Drilling the bellhousing of a D4

I did a conversion on a D2 using a carbide tipped hole saw... drilling was easier than I expected... hole saw still looks good enough to do several more. I think I bought the hole saw from McMaster Carr.

sounds like your hole saw is junk. you have to go as slow as you can 50-150 rpm max i know it hard to go slow but full trigger will get you know where you should be able too feel it cut are you getting any chips ? when i buy hole saw i try and stick with starrett, Milwaukee has a good brand too. you might have work harden it has it change color? if it has you might have to go the carbide way hope this helps

Yeah Ive been running it pretty slow, maybe 80 rpms, would go for 5 minutes, then let the drill cool. Im thinking it might just be my hole saw is junk. Gonna grab a carbide tipped tomorrow and see how it goes from there.

Be careful when finishing a hole with a new saw as there is less material to restrain the advance of the saw when going through the old part, the set isn't worn yet or different and the new saw will be sharp. It is real easy to over feed and chip the teeth.

the biggest thing with using a hole saw is you must remember that the teath are only an 1/8th of an inch deep so once the teeth are below the surface you have stop clean the hole all the time like every 30 seconds as there is nowhere for the swarth to go drill a bit then blow it out with compressed air I think you will find it will work much better I have never used carbide tip holesaws just normal steel ones with plenty of oil and keep blowing them out and drill thru steel an inch thick ok good luck

Paul

Pretty much what Paul says!
I've drilled some good sized holes in thick steel and found that constant cleaning is a necessary chore.
I've used Bi-Metal and Carbides based on availability.
Instead of blowing chips out, I vacuum them as I am usually drilling in a vertical plane. Horizontal like you are going should be no problem. "Heavy Duty" cutting oil(?) could actually have made your project worse as it may not be compatible with the material/cutter.

How much weight should we put on the drill - lean into it, or light?

the biggest thing with using a hole saw is you must remember that the teath are only an 1/8th of an inch deep so once the teeth are below the surface you have stop clean the hole all the time like every 30 seconds as there is nowhere for the swarth to go drill a bit then blow it out with compressed air I think you will find it will work much better I have never used carbide tip holesaws just normal steel ones with plenty of oil and keep blowing them out and drill thru steel an inch thick ok good luck

Paul

[quote="mrsmackpaul"]the biggest thing with using a hole saw is you must remember that the teath are only an 1/8th of an inch deep so once the teeth are below the surface you have stop clean the hole all the time like every 30 seconds as there is nowhere for the swarth to go drill a bit then blow it out with compressed air I think you will find it will work much better I have never used carbide tip holesaws just normal steel ones with plenty of oil and keep blowing them out and drill thru steel an inch thick ok good luck

Paul[/quote]

What you do to help with the chip clearing problem is to let the saw score the circular line, then drill a series of 1/8" or so holes around the circle so some of the swarf will have a place to escape.