Building a Pulse EDM machine

[Mark_f]

I needed a piece of PVC plate 3/4" thick to make the filter holder in my filter unit. This requires a ring 6" diameter with a 4" hole. I priced the PVC plate on line and the cheapest I could find was in excess of $60 with shipping. This, I cannot afford, so........


I cut some pieces of the 6" pipe off, split them in half.



Then I put them in the oven at 250 degrees until they relaxed and flattened out. I then put them on the counter and set a heavy weight on them to hold them flat while they cooled. I now had some 1/4" thick plates.


I coated them with PVC cement and clamped them together. They bonded into a solid sheet 3/4" thick and I didn't have to spend a dime.


I next cut a 3" hole with a hole saw in the center and sawed a circle out of the sheet.


I will put it in the lathe and machine the finished part and glue it into the filter unit.


More to come....
Mark

 

[savarin]

I needed a piece of PVC plate 3/4" thick to make the filter holder in my filter unit. This requires a ring 6" diameter with a 4" hole. I priced the PVC plate on line and the cheapest I could find was in excess of $60 with shipping. This, I cannot afford, so........
I cut some pieces of the 6" pipe off, split them in half.
Then I put them in the oven at 250 degrees until they relaxed and flattened out. I then put them on the counter and set a heavy weight on them to hold them flat while they cooled. I now had some 1/4" thick plates.
I coated them with PVC cement and clamped them together. They bonded into a solid sheet 3/4" thick and I didn't have to spend a dime.
I next cut a 3" hole with a hole saw in the center and sawed a circle out of the sheet.
I will put it in the lathe and machine the finished part and glue it into the filter unit.
More to come....
Mark

Love it Mark, my kind of thinking.
Cant wait to see it in action.

 

[NEL957]

Very nice Mark

 

[Silverbullet]

Got to love the pvc pipe, I have a length with joiners and screw caps I store my steel stock in it outback . Hanging up son I ride my chair up to it open pull out the tubing or angle . Good idea heating and spreading it out to use flat . Might call far a sharp deep relief high speed bit .

 

[Mark_f]

Man, This filter is working out great. I machined the ring for a snug sliding fit in the pipe. I machined a 4" hole in the middle of the ring and a shoulder for the ring in the filter bag to rest in.
I drew a line around the ring to show it's location in the filter. I then slid it down and spread PVC cement around the pipe.

I pulled the ring back up to the line. This must be done quickly as you only have about 15 seconds before the cement locks the ring in the pipe FOREVER! The glue forms a permanent bond that cannot be broken. The parts become one piece.

This is the felt filter bag. It has a metal ring sewn into the top. This ring sits in the shoulder machined into the plastic ring in the pipe.

This is the filter bag installed in the filter. I still have to make a filter basket that goes in before this filter bag.

This all worked so well, I decided to make the lid for the filter from 1/2" thick PVC. Why not, I have the pipe left over.

This is how i will make the lid. ( The same way I made the filter ring).
I cut two 12" lengths of the 6" pipe and split one side. Place in a 250 degree oven for about 5 minutes until soft.
Then lay them on the counter because it is a very flat surface and ........
Put a 3/8" thick flat aluminum plate to cover them and some extra weight until cooled. I have a 1/4" thick flat sheet of PVC for no cost (using left over scraps of pipe). The two sheets of PVC that I made for free in less than a half hour would have cost close to $100 dollars with shipping to order.

 

[rwm]

That's awesome! I'm gonna make some just to have on hand. Some of the PVC I have seen looks like foam in the middle? ANy special type?
R

 

[Mark_f]

That's awesome! I'm gonna make some just to have on hand. Some of the PVC I have seen looks like foam in the middle? ANy special type?
R

This is schedule 40 PVC pipe. If you can get hold of schedule 80 it is thicker. (the schedule 40 is 1/4" thick.

 

[Mark_f]

I will be altering my piping to and from the storage tank and work tank. I found a 3 way ball valve that is fairly inexpensive. By using this, you can't forget to open or close a valve. The valve is either one way or the other. It will make less fittings, Pipe, and be safer. I think it is worth the $27 investment.( probably save that much in parts it replaces). I am working on a drawing for the fluid circuit using this valve.

 

[Silverbullet]

Think I'm going to make some flat pieces to. Thanks Mark , what's the cooking instructions? 20 min to the pound basting every half hour. Lol. Really thanks

 

[Mark_f]

This is the preliminary design for fluid management. The 3 way, L port ball valve is an electric valve. It will connect to a DPDT toggle switch on a panel on the work tank. When the switch is flipped to "FILL" , the ball valve opens from the storage tank to the pump and turns the pump on at the same time to fill the tank. (The other ball valve in the fill line is just to regulate the flow).

When the switch is flipped to "DRAIN", the pump shuts off and the valve connects the work tank drain to the storage tank by gravity. The electric valve has "feedback" signals to light a pilot light on the panel indicating "fill" or "drain" if desired. This neat valve is available in the U.S. for about $400, But can be bought from China for $65.

If I haven't missed anything in this design, it makes the system idiot proof (more or less. I know idiots that can screw up anything)

I am liking this design as there are no valves to "synchronize" and will be a "cleaner" build. Any opinions are welcome here in case I missed anything.