Messages

1091

General Mach Discussion / Re: Anybody using Rutex servo drives?

« on: June 30, 2009, 04:43:47 AM »

Tripleback,

I'm not a fan of Rutex or any other brand, I'm just trying to sort thru the available products and select one that will do the job for me, preferably for under $200. The Gecko is a nice drive, but severely limits the motor speed and the fixed following error trip results in the drive faulting constantly. Gecko is coming out with a new model G320X, but so far, I have been unable to get the specs on it. I just sent the Viper95 back to Canada so I'm still in the hunt for a servo drive. Rutex is one of about 4 or 5 that I'm looking at.

IF the Rutex does what they claim, it would be perfect, but that's what I though about the Viper too, so it ultimately gets down to testing the products in-house, but that is very expensive time wise . .  not to mention international shipping costs.

I am reading some issues with the current Rutex, but those are all interface/wiring problems that get quickly sorted out. The 'blown' Rutex problem was common it seems a couple years ago, but nothing lately. I have not been able to determine what component blew out on the drives. If it was the MOSfets, they are easy to replace with larger ones, and a lot of the newer drives are no longer using MOSfets. An advertised feature of the Viper is 'replaceable' MOSfets, so one might assume this is a common problem.

Other than the amp rating, did you have any other problems with the Rutex? How did the drives run the motors? Was there windows tuning software at the time? How did that work?

1092

Feature Requests / Full featured Serial Communications

« on: June 29, 2009, 03:35:28 PM »

I have been looking at a bunch of different servo drives recently and it seems most like to talk thru a serial port.

Mach has a simple function to dump some characters out a standard serial port and also a very 'bare metal' method of talking byte by byte to a non standard port.

There may well be more stuff available within Mach that is not documented, or that I just have not found yet, but a bi-directional communucation structure would allow clever script writers to utilize the monitoring/reporting/control capabilities that most of these newer drives seem to have, and take a big step toward a true closed loop system for Mach.. 

1093

Show"N"Tell ( Your Machines) / Re: What The World's Been Waiting For - Yet Another Power Drawbar Design

« on: June 29, 2009, 03:24:08 PM »

Well, I got some time to catch up on this thread . . . . interesting new ideas presented . . . BUT

We old engineers have a saying "you can't polish a turd"

All of the problems are the result of relying on friction alone to transmit torque. That's the turd.

My original solution is still the best, methinks. Positive drive = end of problem. Easily accomplished with a dog drive on the end of the spindle as I mentioned previously, and since I now see that the plan was to make new tool holders anyway . . zero added cost except for the dog for the spindle nose, which could be a simple bolt-on. 

Ultimately, I would prefer Vmax' solution of a new spindle (although I would build it differently) as a rugged and permanent high performance solution, but the current scheme could be made to function, I believe.

1094

General Mach Discussion / Re: Anybody using Rutex servo drives?

« on: June 29, 2009, 12:26:58 PM »

Is it possible that nobody uses these drives?

I keep digging up negative opinions, but so far NONE are accompanied by any specifics or even what model drive is at issue.

1095

General Mach Discussion / Re: Has anyone used Viper Servo drivers?

« on: June 27, 2009, 06:34:06 AM »

I have these drives in a couple of machines.They work great.
I have called Larry Kenny a few times with some minor issues and
he is great to deal with.If you have some specific questions post them.

Which model drives you you have?

1096

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: June 27, 2009, 06:29:57 AM »

Sure!  Put me down as one of those individuals who will graciously accept your code for the sole purpose of solving a puzzle.   I'm one of those that use ink and wouldn't think of asking another for the answers........yah, sure. .

Seriously, I promise not to ask ANY questions(within the first year). 

What you are doing control-wise, is exactly what my machines are looking for.

Thanks,
John (bloy)

I just found an early version of the g-code prior to using the new macros and variables. It has only the swap and swap back macros that I have already posted. This code is *somewhat* decipherable even though it is not numberd nor commented in any reasonable fashion, and the treading and peck drilling are verbose g-code for tuning purposes. But if you want to noodle over it, e-mail me your e-mail address and I'll send it to you.

1097

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: June 27, 2009, 06:13:03 AM »

Update:

I have the Viper drive and it will run the motor fast enough. That's about the only positive thing I can say about that product at the moment. I have some more homework to do on the Rutex drive, but I think I'll try one of those next.


The final design for the new head is finished and the material, bearings, and sensors have arrived for the final prototype. Stay tuned . . . .

1098

Show"N"Tell ( Your Machines) / Re: What The World's Been Waiting For - Yet Another Power Drawbar Design

« on: June 27, 2009, 05:57:29 AM »

Couple more thoughts:

Making a spindle from scratch:  That comment was made to Vmax who apparently has the capability to machine a spindle, and who also presented the idea of someone making a custom spindle as a product.  Many moons ago when I had my own small shop for building prototypes and specialized high strength parts, I did my own heat treating and had a tool post grinder, so like anything else, no big deal if you have the tools for it.

That said, I don't think the spindle is, or should be hardened, except perhaps case hardened to a few tens for durability. Spindles are subject to shock loads from chatter and hardened steel is not a good choice for shock loading, unless you are talking about S7, which IS expensive, is precisely hardenable to a specific depth, but you would still leave the core soft and you would still have to be stress relieved after hardening and before grinding.

I presume you can still buy pre-hardened and stress relieved machinable rounds? I used a lot of this stuff before I got my own furnace. However, I think for the purposes we are talking about here, a new spindle made from stressproof steel round with no heat treatment at all would be adequate. I would grind only the R8 taper and then only after the bearings were installed and it was in the head already. I replaced the pathetic bearings in my X2 head and then re-ground the R8 taper and I show zero runout on a .0005 reading Starret, which is more than adequate for my purposes.

Positive drive: Auto-changing an R8 is frought with challenges, but it seems to me that the Tormach setup could be easily modified for positive drive, potentially halving the tension requirement on the drawbar.

1099

Show"N"Tell ( Your Machines) / Re: What The World's Been Waiting For - Yet Another Power Drawbar Design

« on: June 27, 2009, 05:32:56 AM »

This seems similar to this system.
www dot mach-1tooling dot com

I have used it and it works extremely well. Very rigid and accurate. Quick tool changes too.

Kenny

Kenny,

I find that system fascinating.  The pullstud mechanism is precisely what I had in mind for a future "upgrade" to my setup, and proves that it CAN be done.  What really surprises me is the very low drawbar tension - apparently only 600#?  After my testing the last few weeks, I'm amazed that's enough to securely hold an endmill in a collet.  Do you by any chance have a means of measuring (even crudely) how much torque it takes to make a 1/2" endmill slip in a collet using that setup?  I was able to do it by clamping a vise grip on a scrap endmill, and using a $5 hardware store "fish scale" to pull on the handle, then calculate the torque based on the fishscale reading and the length of the vise grip. That would be invaluable in helping me correctly calibrate my drawbar.

I'm going to read their patents and see what I can learn....

Regards,
Ray L.

Ray, isn't this apples to Oranges? This is not an autromatic tool changer.  The 600# is not applicable to your setup. You are relying on friction alone to turn the tool. This setup is using the R8 collet which has a psitive drive. The drawbar has only to keep the toolholder in the spindle and 600# is plenty for that.

I continue to think your #2000 number is closer to the mark. I'm sure you are familiar with breakaway torque and I think the 'problem child' in a friction hold is going to be chatter, where you are going to see extraordiarily high shock loads which are powered by the inertia of the rotating mass and not by the motor HP. 

1100

Show"N"Tell ( Your Machines) / Re: What The World's Been Waiting For - Yet Another Power Drawbar Design

« on: June 27, 2009, 05:23:39 AM »

This seems similar to this system.
www dot mach-1tooling dot com

I have used it and it works extremely well. Very rigid and accurate. Quick tool changes too.

Kenny

This is interesting, but it is not an automatic tool changer.