Thinking of ways to reduce weight off the gantry I thought a small hydraulic motor could be used as a spindle. A quick search found one such as this: http://www.anchorlamina.com/p_hydrmotors.html Plenty of horse power in a small package. Looks like its bearings would take some load and they would be constantly lubed too. Shouldnt be too hard to DIY either. Would need a small pump too mounted off the gantry of couse. Thoughts?

The rpm's are way to low for cutting wood. Link you gave lists max rpm at ~2300.

Yes that particular one is too slow. It's more the concept of using a hydraulic spindle that Im interested in. Havn't looked around for an off the shelf unit too much as I think I will DIY one. Just a simple spindle good for 10,00rpm with a small turbine on top. I figure the pump will need small accumulator tank on it's output to buffer vibrations and provide a steady consistant flow. A small oil cooler can be added and should easily keep the bearing temp real low. Also, no more nasty RF from the motor. Cutting coolant splashing around is safe too, etc,

When you think about it, most the bulk and mass of the gantry is due to these heavy routers. Id be suprized if you couldnt get away with a single rail Y and Z axis gantry that weighed no more than 4 or 5 times the spindle.

When you think about it, most the bulk and mass of the gantry is due to these heavy routers. Id be suprized if you couldnt get away with a single rail Y and Z axis gantry that weighed no more than 4 or 5 times the spindle.

Depends on what size gantry you're talking about. Most 1-1/2 to 2HP routers weigh about 8 lbs. I didn't see a spec, but that thing has to weigh about 5lbs. I don't think yuo'll see that much weight savings at all.
A 40" mdf gantry (complete with z axis) can easily weigh 70-100lbs, so the router is only 1/10 the weight.

Thinking weight of oil in the lines as well + mechanism to guide them.

If you are trying to get rid of RF noise good shielded cable is your soloution.
I run all my servo, sensor and router power cables in the same guide chain (think it's about 1.5" size so it's not huge links) all in the same chain with no gitters due to noise. Other then having good cable on both power to the servos (2 conductor + ground 16ga shielded) and incoders (4 conductor 22ga shielded in pairs) shielded cable to the home/limits and a regular non shielded extension cord for router power.

Run both a bosh and Porter cable router with no rf issues.



b./