Ultimate router for table — would this work?

[marcus]

I've had an idea :? . Is there any reason not to get a nice powerful CNC router spindle, say 3 or 3.5 KW and make a bracket to stick it on a router lift in a table? I could get hold of a collet to fit 1/2" cutters, and an inverter to control the speed. It seems to me that the extra power would make a huge difference to the usability and capabilities of a router table, and would go some way towards bridging the gulf between a big router table and a small spindle moulder — while keeping the ability to use small diameter bits and pass timber over the cutter.

Is there a problem with this? I wondered if the cutters would not stand up to the extra power but I think the CNC boys spin router cutters with bigger motors than that and they don't have problems (?). Or would the extra power be difficult to control when feeding by hand. My guess is it would be OK but I don't know. Am I missing something here?!

 

[dm65]

Horsepower won't be a problem - just ensure you're inverter can run the bit at it's rated speed

 

[Random Orbital Bob]

Aye...like the 90mm raised and fielded panel bits...they need slow speed not horsepower. Heath Robinson jobs like that usually have safety concerns

 

[Richard S]

Let's not confuse horse power with speed, so long as the motor speed, ie RPM can be controlled extra horse power only adds to the torque and therefore can only be a good thing for larger bits. The extra grunt should mean that you can take bigger bites, much like a spindle moulder.

 

[marcus]

Heath Robinson jobs like that usually have safety concerns

I can see where you're coming from here, though I have a fairly healthy regard for my own safety so if I do it I will make sure it is properly specified and not done in a heath robinson sort of way..... Controlling speed shouldn't be a problem — I've seen inverters that will go almost down to nothing and, as Richard says, the extra torque is what will make the difference.

I suppose my concern is that, on the face of it, putting a more powerful motor in a router table is quite an obvious thing to do, so the fact that you don't hear about people doing it makes me wonder if there is a valid reason why it's not a good idea, or whether it's just because router tables are traditionally made for hand-held routers which need to be limited on power to run off a 13amp plug....

 

[dm65]

Let's not confuse horse power with speed, so long as the motor speed, ie RPM can be controlled extra horse power only adds to the torque and therefore can only be a good thing for larger bits. The extra grunt should mean that you can take bigger bites, much like a spindle moulder.

+1

 

[custard]

That would scare the pants off me. A router table is fine for the average router, but stick some behemoth of a motor in and you'll need the more massive components that you'd find on a comparable spindle moulder, like a much heavier mount for the motor, heavier fence mounts, and a sturdier table. Otherwise it'd be like sticking a V8 in a Morris Minor without uprating the brakes.

 

[dm65]

That would scare the pants off me. A router table is fine for the average router, but stick some behemoth of a motor in and you'll need the more massive components that you'd find on a comparable spindle moulder, like a much heavier mount for the motor, heavier fence mounts, and a sturdier table. Otherwise it'd be like sticking a V8 in a Morris Minor without uprating the brakes.

+1 on the heavier duty mounts, but will keep that thought of a V8 in a Morris Minor, thanks

 

[John51]

I'm planning to the same thing, only with a 2.2kw spindle.

Watch out for bait and switch if buying from China. I put the spindle away while waiting for other parts and too late I realised that it's an er16 collect so I'm limited to 1/4" bits. I'm sure the listing said er20.

I think the best way to go is treat it as a Z axis and use the same size and quality linear rails as would be used in a cnc machine for that sized spindle. Won't need a ballscrew though, a scissor jack could be used.

fwir, 2.2k spindles have the same power as 3kw routers so maybe you don't need to go so big. The Chinese VFDs aren't highly thought of and for a Hitachi or Mitsubishi VFD over 2.2kw it gets very spendy.

 

[Myfordman]

If there is any chance your workshop will get cold, make sure you put some antifreeze in the coolant.
A mate of mine let his freeze and it cracked the motor casing and water jacket. It took be a while to devise a scheme to repair it otherwise it would have been a write off.
I've possibly got some suitable inverters - good quality Siemens ones that might be for sale privately.

 

[dm65]

If you don't mind me saying, this sounds like a lot of hassle (though I do believe you can't beat rolling your own)

I might have a brand new 2kw router for sale :wink:

 

[marcus]

That would scare the pants off me. A router table is fine for the average router, but stick some behemoth of a motor in and you'll need the more massive components that you'd find on a comparable spindle moulder, like a much heavier mount for the motor, heavier fence mounts, and a sturdier table. Otherwise it'd be like sticking a V8 in a Morris Minor without uprating the brakes.

Would it need to be built quite that strongly (ie similar to a comparable spindle moulder)? I was thinking that it was the much heavier and bigger cutter on a spindle that requires such a beefy set up — after all, since a 2KW router table needs nothing like the solidity of a 2kw spindle moulder, surely a 3 KW router table wouldn't need to be built like a 3KW spindle moulder (though it would need to be more solid than the 2KW router table)? CNC machines are quite beefy, but again a don't think a 3KW CNC machine is built to the same weight as a 3KW spindle moulder, or anything like.

For example this CNC machine takes a 3KW spindle and it's quite light weight aluminium, it's built nothing like a spindle moulder, it's just aluminium extrusions....

http://www.worldofcnc.com/8-x-4-rack-and-pinion-free-standing-cnc-router-package-p-1328.html

Am I missing something here?!

If there is any chance your workshop will get cold, make sure you put some antifreeze in the coolant.
A mate of mine let his freeze and it cracked the motor casing and water jacket. It took be a while to devise a scheme to repair it otherwise it would have been a write off.

Good point, though I would probably be going for an air cooled one as the water cooled thing seems like too much hassle, much as I like the idea of the quietness.

I'm planning to the same thing, only with a 2.2kw spindle.

I think the best way to go is treat it as a Z axis and use the same size and quality linear rails as would be used in a cnc machine for that sized spindle. Won't need a ballscrew though, a scissor jack could be used.

fwir, 2.2k spindles have the same power as 3kw routers so maybe you don't need to go so big. The Chinese VFDs aren't highly thought of and for a Hitachi or Mitsubishi VFD over 2.2kw it gets very spendy.

Good, glad it's not just me! The Z axis idea is a good one if there is a good way to attach it. It immediately made me think that you could then add on a stepper motor and use it to control the cutter height, which would be fun to do but a bit silly (hammer).

Good point re. the greater power efficiency of the spindles, hadn't thought of that....

 

[John51]

Thinking on, the Z axis/lift could possibly be lower spec than the same sized cnc as the work will be pushed through manually.

Took me ages to set up the VFD, I've used a tap connecter from a T500 still for the water line so will be testing in the kitchen. Can't find my spare soldering iron (eldest borrowed the main one) so the testing is on hold until then.

 

[custard]

Would it need to be built quite that strongly (ie similar to a comparable spindle moulder)? I was thinking that it was the much heavier and bigger cutter on a spindle that requires such a beefy set up — after all, since a 2KW router table needs nothing like the solidity of a 2kw spindle moulder, surely a 3 KW router table wouldn't need to be built like a 3KW spindle moulder (though it would need to be more solid than the 2KW router table)? CNC machines are quite beefy, but again a don't think a 3KW CNC machine is built to the same weight as a 3KW spindle moulder, or anything like.

For example this CNC machine takes a 3KW spindle and it's quite light weight aluminium, it's built nothing like a spindle moulder, it's just aluminium extrusions....

http://www.worldofcnc.com/8-x-4-rack-and-pinion-free-standing-cnc-router-package-p-1328.html

Am I missing something here?!

Interesting point, I use both a router table and a dedicated spindle moulder which besides the usual 30mm spindle also has a special 16,000 rpm spindle with a collet holder. Even with medium sized router bits (like a lock mitre cutter for example) I get better results on the Felder spindle moulder than on the Festool router table. It's not that the router table is terrible, just that the spindle moulder is that bit cleaner and more precise. I don't know for sure but I think it's because the fence, table, mounts etc are all so much heavier on the spindle moulder; consequently I've come to the conclusion that the motor is probably the least important element in the mix. I've also been told that a large number of the Bosch palm routers are used in CNC machines, which also suggests that it's not really about the motor.

 

[John51]

Finally got the spindle running. Resting on a towel by the sink and cooled by mains water.

It is SO quiet. I know there's a hassle to getting the permanent cooling sorted but I'm glad I went with water cooled.

 

[Random Orbital Bob]

That makes perfect sense. It must be why as you go up the cost ladder for spindle moulders....they just get heavier and more cast iron etc. Of course there's an increase in motor output too but the big differentiator is the solidity of the design. Thats what prevents any rattle, which gives the lovely clean cuts. Interesting point.