Cutting tip for hole cutter

[Rich2502Participant @rich2502]

[Rich2502Participant @rich2502]

I’ve got an sheet metal cutter for a drill, the kind with a adjustable L shaped arm, and pilot drill, what kind of profile carbide tip would i need to silver solder on this, and where could i get one ?

[Clive HartlandParticipant @clivehartland94829]

I found it cheaper to buy a kit of those multi teeth circular cutters from Screwfix for about £8.00.

They are great and cut holes in all the materiels that I use.

I doubt I would ever use a single cutter type again.

 

Clive

[PatParticipant @pat]

The fly cuter is a pig to use on sheet metal. These cutters were also known as trepanning tools and often had two blades so that washers could be manufactured. The problem is the breakthrough when the cutters rake lifts the material and causes a massive dig in. This is very nasty process and one that I would rather avoid, Use the fixed saw tooth holes cutters any day in preference to the fly. The other problem is keeping the cutter radius locked.

 

I would keep my money and buy hole saws of the diameters as I needed them thus keeping my fingers. IMO the sets are nice to have but you may end up using only one or two, The versions of hole saw that use a clip on hacksaw blade are also bes avoided as they can wander and dig in.

 

Regards – Pat

[Peter TuckerParticipant @petertucker86088]

Hi Richard,

 

I would salvage a TC tip from a derelict wood saw blade.

 

Good luck.

 

Peter.

[Gordon WParticipant @gordonw]

I would not try to use a carbide tip on the usual drill mounted hole cutter, almost certain to break it. I’ve been trying to get one to work for years now. Only chance is to clamp very firmly onto a piece of thick board eg. kitchen top off cut, and cut from both sides. Following a lot of trials, and advice from this forum I,ve finally ended up mounting on the lathe where possible. Put an angle plate on the cross slide, mount backing board and plate to be cut onto the angle plate. Fit a flycutter on the face plate with a trepanning tool. Advance the saddle with leadscrew handwheel.

[Ian S CParticipant @iansc]

If the item to be bored is small enough to be mounted on a bit of wood and put in the 4 jaw chuck, thats the way I do it. Put a trepaning tool in the tool post, select a low speed and cut the hole. The tool looks similar to a parting tool, but the side on the inside of the bore is relivied to give clearance. With a tool like that I.v cut holes in 8 mm hot rolled plate, I was able to cut half way from one side then turn over and do the other half (had about 10 to do) Then I put a boring bar through, one cut was all that was needed. These were discs, and held in a three jaw chuck, I only needed to be within .5 mm concentricity. Ian S C

[Richard ParsonsParticipant @richardparsons61721]

The dreaded trepan aka a washer cutter!. I have had to use them -years ago. If you are cutting sheet metal then use a leaf shaped blade. The inner side of the blade is flat and the outer domed but coming to a sharp knife edge at the side and the point of the leaf. Using the confounded thing in a chippie’s hand brace the trick is to cut nearly through then turn the sheet over and cut from the other side. By the way make certain the backing board is very hard wood.

For thicker metal the tool is similar to a parting tool but thetrick is to work from both sides.

The golden rule is slow and easy.
Good luck

Dick

[mgjParticipant @mgj]

Ian I agree – I just superglue such items tt a bit of wood, or between 2 bits, and then chomp the hole.

 

Having said that, I’d rather if the thing permits use a conecut, or mark out the hole, and chomp with an air nibbler and then just trim the edges

 

Trepanning I’ve always found one of those things thats nice in theory, but best left to someone else to do.

[StovepipeParticipant @stovepipe]

Otherwise known as a “tank cutter”, after re-reading the OPs post ?

 

Dennis

[Robert Dawes 1Participant @robertdawes1]

Try drilling four holes in a slice of a bit of bar bigger than the hole you need. Three equispaced on a diameter for the cutters and one in the middle for the drill. Sharpen the cutters like a d bit and face them to cut either clockwise or anticlockwise. All clamped with grub screws. You can drill a hole in something like a fuse/circuit breaker box from the outside and mount the cutter block on the inside and pull it out with a battery drill. Saves you taking everything off the wall and taking the innards out to get space. Iv’e had success with roller bearings for the cutters. I used a Quorn to get all the cutters the same length but you could probably do it ok freehand. Three is like the legs of a milking stool and stabilises everything in a way which two cutters won’t. You can make it to cut whatever size you want. Robert.

[PatParticipant @pat]

Hi Dick The washer cutter with its leaf shaped cutting edges has a positive rake which is aimed at trying to avoid the dig in associated with the trepanning / fly cutter. Also the washer cutter works well in either direction of rotation and is a different animal.

 

If the work can be mounted in a lathe (or mill) then the set up will be a lot more rigid and the feed more easily controlled. Double sided tape helps but requires a certain knack to get good adhesion.

 

Regards – Pat

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