Festool 20mm boring bit vs CMT 20mm straight bit - a demo

[fritter63]

Not sure where the best forum for this post is.

LIke many others here, I'm in the process of making my own version of an MFT top with 20 mm holes so I can use the clamping elements. Mine are just narrow box beams that I'm using on a couple saw horses, a configuration I've decided I really like. They're not as wide as those designed by Ron Paulk, but I like the "split" ability of them, and they are easier to move around.

So, I searched the forum and while I certainly found several threads discussing which bit is bets to use for making the 20 mm holes, I was surprised that I couldn't find any strong opinions which to use (a rarity here!). So I ordered both the Festool 20mm bit as well as the CMT 20mm bit a did a test. Here are the results:

Setup: I used the OF 1400 with the LR 32 setup on a guide rail. I made two holes with each bit in 3/4" baltic birch ply:

Here are the two bits (after use, of course!)
[attachthumb=#]

Here are the holes cut by the Festool bit:

[attachthumb=#]

And here is the underside of those holes. Note that the ply was backed by rigid foam insulation

[attachthumb=#]

Here are the holes cut by the CMT bit:

[attachthumb=#]

And here is the underside of the CMT holes, once again backed by rigid foam

[attachthumb=#]

So the results are pretty clear to me. The CMT bit burned the sides of both holes, was harder to plunge, and caused more tearout on the underside (it's not clear how much tearout there would be if backed by plywood or MDF rather than rigid foam).

I'll be using the Festool bit for worktop holes.

 

[peter halle]

Thanks for doing that.  Pretty clear difference.

I am glad you said that that was Baltic birch.  I haven't bought any in quite a while.  That reminds me of a product Home Depot sells as Sandply - which is a nasty product IMHO.

Can't wait to see what you put together.

Peter

 

[sgryd]

Interesting test. Thank you.
I thought ply was less stable than MDF. Are you using ply for a work bench top?
//Michael

 

[ccarrolladams]

Interesting test. Thank you.
I thought ply was less stable than MDF. Are you using ply for a work bench top?
//Michael

Festool uses a denser version of MDF called HDF, which in their case is custom made for them.

My cutting table does not need to be especially stable, so I use 19mm cabinet-grade plywood which for one reason or another was not attractive enough to use for cabinets we sell. I consider this to be a sacrificial surface, so stability is not inportant to me. On the other hand, I find my saw blades stay sharp longer cutting into plywood as opposed to MDF or HDF. On my CNC nested routers I use LBO, mostly because the machines can pull enough vacuum through it to hold the actual work in place. Sometime the task on a CNC router cuts through the work. LDO works for me because it does not dull the tips of the router bits as fast as plywood or MDF, but those would not work anyway because they block the vacuum action.

 

[peter halle]

Carroll,

What is LBO or LDO?  I am not familiar with those.

Peter

 

[ccarrolladams]

Carroll,

What is LBO or LDO?  I am not familiar with those.

Peter

Those are similar products typically used in the sign industry because they weigh less and are very smooth with surfaces taking paint very well.

Possibly the second market segment is the CNC nested router trade. In my shop when both of the Nested routers are busy we can go through 6-8 sheets of LBO or LDO. Before CNC woodworking became popular LBO was mostly sold by sign-making suppliers. When CNC for woodworking grew, my primary supplier of cabinet-grade plywood began stocking those products.

 

[fritter63]

Interesting test. Thank you.
I thought ply was less stable than MDF. Are you using ply for a work bench top?
//Michael

These are box beams that need to be strong and portable.

MDF has no structural strength and is very heavy. It's just sawdust with glue...

 

[Jalvis]

Try telling that to David Marks.....
https://vimeo.com/5082731

 

[fritter63]

Try telling that to David Marks.....
https://vimeo.com/5082731

http://www.infidels.org/library/modern/mathew/logic.html#authority

 

[fastbike]

That particular bit isn't meant to be plunged. Not all straight bits are. You can see from the profile at the bottom.

 

[fritter63]

That particular bit isn't meant to be plunged. Not all straight bits are. You can see from the profile at the bottom.

Yeah, I was wondering.

 

[JeromeM]

Try telling that to David Marks.....

https://vimeo.com/5082731

His assembly table is a fixed one. So the weight of MDF in that particular case is a benefit not a drawback. My assembly table workbench is using MDF chipboard because they're heavy. If I were to make a portable version I would certainly be using plywood not MDF.

I also use the Festool. 20 mm hinge bit and it works quite well although there is some burning. Some of my projects using it are here.  http://festoolownersgroup.com/member-projects/20mm-hole-on-a-96mm-grid-system-(mft-top-style)/

 

[mattfc]

That particular bit isn't meant to be plunged. Not all straight bits are. You can see from the profile at the bottom.

I think the title of this says it all

Festool 20mm boring bit vs CMT 20mm straight bit

If you are drilling/boring a hole, use a drill/boring bit [smile]

 

[HaKLc]

That particular bit isn't meant to be plunged. Not all straight bits are. You can see from the profile at the bottom.

I think the title of this says it all

Festool 20mm boring bit vs CMT 20mm straight bit

If you are drilling/boring a hole, use a drill/boring bit [smile]

Exactly.
Festool bit is a drilling bit, but CMT is a router bit. Nice presentation though.

 

[Jalvis]

Try telling that to David Marks.....

https://vimeo.com/5082731

http://www.infidels.org/library/modern/mathew/logic.html#authority

Using references to validate a perspective is imperative to a discussion.  Imagine if everyone gave information without a reference mentally or verbally?  We need sources to build ideas and solutions which is why you gave a reference for your opinion on my response.  I think you will see that using ply for your table will be lighter but comes with inherent drawbacks of plywood such as chipping and stability which is one reason why the MFT doesn't have a plywood top.

I used David Marks as an example because he's known for using MDF far all kinds of structural uses....Some even accuse him of having stock in MDF.  Depending on support spans MDF and Particle cores are a great material and are used in Commercial and residential applications all the time.

Usually I don't respond to threads like this one due to the maturity of the post, but I thought you could use some help based on your lack of experience.
 

 

[fritter63]

Usually I don't respond to threads like this one due to the maturity of the post, but I thought you could use some help based on your lack of experience.

Now that was just rude and uncalled for. 25 years isn't exactly a "lack of experience".

http://ahsbandguitar.blogspot.com

Later.

 

[Jalvis]

I realize the last of my response to be repugnant.  Although stating my source as a "fallacy" is also distasteful even though my example is the exception not the rule.

Lack of experience as in using a Strait bit for boring...or Stating MDF as having "no structural strength'

Experience has little association with time.

All this being said I'm grateful for the link....I've spent over two hours reading the information and I'm not finished.  Reminds me of college discussions and courses.....Life was good when my only responsibility was learning.

 

[fritter63]

I realize the last of my response to be repugnant.  Although stating my source as a "fallacy" is also distasteful even though my example is the exception not the rule.

Lack of experience as in using a Strait bit for boring...or Stating MDF as having "no structural strength'

Experience has little association with time.

All this being said I'm grateful for the link....I've spent over two hours reading the information and I'm not finished.  Reminds me of college discussions and courses.....Life was good when my only responsibility was learning.

Apology accepted. I only used the straight bit because it was recommended elsewhere.

Be careful with that link, it's a slippery slope.... [cool]

 

[rmwarren]

Usually I don't respond to threads like this one due to the maturity of the post, but I thought you could use some help based on your lack of experience.

Now that was just rude and uncalled for. 25 years isn't exactly a "lack of experience".

http://ahsbandguitar.blogspot.com

Later.

Assume "Fritter" = "Frazier"?

Nice Guitars.

RMW

 

[fritter63]

Assume "Fritter" = "Frazier"?

Nice Guitars.

Thanks.

Uh,  nickname I earned for doughnut preferences during the first Dot-com boom..... (they were free!)