best way to cut polyurethane

[b20a86lude]

i was wondering wats the best way to cut polyurethane bushings from energy suspension thnx for help.

[lostforawhile]

i was wondering wats the best way to cut polyurethane bushings from energy suspension thnx for help.lathe, kind of hard to do on a sander, they melt, cut some down years ago to make my front sway bar bushings. stuff is a pain to work with.

[Hauntd ca3]

if you freeze it good and proper first, it makes it far easier to do anything with.
just have to be quick before it thaws and gets soft again

[Civic Accord Honda]

i would think a dremel would work tho never worked with it so couldnt say for sure
ive used a knife to cut up rubber bushings tho au

[89T]

i use a drill press as a lathe. lol. it works :)

[Rendon LX-i]

a mini tourch...just like i did to removal the lower rear shock bushing and it pushed out like a smoor.....melts it like butter..thats only if your trying to removal it

[cygnus x-1]

Depends on what you want to do. If you just need to cut it in half or something simple then a sharp knife might work. Or if you need to machine it then freeze it in dry ice. And use a compressed CO2 blast to keep it cold longer. It might be mill-able too with really sharp tools if you can find a way to hold it down.

C|

[2oodoor]

mini torch and heat the blade of a utility knife or other knife

[Ichiban]

We machine polyethylene, which is a bit more rigid than polyurethane, but still sort of squishy. I've also machined rubber, which is quite a bitch. I've milled it with carbide and high speed steel end mills, but the best way to turn it is to use extremely sharp HSS with tons of rake and relief, a large nose radius, and moderately light cuts. Chucking and holding the material can be a challenge, as it readily changes shape and likes to bugger off under tool pressure.

[Tomisimo]

lol.. what a thread..

[lostforawhile]

We machine polyethylene, which is a bit more rigid than polyurethane, but still sort of squishy. I've also machined rubber, which is quite a bitch. I've milled it with carbide and high speed steel end mills, but the best way to turn it is to use extremely sharp HSS with tons of rake and relief, a large nose radius, and moderately light cuts. Chucking and holding the material can be a challenge, as it readily changes shape and likes to bugger off under tool pressure.
I put it in the lathe then notched it with a cut off tool,and cut it off holding a hacksaw blade while it was turning makes a mess too.

[Ichiban]

I put it in the lathe then notched it with a cut off tool,and cut it off holding a hacksaw blade while it was turning makes a mess too.

I can well imagine.

We machine this crap called Nylatron, it makes the stupidest floaty stringy rats nest chips you can imagine. Go too fast and it melts.

[2ndGenGuy]

Yay melty twisty burney plastic shavings! Must be fun in your eye!

[LX-incredible]

What exactly are you modifying the bushings to fit?

[cygnus x-1]

I can well imagine.

We machine this crap called Nylatron, it makes the stupidest floaty stringy rats nest chips you can imagine. Go too fast and it melts.


Nylatron. I'll remember that. Is it anything like oil filled nylon? I milled some of that a few weeks ago. Went ok with nice sharp tools. Except that it has lots of internal stresses so it warps like a mofo. Was milling PVC today. I quickly discovered the trick for that is low speed and high feed. Otherwise it just melts into a big wad of goo. And it smells horrible.

C|

[Ichiban]

Nylatron. I'll remember that. Is it anything like oil filled nylon? I milled some of that a few weeks ago. Went ok with nice sharp tools. Except that it has lots of internal stresses so it warps like a mofo. Was milling PVC today. I quickly discovered the trick for that is low speed and high feed. Otherwise it just melts into a big wad of goo. And it smells horrible.

C|

Good christ does PVC ever stink. Last week I had to bore out some sort of housings (x3 of them) to press in some nylon sleeves that were machined at some other shop. The smart ass manager at the shop tells me to measure each sleeve, and make the housing a .001 press fit. Except each sleeve runs out .02-.03 on the OD. And one is clearly .01-.015 under the size on the print. Not what I wanted on a Friday afternoon.

Turns out if the nylon bushing is a little tight, the edge of the metal housing shaves it to size before it enters the bore.:bong:

[b20a86lude]

wow guys amazing respones. thnx i got lots of ideas now
also im modfyin a strut bushing thats tad to big and i need like a inch off of it .

[lostforawhile]

Yay melty twisty burney plastic shavings! Must be fun in your eye!ought to try these hardened castings for my forks, cut with carbide specialty inserts with no coolant,have scars all over my arms from burns http://www.youtube.com/watch?v=cEwPL0ogjLw

[Ichiban]

ought to try these hardened castings for my forks, cut with carbide specialty inserts with no coolant,have scars all over my arms from burns http://www.youtube.com/watch?v=cEwPL0ogjLw

Seen it.

I should post up a video of roughing on a lathe at work, it's the orange Csepel I posted pictures of earlier, taking .7" off per side makes some pretty amazing chips. Got scars from that too. I was threading on it one day, and a chip popped off the tool, hit me in the mouth, stuck to both my lips, and burnt my tongue trying to push the thing off my lips.

[Ichiban]

Nylatron. I'll remember that. Is it anything like oil filled nylon? I milled some of that a few weeks ago. Went ok with nice sharp tools. Except that it has lots of internal stresses so it warps like a mofo. Was milling PVC today. I quickly discovered the trick for that is low speed and high feed. Otherwise it just melts into a big wad of goo. And it smells horrible.

C|

It's dry. Full of Moly powder I believe.

[lostforawhile]

Seen it.

I should post up a video of roughing on a lathe at work, it's the orange Csepel I posted pictures of earlier, taking .7" off per side makes some pretty amazing chips. Got scars from that too. I was threading on it one day, and a chip popped off the tool, hit me in the mouth, stuck to both my lips, and burnt my tongue trying to push the thing off my lips.
been there done that, not as bad as the time that piece of metal i had cut off with the angle grinder, cut it off slapped my hat back on and the hot piece of metal was in my hat. had a burn on my forhead for weeks after that.

[2drSE-i]

So just out of curiousities sake, Cygnus have you ever tried to make your own performance bushings at work? Sounds like you've got some awesome material to play with, you know......when you dont have like uh....work to do.

[cygnus x-1]

It's dry. Full of Moly powder I believe.

Oh, ok. MDS filled. I have a sample of some of that but never used it. I have turned nylon though, and it does suck. At least with milling you get lots of little tiny tough stringy chips, that are easy to blow away. With turning you get one giant tough stringy chip that wants to take over the world, and has the ability to do it.



So just out of curiousities sake, Cygnus have you ever tried to make your own performance bushings at work? Sounds like you've got some awesome material to play with, you know......when you dont have like uh....work to do.

Seems like all I ever do is work right now. It just never seems to translate into very much money. But that's life when you're a small operation.

Never tried to make any performance bushings. It would be more cost effective to cast them though if you wanted to use polyurethane. I've looked into it before but not seriously.

C|

[2drSE-i]

Unfortunately the money just wouldnt be there to produce them, in all honesty. If i ever came up with the cash, would you be able to fab poly bushings or motor mounts if i provided new, oem grade stuff? This is nowhere in the near future, but just for curiosities sake.

[Ichiban]

Unfortunately the money just wouldnt be there to produce them, in all honesty. If i ever came up with the cash, would you be able to fab poly bushings or motor mounts if i provided new, oem grade stuff? This is nowhere in the near future, but just for curiosities sake.

I've thought about this myself, and unfortunately, a lot of these products are somehow bonded to metal backers/sleeves etc. The actual machining of the parts is simple, however the bonding requires dedicated manufacturing techniques (such as pouring the insulator around the sleeve or on the backer) that only major manufacturers have the equipment to carry out. If that makes any sense.

[lostforawhile]

oh, ok. Mds filled. I have a sample of some of that but never used it. I have turned nylon though, and it does suck. At least with milling you get lots of little tiny tough stringy chips, that are easy to blow away. With turning you get one giant tough stringy chip that wants to take over the world, and has the ability to do it.






C|hahahahahahahaha!!!!!!!!!!!!!!!!!!!!!! Weapons of machine destruction

[Ichiban]

hahahahahahahaha!!!!!!!!!!!!!!!!!!!!!! Weapons of machine destruction

Don't laugh. One OD roughing operation on a large piece of this crap produced a ball of chips large enough for our welder to completely hide inside, and jump out at other unsuspecting employees.

[lostforawhile]

Don't laugh. One OD roughing operation on a large piece of this crap produced a ball of chips large enough for our welder to completely hide inside, and jump out at other unsuspecting employees.

has Saddam heard about this? oh never mind , last thing I heard he was "hanging" out somewhere

[gp02a0083]

It's dry. Full of Moly powder I believe.

could be, stuff pretty cheap, i used to work a a moly plant stuff stains everything black like graphite , if you want to know its Mo just put some in water, if the water turns blue its got a certain type of Mo

[cygnus x-1]

I've thought about this myself, and unfortunately, a lot of these products are somehow bonded to metal backers/sleeves etc. The actual machining of the parts is simple, however the bonding requires dedicated manufacturing techniques (such as pouring the insulator around the sleeve or on the backer) that only major manufacturers have the equipment to carry out. If that makes any sense.


For control arm bushings I don't think it would have to be bonded to any sleeves. The poly bushings on my truck for example just slide into the control arm and the sleeves slide into the bushings. The joints do have grease fittings though so that might be the difference. Also, OEM type mounts and bushings always seem to be rubber not poly. Rubber probably wouldn't last as long as poly in a slip fit type application, especially without regular lubing. And OEMs want to minimize maintenance requirements. Anyway I think there are some poly bushings that fit the lower arms aren't there?

For poly engine mounts, they would have to be designed in such a way that the poly is completely captured. Just like the B swap mounts elsewhere in this forum. It eliminates having to bond the poly to the metal and it also makes it so that just the poly can be replaced if it wears out. If you really wanted to bond poly to a metal plate or some such, it might work if the interface surface was textured somehow, like knurling or maybe just coarsely machined. With the poly then poured onto it. It would take some experimentation to get right.

For making motor mounts economically we don't really have the right equipment. The best way to make mounts is to cut the pieces out of say 1/4" steel plate, and then bend (if needed) and weld the pieces together. Plate is best cut with a water jet or laser, which we don't have. It can be done on a mill but it's slower and wastes more material. We don't have any bending machines either. I can weld but that won't help much without the other stuff. We mostly make machines and fixtures for manufacturing, so little if any forming or welding is required. Most everything we make is milled.

Control arm bushings would be easier if they don't need to be bonded to anything. A mold could be machined out of aluminum and casting poly poured in. If it's done right, little to no machining should be required.


C|

[cygnus x-1]

Don't laugh. One OD roughing operation on a large piece of this crap produced a ball of chips large enough for our welder to completely hide inside, and jump out at other unsuspecting employees.


The last nylon job I did was with this oil filled nylon that's bright green. The chips were light and fluffy, and colored neon green. When I was done the base and table of the mill were buried in bright green fluffy chips. It looked like a demented cross between a Terminator robot and a Sesame Street monster! :eek:

Funny stuff.

C|

[lostforawhile]

For control arm bushings I don't think it would have to be bonded to any sleeves. The poly bushings on my truck for example just slide into the control arm and the sleeves slide into the bushings. The joints do have grease fittings though so that might be the difference. Also, OEM type mounts and bushings always seem to be rubber not poly. Rubber probably wouldn't last as long as poly in a slip fit type application, especially without regular lubing. And OEMs want to minimize maintenance requirements. Anyway I think there are some poly bushings that fit the lower arms aren't there?

For poly engine mounts, they would have to be designed in such a way that the poly is completely captured. Just like the B swap mounts elsewhere in this forum. It eliminates having to bond the poly to the metal and it also makes it so that just the poly can be replaced if it wears out. If you really wanted to bond poly to a metal plate or some such, it might work if the interface surface was textured somehow, like knurling or maybe just coarsely machined. With the poly then poured onto it. It would take some experimentation to get right.

For making motor mounts economically we don't really have the right equipment. The best way to make mounts is to cut the pieces out of say 1/4" steel plate, and then bend (if needed) and weld the pieces together. Plate is best cut with a water jet or laser, which we don't have. It can be done on a mill but it's slower and wastes more material. We don't have any bending machines either. I can weld but that won't help much without the other stuff. We mostly make machines and fixtures for manufacturing, so little if any forming or welding is required. Most everything we make is milled.

Control arm bushings would be easier if they don't need to be bonded to anything. A mold could be machined out of aluminum and casting poly poured in. If it's done right, little to no machining should be required.


C|energy suspension makes a series of universal poly motor mounts which i think can be adapted over with some work, doesn't the front cross member unbolt from the car? if it had threaded bushings welded in in the correct places some of the universal mounts could be used to replace the front mount easy.

[b20a86lude]

so wats the verdict wats the best way to cut them iv read alot but not sure havnt cut yet

[b20a86lude]

To make a round bushing that stands out short would all u guys agree a lathe is the best way

[cygnus x-1]

To make a round bushing that stands out short would all u guys agree a lathe is the best way


If it's the kind of bushing I think you're talking about (something like the link below) you could use a mill or a lathe. Just depends on availability and preference. I make lots of round parts on a mill because I don't have a CNC lathe. It might also depend on what kind of stock you are starting with. On a mill it's usually easier to hold on to rectangular things, and on a lathe it usually easier to hold on to round things. But you can do both on either.

But if you are really serious about making poly bushings I think it will be easier/cheaper to have a mold made and then use castable poly compound to mold the parts. Squishy materials like poly are not fun to machine. Which means that whomever is doing the machining will want more money.


http://www.energysuspension.com/universal-products/link-flange-type-bushings-universal-mounts-isolators.html


C|

[Ichiban]

Yes, a lathe. Preferably with soft jaws bored to the OD of the stock. This will increase your holding power. Turn with high speed steel sharpened to an exaggerated positive rake.