I have a huge servo motor that I have been wanting to test. It is a NEMA 34 600 ounce inch motor. So, I decided to build it into an industrial strength fucking machine. Since this is a servo motor with an encoder, it will not get out of step easily. The huge motor will not get bogged down. This machine could do double duty as a concrete breaker.
No idea how fast it will accelerate with all the mass in the motor but I used a rather large pulley so the motor does not have to move much to do a lot of fucking. I tried running it on my 60 volt 18 amp switching bench supply and it sent it into protection mode so until i get the unregulated linear supply that I have on order I will not know how it preforms. The new power supply is 1500 watts at 65 volts and being a simple torroidal transformer supply it should have plenty of reserve power. It cost $200 so I hope it does the job.
Instead of using a timing belt I decided to try a cable drive. This machine has a 5/64″ stainless steel cable wrapped around a drive and idler pulley. The cable is rated at 100 lbs test and the Nicopress crimps that stop it from pulling out of the pulley are rated at 40% of the cable rating. Since the cable wraps around the pulley a few times and takes a sharp bend before the crimp it probably will never slip out of the crimp.
The stroke is limited to 15 inches because of the damage that can be done with this very powerful machine.
I should have the power supply in a few days and can then see what the industrial strength machine can really do. I have some fence posts that need pounding in so maybe I should test it on them.
The stand is temporary, just for working on the machine. It will require a huge base to keep it in place. I have a large sheet of diamond plate aluminum that I will be building this machine upon. It will have a motorcycle seat and handlebars similar to a machine I saw on buttmachineboys. My machine will be better 🙂
It may be difficult to tell from the pictures but this is one heavy duty machine. It uses linear ball bearings which will be durable but a little noisy. If the noise is too much I will make some Turkite sleeves instead. Linear ball bearings are definitely noisy when moving fast.
Once I get the power supply and do some testing, I will post some detail pictures of the drive mechanism.
Perhaps this could generate more activity if folks were to send in clips of themselves and/or others getting slammed by your or their home built machines?
As for your current model, I’d love to see someone use it with a Shane Diesel replica dong on it (I love mine,currently seeking the 30″+ double I’ve heard about).
I would love to get together with others in the Austin,Tx area to bounce idea’s to and fro.
I’ve just seen this post, instead of the v rail type I ordered an Igus Drylin W double rail and carriage, received last week.
They are available in a wide range of size and the rail is cut to length.
It should look like sery similar to what you did but it has plastic sliders instead of bearings so it makes almost no noise.
do you have a link for a good source for these? the quietness aspect sounds good. i found some online and the prices look good too but so far i have not found an easy to navigate site with dimensions and all the options clearly shown.
I ordered directly from Igus website but in France, I don’t know if it is possible in the US
Here is what I ordered:
Carriage: WW-10-80-10
Rail: WS-10-80, 500 mm long
Shagmatic, I’ve read posts on the 3D Printing forums that some people have actually printed their own copies of IGUS bearings…
If you’re interested, I’ll see if I can find the STL files for them.
My Apologies for being away for so long… We wound up with a house guest from New Years until this past weekend… It’s now just the two of us again, so my focus is moving back towards refining my machine… Also finishing up some shop improvements!
Your wire driven version is very interesting… Any particular reason you went to a wire drive over the belt?
That Servo motor on your Industrial machine is pure madness… I love it!!
Is that the motor we’d talked about last year when breaking concrete was brought up?
What changes need to be made to the Shag board and firmware to make use of the servo motors encoder? My only complaint with my machine is it’s slippage and constant need to have the offset adjusted. I am planning on converting it to belt drive, or possibly wire drive once I hear your reasonings, which should all but eliminate any slippage. It’ll still be possible for the current motor to miss steps, but if I go direct drive and still have need to constantly adjust offset, then I’ll know I’ve had a missed step issue all along. 😉
printing bearings sounds interesting but i am not sure i have any filament that would made a decent bearing. i have just ABS and the other really soft stuff, forget what it is ??? i have about $17,000 “worth” of rulon J that i can use to make my own. i was going to try that but decided to try the ready made ones and it is much easier 🙂
i did try a servo motor using the gecko driver. it handles the encoder. however it worked really badly. i called gecko and they explained why. servo motors such at low RPM. it would work if i had at least a 5 to 1 gear ratio.
the motor on my unstoppable machine is actually a double stack nema 34 stepper. works great. it is so overpowered that it does not miss steps as long as you use a reasonable accel and speed max. these do need to be changed in the firmware. there is currently no way to limit acceleration when using the joystick, only with the three know control. i could add acceleration limit to joystick use but there is really no point as far as i know.
i used a cable for a few reasons. a timing belt is not needed because there is no need for precise positional accuracy. it is a little difficult to connect a timing belt to teh carriage. i did it on the vee way machine but this is a pretty light weight machine. i wanted something stronger and not likely to break for the unstoppable machine. the only problem with the cable drive is that there are no stock pulleys for it, you have to make your own.
Here is a Link to the Filament to print the IGUS bushings. This stuff was developed by IGUS for 3D printing… It ain’t cheap though!!! Then again, neither are the ready made bushings!!
http://tinyurl.com/y88lbay4
Could you not use a pulley like this one for a cable/wire drive?
I’d worked with something similar back in the day when I repaired black and white copiers… The scanners were cable driven and the motors had a pulley on them similar to this with several wraps of the cable… Never slipped.
http://www.ereplacementparts.com/images/part_884352.gif
the filament is really interesting but quite expensive. my 3D printer fucks up so much and the amount of experimenting necessary to get good adhesion etc is usually very wasteful of material. not a big deal if it costs $10 a pound but this stuff is more like $200 a lb. interesting that you can get CAD files of the IGUS bearings to use for printing.
the pulley looks interesting too. my pulleys do not have spiral grooves, because they would be too difficult to machine. the only concern is whether there are enough grooves to provide enough linear motion. the problem with the servo motor was that it needed a gear reduction. if the pulley is just the right diameter and has enough grooves it might be perfect. what is the diameter? does it have holes and some way to clamp the cable? with a spiral pulley i think you get linear motion of pi times the number of grooves minus 1 but it might be minus less or more. with my pulleys you need to sacrifice more like 2.5 wraps because the cable always needs one full wrap at each extreme to prevent it from winding in the wrong direction. the spiral grooves prevent that so you just have to stop rotation with maybe a 90 degree safety margin.
what is the diameter of the pulley and what does it cost?
this page give some hints as to the size and details of the pulley. it looks like it is a pully for a serpentine belt not for a cable and it also looks like it is pretty small in diameter. so it looks like more looking is needed to find a suitable ready made pulley. i bought an old surplus scanner about 30 years ago that used the spiral cable pulleys. this is what made me think about trying it for the Shagmatic.
http://www.ereplacementparts.com/porter-cable-360vs-type-3×24-variable-speed-belt-sander-parts-c-129_1997_2027.html
The Scanner drive cable system is exactly what I was referring too. I worked on Ricoh black and white copiers about 25 years ago, which was where I was introduced to that type of drive system.
I’ve done a LOT of searching and have really come up with a hot, steaming cup of jack squat. It seems that manufacturers have retired using cable drive systems.
I’m going to stick with the same motor I have, and change out the friction roller drive for a belt… The XL belts are leading my list at the moment. I think I’ve come up with a fairly simple (in my mind) retrofit.
I’ll keep you posted!
P.S…. It’s really good to be getting back into the swing (stroke??) of things!!
Came across this on the RobotDigg website. It’s for NEMA 23 motors, so concrete smashing wouldn’t be on the menu but I think this might be a viable route for some people. For the cost, it might be worth looking at… Thoughts?
https://www.robotdigg.com/product/1101/Robocults-belt-driven-linear-guides
All variations they offer are under $100…
looks pretty light weight but worth a try. i just used the timing belt machine with husband a couple of days ago and it was more than strong enough. responded quickly and never seemed to miss a beat. it has a NEMA 24 motor that has the same mount as a 23 so it could be used with this system. My main concern is the small platform but maybe there is an option to make it longer.
I could not find the larger units nor the various options. The big one is supposed to handle 25 kg as opposed to 10.
one other thing. my timing belt machine has a guide at the end of the vee rail unit to support the ram tube. this could be added to the above unit if a larger carriage is not available.
did not see information as to the materials for the rails and bearings. my vee rail uses rollers and aluminum rails. not the most wear resistant design so it will be interesting to see how it stands up. maybe the above unit has better design.
i looked the site over again and again and can not find information on the heavier unit. also could not find any specs or information as to what is what. for example it is mentioned that they are up to 3 meters long but there only seem to be 200 300 and 500 numbered units which i assume are MM lengths. still trying to determine what rollers or bearings are used and other details. anyone want to try one?
I’m thinking I’ll give one a shot… If it doesn’t work out for the fucking machine, I’ve got a few other projects that it would be ideal for.
Question…
How much change is there in the coding/wiring to go from a stepper motor to a Servo motor? Not sure it’s worth the effort, but I find the advantage of servo motors over steppers very appealing. Now that you’ve played with both, what are your thoughts?
the code needs to be adjusted minimally. just need to set appropriate max speed and acceleration. the servo will work fine with the default settings but can run faster so the max might as well be increased. if you use a gecko servo motor drive there is no wiring change. it takes step and direction signals just like the stepper drives. setup of the driver can be a little confusing. servo motors absolutely such at low speeds. i tried one on the unstoppable machine and it did not work at all. i spoke to the support people at Gecko and was informed that servos do not work well at low speeds. they can run very fast so the solution is to gear them down a lot. for the cable machine i made a very large pulley and this forced the servo motor to run much too slow. if i had made a smaller pulley (about 1/3 to 1/5 the diameter) it would work well but that would require many wraps on the pulley to get a reasonable stroke. the cable walks across the pulley and creates alignment problems if it walks too much. i’m sure there are solutions but can not think of any now. the nema 34 double stack (massive) stepper is difficult to stop so i am not going to bother trying the servo for a while. they work really well on my router but that is geared about 5 to 1 by the ball screws. could make a ball screw machine with a servo.
I’ve considered a Ball Screw or Acme threaded type drive, just hadn’t really done the math to see if the speed would be in the right range.
I’ll be ordering the parts I need to convert my friction drive Shagmatic to a belt drive this weekend… Should be pretty simple.
If servo motors like higher speeds, then gearing down would make sense, but then I would think at ‘balls to the wall’ speed, the servo motor would be flat out screaming… but then again, at that speed, I doubt it would be heard over the ‘fuckee’!! 😉
I came across this on the same website as the linear drives… I’m guessing this is something similar to what ShockSpot uses. It’s pricey at just under $700, but it has an 8″ travel, and it’s max rated speed is 10″/second… That would make ANYONES day!
At what speed does good quality lube break down? Maybe look to Castrol or Valvoline for lube at these speeds! LOL!
https://www.robotdigg.com/product/947/Servo-Motor-Electric-Cylinder-4-Motion-Simulator
that unit is probably a ballscrew with belt drive from the motor. you could make the same thing for less with more stroke if desired. it is nice to have some extra in case the machine moves or ??? i made a machine with a 4 start screw and plastic nut. it worked OK but was difficult to service. also needed a square rod so it would not turn with the motion of the screw. a ball screw would be better than the plastic nut. the ball screw and servo are a good match because of the (typically) 5 to 1 ratio of the screw. servo motors are pretty quiet even at high speed.
interesting, like nothing else out there thats for sure pretty cool