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  #1  
Old Wed 23 April 2008, 08:54
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
A shy man from Spain sent me this mail:

Im a new Spanish reader of your work.
I love this forums and the serious it work.

Sorry, no post this in the forum because my english not is well and im not a teacher now.

My first question is about the weight of the x-axis (full mounted) Mechmate, not see it in the forum,
and the maximum speed with this configuration:
4x PK296-A2A-SG7.2
4x G203V
1x PMDX-122
1x ┐power supply with a 56V 300VA?

I intend to see if the speed is adequate for plasma and router in the same mechmate.

for plasma:
A good speed is between 15 m/min and 40 m/min.
I see it is over 50 and 200 ipm or more is good for work some materials.

for example:
12mm in 3050mm/m = (120 ipm) (Mild steel) (200VA)

If you see good, you can put this question corrected in the forum please.
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  #2  
Old Wed 23 April 2008, 10:34
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
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Shy man from Spain,

Do not worry about your English. The day I can speak any other language as well as you, I will celebrate.

I have made 50 trips to Germany for business and I work very hard at my German and, trust me, your English is better than my German.

I, for one, greatly appreciate the international flavor of this forum.

Gracias!
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  #3  
Old Wed 23 April 2008, 12:18
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
I agree with Marc. Also, there are several Spanish speakers on this forum that will probably be glad to translate like some of our French and Afrikaans speakers have done. It can't hurt to ask.

Did you answer his questions Gerald?
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  #4  
Old Wed 23 April 2008, 13:12
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
I was hoping that you would answer him Doug

Seriously, you have done some speed trials and know what a top jog speed can be (the plasma only runs at jog speeds and loads). I have never done full speed trials for jogging, and besides, I havn't run gearboxes.

I know that the gantry (with 15 kg spindle) weighs about 80kg [180 pounds]. With plasma that may be around 70kg
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  #5  
Old Thu 24 April 2008, 12:06
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Gerald: I was thinking I ought reply but didn't want to give him conflicting info if you had already answered.

Shy Guy in Spain: I have recently completed a MM using those exact parts but with a different power supply. My power supply puts out 35V and that's what I suggest you go with. It will allow you to wire the motors so that you can get more speed. A 56V supply will give more torque but less speed. Since you aren't pushing a cutting tool into wood, you won't need the torque. You didn't mention what size pinions you plan to use. I have 35 tooth pinions on the motor shafts. Most of the guys are using 30 tooth pinions. With the parts you listed (but substituting a 35V power supply and using 35 tooth pinions) my system jogs at 15.5 inches per second. According to my calculations, that is approximately 930 ipm. It is probably slightly faster than that because I started the stopwatch when the gantry was sitting still so it had to accelerate from a dead stop. I think you could add larger pinions and make it go even faster since you won't have a heavy router on the car. Also, my gantry tubes are 1/8" thick so performance might improve slightly if you were able to find and use thinner walled tube like Gerald recommends.

I hope that answers your questions.
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  #6  
Old Thu 24 April 2008, 12:49
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Thanks Doug, nicely covered.
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  #7  
Old Thu 24 April 2008, 14:39
isladelobos
Just call me: Ros
 
Canary Islands
Spain
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Yes !!! many thanks, is very helpful.

, this is first shy post. helped, somewhat, by the translator of google, not to put much leg.
I think made my first MechMate router and then to test plasma.

Ok Doug, 930 ipm is more than I thought, is good news, thanks for your tests.

I see is very dificult put the plasma and the router in the same machine, by cleaning and Precision, I believe that by increasing the teeth of the gear is lost in precision.
the solution would be to change the gear, the drill and the kitchen table, each different material, let alone software settings.
It is possible to regulate speeds on the fly?


www.hypertherm.com
I see in the hypertherm web, for cut a 0.8mm (22GA) thickness, we need aprox.: 12700mm/m(500ipm). this is the smallest and possible, the most commonly used thickness.

And for cut 25mm (1inches) thickness, we need aprox.: 406mm/m(16ipm).
This with the plasma cutter model powermax1250 Price: $2,999.00

I join the group, especially for reading and learning.
again, thanks
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  #8  
Old Thu 24 April 2008, 19:10
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Hey Ros,

Yes it is easy to change the speed using the software. I recommend Sheetcam which is designed to run both a router and a plasma cutter.

Good luck.
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  #9  
Old Thu 24 April 2008, 23:47
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Ros,
Can I suggest that you use PK296-A2A-SG3.6 motors instead? This should give you:
- high speed for the plasma,
- and still a good cutting quality for wood.

Remember that some of us use "1.0" motors (no gearboxes) and still cut okay in wood. We cannot reach the high speeds because we have too little torque.
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  #10  
Old Fri 25 April 2008, 06:06
isladelobos
Just call me: Ros
 
Canary Islands
Spain
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Quote:
I know that the gantry (with 15 kg spindle) weighs about 80kg [180 pounds]. With plasma that may be around 70kg
Gerald, my question was, weight horizontal drag, on x-axis, sorry my english.
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  #11  
Old Fri 25 April 2008, 06:50
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
I have never measured it, but I would estimate it as much less than 1kg [2.2#] . The biggest drag will be the cable and hose for the plasma.

Greg, if you are reading this, you have a free gantry without motors at the moment, do you agree that the gantry starts running with less than 2 pounds pressure?

The friction with V-rollers is much less than with linear bearings because there are no seals.
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  #12  
Old Fri 25 April 2008, 10:48
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
That's a good question. Believe it or not, I don't own a small scale. I'll buy one on my lunch break and measure the force tonight.

Just to the touch, it's not much force and the gantry "glides" nicely to the end.

I'll report results tonight or tomorrow morning. I like aquiring data.
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  #13  
Old Fri 25 April 2008, 18:46
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Here's my data

I had gantry, Y car, and Z slide riding the X rails. Rough weight (one of the fish scales broke already) 80 lbs [36.3 kg]

Scale: 0 -50 lbs [0-22.6 kg] range. 1/2 lbs [.22 kg] increments.

Breakout force: 1.75 lbs [0.79 kg]

Rolling force: 1.0 lbs [0.45 kg]

Hope that is helpful.
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  #14  
Old Fri 25 April 2008, 18:49
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
That is really helpful. Thanks!
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  #15  
Old Fri 25 April 2008, 19:52
isladelobos
Just call me: Ros
 
Canary Islands
Spain
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To calculate as an engine that we need to pull weight is easy
but what really difficult, is calculated as an engine need, when there are so many variables such as speed motors, as drill cutting quality, speed of the spindle and hardness of wood used.

It's good to know that there are weight, but really knowing the maximum weight that can withstand our engines, it should be an individual study of each company.

Thank you Greg, seems very slight for our engines.
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  #16  
Old Sat 26 April 2008, 00:23
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Greg, you have a gantry weight of 80 pounds [36kg] so far. I presume that is without:
- 4X stepper motors, baseplates, springs, fasteners
- Router or Spindle, with brackets, gas spring, fastners
- dust collection foot and end of hose
- Pushbuttons, cables, cable chains.
- y-rack, ?

For the 80kg [176 pounds] that I measured, it included all of the above as a live system. Also, our gantry is for a Y dimension of 1850mm [6 foot],
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  #17  
Old Sat 26 April 2008, 00:28
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Ros, we have not measured the friction of the gear rolling on the rack. This difficult to measure because the motor has magnetic detents which show a false high force.

My estimate of the "friction" at each motor is about 1kg [2.2 pounds].
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  #18  
Old Sat 26 April 2008, 09:58
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
My 80 lbs [36kg] is
- Gantry
- Y rails
- Y car
- Idler wheel and baseplate on Y car
- Router bracket (No router)
- Spider bracket, Z slide, and gas spring
- Cable chains on both X and Y
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  #19  
Old Thu 01 May 2008, 19:49
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Welding supply...ask for it. It's not something they usually get requests for from non-commercial users. You may have to assure them you using it for plastic polishing and not making a zeppelin.

7.2 gearboxs I am using a 20T pinion @25Khz = about 225 ipm jog
@ 45Khz = about 275
7.2 gearbox w/ 30T @ 25Khz = about 340ipm or about 6 inchs/second Doug is getting his table to achieve about 12" /second with 35T pinions.

Now, these speeds are well below what you can achieve mathematically. But, at these speeds, with my computer, etc....These "sound" about right.



I hope this helps.

Sean
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  #20  
Old Thu 01 May 2008, 21:38
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Sean,

I'm actually jogging at 15.5 inches per second but I didn't build it to jog, I built it to cut. If I were doing it all over again, I would get a smaller pinion like you did or a 30T pinion.
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  #21  
Old Fri 02 May 2008, 05:32
isladelobos
Just call me: Ros
 
Canary Islands
Spain
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dis is a good tool to make different measurements.
Attached Files
File Type: rar Calculator.rar (80.5 KB, 156 views)
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  #22  
Old Fri 02 May 2008, 07:01
Robert M
Just call me: Robert
 
Lac-Brome, Qc
Canada
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Thanks Ross, Very nice of you to share this great tool !
Robert
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