quick router table top - critique before i action it?

[julianf]

So i was going to get a lump of cast machined down, but just got a quote on getting some 8mm steel plate lasered, and its basically less than the cost of a decent cutter.

Im well aware of the flatness issues with steel vs cast, but, in my opinion, if an 8mm steel plate starts out flat, its probably going to remain flat enough for my work.

This is my plan for a triton tra001. Theres no big insert place cut out, as ill get the mounting holes lasered direct into the plate, and then countersink them.

The yellow is 50mm angle frame below, which ill bolt to the plate. Id weld it, but the heat may cause distortion, so ill use M8 countersunk.

Size is 700mm x 500mm. I dont want to give up more space. Its for template routing only.

I understand that a sheet of mdf would do the job too, but the 8mm laser cut steel below will probably cost me about £35, so its hardly worth driving to the shops to pick up a sheet of mdf.

One thing im not sure about is dust extraction - ill enclose the supporting frame and stick a dust port on, but, assuming i use a 75mm insert, theres not really going to be much space for the dust to get into the lower section.

I guess i could stick a load of holes around the outside of the plate, just inside the frame, but that seems a little unconventional?

This is just for template routing, nothing else.

 

[julianf]

So ive stuck a whole load of 12mm holes in it with hope that chips may disappear down them?

Ill have to add a chamfer to them all, otherwise the job will get caught on them. Do you reckon this will work or a waste of time?

I think there are 38-off them. Total area about 4800 sq mm. A 100mm dust port has an area of about 7800 sq mm so close to double the CSA and way less resistance.

Im not even sure if 12mm holes are large enough for router chips.

 

[novocaine]

Its a router table. Nearly flat is good enough.

Dust extraction is best from above and preferably in the fence as well.

Stop over thinking it. That way madness lies.

 

[julianf]

I don't think the 12mm holes will work.

I think chips will go half way in, but not the whole way, and then they will stop the job sliding around.

I think I'll either need to loose them or make them larger.

 

[julianf]

I dont know why i couldn't just get the hole spacing off Triton, but it seems not...

Anyway, i cut a couple of test plates on my own machine today to verify the mount points. I was 0.2mm out on my manual measuring the first time, which, if im countersinking (rather than counter boring) the mounting holes in the top will pull things more than i want.

Anyway, its spot on now - 145.9mm PCD for the UNC threads. I have the height adjuster position as a 12mm hole, 8 degrees off center, on a 188.0116mm PCD - which is obviously nonsense, but its close enough.

Centre hole is 98.3mm. Ill cut my own inserts anyway, and if i cut them from 8mm alloy, they should just drop in and be level.

Dust holes are 17mm. I realise they probably wont work, as, if they did, they would be on the commercial tables, but i cant see why not, and im willing to risk it.

Ive sent the job to laser firm now, so theres no going back.

 

[julianf]

Picked up the part from the laser cutters today. Not the best photo below, but you get the idea -

I thought the cut would get a bit ragged on 8mm, but it is impressively clean.

I need to do a bit of countersinking on it, and weld up the frame to sit it on. Im quite eager to do that, but im not sure when ill be able to.

This also arrived this morning in preparation -

Impressive service from wealden tools. I called them up yesterday for advice on the best cutter to use on this, for the work i want to do, and the part arrived this morning.

 

[julianf]

It needs sides, otherwise the dust extraction isn't going to work at all -