63 dia hole in plate

[howardm]

Hi,
I am looking to an alternative to having to buy a rotabroach 63mm cutter at 80 squids.
I have 12 brackets, 80x80x8 angle 90 long and need a 63 diameter hole in one face. Any suggestions.?
thx
Howard

 

[brightspark]

Hi,
I am looking to an alternative to having to buy a rotabroach 63mm cutter at 80 squids.
I have 12 brackets, 80x80x8 angle 90 long and need a 63 diameter hole in one face. Any suggestions.?
thx
Howard

buy a 63mm starret hole saw and an arbour slow speed with cutting compound in a pedestal drill no problem. ive cut through a half inch rsj on a building with a 3inch one using a power drill about 20 quid with arbour. depends on the acuracy required

 

[madkayaker]

hole saw low speed and plenty of coolant

 

[Hitch]

Id go with the holesaw, but get a couple.
Starrett, Bahco...both good quality. The red screwfix own ones are pretty good too.
Id steer clear of the Bosch ones with the quick release arbour though.

 

[howardm]

Thanks guys,
Screwfix are out of stock, so they are on order.
Ay least I had some other bits to get on with today.
Two steps back one step forward.

 

[Drains]

Id steer clear of the Bosch ones with the quick release arbour though.

A lad at work was using one of those last week - 89mm. I re-ground it four times. Poo.

 

[Burf86]

get a ring as a guide and use a plasma cutter

 

[greek]

try lenox holesaws 1 is good for 80-100 holes in 3mm

 

[nodeward]

trepan it, thats how i would do it, might take a bit longer but you wont go through a load of hole saws

 

[Slim Shady]

Ridgid one are good buy pricey. Last ages if minded

 

[inchpincher]

A lad at work was using one of those last week - 89mm. I re-ground it four times. Poo.

How do you re-ground a hole saw?

ta,

 

[brightspark]

How do you re-ground a hole saw?

ta,

with a dremmel and a diamond cutter touch em up on the cutting edges it works a few times

 

[Drains]

I do it with a 115mm cutting disc - 1/8th thick type. Saw in left hand, angle grinder in right, Get the angle right and dip disc into the teeth, turn the saw to the next tooth, do it again.
Once you get a rhythm going, it's easy. And it works. The tooth geometry may change a little - depends on the profile of the disc, the angle you go at etc, but as Brightspark says, you can do it a few times (depends on what kind of saw it is as to how much of it is hard enough). Saves pounds, downtime, and trips to the suppliers.

Also, you don't need to worry about getting all the teeth the same, as most holesaws start life with variable tooth size. It means not all the teeth cut, and as a high one gets blunt the next takes over.

 

[inchpincher]

Who would of thunk it, thanks guys, looks like my bosch ones will be getting a new lease of life lol...

 

[ronan]

You could also cut the holes in a milling machine if you had access to one , drill first and then use a boring head , depends how accurate it has to be, i'd steer clear of the eclipse holesaws though as they are (or used to be) really brittle.

 

[howardm]

Change of design needed methinks.
A three of of twelve holes , and, drill brushes expire.

 

[brightspark]

drill must have been on the way out to start with a decent 650w drill will last for years .i use 25mm augers all day long it dont slow the dril down it pulls u round with it brown trouser and bycyle clip job

 

[Welderpaul]

What you making Howard?

 

[howardm]

Hi Paul,
It's a yacht cradle, hopefully........
Heres more pics of current progress

http://s176.photobucket.com/albums/w197/aitchem/Cradle/

Howard

 

[Welderpaul]

Looking good! Probably have got some flat plate plasma-cut to form the hole, then welded to a plain flat to form the angle (Or folded it from one piece of flat once the hole had been plasma cut if you have access to the kit)
Those tubes slide into the holes? Hole looks very close to the edge of the angle?