Tapered round nose router bit.

[davidjonah17]

Hi,

I'm after a router bit. I'm not sure if it can be bought 'off the shelf' or would have to be custom made. Does anyone know a place to buy a round nose bit that is tapered? (Wider at end of bit). Or maybe another way of describing it would be a dovetail bit that is curved at the bottom.

I've attached an image that shows the profile (not exact measurements but explains shape).

Thanks for any help!

 

[carlb40]

Not sure i have seen any router bits off the shelf like that. You might need to contact Trend, Titman, Wealdens and see if they can make one for you.

 

[davidjonah17]

Yeah, I was thinking that might be the case. That usually means more expensive too! Thank you for the mention of the companies to contact though.

 

[marcros]

Is it worth trying to modify a dovetail bit with a diamond file? May or may not work.

 

[Grahamshed]

I get the feeling that having one specially made would be horrendously expensive so marcros's idea has to be worth trying.

 

[carlb40]

Is it worth trying to modify a dovetail bit with a diamond file? May or may not work.

Good idea. If it doesn't work i wonder if a local machine shop/ engineering firm or anywhere that deals with saw /cutter sharpening could just regrind the bottom of the TCT to the profile? That would be cheaper than a custom cutter.

 

[marcros]

Or other option- modify a solid carbide milling bit- probably cheaper than the dovetail bit and you can't run out of meat.

 

[deema]

Got to ask,what's it for? I've been trying to think why you would want the curve at the bottom of the channel? Just curious! Can't offer any suggestions unfortunately.

 

[Steve Maskery]

Back in the 80s I worked for a software house and I dealt with customers in the CNC world. One customer wanted to mill out recesses in moulds for vacuum-formed packaging - mince pies, sausage rolls and the like. The cutter had to be tapered to allow for mould release (the reverse of your profile). We had to have it specially made by modifying an off-the-shelf end mill. It was not as tapered as yours is.
I've not idea now how much it cost, but I do remember that it was not difficult for us to find a local engineering company who was happy to do the job.
The guys at East Midlands Saw and Tool in Long Eaton are helpful chaps.

 

[The Bear]

Whats it for, how big is it, what does the finish need to be like, how accurate does it need to be????

Depending on your answers there may be other ways to do this, such as utilising the tilt on a table saw.

Regards

Mark

 

[davidjonah17]

Thanks for all replies. It's a groove just over 50mm long and needs to be accurate and have a nice finish. I can achieve this same effect already with a few other methods but if I could find a router bit to create this shape in 1 pass it may be an easier process. Everybody's responses have been much appreciated.

 

[rafezetter]

Thanks for all replies. It's a groove just over 50mm long and needs to be accurate and have a nice finish. I can achieve this same effect already with a few other methods but if I could find a router bit to create this shape in 1 pass it may be an easier process. Everybody's responses have been much appreciated.

I was going to say surely 2 passes - 1 with modified ball tip cutter, (sides heavily tapered at an angle over what you need for the sides) then 2nd with dovetail would do it; lots of faff yes, but how many of these are you doing to warrant the cost of custom made router bit?