Messages

711

Tangent Corner / Re: Electro-Punch design

« on: January 25, 2016, 02:05:17 PM »

I did some "hammer" experiments while the wife was shoveling ..(grin)   Grin will post a pic and and notes soon.

Just remember, this is a kid friendly forum. 

712

Tangent Corner / Re: Electro-Punch design

« on: January 25, 2016, 11:48:53 AM »

Nice Ian!

713

Tangent Corner / Re: Electro-Punch design

« on: January 22, 2016, 01:32:17 PM »

The trigger and sear would forever be a problem child.

Why is that? 

714

Tangent Corner / Re: Electro-Punch design

« on: January 22, 2016, 10:03:56 AM »

How about a motor turning a flywheel and an electric clutch to engage/disengage? Or, I had a friend do something very similar a while back using a servo and drive with detect switch going straight to the drive. Its insane fast and does it all day. Get a good braking resistor for sure. I was wondering how it would hold up starting and stopping so quick and so often but been running without issue for a few years now I guess. All day every day or close to it.

715

Mach4 General Discussion / Re: Backlash not applied during manual JOG?

« on: January 20, 2016, 05:42:22 PM »

charliex, we do agree on somethings but you are clearly not getting what I am saying. That does not bother me in the least. What does bother me is others may see this and some will hear what they want to in your post and believe it.

if a major fault appears that is something else

This is almost funny. To a machine controller backlash is this something major. It does not get much more major than this. There is no degree of backlash only varying amounts. It either exist or it does not.  Backlash is the distance the driver went around the course with the steering wheel disconnected from the shaft. No control!    Backlash is the additional length of wire needed so that the O2 sensor you keep talking about can be connected. Backlash is the length of fuel line needed to connect the fitting on the tank to the fuel pump. Backlash is the distance between the connecting rod and the crank when there is no rod bearing installed. Backlash is that tick you hear when a pushrod gets bent. Believe me charlie.............. backlash can be some serious juju.

I really am on your side, you just haven't figured that out yet. Do not underestimate the implications a "little backlash" can have.

716

Mach4 General Discussion / Re: Backlash not applied during manual JOG?

« on: January 20, 2016, 04:27:56 PM »

Charliex, you are totally missing the point here I was trying to make. I agree that the O2 sensor is a good thing and works well when it has control and overall is a good thing. However, if it does not have control the best it can do is indicate troubles with things that are beyond its control. Backlash is just that, a range of motion in which the controller has no control. This is not a best case, worst case scenario, it is not that complicated. Either the controller has control and can do all sorts of great things of varying degrees with the motion or it does not. There is no middle ground there. Backlash comp is asking the controller to control something it has no control over. By admitting the machine has backlash you are admitting there is nothing the controller can do and it is time to call in the mechanic, no two ways about it. Either the mechanics or your machine is capable of holding tight enough tolerances to do its job or it is not. If it is not asking the controller to control something it has no control over is non-productive.

The only effective way to combat the ill effects of backlash is programming strategy and it is not great. It does not fix backlash but does give some control over it.

717

Mach4 General Discussion / Re: Backlash not applied during manual JOG?

« on: January 20, 2016, 01:26:15 PM »

Hello Charlix, welcome to the forum.

We all know that allowing misinformation to be repeated is the stuff that turns myths into legends right? Well, this is the only reason I'm going to hit on this topic that has been discussed many, many times already.  

As for the car analogy, that is what a closed loop O2 sensor does, it looks for changes in the fueling so it can feed back to the engine controller and trim for fuel changes, small air leaks, and a whole host of other things that are correctable by software for a small hardware issue which will occur on every car eventually. That seems a lot closer to backlash than a loose steering wheel.

This is where you are dead wrong. While your analogy of an O2 sensor is fairly accurate the only way it can work properly is if it has full control of all elements involved. Should the ECM decide the mixture is a little rich and needs to adjust the air/fuel ratio by lowering the pulse width of the injector. It does so but the actual time the injector is open for does not actually change because there is a piece of trash in the injector keeping it open. This is something the ECM assumes it has control of but actually does not. What now? How does the ECM fix something it has no control over? Does it cut off the fuel pump to lean it down resulting in starving the engine for fuel and ultimately shutting it down? Does it inject air to adjust the A/F ratio and in the process raise the RPM of the engine? Do you add a pile of telemetry sensors and mood recognition to read the environment and drivers face so you can take all of that information to make an educated decision about what is the best option? These things and lots of others could be done to compensate but at what cost and what sense does it make to even try to. The best possible outcome would be piss poor at best.

You can avoid reality but you cannot avoid the consequences of avoiding reality.

Mach3 does have backlash comp. that works as good as any but I wouldn't get Mach3 or Mach4 or any other controller expecting it to be able to fix all the woes introduced with backlash. If I knew of one that could manipulate physics I would sure point you to it.

718

General Mach Discussion / Re: Physical buttons for plasma

« on: January 19, 2016, 08:44:27 PM »

I already have two units and the only other 2 are occupied and anyway not everyone is a rich kid like you and Brett, so wouldn't be able to afford it even if empty Cheesy

Tweakie, don't believe everything you hear. I'm so poor I can't afford to buy fruit. The only way we get any fruit to eat it is to peel it off the wallpaper.  

719

General Mach Discussion / Re: Physical buttons for plasma

« on: January 19, 2016, 11:09:36 AM »

What are people thoughts on having a water table?

I have been trying to work out how I can get the table into the back section of my workshop and it would be extremely tight with the bandsaw and the plasma. If I did away with the water table and just has a portable grid of 2500mm x 1250mm that I could pull forward when I am using the plasma it would make things a bit less cramped.

Pics below of with and without the water tray. In the second pic the grid would be in this position when not using.

Hood

I think you will want a water table Hood. Probably as much as doors on the Chiron. I imagine you will be keeping it hot. They can generate a lot of slag and smoke quick fast and in a hurry.

720

General Mach Discussion / Re: Physical buttons for plasma

« on: January 05, 2016, 11:53:01 AM »

(8' x 4')

Good! I'm so glad to see you building one and I am most interested in how much you use it/like it in a years time. If my rich uncle had got out the poor house 10 years ago you would have had one then (hes still not out BTW). I just think you will get a lot use out of it. I can hardly wait to see some of the work you will produce with it. 

You settled on motors and drives yet?

Brett