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Old Dec 08, 2012, 07:44 AM
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Do you think the GGCv2 will work with Mach 3 and a HobbyCNC 4 Axis pro board? I don't relish the idea of building another machine and hobbling it with a 32 bit copy of Windows 7 that won't see over 4 gigs of ram just to run an LPTx port... Saves me putting up a second PC and controller since my table converts to a Mill...
The GGC is not compatible with MACH3. It works only with GMFC.

Gilles
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Old Dec 08, 2012, 01:23 PM
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Originally Posted by gm.cnc View Post
The GGC is not compatible with MACH3. It works only with GMFC.

Gilles
Rats!!!

Mach 3 creates a problem, My foam cutter doubles as a router/mill and I want to be able to run both modes without having 2 completely different setups coming of the USB...

This means one setup off GGC and HobbyCNC and another of Smoothstepper and 2 HobbyCNC EZ controllers modified to be 6 individual boards. (Hobby knife time on a few traces.) That leaves be with 2 spares in case of failure...
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Old Dec 08, 2012, 06:15 PM
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Rats!!!

Mach 3 creates a problem, My foam cutter doubles as a router/mill and I want to be able to run both modes without having 2 completely different setups coming of the USB...

This means one setup off GGC and HobbyCNC and another of Smoothstepper and 2 HobbyCNC EZ controllers modified to be 6 individual boards. (Hobby knife time on a few traces.) That leaves be with 2 spares in case of failure...
hum... I should look into how to develop a plugin for MACH3....

Gilles
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Old Dec 09, 2012, 10:59 PM
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Originally Posted by RCWorks View Post
Do you think the GGCv2 will work with Mach 3 and a HobbyCNC 4 Axis pro board? I don't relish the idea of building another machine and hobbling it with a 32 bit copy of Windows 7 that won't see over 4 gigs of ram just to run an LPTx port... Saves me putting up a second PC and controller since my table converts to a Mill...
Hey RCW

No, not exactly. A GGCv2 only talks with GMFC. A GGC is not some universal USB interface for Mach3 or even with other Foam Cutting software. GMFC will not talk to Mach3 either. GMFC is its own Controller, doesn't speak G-code, well it does speak Gilles Code. :-)

Mill, not sure how you are controlling it. No expert here but I have read a little where people are wanting USB but IF I understand enough I guess there is the Smooth Stepper interface??? Otherwise it's parallel port.

I run my CNCRouter/Gecko on Parallel and GMFC/GGC USB from the same computer, just one at a time. Now GMFC can run through a GGCv2 plugged into the Gecko but no Mach3 running.

"building another machine and hobbling it with a 32 bit copy of Windows 7". If you're implying to run 64 bit Windows??? I will have to wait on Gilles for an answer but I think he posted not too long ago that No 64 driver for GMFC.

Will a GGCv2 plug into the Hobbycnc board and run GMFC, certainly.

I have watched youtube versions of guys cutting wing cores via Mach3 and Gcode, IMHO they are working too hard. Say you want to make a simple change, 2 mm's longer Root Chord or a new Airfoil. You have to go all the way back to what ever you used to generate the G-code, say Profili2 Pro , make the change, generate the G-code again and reload into Mach3. GMFC, change it and your done in 10 seconds or less and lets go.

Dan
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Old Dec 10, 2012, 12:08 AM
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Hey RCW

No, not exactly. A GGCv2 only talks with GMFC. A GGC is not some universal USB interface for Mach3 or even with other Foam Cutting software. GMFC will not talk to Mach3 either. GMFC is its own Controller, doesn't speak G-code, well it does speak Gilles Code. :-)

Mill, not sure how you are controlling it. No expert here but I have read a little where people are wanting USB but IF I understand enough I guess there is the Smooth Stepper interface??? Otherwise it's parallel port.

I run my CNCRouter/Gecko on Parallel and GMFC/GGC USB from the same computer, just one at a time. Now GMFC can run through a GGCv2 plugged into the Gecko but no Mach3 running.

"building another machine and hobbling it with a 32 bit copy of Windows 7". If you're implying to run 64 bit Windows??? I will have to wait on Gilles for an answer but I think he posted not too long ago that No 64 driver for GMFC.

Will a GGCv2 plug into the Hobbycnc board and run GMFC, certainly.

I have watched youtube versions of guys cutting wing cores via Mach3 and Gcode, IMHO they are working too hard. Say you want to make a simple change, 2 mm's longer Root Chord or a new Airfoil. You have to go all the way back to what ever you used to generate the G-code, say Profili2 Pro , make the change, generate the G-code again and reload into Mach3. GMFC, change it and your done in 10 seconds or less and lets go.

Dan
My table is an "H" frameon 2 posts in the center attahed to a send H frame below on casters... On the top frame I have mounting at every inch. The X axis's are common to the Foamcutter and the Mill, to switch over I remove the uprights(Y axis's) and place the Y-Z axis between to risers at a distance of 3 feet. This gives me a table milling area of 24 x 39 usable. The Foamcutter is unique as I have 39 inch X's but the distance in between is variable... I can narrow it down to 6" and cut an extreme angle if I need to or cut a 48 inch core in 1 piece.

For now it looks as if I will have 2 controller boxes... a GMFC with a GGCv2 and a 4 axis HobbyCNC proboard and 24volt power supply... and a Smoothstepper with a HobbyCNC proboard with a 36 volt supply.

I also have a couple of platforms that mount between the X axis for foam cutting and one for milling. My next little project will be a pair of sighting lasers to make sure that everything is level on setup and that the X axis's are even for slaving.

I just wanted to end up with a machine that could use the first PC I ran in to at any seller of PCs and get one that works for this out of the box(No installing of a 32 bit OS to make Mach 3 happy.)... My old cutter is being retired, it was in operation since 2001 and still runs Windows 98 SE and GM software version 2.19. I was there about the time Gilles was starting out. I go by the rulw of old techs... "If it works don't touch it, for if you do it will be up beyond all repair and need replacing!". So since this machine has gone through 2 controllers (Foam Lynx and still has a HobbyCNC foam board) about 4 bow power supplies and the old drawer slides have gotten loose I figured it was time to put in something more lasting, the basis for this machine is heavy duty router parts.

Limited space maximum machine. Between the shelving, metal lathe, mig welder, air compressor, tool box, regular mill and table I am tight on space. My handyman will be building some more shop space this spring. I will add 20x20 and that sould ease the crowding. I have some shelves going up high on the wall for the lesser used items.

While I have had the HOBBYCNC foamboard since Dave went to the chopper style, I have not once used the heat control on it, it's never been wired to a bow power supply. I never had the time to mess with it, I used 24 volt center tap 5 amp transformers and rounter speed control and set it up on a digital voltmeter to make sure it was constant. Cutting coroplast at speed was a bit rough on the transformers. Even the wing tips on my flying wings is CNC cut...10 at a time.
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Old Dec 10, 2012, 02:08 AM
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...

I just wanted to end up with a machine that could use the first PC I ran in to at any seller of PCs and get one that works for this out of the box(No installing of a 32 bit OS to make Mach 3 happy.)... My old cutter is being retired, it was in operation since 2001 and still runs Windows 98 SE and GM software version 2.19. I was there about the time Gilles was starting out. I go by the rulw of old techs... "If it works don't touch it, for if you do it will be up beyond all repair and need replacing!". So since this machine has gone through 2 controllers (Foam Lynx and still has a HobbyCNC foam board) about 4 bow power supplies and the old drawer slides have gotten loose I figured it was time to put in something more lasting, the basis for this machine is heavy duty router parts.

.....
GMFC with the GGC V2 runs fine on windows 64bits. But I don't think that there will be a 64 bit GMFC driver for the parallel port. I just don't have such machine and the parallel port is now outdated tech...

GIlles
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Old Dec 10, 2012, 03:16 AM
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Ahh, thanks Dan, I think I get it now. The above sentences were the key. I had been slavishly following what the GMFC help file said about adjusting the wire heat ("right heat value will be found when the foam block is closed to be moved by the wire, but still does not move") without realising that the real objective is to tweak the heat values that ensure the kerfs at the min and max speeds are identical.

Just one closing question about "min" speed then. Is there any benefit in choosing a min speed which is much less than half of max speed, given that it is very difficult to cut a wing with taper ratio greater than 2 ?
Dang tough to explain, the issue of cutting greater than 2:1 is or can be related to the MIn/max speed issue but not exactly as they're separate issues.

The Max/Min setting are more for cutting speed vs what YOUR machines Max speed is. Let's break is down a bit and see if this clears it up. The speed issue can occur even with a much smaller taper ratio than 2:1.

IF you have a very fast machine even setting up a Max/Min Foam type, the actual foam cut speed may not ever get lowered by GMFC as your machine has extra speed and heat available.

But if you have slow machine cutting near the machines Max speed even a small taper could cause a GMFC speed error ( speed up right X ) or, cut slower.

And or it gets even worse, a small taper but a narrow width core on a wide machine.

Some Examples:
Your machine max speed is 3.7 mm/s AND you decide to set up a Single speed Foam type at 3.7 mm/s just because you can. AND of course you have enough heat power available to cut at 3.7.

All is well at 3.7 until you cut even a small taper. If your core width is right at the table width in theory the tip side motor would just have to slow down a bit so it starts and finishes the tip side at the same time the root side is done. I doubt it could cut at the full 3.7 but.... something a little less. Even a small but wide tapered core might have to cut at say 3.5 or 3.4 mm/s, something a bit less than the max 3.7 so you should still get a speed error msg.

IF the core is as example half the width of your table, and you are cutting with the block centered... the root side motor will have to go much faster than 3.7 to maintain the 3.7 mm/s wire speed at the foam block or core. Draw the taper line(S) all the way to the root side ( just look at the cut screen in panel cut and you can see that ) and the distance is much greater therefore the motor has to go faster but it can't as it is already going the Max of 3.7. The tip side motor going slower won't be the cause of the speed error.

Solutions:
1. Increase speed - you can't
2. Try cutting the core not from center but on the table edge of the Root side. This sometimes will solve the problem, depends on taper and width. NOTE: I would recommend learning how to cut from the table edge anyway, Gilles taught us that at the seminar, much better method.
3. Narrow the table much closer to the core width. Requires a new bow, new foam type with a proper speed/heat combo and a pain but doable.

4. Set up GMFC as you are trying to do with a Max/Min and a proper heat for both and GMFC will automatically lower the speed somewhere in between the Max and Min AND a heat to go along with it. This still assumes the Min speed is still fast enough. If you try to cut a high taper AND a narrow core on the same table width you might still not have enough speed to cut. AND GMFC will cut at the max speed it can actually cut at. This is the advantage of a Max/Min setup, it's automatic for one and say like me, a single slower speed setup might be slower than necessary where GMFC will cut as fast as the machine can. Ex: I have a 3.2 mm/s and a separate foam type at 2.5. If I can't cut at 3.2 then I choose my 2.5. But the machine can actually cut at 3.0 GMFC automatically takes care of this. For me is a bit slower but more accurate.

The next issue and why I don't use this function ( I set up a Single Foam type with one speed/heat combo and something slower ) as it's difficult if not impossible to be accurate over the entire large speed range. If the Max/min range is rather close it's close enough but if you cut say a 2 panel multi taper half span and the outer is a higher taper where GMFC cuts the inner at say 3.5 mm/s and the outer at 2.8mm/s the 2 panels most likely wont' match up perfectly. If both panels cut at near the same speed then they will match up.



The greater than 2:1 is sort of the Voodoo of foam cutting. It's a problem with any software, it's not an issue just for GMFC. We cut with one wire and one heat and over 2:1 it's just asking too much. If you lower the heat the root drags but with enough root heat and the wire moving so much slower it over melts the tip. IF you adjust the tip Kerf enough to correct the over burn on the tip, everything in between will be wrong ( too large ) until your close to the root side. This is why the recommended method is the split the core width in half to reduce the error.

Other solutions:
1. Reduce cut speed which also reduces heat. Less TOTAL heat being given off the helps a lot but may still not be enough.

2. A smaller diameter wire also helps but takes more power to run.

Some have tried blowing a fan on the tip or adding a heat sink on the wire, I have no idea how to keep accuracy doing that. Maybe fine on a single half span, at least LOOK OK but not measure accurately.

Regards
Dan
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Old Dec 10, 2012, 03:45 AM
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For now it looks as if I will have 2 controller boxes... a GMFC with a GGCv2 and a 4 axis HobbyCNC proboard and 24volt power supply... and a Smoothstepper with a HobbyCNC proboard with a 36 volt supply.

That would probably be easier than unplugging and plugging in motors on one board and if the new Y& Z motors have a different rating changing amp draw setting as well on the HCNC board.
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Old Dec 10, 2012, 11:31 AM
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For now it looks as if I will have 2 controller boxes... a GMFC with a GGCv2 and a 4 axis HobbyCNC proboard and 24volt power supply... and a Smoothstepper with a HobbyCNC proboard with a 36 volt supply.

That would probably be easier than unplugging and plugging in motors on one board and if the new Y& Z motors have a different rating changing amp draw setting as well on the HCNC board.
All 6 steppers are the same Daves 305 in/oz I will just be moving the X axis's over and switching out the Y and Z for the part that goes across the table when the X's are back at Zero.

I'll have limit and home switches on this on too... While it was not an issue on the old machine.

My X axis's are rack and pinion driven, the y's are 5 start 1/2 in acme scres at .5 inches per turn. The Y and Z of the routher... Y is rack and pinion and Z is another 5 start lead screw at a half inch per turn..
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Old Dec 17, 2012, 12:29 PM
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GMFC version 3.90.4

Hi all,

There is a new version of GMFC EXPERT and the PRO online. It implements
the choice of the reference point for the basic height.

Beware that the format of the .cnc projects has changed and that saved
projects can't be read by the previous version.

Enjoy,

Gilles
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Old Dec 22, 2012, 07:14 AM
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Dang tough to explain, the issue of cutting greater than 2:1 is or can be related to the MIn/max speed issue but not exactly as they're separate issues.
Thanks Dan. My understanding is slowly increasing...

I've managed to do some testing with various heat and cut speeds (after first discovering and then fixing my PWM hot wire controller which had been going berserk).

1. Firstly, I did straight cuts at a number of different cut speeds. For each speed I tweaked the heat setting until the foam block was just on the verge of sliding along the cutting table, as per the GMFC help file. I also checked and the surface of the cut foam had just a few very fine hairs, so I was happy that this was a sign of non-contact cutting by radiation. I've put the results into Excel and produced the following chart. Interesting that it is not a linear relationship.


2. Now even though the maximum speed that my cutter is physically capable of running at is 4 mm/sec, I settled on 3.3 mm/sec as my "maximum speed" for the foam management screen in GMFC, and also chose 1.5mm/s as my "Minimum speed". I did some kerf test measurements on a 2:1 tapered block and entered the corresponding values in the "Kerf for speed S" and "Kerf for speed S/2" boxes. The following is the resulting screen in GMFC.


3. Now, I also did a kerf measurement at my "minimum speed" of 1.5mm/s with heat at the ideal value of 30% (as deduced from step 1 above). It did NOT match the kerf for my maximum speed - it was greater (0.825mm vs 0.635mm at max speed).

So, do I:
a) decrease the heat at min speed BELOW the ideal value, and accept that this will give more wire drag than ideal
b) increase the heat at max speed ABOVE the ideal value, and accept that this will give more kerk than ideal
c) get a life, and stop worrying about 0.2mm differences in a piece of foam...
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Old Dec 22, 2012, 04:44 PM
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Hi Geoff

Excellent write up. I spent a number of hours and lots of foam years ago just manually adjusting the Max/Min relationship trying to get it work across the entire range I don't recall but my Range was not as great as yours, 3.2 Max to maybe 2 or 2.5. Anything much greater than 2.5 would basically defeat the purpose of this option.

I emailed Gilles what am I doing wrong. Gilles answered, "sure, it's an approximation" :-)

So without doing all your nice Excel graphs I came to in a round about way that yup, it's a linear issue and can't be done. Only Gilles knows how the programming is done. If linear though, just maybe Gilles could use your Graph for a non-linear solution though I bet that is easier said than done.

1. Down load the latest version. After years of harping Gilles just changed the description to "Variable Heat" control. Many think since they have GMFC or the Computer controlling the heat they MUST check this box. Unchecked you get a single speed/heat/ & kerf(s) value and GMFC still uses it.

2. The value of this Option is for a slower machine to allow GMFC to cut your project as fast as the machine can do. Excellent for production guys but for the Hobby guy as few lost minutes cutting is OK.

If you look at the motors and Pitch of RCWorks machine above, he will be hard pressed to get a Speed Error as that machine will be very fast yet he too will be cutting foam around a 3.5 mm/s Max, so lots of speed "over-head" available if needed. That machine should be capable of , wild guess 400 + mm/s.

3. Your solution would be the same as I did on my old slower machine 3.7 Max. Uncheck the box and set up one or even two more Foam Types using your gathered info.

Best since you are "close" would be to leave it GMFC for reference. Duplicate ( copy ) as New Foam type and then uncheck the box. Keep it around, you can use it to see just how fast your machine can in fact cut a new project. You have say set up 3 Foam Types, 3.3, 2.5 & 1.5 mm/s. Select the Variable Heat and GMFC says it can cut this Project at 2.9mm/s, then select your 2.5 speed and have at it. You second panel says 2.3mm/s so choose your 1.5mm/s to cut that one. Takes longer but you know they will match up.

Then what are you cutting? A Foamie combat wing, then your C) answer would apply. :-) .2 off when it's going to be taped all over , get a life. :-) The two half span panels cut at the same speed will match up. ah, but now you are doing a 3 panel DLG, "tain't gonna" happen. Cut at different speeds most likely it will be wrong and you wont' need Digital Calipers to tell you that when you match em up. Here we are trying for perfection in matching up AND accurate.

So I would add
d) Uncheck the box and set up at least one slower speed though 3 total would be nice to have.

Dan
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Old Dec 22, 2012, 08:03 PM
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Thanks Dan. I suspect the non-linearity is not news to Gilles - the french boys did a lot of testing in the early days, and I'm sure they've already investigated this in depth.

I'll do as you've been telling me for the last few posts, and set up a few fixed-speed foams Appreciate the detailed responses - it's helped me gain a much deeper understanding of getting good results from GMFC.

Oh, and I tried the latest version of GMFC PE but it crashes when I go into the Foam Management screen (under Win 7 64-bit). Back to v3.89 for me
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Old Dec 22, 2012, 10:22 PM
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Welcome Geoff

Yes they did do a lot of testing and for ever grateful, Vive la France.

Oh oH Gilles, bug report with PE. :-)

My solution worked for me, not necessarily to only way to go. Plan B is to change out lead Screws or increase Motor Voltage to gain some extra over head speed. Cutting anywhere around 2 mm/s is like watching paint dry but I am quite happy around 3 to 3.5.. :-)

I stole the linear slides off the wire cutter to build the router. The router build enlightened me to what can be done with various methods. When I put the wire cutter back together I am considering Belt Drive for "X". I have 3/8-10 2-start lead screws for the wire cutter and it's that's plenty, this would just be for fun. We will see how that goes.

Curious as to what your Wire Diameter is.
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Old Dec 22, 2012, 10:31 PM
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Curious as to what your Wire Diameter is.
0.4mm (0.016") stainless steel wire (fishing trace - very easy to get from the fishing shops around here, in any number of sizes). I was using thicker stainless wire (around 0.6-0.7mm I think) but thought the smaller diameter would help bring the kerf down, and I had plenty of spare capacity in my power supply to drive it.
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