How to bore a hole through a cylinder of reconstituted foam?

[mart]

I am going to buy some reconstituted foam rollers for my weight bench (because I am lead to believe that this is the firmest type of foam know to man (or woman). How am I going to bore a hole through the center fairy accurately but it does not have to be perfect. (I have already considered a hot poker)

I’m going to upgrade the foam cushion rollers on my weight bench because they are such poor quality I can feel the steel bar (that runs through the center) pressing in to my leg(s)

Now I can hear you saying, “Mart, just buy some proper ones online yer tight wad”!

Trying to source some professional grade rollers (like they use in commercial gyms) is like pulling teeth when I get on the phone, but it was a woman on the other end of the line.

“What make is your bench” ?
“That doesn’t matter because you only need the internal diameter of the roller and maybe the length / width of the roller”
“But we need the make of the equipment”
But I want to buy rollers that are designed for a commercial grade bench not my bench, and I can give you all the sizes that you want”
“But they are all different, we need to make sure it will fit your bench”

I’d lost patients at this point. What if I have put a different bar through the frame. It is not going help anyone identify the roller size type now is it? In fact the one in the pc is not the orginal bar.

The pic is of the rollers that I am using at the moment, that I want to replace.

 

[DrNik]

if you ues heat make sure the hot bar is smaller than the finish size as it will shrink back quite a bit, im sure they mould it exactly as the picture,plenty of places in china, but how about asking a local DK Gym or a company that hires out or sell equipment, thats the easiest way save trawling round the net

 

[mart]

Yes, someone else mentioned hot wire. Must remember the shrinkage aspect.

I`m not sure how I will keep in the center though going all the way along.

 

[Wendelspanswick]

I would be tempted to use a length of tube with basic teeth cut into one end, like a really long holesaw, and weld a stub on the end to fit a drill.
I have cut foam with an electric carving knife and a TCT brick blade in a sawzall (reciprocating saw) and both worked well.

 

[gordon stephenson]

How about compressing the length between 2 plates with a hole in the centre,then use a wad punch type cutter to cut the hole.

 

[gaz_moose]

get a bit of tube the right size, chamfer the edge so its sharp like a knife and twist it through. I used to use this method to get smaller sausage shapes out of a big chunk of foam.

have you looked into car rollcage padding that's quite dense.
the padding at my gym is foam rubber.

 

[mart]

How about compressing the length between 2 plates with a hole in the centre,then use a wad punch type cutter to cut the hole.

Gordon, I have just been on Google images to see what a wad punch cutter looks like. Out of interest, what are those type of cutters normally used for-type of job & materials etc?

 

[AndyStobbs]

Gordon, I have just been on Google images to see what a wad punch cutter looks like. Out of interest, what are those type of cutters normally used for-type of job & materials etc?

Making holes in
Leather strapping,
gasket paper
tarpaulin

etc

 

[mart]

get a bit of tube the right size, chamfer the edge so its sharp like a knife and twist it through. I used to use this method to get smaller sausage shapes out of a big chunk of foam.

have you looked into car rollcage padding that's quite dense.
the padding at my gym is foam rubber.

Gaz, that is like the same principal of how an apple corer works isn`t it. I think that if I can make the tube sharp enough it should go through ok.

I have bought the reconstituted cyclinders of foam now and they are not as dense as I had hoped. I may still have to consider looking for that rollcage padding (I guess Google would be the place to start)?

 

[gordon stephenson]

Wad punches can be used on any material softer than themselves,When punching make sure you are not punching through to a steel surface, punching on to hard wood end grain is ideal, or a lead sheet,aluminium.copper etc. Also have you tried the foam split tubing that is used to fit over scaffold tubes when they are used in walkways to protect the pedestrians.

 

[Robotstar5]

Would Armaflex be any good?