20mm plunge bit

[JesseC]

I purchased the Festool 20mm bit and am really not happy with the results. The holes are consistent and clean, but they are to big. When measuring them with a caliper they all measure 20.17mm which I feel is introducing too much slop when used with dogs.

I have seen a few people are using bits that were designed for boring machines, and sound like they are getting good results.

What bits are you using for your home made MFT tops to get consistent 20mm holes?

Thanks,

Jesse

 

[ear3]

I used the CMT 20mm boring bit for my workbench, and would not recommend it.  The cut quality was fine, but it burnt the heck out of the MDF, which I understand doesn't happen with the Festool bit.

I purchased the Festool 20mm bit and am really not happy with the results. The holes are consistent and clean, but they are to big. When measuring them with a caliper they all measure 20.17mm which I feel is introducing too much slop when used with dogs.

I have seen a few people are using bits that were designed for boring machines, and sound like they are getting good results.

What bits are you using for your home made MFT tops to get consistent 20mm holes?

Thanks,

Jesse

 

[Cheese]

I used the Zobo 20mm bit in hard maple.

The holes vary from 19.9 to 20.0mm.

 

[DB10]

When I needed to knock up a MFT top, I used 20mm Zobo as well, the dogs are a really snug fit.

 

[rst]

I'm not sure what you are drilling, but I've drilled at least 900 holes with my 1400 and the Festool bit with not discernible play in my dogs.  I drill at speed 4, steadily, and without stopping.

 

[Svar]

I used 20 mm 3/8" shank Magnate 1808 Hinge Boring bit from Amazon to drill about 100 holes in MDF with perfect results. I think the speed was 15000 rpm. I used precision ground and polished 20.00 mm steel rod to check the size. It fit all holes snugly, just tight enough not to fall through under its own weight. On the other hand Magnate 25 mm bit was oversized, more like 25.3 mm.

P.S. Considering my and other people experience, bit sizing, even from the same manufacturer, is simply not consistent. This is in addition to router runout, technique, speed, material, etc. Check your bit with caliper.

 

[Birdhunter]

I got a bunch of perfect 20mm holes using the Festool Zobo bit in a drill press
I wonder if the drill has a minute amount of wobble, the hole could be larger than the drill diameter. Measuring the drill diameter could be interesting.

 

[bkharman]

I purchased the Festool 20mm bit and am really not happy with the results. The holes are consistent and clean, but they are to big. When measuring them with a caliper they all measure 20.17mm which I feel is introducing too much slop when used with dogs.

I have seen a few people are using bits that were designed for boring machines, and sound like they are getting good results.

What bits are you using for your home made MFT tops to get consistent 20mm holes?

Thanks,

Jesse

What were you using to cut?  1400, 1010?  What speed?  Were you on a LR32?  What dogs were you testing/fitting with?  What type or wood or was it MDF?

I have drilled several hundred holes in maple and MDO/MDF and they fit my Precision Dogs and Qwas dogs great!  My Parf dogs are a wee bit smaller and aren't as snug, but they are the exact same way with my MFT 3 and always have been.

Cheers. Bryan.

 

[JesseC]

The top that I am working with was left by one of my former tenants and is being used as a piece that I can learn from. The top 1/4" looks to be MDF with a melamine coating, which burns a lot. Under that it appears to be OSB which when cut slow cuts without any burning.

I used the CMT 20mm boring bit for my workbench, and would not recommend it.  The cut quality was fine, but it burnt the heck out of the MDF, which I understand doesn't happen with the Festool bit.

I purchased the Festool 20mm bit and am really not happy with the results. The holes are consistent and clean, but they are to big. When measuring them with a caliper they all measure 20.17mm which I feel is introducing too much slop when used with dogs.

I have seen a few people are using bits that were designed for boring machines, and sound like they are getting good results.

What bits are you using for your home made MFT tops to get consistent 20mm holes?

Thanks,

Jesse

 

[JesseC]

I am using and OF 1400 as well and regardless of the speed I get burning in the top layer, of what appears to be MDF. I suppose I could try to cut slower, but I was applying the same pressure the whole time so I do not know that the speed was the issue. All holes were cut with a single plunge.

I'm not sure what you are drilling, but I've drilled at least 900 holes with my 1400 and the Festool bit with not discernible play in my dogs.  I drill at speed 4, steadily, and without stopping.

 

[JesseC]

I believe that I have seen one of your posts in the past where you note that bit worked well for you, and it is in my cart with the Amana adapter as we speak. I bought the Festool bit based on reviews that I have seen that indicated that the bit was great for this purpose.

I agree and understand that there can be some variance between products, but when you are dealing with what is supposed to be a premium product and the manufacturing is that far off it is disappointing.

I put my calipers on the bit and it measured 20.11mm, my holes measured 20.17mm so there has either been a consistent runout of .06mm, or I was not able to get an accurate measurement of the bit. I got a measurement of 20.17 multiple holes, so I am fairly confident in that measurement.

I used 20 mm 3/8" shank Magnate 1808 Hinge Boring bit from Amazon to drill about 100 holes in MDF with perfect results. I think the speed was 15000 rpm. I used precision ground and polished 20.00 mm steel rod to check the size. It fit all holes snugly, just tight enough not to fall through under its own weight. On the other hand Magnate 25 mm bit was oversized, more like 25.3 mm.

P.S. Considering my and other people experience, bit sizing, even from the same manufacturer, is simply not consistent. This is in addition to router runout, technique, speed, material, etc. Check your bit with caliper.

 

[JesseC]

I was using an OF 1400 with a LR32 set up at speeds of anywhere and everywhere between 1 and 6. I did not have as much burning at 1 in the top layer of MDF as 6 but the hole size was consistent at 20.17 across the board.

They are Precision Dogs, that I am very happy with. I went all in, and with all of the items that I ordered I ended up with 16 dogs that were 19.96mm and 4 that were within .01mm of 19.96mm.

I was using a top that was left behind by a former tenant and the top 1/4" appears to be MDF with a melamine coating over 3/4" OSB. I can try some other scraps, but based on the consistency of the hole I would not think that the material is creating some sort of runout.

purchased the Festool 20mm bit and am really not happy with the results. The holes are consistent and clean, but they are to big. When measuring them with a caliper they all measure 20.17mm which I feel is introducing too much slop when used with dogs.

I have seen a few people are using bits that were designed for boring machines, and sound like they are getting good results.

What bits are you using for your home made MFT tops to get consistent 20mm holes?

Thanks,

Jesse

What were you using to cut?  1400, 1010?  What speed?  Were you on a LR32?  What dogs were you testing/fitting with?  What type or wood or was it MDF?

I have drilled several hundred holes in maple and MDO/MDF and they fit my Precision Dogs and Qwas dogs great!  My Parf dogs are a wee bit smaller and aren't as snug, but they are the exact same way with my MFT 3 and always have been.

Cheers. Bryan.

 

[MGB]

I used an offshore boring bit, made for a router. It was the only one I could find aside from festools.

I had to use a fast feed rate, with a low speed to eliminate any burning.

All my dogs fit well, I figured if I ever wanted to tighten things up, spraying a coat of clear over the top would take up that 0.05 of a mm.

 

[bkharman]

I was using an OF 1400 with a LR32 set up at speeds of anywhere and everywhere between 1 and 6. I did not have as much burning at 1 in the top layer of MDF as 6 but the hole size was consistent at 20.17 across the board.

They are Precision Dogs, that I am very happy with. I went all in, and with all of the items that I ordered I ended up with 16 dogs that were 19.96mm and 4 that were within .01mm of 19.96mm.

I was using a top that was left behind by a former tenant and the top 1/4" appears to be MDF with a melamine coating over 3/4" OSB. I can try some other scraps, but based on the consistency of the hole I would not think that the material is creating some sort of runout.

Is there anyway you can bore out another workpiece?  Or even flip you current workpiece?  I suspect that it is the melamine that is maybe the issue. Try just a scrap piece of pine or something.

 

[JimD]

I used a Freud when I built my Paulk style workbench.  I don't have any dogs nor have I measured he holes but the bit cut 3/4 plywood smoothly with no burning.  I had pre bored it with a 1/2 spiral up cut bit while I was waiting on the Freud to come mail order.  I need to make another bench top and plan to try it without the pre-boring. 

 

[Crazyraceguy]

I did mine with the Freud bit too. It only comes as  1/4" shank, so I was worried about some deflection,  but it never happened.  I did "pre-drill" them all with a 1/2" straight bit first though. I figured the smaller initial hole would allow for some clearance that would make for a quicker/cleaner/cooler cut. I used a Dewalt DW618 with the dust extraction up through the plunge column, it did work out great but it was a whole lot of work. My table is a full 4'×8' and 1 inch thick with 276 holes. 
Each one cut 3 different times. First cut with 1/2" bit, then with 20mm Freud bit, then turned over and chamfered on the bottom so that the clamps would fit in the holes too.

 

[mwildt]

[member=59428]JesseC[/member] Curious what the outer diameter is on the Festool bit ? Could consider machining it a tiny bit if not spot on.