3:30 that's correct, the jaws act with compression and shear, and when a piece of rock broke, have to slide forward and take another bite and another till the exit. You desgin something call "simons" (if i remember correctly from school, i'm a mining technician) if you want work with pure compression look at "blake type". The problem is that they produce a "flake shape" so those crushed material are not suitable for cement when you want some poliedric pieces, so you can use this crusher only for primary purpose followed by other designs. If you look at a cone crusher in section is not different from a jaw one, just roll a big a plate into a circle ;)
I don't worry overmuch about the looks of a part or even an entire device when prototyping. Almost always, the first few tries have a fatal flaw, maybe several, and several things that need tweaking. Looks like you have something that works rather well, just a few minor changes in material to improve. You will probably do that if a part fails. Looks good! I like the explanation of your choices and results, warts and all. Sometimes it is really helpful to know what NOT to do.
Sounds like we have that in common! I certainly think this will require work to maintain and keep functioning, but fortunately I like making things! Thanks for watching Jeff!
bro...i try not to comment, but when i see a obviously competent machinist just hammering themselves much to the delight- of the average shop dwelling, im better than you, done more than you, and can outprogram you machinist 5150....i hurts me. Being an ex machining, recently turned truck driver to get the hell away from an industry i love, your kicking ass dude. tooling marks happen whenever they want. that is the sick evil of this industry. Whats the final use of the product...to smash rocks? sweet, it works...send it.
Pretty much everything you said about the material and heat treating was wrong. Your process was wrong as well. I don't have the desire to explain it all but I can tell you if you grab a Machinist's Handbook you will be able to learn enough from it to do what you need to do. I appreciate your little crusher though. Cheers
what speed are you running it at? i found a used Sepor 2" crusher at auction less motor and sheaves, Sepor said to run it at 1750 rpm at the crusher shaft.....
I like what you have done. The small rock crusher would be perfect for a project I’m working on. Can’t we just buy a set of plans, rather than signing up for a membership to something I won’t use.
Hey bud, I crush for america rock in eastern oregon. Have you thought of a gear reduction box? That would give you the torque you need. Compared to a full size like my telsmith, it's not the torque from the motor that breaks the rock. On opposite sides of your eccentric shaf you have a fly wheel and on the other your shiv. (That's what we call pulleys). They weigh about 2 tons a piece. Combined with the weight of your jaw dye(3tons), etc, etc. Now, the motor is a 3ph 480v 250a 300hp motor, the motors job isn't to break the rock. When I start her it takes roughly 300a to get her moving then at full rpm she drops to 100a. That's just to keep it in motion, when I start putting rock in her she pretty much stays at 100a. All of that momentum and weight is what breaks the rock, all the motor does is keep the weight and momentum going. With the scale I'm scratching my head on how to go about that without it looking rediculace, anyways. Good job on the build bud!.
We supply crusher spares and do repairs on crusher parts at work. Seeing baby jaws like this made me smile. The ones we work on are like 1m x 1.5 meters and bigger. Reworking manganese steel is a pain.
You could surface harden those 42CrMo jaws. Heat to 870-900 Celsius and quench in water. Hardness is 54 HRC minimum, when starting from the Q+T condition. Do a stress relief at 150-180 Celsius for an hour after hardening.
Hmm interesting... I was a little wary of a water quench because I had heard it can cause cracking, but it would certainly be more convenient than oil quenching
I was interested how Rick crushers worked . The flywheels on compressors have a taperlock so they can clamp onto the shaft pretty good. Hey but gotta learn as you go. I think I might have put the crank bearings in the half inch plate and used end caps to hold them in. Rock hard ness is constant. I think your right about the scaling down makesca difference. And the belt could could of been part of the flywheel. Nice work though
Could you add jack screws from the side of the housing to back up the adjustable jaw if it works the shoulder bolts free? Enjoying the builds and commentary also.
HEY I THINK ITS GREAT! IM IN THE SAND AND GRAVEL BUSINESS AND HAVE RECENTLY DISCOVERED RC HEAVY EQUIPMENT, ITS AWESOME, AND WHAT I NEED NOW IS A SMALL GRAVEL PLANT, I HAVE BUILT A PROTO TYPE IMPACT CRUSHER WHICH WOULD BE PLACED BEHIND THE JAW, IM SURE YOU KNOW THIS BUT IM BUILDING SMALL CONVEYORS A SMALL WASH PLANT BUT TIME IS A KILLER, THE REAL THING IS MORE PROFITABLE AND NOT MUCH TIME FOR THE ADULT TYPE TOY, IT WOULD BE AWSESOME IF YOU COULD BUILD ONE OF THESE FOR ME! ITS THE PERFECT SIZE, IM HOPING YOULL SAY YES, PLEASE! LOL IF SO HOW MUCH? OH MY!
Hey! Sorry it took me so long to reply. I don't suppose you've seen RCSparks' "RU-vid Gold" series? It's awesome! That guy's got some serious money though. His machines get up into the 10K range :P. I don't sell anything yet, but I'm hoping to incorporate some time in the near future so I can sell things. There's been a lot of interest in this crusher, so that might be a good candidate!
All the bearings should be bushings and should be equipped with grease nipples. Regular greasing is the only way to keep rock dust out of the bearing. the seals on sealed ball bearings are not tight enough to keep rock dust out and not durable enough for the gritty enviroment of a rock crusher.
If you really want this crusher to do a lot of crushing you should mount all the bearings in the cheek plates. The two bearings in pillow blocks put all the force of crushing against 4 small bolts. when you hit a especially hard rock or someone drops a hammer into the crusher under power they will sheer off. Yea, people do accidentally drop chunks of metal into crushers sometimes. My lab crusher has been rewelded twice when the main bearing which butts into the cast iron body of the crusher cracked the cast iron due to accidental attempts to crush large rocks. Give the main bearings lots of support.
If you were to drill holes in the side plates in line with your jaw hold down bots you don`t have to disassemble the crusher if you want to change jaws.Hope it works for you!
Cool stuff. One comment: you specify that METRIC dowel pins are oversized. AFAIK, all standard (non special) dowel pins (inch or metric) are oversized by roughly 0.0002”.
also...try coolant instead of oil when drilling. I've switched and my drills are lasting longer, chips evacuate better and the metal doesn't work harden as easy.
I have not searched all the comments so I apologize if you already answered it. I would like to know more about the crankshaft offset and the angles of the jaws are there some industry rules of thumb? Thank you Vince
I just kind of estimated it. The jaws are adjustable at the top and bottom, so you can set any angle you want. I found that a shallow angle was more likely to pop rocks out, but an angle that was too steep resulted in limited crushing. I think the offset was about 1mm. Because the stone is so brittle, you really don't need a lot of motion.
Nice build but so much machining and precision put into it. Couldn't a person build a lasting one more crude and without all of that machining but with heavy steel welded together? For example, the eccentric shaft could be a piece of larger shaft with an off center hole drilled through it and slipped over the smaller diameter main shaft then welded on. Also use pillow block bearing mounts. So what I understand from what you say, the larger diameter and heavier that pulley hub is, the less power of motor needed. I guess there are limits to that to reach a proper balance. It could be considered an inertia powered crusher as well. BTW what type of ribbed belt is used to transfer the power?
Yeah absolutely. I think the "cost of goods" of this could be cut in half easily. I think using a rectangle tube as the body, standard pillow block bearings, an eccentric collar (like you suggested) and a few other cost cutting measures would make this less expensive. I've had a few people inquire about lower cost versions of this, so I may investigate further. You're right about the flywheel. I didn't get into it (I may do a video about flywheels), but basically the bigger the flywheel, the longer it takes to "charge" but the more work it can do. The only caveat is that the motor has to be adding more energy than is expended, even if it can't supply enough torque. Thanks for the comment!
Submerge it in water up to about .1 inches from the top after you brush on elmers paper glue and sprinkle on bone meal or charcoal or any finely powdered carbon source let it dry . once submerged you can use a compressed Gas (like oxygen )torch to harded the teeth leaving the rest of the plate soft and shck absorbant. I also wonder if if Nav-Com gaskets could be made and used to disipate excess vibration. Being as it is a special closed cell polymer foam designed specifically for reduction of harmonic vibrations caused by machine shop tools like mills and laiths and cnc setups....the pad is placed between the floor and stand or machine base before it is ankered on lag bolts set into the floor or concrete pad...after it wss found to be succesfull it has simce been used in the firearms industry as recoil pads and a harmonic tuner that slides over a rifle barrel and you move it up and down the barrel until your target groups become as consistant and as small as possible...i dont see why it could not be handy on rock crushers and shaker tables to help lengthen the usefull life of the gear. Vibrations destoy everything.
So much to look up, thanks for the tips! So heat treating while the part is partially submerged? You must need a ton of heat to heat up just the teeth without just boiling the water. I had never heard of Nav-Com, I'll have to check it out. I'm always interested in vibration damping materials because, as you said, vibration destroys everything.
28:00 What is that tool? Is the pilot attached or an attachment? Why even have the pilot!? WHAT IS LIFE!!! Never saw an endmill with a pilot like that before, its interesting... Could always nitride or parkerize or even just cold blue your bare steel part to help with rust prevention, then smother them with wd-40, dont want to lose that machinists perfume!
That's called a counterbore tool (www.amazon.com/Counterbores/b?ie=UTF8&node=256258011). They really shine on drill presses because they self align. The only problem is drill presses usually run too fast for them, so they work best on a nice, low RPM drill press. Life is difficult to define but I think it's based around something's ability to metabolize, self sustain and reproduce. Is fire alive? I don't know. Case hardening would certainly be a good way to go. I'm sure they do something similar in real crushers
Any time I'm building anything that will be subject to moisture or activity that will damage a paint finish, I make it out of 303/304 stainless steel or aluminum. The body of your crusher, your bearing blocks, pivot and drive axles, much of the design, with the exception of the jaws, could be stainless and just as strong as A36. The jaws could be stainless too like a 440C, but would be better served with O-1, since they're a wear item.
But as you mentioned in the video, this was known to be a high stress item, and therefore prototypical in nature. I would proceed precisely as you did, making the first one out of A36 and working out the details. Stainless is more expensive in raw form, heavy, hard to machine and very hard on the machines and especially the tooling. I wouldn't commit a pile of stainless to an experiment either.
Glad I could be of help! I'm sure AR500 would work great for jaws. I also thought about S7 and A2, but they were a bit expensive for parts I wasn't sure would work :P
With MIning Equipment like crushers it is frequently used outdoors where it gets rained on. The mass of metal loss from rusting compared to metal loss from grinding steel against tons of rocks is very small. The crusher will wear away the jaws and cheek plates way sooner than it will rust through anywhere. nice video.
Thanks for the comments! I learn so much when experienced people like you post haha! So bushings are okay in the cheek plates? Can you get them with some kind of sealing arrangement or do they just power through the dust? One thing I have come to appreciate about bearings mounted in flanges is that when the crusher does get overloaded it just moves the bearings and nothing breaks. Ruins the paint, but that was'n't exactly winning any awards :P. I am looking to simplify the design a bit, so I'm definitely going to take your suggestions into consideration. Thanks for commenting!
@@TabletopMachineShop HI, i ran a Assay business for 30 years where i used the jaw crusher and pulverizer to turn rocks into powder for the fire assay. so i have a little experience on small crusher design and use. use bushings and put a zerk fitting on them so you can inject grease into the bearing which forces dust out. it's not perfect but it works.
Hi! Can your driveshafts be better cause their heat treatment was followed by a slow cool down, in that they became less brittle than if they were harder? Is it correct to say that softer steel is more ductile? This might reduce the danger of stressfractures forming cause there is a bit more “give» in the material as it is now, less rigid but better at absorbing shock?
I believe you actually have to harden 1045 first and then heat and cool slowly to soften it a bit to remove the brittleness. Softer steel is more ductile but also weaker, so it will break more easily but less dramatically if that makes sense... I think ideally you would want hardened and tempered back to a less hard state so you get some springyness without deformation, much like you said
Funny thing about those lock washers; if they failed as often as the internet would have you believe, they wouldn't have been sold for decade upon decade. Are there better designs of lock washers available? Sure, but they cost a lot more than the standard one that usually works okay.
Ya I agree. There are places they really don't work (like curved surfaces and slots) but i've never really had an issue with them on flat surfaces. I guess there are better ones, like the toothed ones, but they have a larger OD
failure mode with spring washers is that they spread with torque. as you have these in a counterbore, they are constrained from spreading, so less likely to fail, but they are not suitable for handling any real fastener torque, you are better off with a plain flat washer. :-)
Hi! I think ive answered you on Patreon, but just in case you didn’t see it i designed it in Solidworks but i did upload step files which F360 should be able to open. I cant save to fusion 360 native file format but if theres another one youd prefer let me know!
Nice, you killedit. I HATE you for beating me to it, but admit,.... You did very well... excellent !! Now,.... a Miller Table, to make some profits on her jaw crusher unit ??
They make some cool stuff! I've had some people inquire about if I sell them, but as it is its too complicated. I was thinking of seeing if I can make one out of some rectangular steel tube to get the hypothetical price down. Who knows, maybe people need to crush tiny construction debris haha!
@@TabletopMachineShop ... how about a diversification.... surely your crusher can crush food scraps, bones, rinds, shells... or perhaps hammermill version might be better for that ? I dunno if I am joking,....garbage disposal units have become WATTPigs and expensive to maintain... not to mention repairability. Yours could eat when you are ready to feed it... not wasting organic compostables.
Thanks for watching! Stainless fasteners are just much weaker than alloy steel fasteners, so in such a precarious situation it would be better to have a stronger screw
Great video Greg. I love the detail in the video. I especially like the segments where you're talking about making something, and then we get a quick flashback of the machining, like at 6:47.
Thanks! I think I'm going to keep inserting machining footage as I talk about parts, but I'm going to try harder to get more complete footage. I have no idea how or why I don't have footage for cutting the pulley grooves for example!
I bought a large jug of real quenching oil once, and was told the oil should be heated to 80°C to work best. The oil is to thick at room temp. Water works too, but will not quench as hard.
I used old motor oil (not enough of it though). I've also heard that water can cause cracking because it cools the material so fast, but I may go ahead and try it anyways because it's so much more convenient. I'll have to look into real quenching oil
I've always been told to use USED motor oil bc of the added carbon from the carbon build up from the motor and that the higher the mileage on the oil the better. And I'm ashamed to admit that I've never heard of an oil made for quenching. Makes sense though. They make everything for everything. Doesn't necessarily mean its the best choice, but I may look for some and give it a shot.
I work on crushers for a living, you might want to build this but it has too many design flaws to be used, the three part eccentric shaft coupled with unevenly weighted flywheels means it will fail, the adjustable fixed jaw will come loose, no cheek plates means side of crusher body will wear out, the mounting system for the jaw liners means they will come loose, the eccentric bearings are not located and will come loose, the toggle will wear out fast, it looks like a fun build but don't think you will crush a hundred kilos of hard rock.
Baby steps -- I want to slowly build up to the lathe bed so I don't do something wrong :P. I might do a spindle housing or something to evaluate the vibration damping performance before I do the whole base. I'd also like to try to 3D print a mold and see how that works for smaller things
@@TabletopMachineShop yeah that makes sense , from what I've seen the finer your rocks are the better , seen some people use super fine sand , almost looks like powder , seemed to have good results , also a 12-13% epoxy content is the ideal amount. I'm planning to do a similar project but I want a mini mill . Very interested to see your results . Also I know you were talking how it would be too expensive to sell the turrets , I'm in manufacturing , and I'm very good at making things cheaper . If you ever decide to maybe make a business of selling them I would be interested in helping / partnering on it . If you want to see what I do for a living, this is my company blklblbipod.com I designed and machine these in Calgary Canada . Cheers
Tabletop Machine Shop im a prototype machinist myself ... I recognize passion when i see it .. You got it .. Im pretty sure you'll end up with your own shop someday !
I work as a test engineer but have been doing machining as a hobby for a long time. I can't really call myself an engineer because I'm not a Professional Engineer and that would be illegal, but it's what I went to school for.