Rapid and Cutting Feedrate

Hello,

Can I combine the rapid feed rate and the cutting speed?

I don't understand why these two speeds are separate.

If I want to move slowly then I want to control both at the same time.

On some machines the rapid rate is extremely fast - too fast for an operator to stop an impending problem.

In these cases it's desirable to permit slowing the rapids down while not affecting the actual cutting feed rate.

The two overrides can't be 'combined', but depending on how you have configured them you can control both with a single input.

How are you currently controlling them?

because G0 is very different to G1, G2 and G3 motion.

G0 is a non cutting feedrate to get the tool from A to B as quickly as possible

can you explain what you want to do

currently i controlling them with the 2 sliders on probe_basic....

but i will install a poti for feedrates and spindlespeed

so i will do one poti for cutting and rapid feedrate and a second poti for the spindlespeed

you can control both with a single input.

yes that´s what i mean

Something else to consider - there's usually a maximum value difference between rapid and feed overrides.

FRO can, depending on configuration, be set to a value somewhere between 0 and 150% of programmed feed.
RRO is 0-100%, since you can't go faster than the MAX_VELOCITY of that axis.

If you link the inputs to RRO and FRO together, turning FRO up past 100% won't do anything to the RRO.  However, if you have FRO at 150% and then turn it down RRO may follow the decrease and go down below 100%.

Whether you use a pot or an encoder, it may take some fiddling to get both overrides to work as you wish.

I'm using probe basic, and what I've done is keep the RRO and FRO separate.  My FRO is controlled by an external encoder, and my RRO is controlled using momentary pushbuttons with pre-set values.  I didn't think I'd ever need to adjust rapids to something like 78% or 13.5%... just Fast / Slow / Really Slow.

Works well, and if it sounds useful to you here's a post on using mux4 and Classic Ladder to duplicate.
forum.linuxcnc.org/24-hal-components/479...lassic-ladder#262309
 

i don´t have ClassicLadder and mux4.

i will it do just with analog Potis

you can use the main velocity slider which will limit all motion to the velocity percentage calculated by the slider. this will limit all motion so that rapids and feed are limited to the same maximum.

where i can find the main velocity slider?

its the top slider in PB sliders column

ah ok than i can configure my poti to the main velocity slider?

this will change rapid and cutting feedrate at the same time?