How well do they hold up to coolant residue? Coolant is usually pretty harsh on plastics. That is my worry about printed gripper jaws.
Largest Manufacturing Technology Community on the Web
Stay Connected:
Recommendations on robot grippers
- Thread starter wmpy
- Start date
- Replies 31
- Views 2,030
How well do they hold up to coolant residue? Coolant is usually pretty harsh on plastics. That is my worry about printed gripper jaws.
Digital Factory
Aluminum
- Joined
- Apr 1, 2023
- Location
- Southern California
I used PETG to print spring loaded "hands" on our lathe turrets when we need to hold parts and cycle the chucks in cycle. You can also get an assortment of reinforcements in PETG filament if you need add some beef to whatever you're printing.
PC would be another ideal material for this but PETG is so easy to print and readily available I've never bothered.
DavidScott
Diamond
- Joined
- Jul 11, 2012
- Location
- Washington
Nylon would be an excellent resin for coolant exposure since it is very, very, resistant to chemical attack, as well as strong, abrasion resistant, and generally quite tough. If you use a grade that likes to absorb water, 6/6, then it will expand up to 3%. If you use a better grade in the 6/12 variety then it is far less of an issue. By the way, most plastics absorb water, just to a lesser extent. I used to design and make plastic parts for sailboarding so have quite a bit of experience with this topic.
Polycarbonate is about the worst resin to use with coolant/chemical exposure. Many grades will simply crumble in a few months with no load on them. Some will fail from exposure to oil from our skin.
Last edited:
PC is resistant to water, oil and paint thinner (hopefully not a lot of that in your coolant!) my bad ass-u-me ing it would hold up to coolant as well... Got a few old Nalgene bottles that have been filled with just about everything other than water to prove it.
So stick to PETG if your printer doesn't have a high temp hotend and a heated chamber
So stick to PETG if your printer doesn't have a high temp hotend and a heated chamber
DavidScott
Diamond
- Joined
- Jul 11, 2012
- Location
- Washington
I come here to learn so take this in that spirit. Please take note that I said GRADE of PC and not all PCs. Obviously whoever specced the grade of PC to make the Nalgene bottles did their homework, knowing that it would be exposed to many oils and who knows what will be put in them. I also think PC is often used for the windows in our machines with no or little ill effect. On the other hand, I personally have had the crystal of a vacuum gauge and the bowl of a water separator develop cracks and crumble away when exposed to my coolant, and Blum learned the hard way about it in the windows of their probes. Not all grades of PC will do this, but most will. So if you are going to use PC for an application that will see any chemical exposure, including skin oil and hand lotion, then you need to do your homework or you're pulling the lever on a slot machine, with worse odds of winning.
JuicyBurger
Plastic
- Joined
- Jun 10, 2023
I used to sell robots for CNC machine tending (mainly UR, also Motoman, Denso, Omron/Adept) and it always surprised me that a machine shop would find it hard to make custom fingers for grippers. I'd say just machine them out of aluminum and move on. That being said, 3D printed is fine although I never did it for a coolant machine tending application.
So it totally depends on all the factors. But here you go:
Robotiq or OnRobot (haven't seen anyone mention OnRobot yet. I think they are beating Robotiq in the market now, every gripper can be quick swapped and auto-identifies and updates tool center point coordinates)"
If you are doing a co-bot
If you are setting it up yourself and have little automation experience
If you value plug and play and the least "unknowns" to get it running asap
If you don't want to run air
Schunk/Zimmer:
If you don't care about money and you want it to run forever
SMC:
if you do care about money and can handle it probably only running for 20 years.
Something I like to bring up when dealing with robot end-of-arm-tooling is that most people assume you need to buy some sort of fancy robot gripper to go with your fancy robot. The truth is you could bolt a 2x4 to the tool flange and then ziptie a nail gun to it and figure out how to trigger it with a relay and it would work just fine. So if you've got a handy kid on staff that's looking for a fun project you could make a gripper from some cheap pneumatic cylinders and some garbage linear bearings. Or anything. But the industry robotic grippers are in fact very nice. For example with Robotiq or OnRobot you have complete control over how far they open/close, how fast they open/close and with how much force. Which can be really useful when you need to open the fingers to a specific width to fit into a tight spot on a certain part. And programming it takes 5 seconds. It takes a bit longer in terms of thought, design and implementation to do this with pneumatics but most integrators do in fact use pneumatics for the low cost and reliability.
This is just talking about 2 finger parallel grippers. You can also use vacuum, magnetic, rotary grippers, etc.
Robotiq Hand-E has less force than the 2F-85, but the Hand-E is IP67 which is usually a plus when dealing with coolant. And even if you think coolant won't get on it, it's always dripping from somewhere when the robot goes in to pick up a part. You might want to look at getting an inexpensive robot suit as well if you use coolant that can drip, I've seen the last joints on UR fail within a year from seemingly nowhere. Coolant dripping.
I've done a lot of random applications so if you have any questions feel free to throw them at me.
So it totally depends on all the factors. But here you go:
Robotiq or OnRobot (haven't seen anyone mention OnRobot yet. I think they are beating Robotiq in the market now, every gripper can be quick swapped and auto-identifies and updates tool center point coordinates)"
If you are doing a co-bot
If you are setting it up yourself and have little automation experience
If you value plug and play and the least "unknowns" to get it running asap
If you don't want to run air
Schunk/Zimmer:
If you don't care about money and you want it to run forever
SMC:
if you do care about money and can handle it probably only running for 20 years.
Something I like to bring up when dealing with robot end-of-arm-tooling is that most people assume you need to buy some sort of fancy robot gripper to go with your fancy robot. The truth is you could bolt a 2x4 to the tool flange and then ziptie a nail gun to it and figure out how to trigger it with a relay and it would work just fine. So if you've got a handy kid on staff that's looking for a fun project you could make a gripper from some cheap pneumatic cylinders and some garbage linear bearings. Or anything. But the industry robotic grippers are in fact very nice. For example with Robotiq or OnRobot you have complete control over how far they open/close, how fast they open/close and with how much force. Which can be really useful when you need to open the fingers to a specific width to fit into a tight spot on a certain part. And programming it takes 5 seconds. It takes a bit longer in terms of thought, design and implementation to do this with pneumatics but most integrators do in fact use pneumatics for the low cost and reliability.
This is just talking about 2 finger parallel grippers. You can also use vacuum, magnetic, rotary grippers, etc.
Robotiq Hand-E has less force than the 2F-85, but the Hand-E is IP67 which is usually a plus when dealing with coolant. And even if you think coolant won't get on it, it's always dripping from somewhere when the robot goes in to pick up a part. You might want to look at getting an inexpensive robot suit as well if you use coolant that can drip, I've seen the last joints on UR fail within a year from seemingly nowhere. Coolant dripping.
I've done a lot of random applications so if you have any questions feel free to throw them at me.
So you're a salesman, not a machinist.
You wouldn't understand. There's significant opportunity cost to making one-off parts like robot fingers. Successful shops are extremely selective at what they make vs what they buy. 3D printing helps bridge the gap.
It's not that making fingers is hard. It's that it's a fucking waste of time.
Rather than scoff at your former customers' reactions, try to understand where they're coming from. Honestly you should've figured that out a long time ago.
Last edited:
JuicyBurger
Plastic
- Joined
- Jun 10, 2023
Hello and thanks for the response, although you seem to be in a somewhat aggressive mood that I'm sure has nothing to do with me. Hope your day gets better.
Yes it surprised me which one could reword as "I didn't understand". "Wouldn't" is a stretch.
Yes I used to be a salesman. Although more accurately worded: a highly skilled mechanical engineer and automation consultant. Currently I don't think I'd call myself a machinist, but I have machined things and I have machines and I have a machine shop. What arbitrary line would you define... where crossing it would make someone a machinist?
Maybe you didn't manage to see the part where I said 3D printing is fine and I hinted/said that I did in fact do 3D printed robot gripper fingers. I did many, actually. I mainly meant to point out that many machine shops spent a ton of time worrying about how to get fingers, or which grippers to use, when they had all the tools at their disposal to just go make some. The amount of time spent in analysis paralysis was generally greater than the amount of time it would take to hop on a manual mill and just make a couple aluminum fingers
Lastly I'm not sure "being surprised" is anywhere near "scoffing at my former customers' reactions". I understand very well everything you say/assume that I do not understand.
Honestly I'm just going to move on assuming your post is a joke and take it light hearted. Because there's no way I see that someone could jump to so many assumptions and write so many negative things in one post without trying to be funny and accidently sounding rude.
Yes it surprised me which one could reword as "I didn't understand". "Wouldn't" is a stretch.
Yes I used to be a salesman. Although more accurately worded: a highly skilled mechanical engineer and automation consultant. Currently I don't think I'd call myself a machinist, but I have machined things and I have machines and I have a machine shop. What arbitrary line would you define... where crossing it would make someone a machinist?
Maybe you didn't manage to see the part where I said 3D printing is fine and I hinted/said that I did in fact do 3D printed robot gripper fingers. I did many, actually. I mainly meant to point out that many machine shops spent a ton of time worrying about how to get fingers, or which grippers to use, when they had all the tools at their disposal to just go make some. The amount of time spent in analysis paralysis was generally greater than the amount of time it would take to hop on a manual mill and just make a couple aluminum fingers
Lastly I'm not sure "being surprised" is anywhere near "scoffing at my former customers' reactions". I understand very well everything you say/assume that I do not understand.
Honestly I'm just going to move on assuming your post is a joke and take it light hearted. Because there's no way I see that someone could jump to so many assumptions and write so many negative things in one post without trying to be funny and accidently sounding rude.
I have 3 Fanuc,3 gripper arms, a UR and OB7, the Fanuc arms all have Schunk and the oldest ( 10 yrs) has well over 2 million cycles and ZERO problems, just start with the best, build quality steel fingers w/serrated faces and as much adjustability into them as you can and you only do it once, i have a set of fingers/bases for a schunk 140 that goes from 0"- 4".
For the 3d printed gripper fingers being used out there, do you have a machined base jaw that these fingers are mounted to? It seems like the interface to mount directly to a Schunk gripper body wouldn't lend itself to 3d printing all that well.
gkoenig
Titanium
- Joined
- Mar 31, 2013
- Location
- Portland, OR
Use the BSWB quick change plug kits. You can fasten the studs into the 3D print easily enough, and it negates the need to make giant bores through the fingers.
BSWS-PGZN-plus Jaw quick-change system -
SCHUNK has the world's largest gripper system and clamping technology range and the broadest standard gripping component program on the market.
