RE: [CAD_CAM_EDM_DRO] Re: spindle counterweights

Bridgett ( my Bridgeport series II mill) has a similar system on the
knee. The difference is that there is no surge tank, but a regulator
running to my compressor. As the knee moves up air flows into the system
to keep the pressure in the cylinder from dropping. As the knee is
lowered air is vented from the cylinder by the regulator to keep the
pressure from rising. I was surprised, but you only have to lower the
knee about 1/2" to get the regulator to vent.

I am guessing that unless you have very limited travel and the surge
tank is quite large you will get a lot of pressure variation with a
closed system. You may want to consider an open system like on Bridgett.
It works very well.

Tim
[Denver, CO]

> -----Original Message-----
>
>
> I just joined this group after following it for a couple of weeks.
> I'm in the process of assembling a CNC router. The Z
> axis will be fairly heavy as I plan on using a 3 1/4 hp router head.
> My plan is to use a pneumatic cylinder to balance the weight on the Z
> axis. The cylinder will be connected to a small surge tank. The
> pressures will be controlled by a regulator with pressure guage.
> Hopefully the system will be tight enough so that an external air
> supply will not normally be required. Has anyone tried this system
> and/or do you have any alternate suggestions? Bob Lemon
>
>
>
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