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The panel for my own machine was called "OTT for DIY" at the time but I disagree, for me it was just normal. For example if you could easily produce mechanical items to a particular tolerance and finish, why would you choose to make one inferior ? I can see that cost is a factor but that does not mean you make it less safe, you just have to reduce the number of features while keeping the core safety aspects.
I think the thing going amis here guys is the difference in cooling vs contamination free.
So, what you should have is a negatively pressurised enclosure but also have filters on the intake to stop contamination.
Cleaning a filter would typically be less evolved than cleaning a populated enclosure.
Like Eddy says, do what you want but put "safety" as close to the top of the priority list as you care for, heat control is one of the higher items on my safety check list ;-)
.Me
Something like this is perfectly enough http://www.hobbyking.com/hobbyking/s..._Gas_Car_.html
Most of these filters filters if they are a good brand, could filter up to 5 microns with excellent flow.
http://www.mycncuk.com/attachment.ph...id=14568&stc=1
Definitely the enclosure has to be airtight apart from the filter , i thought that was clear, who wants to spend time cleaning enclosures. And a good thing to note is that when cleaning filter enclosure with a compressor, we Must be sure the air is dry. Spitting water drops on a couple of hundreds euro BOB could hurt.
But as i see it, there is not a law or something. I would say - negative pressure if all is in straight line and easy to cool. Intake ventilators to help the airflow if necessary, especially when there are some obstructions, otherwise-not. Hot things, air out- up in the enclosure, intake from bottom. All in straight line without obstruction if possible.
I would say also - forget 12v PC fans and similar. 220V - ~20-30w ventilator or 2. One all time, second when necessary. Little OTT here will not hurt.
Thanks silyavski. I'll be using a cheap controller I bought before I joined this group and I hope to upgrade to CSLABS CSMIO/IP-M later this year so no dual axis homing.Quote:
Originally Posted by silyavski
In bench testing I've been able to control my VFD speed from controller but I'm unable to figure out how to switch it on and off with my controller. My VFD is a Sunfar E300. The model number says E300-2S0022L. Attached is the manual
http://www.mycncuk.com/attachment.ph...&stc=1&thumb=1
Tony, thanks for the info and reassurance. Your suggested approach makes sense and I'm going to follow that. I had a look on the PILZ website but there's a lot of stuff. Sorry for my ignorance but what does this thing do on a high level and where does it fit in? Which model number should I be looking for to get some docs?Quote:
Originally Posted by TonyD
Thx Eddy, I get what you are saying. What is the absolute minimum core safety aspects considering I'm the only one who is ever going to be using this machine and I do have 100's of hours machining time on my old router so I've got a fair idea of what can go wrong from an operating point of view? In my mind estop is a nice to have as long as I have a nice big circuit breaker handy that will cut power to everything :-)Quote:
Originally Posted by EddyCurrent
Thx, these type of filters are a good plan. I think you are right about the 12V PC fans, they are weak and I'll go for a bigger 220v fan or two. I'm not sure I'll be able get my box 100% air tight where the wires come in etc so it might be better for me to put my big fans on the bottom (cooling air input side) with filters to try and get a bit of positive pressure then I don't have to worry about small aluminium chips getting into my box.Quote:
Originally Posted by silyavski
Quote:
Originally Posted by mitchejc
These are the basic steps to make the VFD work with your spindle:
F0. 0 1: External input signal (0~10V / 0~20mA)
F0. 2 1st part of LED 1:Control by external terminal
F0. 2 3rd part of LED 1: Valid
F0. 2 4th part of LED: Self-startup when power-on 0: Prohibit
F0. 4 Upper freq [F0.3] ~ 1000 Hz 400/ if your spindle is 24000rpm, if not divide RPM/60
Check if these 2 are by default 10: if not set
F0.5 Acc time 10:
F0.6 Dec time 10:
Spindle speed control:
connect from BOB to terminals 10V/+/ and CM/common/
F1. 1 AI input upper volt [F1.0] ~ 10.0V , Leave that to 10 if you board outputs 0-10VDC for spindle control, change to 5 if the board outputs 0-5VDC
F1. 3 Max setting freq 400/if your spindle is 24000rpm
Protection:
connect terminals Ta Tb /NC normally closed/ to the ESTOP circuit, so that if the inverter trips it will stop the machine
When you are finished with all of the above:
F0. 10 Parameter read-in protection 2: Only allow to modify this parameter
How to turn it on off and the speed control:
not all the info is relevant to your case, so remember your settings from above, but read about mach 3 , relay assignment and checking the speeds. You will need a cheap tacho
If you dont have a relay output/alsmost impossible/ , you will need a cheap ??V relay/depends of voltage output of your board/ from ebay.
http://www.cjh.com.au//PWM%20Spindle...ng%20Mach3.pdf
In crude terms, imagine two relays in parallel, both powered by a feed via the normally-closed estop switch. Each relay has a normally-open contact and these are wired in series and used to supply a control voltage to the external system - exactly what it does is up to you. So, in operation, both relays are activated, both relay contacts closed, and external system enabled. Hit the estop, the relays drop out, and the external system is disabled. Two relays mean that even if one contact sticks, the estop still works. For greater reliability, the two relays can be fed via a double-pole estop switch and two cables although I'm not sure if many people go this far. As it stands, though, the system would restart when the estop button is released or unlocked, so the safety relay box has a couple more relays which are associated with a reset or enable external switch which has to be pressed to get the main relays into their operational state. My Pilz relay actually has three sets of contacts so it can control three independent external systems/devices (maybe enable inputs on stepper drivers, ditto on VFD, and estop input to Mach3, for example). And that's one of the simpler Pilz devices! I bought mine as a new-but-obsolete version from eBay so the model number isn't very relevant (and I can't remember it off-hand).Quote:
Originally Posted by mitchejc
As to where it fits in - a normal estop setup can only switch one circuit. Generally, you want to switch more than that (as per comments above) so you are going to need some kind of relay setup or somesuch to handle multiple independent circuits, but for emergency use it needs to be reliable which a single relay might not be. Add in the need for an explicit reset switch so if estop is hit, then things really stay off, and it gets a bit more complicated still. The Pilz "relay" packages all that functionality into one box. You might want to trip the relay with the limit switches as well as estop but that's a decision for the machine builder.
Safety relay info from a previous post.
http://www.mycncuk.com/threads/7723-...0325#post60325