Why NOT plastic for a base plate?

[Suzuki4evr]

I just received my three phase motor and vfd to convert my mill to three phase. I don't really want to put a slot in the new motors flange because that could forfeit the guarantee.

So I wanted to make a new base plate that sits on the ram and put the slot in that for tensioning the v-belts. My question is if there is a reason for NOT using something like HDPE. The section where the motor sits is 40mm thick. The pics below are of the current moror and I basically want to make a new base plate as cheap and functional as possible. I know ali or cast iron is preferable but.........budget.


Any thoughts are welcome.

Michael

 

[DavidR8]

What about phenolic?

 

[Suzuki4evr]

What about phenolic?

If it is cheaper than HDPE and dence enough then I'll go for that. Thanks David

 

[C-Bag]

Are you sure I chunk of HDPE that big is cheaper than a chunk of steel? Plastic in big chunks on eBay is surprisingly expensive.

 

[Larry$]

I'm chicken. I'd stick to metal. This is a long term thing. Will the plastic deteriorate from heat, ozone?? or weight?
The new motor will likely have the same C face specs. Just interchange them. I don't think that plate is an integral part of the motor.

 

[kb58]

My first thought was "cold flow", which is an issue with certain plastics to a varying degree. Phenolic would be better, but yeah, seems like a scrap piece of flat metal should be at any scrap yard.

 

[Suzuki4evr]

Are you sure I chunk of HDPE that big is cheaper than a chunk of steel? Plastic in big chunks on eBay is surprisingly expensive.

I sent out quote requests today so I will find out tomorrow.

 

[Suzuki4evr]

I'm chicken. I'd stick to metal. This is a long term thing. Will the plastic deteriorate from heat, ozone?? or weight?
The new motor will likely have the same C face specs. Just interchange them. I don't think that plate is an integral part of the motor.

That is another option I am considering.

 

[Alexander McGilton]

I had the motor to my Chinese made lathe catch fire on me when the starting contacts maintained contact while running. It likely was not made to CSA or NEMA regulations. the lack of a thermal over load is a strong indication to that. Had to replace the motor.

I recommend that you at minimum use self extinguishing materials to your motor mount, ideally steel as said before.

 

[benmychree]

Phenolic would be a good choice, it is hard and rigid and does not deteriorate. and is easy to machine with ordinary tools, including sawing.