Hole Saw - experience - help please.

[Richardgregory]

I'm sort of a newbie when it comes to wood working and especially using a hole saw to drill a 3.5 inch hole into 3/4" plywood for a trackball.

I am using a Dewalt 20Volt Brushless drill and set the speed setting to 1 for higher torque instead of higher speed and the setting of the drill to the drill driver setting.

When I went to drill the hole, my experience was that the drill would catch on the wood and with such force that it through my grip off as my wrist went flying. 

What am I doing wrong?  Is it the drill that might not have enough power?  Or something else....

Would appreciate any help for next time...

Thank you

[Mike A]

It is a big hole saw for a hand drill. I find that high speed and a light touch helps keep it from binding.

[MartyKong]

I used a hole saw bit to drill my trackball hole. Whether you use high speed or low speed you need to keep the hole saw drill bit even especially when you start the hole. If you rock/angle the bit it can bind in the hole .... not great for the wrists! Start with a practice piece of wood, keep the bit square with the wood and apply light not heavy downward pressure until you get used to drilling it. The larger holes are more sensitive to binding but after you drill a few you'll get the feel for it

[jennifer]

 

[jennifer]

 

[bobbyb13]

It is a big hole saw for a hand drill. I find that high speed and a light touch helps keep it from binding.

This is it.
And be mindful that your drill is as perfectly square to the board as you can manage.

[tron319]

I needed to the do the same thing (3 1/4" hole) for a trackball.  I went with a forstner bit instead of a hole saw.  Found a decent not expensive one that worked perfectly on multiple panels.  Technique:

- Center punch the center of the hole (just a small mark to know where the tip goes)
- I used a drill press set to low speed and a backing board
- Drill into the panel until part of the hole is cut - say 1/8" into the wood
- Then I removed and cut out a hole about 3" with a hole saw.  The reason is to get rid of a bunch of the material from the center.  The rough edge of the hole saw is no problem as I'll finish with the smooth the forstner bit
- Put the panel back on the drill press, align the forstner bit to the groove you already cut and finish it right through

The last step is very easy as a bunch of the material was removed with the hole saw.

I did the forstner cut on a drill press but you could do both with a hand drill ensuring you keep it vertical/level.

Hope that helps!

[Gilrock]

Those big hole saws tend to wobble a bit before they get buried a bit into the wood.  It can tend to make the edges not very clean.  If that matters you can use the technique I use for another reason.  Ever cut a hole too small and need it bigger.  Well with the wood gone there is no way to guide the pilot drill bit.  So grab a scrap piece of wood where you're not too worried about being clean and cut out a hole.  Then clamp that piece of wood on top of the board and it will guide your hole saw for a nice clean start.  It needs to be thick enough that the saw is captive in the hole before the pilot drill hits the wood.  And like someone said to get it clean on the backside if its your first cut you can flip it over after the bit comes through and get it started from the other side to prevent blow out.

[Richardgregory]

Thank you!  That might have been it....maybe I wasn't completely square with the wood, and the slight angle was enough to bite into the wood and thankfully, my wrist was okay.  I'm actually a bit afraid to practice, but I know as they say, practice makes perfect, so I will - thanks again.

I used a hole saw bit to drill my trackball hole. Whether you use high speed or low speed you need to keep the hole saw drill bit even especially when you start the hole. If you rock/angle the bit it can bind in the hole .... not great for the wrists! Start with a practice piece of wood, keep the bit square with the wood and apply light not heavy downward pressure until you get used to drilling it. The larger holes are more sensitive to binding but after you drill a few you'll get the feel for it

[Richardgregory]

Thanks Jennifer - I have a drill press, but the challenge is the board is too big for me to secure to the drill platform   I think I'm using a bimetal saw too...not sure, but good to keep in mind.  Cheers!

I must say cutting into MDF was so much easier when I was working with that material!

The bigger the cutter more cutting surface, and consequently more Friction, a bimetal
works nice on ply because the teeth are smaller (usually 18 to a inch) and will be less grabby they also make an arbor with locking pins, (cost a little more) but it is spring loaded, (and well worth the extra cost) It will lock into the little holes on top of the cutter so all the stress isn't just on the center hole ( it will strip out on larger cutters) ... A drill press would be best, but if slowly cut halfway though flip it over, and using the center hole, finish the cut the tearout will be minimal, and contained in the hole...Or use a backing board behind the cut... And don't use an impact drill...Slow, even smooth, let the cutter do all the work.

[Richardgregory]

Thank you!  I'll try it in my next practice run. 

I needed to the do the same thing (3 1/4" hole) for a trackball.  I went with a forstner bit instead of a hole saw.  Found a decent not expensive one that worked perfectly on multiple panels.  Technique:

- Center punch the center of the hole (just a small mark to know where the tip goes)
- I used a drill press set to low speed and a backing board
- Drill into the panel until part of the hole is cut - say 1/8" into the wood
- Then I removed and cut out a hole about 3" with a hole saw.  The reason is to get rid of a bunch of the material from the center.  The rough edge of the hole saw is no problem as I'll finish with the smooth the forstner bit
- Put the panel back on the drill press, align the forstner bit to the groove you already cut and finish it right through

The last step is very easy as a bunch of the material was removed with the hole saw.

I did the forstner cut on a drill press but you could do both with a hand drill ensuring you keep it vertical/level.

Hope that helps!

[PL1]

Another option is a Dremel or router with a circle-cutting jig.






Scott

[Zebidee]

When using a hole-saw, it always helps to pre-drill the centre guide hole to same size as arbor (that's the drill bit in the middle). That helps keep your work central so you can focus on cutting the outer circle. The arbor shouldn't be doing any cutting work at all, just guiding the hole saw into the cut.

[Richardgregory]

Thanks!  I didn't know such existed.  I have a dremel tool, so I could try this as well, but I'm not sure how great it will be on 3/4" plywood.

Another option is a Dremel or router with a circle-cutting jig.






Scott

[PL1]

Thanks!  I didn't know such existed.  I have a dremel tool, so I could try this as well, but I'm not sure how great it will be on 3/4" plywood.

If you try to do it in a single pass, it won't be very good.   
- Multiple shallow passes are the way to go.
- Drill the pivot hole all the way through.
- Cut most of the way through on one side -- preferrably the top.
- Insert 3 or 4 dowels/wedges in the cut to hold the center plug in place or use double-sided tape to fasten the center plug to a board and clamp the control panel to the board. Either way, you don't want the center plug to shift when you finish the cut or the Dremel might take a bite out of the otherwise perfect hole.
- Finish cutting through from the other side. (reduces splintering/blowout)


Scott

[Mike A]

Leave it to a forum to totally overthink a simple job.

[jennifer]

 

[bperkins01]

I started reading this and PL1 has the best answer.. (because it was the one I was going to recommend of course)
Small holes are easiest with a Forstner bit for good control.  After they get to about 2-3 inches - the router adapter is the way to go.  You don't even need to go buy a nice one..  screw 1/4" ply to the base and just make one..

A drill press will let you use a large hole saw with teeth relatively easily.

Hole saw bits with teeth will fight you drilling by hand.  Chances are you also had your drill on max RPM?  Go minimum until the hole  is started.
faster is not better

[javeryh]

Probably too late but what I do is use the hole saw to drill a hole in a 1/4” piece of scrap MDF and then use that as a template with some double sided tape for the router.  Perfect hole every time.

[Ond]

Probably too late but what I do is use the hole saw to drill a hole in a 1/4” piece of scrap MDF and then use that as a template with some double sided tape for the router.  Perfect hole every time.

This is the clever way to cut perfect holes and other shapes. A router with a flush trim bit cutting along a template can cut through thick timber, recreating the exact shape every time.