Planning - Bridgeport Interact 1 linuxCNC Retrofit

Can an 7i77 drive 24v relays directly? (Stock Bridgeport relays)

I have traced and labeled all my wiring, also I have the enables, releases and limits switches ready to go. I have driven all my axis with a 1.5v battery. My air solenoid is toast (seals gone) I need to buy another AE-1001, so far I haven't found a direct replacement - any suggestions? (I might just go with an 1:1 pulley and remove the entire assembly with a VFD, braking resistor, and single action air valve for the pneumatic brake)

Now it's time to decide on either a pico driven system or a Mesa driven system. I saw a earlier post by PCW stating they were catching up on orders. I really want to buy a 5i25 / 7i77 combo and probably a SS board. If PCW you are reading this post do you have the ability to ship a 5i25/7i77 plug and go kit without flashing the firmware so that the end user can? If that is a option then perhaps it can take the work load off of you and allow me to do it. I would be more than willing if it helps. (I'm in Alabama, USA!)

Also I don't know if others know or not, but Mesa did put a shipping disclaimer on their web store explaining they were behind on orders and approximate shipping time 4-6 weeks.

I'm probably going to pull the trigger on Mesa and go for it. Undecided

cncnoob1979 wrote: Can an 7i77 drive 24v relays directly? (Stock Bridgeport relays)

"
The 7I77 field outputs are high side or sourcing type MOSFET drivers, that is they source positive voltage to a ground referred load. For example with a standard 24V field power, +24V connects to the 7I77s field power input (on TB2) and the outputs on TB7 and TB8 now source +24V power to loads. All 7I77 loads will have one side returned to ground or the negative lead of the 24V supply. The 7I77s outputs can drive loads of up to 350 mA."

"The output driver chips used on the 7I77 have built in Zener diode clamps to clamp inductive turn-off (fly-back) spikes. This means that flyback diodes are not normally required on small (less than 60 mA) inductive loads. If high current inductive loads are switched or inductive loads are switched at high frequencies, they must have flyback diodes to limit power dissipation in the 7I77's driver chips."

( www.mesanet.com/pdf/parallel/7i77man.pdf )

A typical 24V relay I looked at has a 37mA coil current, so could be connected directly. A higher-current relay would need a diode adding Many relays have a diode included. If the coil connections have a polarity marking, then that indicates that a diode is already present inside the relay.

Thanks Andy, I should have read the manual! Sorry about that!

I've got my mill thinking it's running all day long. Just to check out the oiling system. The saddle, table and knee are all pouring oil (after 12hrs), but the head does not seem to be getting a lot of oil.




I've attached a photo of the lower oiler for the quill. I maybe have had a few drop. I don't know if this is normal or what. The orifice for it is a 00. Does that sound sufficient to you?

cncnoob1979 wrote: I've attached a photo of the lower oiler for the quill. I maybe have had a few drop. I don't know if this is normal or what. The orifice for it is a 00. Does that sound sufficient to you?

I have never had a machine with central oiling, so I can only speculate. But 00 sounds like it would be the smallest of all.
Perhaps they wanted to make sure that oil didn't drop on the workpiece?

Andy,

I think I will be disassembling the oil lines, remove the table etc.. and check each oil orifice.

I just purchased a used Intel D945GCLF2 , PBGA437 Motherboard with 2GB ram. It is PCI only so I will be going with the 5i25/7i77 combo.

The metering valves for the oiler can plug up with time, I had to replace all of them on my surface grinder to get the central oiler working. I would replace the metering valve with the same number if you suspect it is plugged up. If you have another metering valve with the same number swap them to see if that changes the volume of oil. Just because I don't use the grinder much any time I'm near by I give the plunger a pull to keep fresh oil in the metering valves.

JT