrating. Even when I can it's stupidly priced.
I find B&Q and screwfix tend to do alright for a lot of stuff, only rarely do I need to order online for something that the US makers are getting in their hardware stores
Here in italy we have untreated rods and nuts, they are just plain steel. They are stronger and more precise then the galvanized ones. Are they available in other countries?
Normally coated fasteners are zinc-plated rather than galvanized in the United States. I expect Canada is similar. But your thought on surface-coating does bring up the interesting point about dimensionality. Sometimes no effort is made to account for reduced tolerances and parts fit poorly, sometimes only minimal effort is made in that excessive clearances are left prior to coating and parts fit poorly. AvE did a video comparing the various quality of fasteners, the cheaper fasteners tended to be over-spec as far as strength was concerned, while the more expensive ones tended to be right on-spec. The more expensive ones were easier to torque properly.
@@alans1816 Galvanized and zinc plated as TWX1138 said are not the same thing. Zinc plating is very thin. Galvanized means dipped in molten zing and is much thicker.
@@TWX1138 galvanized is zinc. The other common plating is chromate. That's the gold colored hardware. Hardware comes in fit classes. It is supposed to be looser and tighter. What you're getting at a hardware store is class 1 fit. The sloppiest stuff going.
You could get a good Grade 5 or Grade 8 nut and go to a shop and get them to thread a piece of cold roll steel for you. It shouldn't cost too much. That would be something that would be available to just about anyone.
Your reasoning is certainly valid but buying Acme threaded parts is no harder than ordering a set of your plans. I couldn't buy your plans at the store either so I ordered them. Same with Acme stuff. I've lived in small rural towns and in major metro areas so I understand the difference when it comes to specialty parts. There are plenty of places that will deliver to your door. The failure is no surprise with a loose fitting nut. What percentage of engagement do you think you have with such a loose fitting nut? Not much. Add the soft steel to the equation and failure is imminent. Sure, you have to order Acme threaded components but they're as close as eBay. Take this as a positive comment. I really like your channels.
My plans aren't shipped. There are places in the world where people buy my plans, but wouldn't trust the delivery system to order goods online. Or the shipping is expensive. Or the import duty is expensive.
@@IBuildItScrapBin Fair enough. Some of the small towns I've lived in were pretty third world but they were still in the US so stuff would arrive eventually. I didn't consider the viewers with delivery difficulties. Sorry. I know your plans are delivered by the Internet. I've bought some. Thanks for your great content.
@4:30 has to be the smoothest execution of "Deez Nuts" on youtube. And yea, non standardized crap sucks, I can't help but think a large portion of that sort of crap stems from asshole suppliers trying to ensure that they keep you / a company over a barrel. That's generally when there is some industry standard or rule of thumb that everyone else adheres to except company "Y" and it just so happens their shit is 3 times the others cost. Of course this is only realized after their product(s) have been implemented. Don't get me wrong, occasionally deviation from the norm is due to a improvement or value gained by someone who found a better way. More often than not though, it's to have proprietary shit that can't be easily replaced by a more cost effective solution. When you encounter bullshit like that you should refer them to deez nuts.
From a mechanical standpoint, by hammering it, you would concentrate the force to a smaller area that the thread is engaged, subsequently increasing the stresses on the engaged area, and hence increasing the chance of it stripping it. On the other hand, if you have two nuts glued or welded together to bear the forces, you half the load on each thread and significantly decrease the chance of stripping the threads. You would be still using the non-specialty parts, but tackling it scientifically using regular hardware store parts.
I don't mind people showing things that go wrong. We learn by our mistakes and those of others. Normal threaded rod is a fraction the cost of acme rod and if it works, then fine.
National Oval thread. Similar to National Fine (NF) or National Coarse (NC) thread. Most useful when you are trying to aggravate one of your co-workers :)
That is actually not ACME thread. Acme thread is the pattern used on machine tools that is flat on the ridges and valleys. That is standard all thread rod. Acme thread is trapezoidal.
4:40 The nut was Piss Wobbly Slack as doubleboost would say. How It's Made Nuts and Bolts ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-3kxcw08p_oY.html
I can understand your desire to source the materials locally, but, and I'm not sure this is true, is Acme threaded rod better? When you're building something that you'd like to minimize the chances of failure, my guess is Acme rods use a better/harder steel. I know I could be wrong on this but from my limited use, simple threaded rods/bolts use cheaper softer "junk" china metal.
The geometry of the threads is the main factor. Trapezoidal threads move better than V shape all thread does. 400% better. What's going to grab more sharp teeth or flat teeth? There's more to it than that but that's part of it.
Hmmm..very suspicious, the whole thing.. Maybe you had bad luck with the material. Usually the hardware shops dont sell the best quality^^... As far as i can tell, i never had such a incidence. I have built a post vise for metal working, using a M20 rod and i am abusing the hell out of it. I keep it lubricated and i can see no sign of wear on it.. Also i have built a solar tracker for my PV system. The M10 Rod + coupling nut (more threads) does well since 8 years now... Every day from east to west and back in the night time... Hmm..perhaps we have better treaded rods over here in Europe. ;)
It's a fair point but I can't help feeling if you are building your own table saw you are probably not all that concerned about getting on the internet and ordering up a length of acme rod.
