Festool 20mm Hinge Bit + Router Runout.

[lasttoleave]

Hello,

I have a newly purchased 20mm Festool Router bit that I am hoping to make some different sized MFT style work spaces with. I have two Triton routers that I rate very highly, although obviously not quite up to festool standards.

I did some test holes with the 20mm bit and found the resulting holes were measuring 20.3mm and were rather rough with ridges on the internal face. I tried plunging in various stages on the slowest speed to reduce burning, but all of them ended up inconsistent and nowhere near clean or accurate enough to use on an MFT top. I'm using precision dogs and they fit the original MFT holes perfectly.

I highly doubt it is the bit itself causing the issue, but I have only seen a few people say the bit actually fits these bench dogs as well as the MFT. I can now only assume that it is play in the plunging mechanism of my router itself whilst I've never noticed any issue before, I expect that's because I nearly always plunge, lock the height and then do my routing. Here I am relying on the accuracy of the plunge mechanism not to cause any runout.

Everyone here seems to use Festool routers for this task understandably, and as much as I would love to purchase an OF 1010/1400 I don't have that kind of money at the moment. My plan was to get a template CNC'd with 30mm holes to match a guide bush, then use the guide bush and the 20mm bit to bore my holes, but I need to sort out the sizing first.

Assuming it's a bit of play in the plunging mechanism, theres nothing I can really do to improve this except use a smaller router bit and guide bush with a template machined up to result in a smaller router bit creating a 20mm hole.. but I think this will be much more harder to get as accurate.

Does anyone else think this is likely to be the cause? Or does anyone have a suggestion of something to try to improve the situation? I haven't read anyone here saying the bit creates anything other than finely bored holes.

 

[ear3]

How is the router secured when you're doing the plunging -- could this be causing some slight movement?

Have you seen the Wood Rave template?  Picked one up to make my own bench, though have yet to use it:

http://woodrave.blogspot.com/p/blog-page.html

Hello,

I have a newly purchased 20mm Festool Router bit that I am hoping to make some different sized MFT style work spaces with. I have two Triton routers that I rate very highly, although obviously not quite up to festool standards.

I did some test holes with the 20mm bit and found the resulting holes were measuring 20.3mm and were rather rough with ridges on the internal face. I tried plunging in various stages on the slowest speed to reduce burning, but all of them ended up inconsistent and nowhere near clean or accurate enough to use on an MFT top. I'm using precision dogs and they fit the original MFT holes perfectly.

I highly doubt it is the bit itself causing the issue, but I have only seen a few people say the bit actually fits these bench dogs as well as the MFT. I can now only assume that it is play in the plunging mechanism of my router itself whilst I've never noticed any issue before, I expect that's because I nearly always plunge, lock the height and then do my routing. Here I am relying on the accuracy of the plunge mechanism not to cause any runout.

Everyone here seems to use Festool routers for this task understandably, and as much as I would love to purchase an OF 1010/1400 I don't have that kind of money at the moment. My plan was to get a template CNC'd with 30mm holes to match a guide bush, then use the guide bush and the 20mm bit to bore my holes, but I need to sort out the sizing first.

Assuming it's a bit of play in the plunging mechanism, theres nothing I can really do to improve this except use a smaller router bit and guide bush with a template machined up to result in a smaller router bit creating a 20mm hole.. but I think this will be much more harder to get as accurate.

Does anyone else think this is likely to be the cause? Or does anyone have a suggestion of something to try to improve the situation? I haven't read anyone here saying the bit creates anything other than finely bored holes.

 

[Michael Kellough]

You can read that the Festool 20mm hinge boring bit makes oversized holes here.

 

[John H]

[list type=decimal]
[*]Purchase a replacement MFT "Plate" to be used as a template  (usually around $90
[*]Clamp the template to your work-piece with a backer board underneath
[*]Use 5/8" drill bit to remove the bulk of the material from the holes
[*]Use a router with a 1/2" flush trim bit (bearing on top) to clean up the holes - leaving a perfect copy
[/list]

 

[lasttoleave]

How is the router secured when you're doing the plunging -- could this be causing some slight movement?

Have you seen the Wood Rave template?  Picked one up to make my own bench, though have yet to use it:

http://woodrave.blogspot.com/p/blog-page.html

Hello, I have seen the Wood Rave template but it is producing the holes that is more of an issue at the moment. for my test holes, I had the router secured to an oversize base plate which was clamped very securely to the MDF, so I am confident there was absolutely no movement between the base and the MDF itself.. which leads me to believe it must be the runout either caused by the plunging mechanism or maybe the collet/arbor itself?

You can read that the Festool 20mm hinge boring bit makes oversized holes here.

I am less concerned with the holes being oversized at the moment as the bit itself measures in at exactly 20mm, if not a hair under using two sets of vernier calipers, so I am confident that the design of the bit is not the reason, and I am doubtful it's a fault with the bit (yet).

[list type=decimal]
[*]Purchase a replacement MFT "Plate" to be used as a template  (usually around $90
[*]Clamp the template to your work-piece with a backer board underneath
[*]Use 5/8" drill bit to remove the bulk of the material from the holes
[*]Use a router with a 1/2" flush trim bit (bearing on top) to clean up the holes - leaving a perfect copy
[/list]

I tried this, with three different brands/sizes of flush trim bits and they each came out inaccurate/unsuccessfull. It also shaved the original holes ever so slightly towards one edge which meant my dogs were loose on the few holes I did test route.

At the moment I am just trying to get closer to the results others seem to be having. This was tested on 18mm MDF, the same as the MFT table. But I can't get the bit to bore a clean hole whatsover at the moment. Can anyone weigh in with their experience using this bit? It seems to take a reasonable amount of pressure to bore the hole, which appears to be unavoidable.

I would like to find out what is actually causing the runout, I might see if I can borrow a router from a friend and compare results.

 

[tbellemare]

I'm pretty certain, as "lasttoleave" stated, that it's not the bit.

There are a lot of variables, not the least are the router and collet. There's also how securely the router is located relative to the work piece and how planer the work piece is as presented to the router base.

The Festool 20mm boring bit, 491072, has a very sharp perimeter cutting edge that normally maintains a near perfect hole surface but if it isn't plunged straight down, it will open up the hole. The LR 32 set up works so well because it locates the router quite securely in the intended spot and a clean plunge is easy.

Tom

 

[lasttoleave]

I'm pretty certain, as "lasttoleave" stated, that it's not the bit.

There are a lot of variables, not the least are the router and collet. There's also how securely the router is located relative to the work piece and how planer the work piece is as presented to the router base.

The Festool 20mm boring bit, 491072, has a very sharp perimeter cutting edge that normally maintains a near perfect hole surface but if it isn't plunged straight down, it will open up the hole. The LR 32 set up works so well because it locates the router quite securely in the intended spot and a clean plunge is easy.

Tom

The 8mm collet is brand new as this is the first 8mm bit I have owned. But in order to verify this I have actually done some more testing:

Firstly, I removed the larger triton from the table and put the 20mm bit in the collet. I then inverted the router and protruded the bit just high enough to expose the visible shank. I got a dial caliper clamped to the router base and measured for runout. it's within 1 thou, so I am now certain it is not the runout of the actual collet/arbor.

I bored a few test holes with the larger router in the same manor, I screwed it to an oversized base plate and tightly clamped the base plate to the MDF, which was clamped to my MFT. I can't really see anything that about this set up that would yield such different results than others.

I have tried varying the motor speed and plunging speed with no real difference. The bit just seems to want to burn a lot, so I have to raise it back up to remove some loose chips and to reduce the heat before plunging back down, the hole clears in about 2-3 plunges, but it's a nasty result.

I should also mention that without the height lock on (for obvious reasons when plunging) I did notice a tiny amount of play in the smaller router, which I assumed may have been the cause, but the larger table mounted router has absolutely no detectable play in it whatsoever, probably because it has lived in the table since day one.

Should the bit be expected to cause burning quite this badly? I am running out of ideas on how to remove any more variables. I am running on the slowest speed but I can't work out why the holes aren't coming out clean.

 

[tbellemare]

How bad is the burning, and exactly what is it you are using for a work piece?

Can you make a short video of plunging a hole? It might reveal something???

I'm grasping for straws but have sold well over a hundred of these bits and never had anyone tell me they weren't happy. I have one myself that I use for demo's. It gets dirty pretty fast in certain materials and that can cause problems. Those problems start with burning and that never has a happy ending...

Tom

 

[Holmz]

...
I tried this, with three different brands/sizes of flush trim bits and they each came out inaccurate/unsuccessful. It also shaved the original holes ever so slightly towards one edge which meant my dogs were loose on the few holes I did test route.
...

In addition to runout, you would want to check the bit is normal to the face, and that the plunge is normal to the bottom face.
As the router also had a poor result there may be more than one thing happening.

If the "... ever so slightly towards one edge ..." changes when when the router is rotated 180 degress, then it is the co-linearity of the bit with the base & plunge.

Was the "Ever so slightly" tapered?

 

[rst]

I have bored at least 600 holes with that the Festool bit, LS32, and my 1400.  All the holes were perfect.  You may want to check your router, using a dial indicator against shaft where the collet is inserted to check for bearing wear.

 

[Holmz]

I have bored at least 600 holes with that the Festool bit, LS32, and my 1400.  All the holes were perfect.
...

I was having a hard time finding the part # for the 8-mm shanked 20-mm bit.

 

[rst]

The Festool bit I used was from Bob Marino... 491072

 

[lasttoleave]

In addition to runout, you would want to check the bit is normal to the face, and that the plunge is normal to the bottom face.
As the router also had a poor result there may be more than one thing happening.

If the "... ever so slightly towards one edge ..." changes when when the router is rotated 180 degress, then it is the co-linearity of the bit with the base & plunge.

Was the "Ever so slightly" tapered?

I think I might have explained that situation poorly, but I was trying to copy an existing MFT top and I was routing with a template flush trim bit. I set the height of the router so that the bearing was exactly halfway into the template hole, and I was finding that the exposed cutter just shaved template enough to notice.

I have put the longest bit I have in and used a square on the base and checked at various angles but it all seems to be dead square, I've also used that bit to trim some hardwood and the results were dead square as well which would rule out any serious misalignment between the base and bit.

I've now tried the 20mm bit on 18mm MDF and 12mm plywood that the clamping sub base was made from, all have similar results with both routers.

How bad is the burning, and exactly what is it you are using for a work piece?

Can you make a short video of plunging a hole? It might reveal something???

I'm grasping for straws but have sold well over a hundred of these bits and never had anyone tell me they weren't happy. I have one myself that I use for demo's. It gets dirty pretty fast in certain materials and that can cause problems. Those problems start with burning and that never has a happy ending...

Tom

The burning is quite severe but it helps if I plunge in short bursts, but this seems to exaggerate the ridges on the internal face.

I don't think its the bit, and I can't really change much about the placement of the router itself which leaves inaccuracies of the router and its plunging action. I have a friend who owns the OF 1010. Do you think its large enough to cope with this job? Or would I really need to try and find an OF1400 to test this properly.

I noticed the bit gets nasty quickly in mdf but I've been cleaning it between tests.

 

[tbellemare]

The 1010 should handle it.

Tom

 

[lasttoleave]

The 1010 should handle it.

Tom

Thanks, I'll take the bit over soon and see how it handles it. Do you happen to know from yours or customer experience whether the 20mm hinge boring bit creates holes suitable for qwas/precision dogs or if it consistently leaves them oversize at 20.2mm?

 

[tbellemare]

'Sorry, but I don't know the answer to that. Perhaps a question for Steve Adams (Qwas). He seems to have pretty intimate knowledge of just how his products perform in various applications.

Tom

 

[rst]

I use Precsion dogs and they fit snugly, with no slop.

 

[Holmz]

...but it helps if I plunge in short bursts, but this seems to exaggerate the ridges on the internal face.
...

Are the ridges the full circumference? or they only 1/2 around?

 

[Bohdan]

Set the router on its slowest speed and plunge as fast as you can in one go. See if that makes a different sized hole and eliminates the burning.

 

[rst]

When I make my holes in MDF, I make my plunges one continuous plunge, adjusting the speed depending on bit size.  Even when metal machining, with the rigidness associated with that type work there is ridging, probably not as pronounced, but none the less present.  In metal working precise holes are made oversize and then reamed to final size.  Try slowing the speed, adjusting plunge rate and making a continuous plunge.