Thread: Radial arm saw blades

Originally Posted by thebicyclist

More then that; it is dangerous to push cut.

When you pull cut the first teeth are pushing the work back into fence and down towards the table, when you pull cut the first teeth are pushing the work forwards into the operator and up into the blade...

Hmmm. The rising teeth may try to lift the work, but the blade rotation is the same so I can't see it pushing the work forwards ... ?

Paul McGee

Originally Posted by elanjacobs

it is designed only to pull into the work

ditto

I have an old Supersaw RAS, with a 100mm x 12" trenching st and it needs a firm hand to control it on the pull stroke, but much easier to make a push cut - so I was interested whether anyone else had found that.

Thanks,
Paul McGee

I do lots of push cuts Paul. Depends on the material and depth etc.
Same with dado.
Do love the RAS and with lots of jigs I have made can do many things. Rarely use it for ripping except for thin material where accuracy is important.
You just need to be aware of what you are doing, which is the case with all machines.

cheers
conwood

Originally Posted by pmcgee

I have an old Supersaw RAS, with a 100mm x 12" trenching st and it needs a firm hand to control it on the pull stroke, but much easier to make a push cut - so I was interested whether anyone else had found that.

Thanks,
Paul McGee

Hey Paul,

I'm taking back my "Ditto". That is a Beasty you have there, & I can certainly see how you would have more control over a push cut. That setup would take some hanging onto I recon.

I guess it's fair to say that a pull cut would be best in most cases, same as pushing timber through the blade on a table saw is the preferred method, but when cutting coves, you need to adjust the rules.

The number one rule is to be able to count to 10 at the end of the day.

Steve

When looking at a Radial Arm Saw is it better to get a larger machine say 12 inch? I believe you can use a smaller diameter blade on a larger machine

I have used a smaller blade on my RAS and it worked ok. But I did that as an "emergancy". I've now got the proper size back on, and see no reason for using the smaller blade again, until another "emergancy" arises.

The problem with a smaller blade, is that you loose clearance above your fence/job and the motor body as you lower the cutting head for a full depth cut. That may, or may not be an issue for you.

Cheers

I have a DW1251, now about 30 years old.

I'm a fan of negative rake blades, using -5 degrees preferably. More teeth for finer cuts and smaller work, and less for bigger timber and coarse work.

For trenching, or in my case its more likely to be tenoning, I use a NZ made variable wobble saw. The eccentricity is variable between about 1/4" and 3/4" and it has just a few very positively raked TCT teeth. To counter the grabbing tendency, the teeth must be extremely sharp, and the assembly is relatively small in diameter (about 175mm?).

Generally zero & neg. rake is used for crosscutting purposes. In critical materials, such as veneered and coated surfaces, more teeth and neg. rake combine to leave less breakout and splintering.

Positive rakes are generally better suited to ripping cuts, with more rake, and fewer teeth providing a coarser cut but better performance in thicker and heavier materials.

Personally I would not recommend using a RAS for ripping. I know it's possible. I've done it myself, using a chip limiting blade. However, the RAS performs poorly in my opinion, and the action is quite dangerous in having a somewhat exposed blade spinning above the workpiece and in front of the operator in the direction of feed. I just don't trust those anti kickback pawls either.

I'm not really sure if RAS are still available. The local TAFEs decommissioned and disposed of all theirs as too "dangerous". Probably a wise move considering how rough and hamfisted some apprentices are with tools and machinery. I guess they just don't fit in with current OH&S legislation.

I still think they're a superior tool in many ways (e.g. trenching and tenoning) to a SCMS. I know which tool I'd rather use for making windows and doors.

Originally Posted by Ratbag

I'm not really sure if RAS are still available. The local TAFEs decommissioned and disposed of all theirs as too "dangerous". Probably a wise move considering how rough and hamfisted some apprentices are with tools and machinery. I guess they just don't fit in with current OH&S legislation.

They are certainly still available and fit in with OH&S in the North Island of Oz, I'd be interested to know what the TAFEs replaced them with

hi elan, do you have to clamp work pce down or not i have a dewalt radial arm saw and have never used it yet so was just wondering. cheers peter(grandad)

No need to clamp anything, just hold it against the fence with one hand and pull the saw with the other

Originally Posted by checkerflight

hi elan, do you have to clamp work pce down or not i have a dewalt radial arm saw and have never used it yet so was just wondering. cheers peter(grandad)

And don't pull it out in a rush. Keep a firm grip on the head and pull it out gently. If the blade jams, be ready to push the head back in quickly.

I guess the phrase, slow and steady wins the race, is applicable here. )

Cheers

Originally Posted by elanjacobs

They are certainly still available and fit in with OH&S in the North Island of Oz, I'd be interested to know what the TAFEs replaced them with

Festool Kapexes, with which they've had no end of trouble!

Extremely bad move, in my opinion.

Delicate, fragile machines & apprentices just don't play well together.

Dumb, just plain dumb