Cutting 6" diameter hole in 3/4" rubber mat

[Bill D]

I want to put a horse stall mat under and in front of my lathe. To go under I need to cut two six inch diameter holes for the lathe feet pads. I was thinking hole saw or jig saw. Mat is too big and heavy to use a flycutter in the drillpress. I cut straight cuts with a razor knife but curves that tight would be hard to do. What about a grit edge holesaw. I could reuse that for cutting plasterboard for ceiling light sand ducts.
Bill D

 

[Garwood]

I have holesawn lots of 5" holes in 3/8" conveyor belting to make rubber pads for my skates. Helps to have a wood backer.

If there was a way to hold a razor blade very rigidly that would be an ideal way to make the cuts. I cut a fair amount of reinforced silicone tubing. I do it using a mandrel in the lathe and a toolholder I made that holds a razer blade. When the blade is rigid it cuts through like butter.

Horse stall mats aren't reinforced. They cut pretty easily. As mat in front of a lathe horse stall mats really hold in the hot chips. Wood slat mats work alot better IMO.

 

[David Ferguson]

Any chance you could "sharpen" a piece of pipe and punch the holes using a press, trailer tongue, or even a hammer and block of wood.

 

[DDoug]

So your going to jack up the lathe to get the floor mat under it ?
Why not simply cut out some slots ?
Jigsaw should work well.

And why all this precision hole slicing anyways ?
it's going under a lathe

 

[Scottl]

Do you have a hand tapper?

It's very easy to make a beam compass attachment that holds a blade. You simply apply a lubricant such as 50/50 dish soap and isopropyl alcohol and turn the crank until it cuts all the way through. Cutting distance from an edge is limited by either the spindle to post dimension or how large a diameter you can swing with the arm rotated on the post.

Basically creating a DIY version of the old gasket cutters that used to be found in so many garages.

 

[henrya]

I’d use a regular hole saw and have someone keep a stream of water on the cut. Lay the mat over some wood to keep the mat flat and support the cut.

 

[michiganbuck]

Likely you watched this video
It seems there is no quick easy way.

 

[Scottl]

If you are willing to sacrifice a hole saw grind off the teeth and grind a scalloped bevel similar to some cooking knives. Use with a good lubricant which can be as simple as dish detergent in water although I prefer a 50/50 mixture of dish soap and alcohol which is what I use when I cut circular gaskets on the lathe with an X-Acto knife in a boring bar holder and a sacrificial liner such as white Azek on a face plate.

 

[DDoug]

If you are willing to sacrifice a hole saw grind off the teeth and grind a scalloped bevel similar to some cooking knives. Use with a good lubricant which can be as simple as dish detergent in water although I prefer a 50/50 mixture of dish soap and alcohol which is what I use when I cut circular gaskets on the lathe with an X-Acto knife in a boring bar holder and a sacrificial liner such as white Azek on a face plate.

If you've got a 6" hole saw, why not just us it as is ?

 

[dalmatiangirl61]

Use a regular hole saw with a wood backer, make sure the drill bit is long enough that it engages the wood before the hole saw engages mat. Maybe try sandwiching the mat with a piece of 1/4" plywood on top so the hole saw does not drift.

 

[no704]

you can get '"knife edge" jigsaw blades.

 

[Strostkovy]

Oscillating saw is 100% the way to go. I don't hate my wrists enough to use a 6" holesaw in rubber
Jigsaw probably works but sounds like a pain.

 

[Hightemp]

Round hole is definitely tougher. For straight cuts, if you haven't done many yet, I found a pretty easy way. First cut just use a utility knife and straight edge. Don't have to go too deep or push to hard. Then bend it so the cut opens, stand on it, and then freehand right in the open cut. It opens right up with barely any pressure.

 

[Scottl]

If you've got a 6" hole saw, why not just us it as is ?

Because it requires a lot less force to use a knife edge with lubricant and doesn't leave "fuzzy" edges. Horse mats are tough and friction will make the saw quite hot.

A thinner, cheaper metal cutting hole saw would be the easiest to modify and could easily be done on a belt sander.

 

[DDoug]

Because it requires a lot less force to use a knife edge with lubricant and doesn't leave "fuzzy" edges. Horse mats are tough and friction will make the saw quite hot.

A thinner, cheaper metal cutting hole saw would be the easiest to modify and could easily be done on a belt sander.

"fuzzy edges" on a floor mat placed under a lathe ?
Who cares ?
Get the damn job done already.
Maybe the OP could take this inexpensive horse mat to a waterjet shop and $300 later, have the "Mat of his dreams"....

 

[boslab]

I’d use a router with a template guide, I’ve had success with this before, but not on steel reinforce belting!
Mark

 

[kwfiggatt]

Here's a cool trick for using a hook style razor blade in an oscillating saw. Captain Hook That'd be what I'd try for cutting the rubber mats...

 

[seiner]

bevel the inner edge of a 6" cylinder, something hard and push it through with your hydraulic press on a wood backer. easy peasy hole punch.

 

[Bill D]

Turns out a #10 can is about 1/2" too small a dimaeter. I wa sthinking het it with a torch and melt it through. Make lots of nice smells that way.
Bill D

 

[GregSY]

I've done this with 3" holes. I tried many methods (punching, drilling, hole saws) and what worked best was machining a piece of Sch 40 pipe to make what would be a punch die with a sharp edge but then welding a 3/4" shaft to it so I could spin it in a drill press. Fairly slow rotation and moderate down pressure with a little WD40 type oil produced a very clean cut. It was a very controlled, low energy situation, which I like because it allows me to get a good result while wearing open toed shoes, shorts, and dreaming of the old country.

For a 6" hole...I'd use some 6" exhaust tube from the local diesel shop and weld a back to it so I could chuck it up.