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  #61  
Old Mon 25 June 2007, 06:17
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Thanks Gerald,

Greg
  #62  
Old Mon 25 June 2007, 11:16
Hugo Carradini
Just call me: Hugo
 
Pto. Ordaz
Venezuela
Hello Gerald and friends. I was wondering what is the best trick to cut the surface off a cable for making different connections, with out cutting the cables underside. żDo I have to be a surgeon?
Hope to be finishing soon my working area (Its been raining almost every day and had not time to finish roofing) so I can post new progress.
  #63  
Old Mon 25 June 2007, 12:38
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Welcome back Hugo!

I bend the cable over a finger in the one hand, and then use a very sharp knife to push down onto the tight skin of the cable with the other hand. First you need to drag the blade slightly so that the skin starts splitting under the pressure of the blade. Stop slicing/dragging while the skin splits, and the blade will stop at the next layer. Then roll the cable a bit over the finger to slice in from another angle - about 4 places around the cable and then the outer case breaks off at the knife marks.
  #64  
Old Sat 25 August 2007, 03:05
bbreaker
Just call me: Mickey
 
Galgan
France
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I found a multicores cable, is it good for us ?

NEXANS LYFLEX B

and the link :

http://www.nexans.fr/eservice/naviga...nId=126876#top
  #65  
Old Sat 25 August 2007, 05:04
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
That cable looks very good.
  #66  
Old Mon 03 September 2007, 01:44
bbreaker
Just call me: Mickey
 
Galgan
France
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Ok, I've got my wire, but some are Unshielded, is all wire necessary shielded ?

I think Motor, Spindle, can be shielded and other's ?

Michel
  #67  
Old Mon 03 September 2007, 04:58
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
You might be lucky, you might not. I didn't take any chances, so I recommended all screened cables. Before, I did have some bad experiences with unscreened cables, and I personally won't take the chance to order some unscreened cables. But, if I have already purchased the cables, then I would try it.
  #68  
Old Fri 07 September 2007, 21:01
jbmclain
Just call me: Joe #42
 
Birmingham, AL
United States of America
Gerald, I have 2 phase Oriental motors w/ ( 6 wires).
I have come across some 7 conductor shielded 18 Ga stranded wire. Is this good or over kill?

Thanks
joe
  #69  
Old Fri 07 September 2007, 21:44
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Hi Joe

The drive (eg Gecko) will only accept 4 wires. You don't run all the motor wires all the way to the drive. With your motors you will only connect to 4 of those 6 wires.
  #70  
Old Sat 08 September 2007, 07:05
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Gerald, What about the gauge?

Next question,

Would it be smart or dumb to run cable with extra wires. If a wire breaks, you have spares ready... or would you assume that since they are all flexing together, If one goes they are all about to go?
  #71  
Old Sat 08 September 2007, 07:27
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
My suggestion for the motors has always been 18 gage, mainly because it is a substantial, strong wire. You could go thinner. Quoting Mariss Freimanis on 29 Aug. '07:

"Most will agree 22-gage wire is pretty small (0.64mm or 0.025"
diameter). Let's see how it would work out wiring to a 7A per phase
motor 10' (3m) away.

22-gage wire has 0.16 Ohms resistance for a 10' length. Two wires are
needed per coil so that's 0.32 Ohms. The voltage drop will be 2.2V due
to wire resistance at 7A. If your power supply voltage was 65VDC then
it just became a 63VDC supply as far as the motor is concerned. Will
your motor know the difference? Not at all; it draws 7A at low speed
where supply voltage doesn't matter.

At high speed your motor phase current drops to 3A. The cable drop
becomes 1V, the supply becomes 64VDC instead of 65VDC. Does the motor
care? Not at all again.

Will the cable melt? Cable dissipation is 7^2 times 0.32 or 15 Watts.
That works out to about 1/8W per inch. It will be warm but not hot. At
high speed it's 3W and 0.024W / inch. Not even warm."

Yes, if one wire is becomes faulty, dump the whole thing
  #72  
Old Fri 05 October 2007, 10:28
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
For the past few days, I've been trying to locate a source for decent quality flexible cable. Good grief. I can't believe how hard it is to get someone to call me back with a price. Since I don't want to buy 500 feet of cable, they won't deal with me or they leave me hanging. I spoke with a salesman at the Lapp factory and he said they will sell short lengths of cable to distributors. Then when I contacted the local Carlton-Bates office, one salesman said he'd call back with a price. He never did. The next salesman said they only sell spools of wire. Yeah right.

I know that there are some small company owners that read this forum who deal in motors and circuit boards for CNC machines. Some have invested lots of time and money in R&D on their products. Maybe one of y'all would be interested in taking advantage of a business opportunity. I'm not suggesting that there is enough demand just from Mechmate builders to justify buying large spools of the cable we need but surely there are other CNC machine builders/owners seeking a source for small amounts of decent cable. There has to be some commonality in the types of cable we all desire. Heck, Lapp and Alpha don't sell that many different variations in continuous flex cables. I'd be willing to purchase cables with an extra conductor or maybe a larger guage if I had to. A seller could probably get by with a limited inventory in the beginning in order to get established as a dealer willing to sell short lengths and then expand the product line as demand increases.

However, if you want to get my order, you better hurry because I'm not the kind of guy that sits around on his butt waiting for things to happen. I'll eventually find a source and I'll post the contact info here for everyone else.

My next call will be to the regional sales manager for Carlton-Bates to let him know he has a lazy sales staff. If he doesn't care, maybe the vice president for sales at the Carlton-Bates Corporate headquarters will.
  #73  
Old Fri 05 October 2007, 13:31
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
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Doug,

I really like the way you think! Keep it up.

Marc
  #74  
Old Fri 05 October 2007, 16:11
garyc
Just call me: Garyc
 
Charlotte, North Carolina
United States of America
Here is a link for you:
http://cgi.ebay.com/Stepper-Servo-Mo...QQcmdZViewItem
  #75  
Old Fri 05 October 2007, 19:24
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Gerald,

I think I've found a reasonable deal on cable for us North American builders and I'd like to get your opinion on its quality. It has a braided shield and a 10X bend radius.

The salesman at Tannehill is named Dennis and was very helpful. I gave him the part numbers for the Olflex 115CY cable you said was good. He said they didn't have it but that Helukabel makes exact duplicates of the same stuff (type F-CY-JZ , flexible, Cu-screened, grey) and he'd get those prices for me. He called back later with the info below.

Here is the link to the cable on Helukabel's website.

http://www.helukabel.de/index.php?la...masterid=16320

These are his prices:

1.0mm squared (18 AWG) 4 core - $1.44/foot
2.0mm sqd (14 AWG) 3 core - $2.42/foot
0.5mm sqd (21 AWG) 7 core - $1.55/foot
0.5mm sqd (21 AWG) 2 core - $.93/foot

For each type of cable, there is a $25 cutoff charge.

He said the prices he quoted me could be obtained by anyone who wanted it. If Gerald says this is good stuff and anyone else is interested, Dennis's contact info is:

Dennis Holtgrave
Lapp Tannehill, Inc.
8675 Eagle Creek Parkway
Savage, MN 55378
952-881-6700 ext 3614
952-881-0743 fax

dholtgrave@lapptannehill.com

PS. I left a civil voicemail for the sales manager at my local Carlton-Bates but he never called back.
  #76  
Old Fri 05 October 2007, 19:27
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Oh yeah. Thanks Mark. And GaryC, I'm looking for braided shield so I don't have weird problems popping up later when the foil wears out. Thanks for the referral anyway.
  #77  
Old Fri 05 October 2007, 20:02
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Those Helukabels look just right technically, but it is still expensive compared to other parts of the world. Your government may have a high import tax on foreign cable from Germany . . . .
  #78  
Old Sat 06 October 2007, 08:35
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Thanks Gerald. Yeah, I noticed they were expensive but the price seemed to be a bit lower than what other guys had been posting over the past few months. Oh well, we all have our challenges getting parts depending on where we live in the world. I guess the ideal fulltime job to have, if you are building a Mechmate, is an international airline pilot.
  #79  
Old Sat 10 November 2007, 19:24
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
If anyone is planning to order cables soon, please wait. Within the next couple of weeks, I hope to finish routing the cables on my table and I'll try to give y'all a more accurate estimate of the lengths required. This stuff is pretty expensive so you don't want to waste any if you can help it.

Tonight, I almost ripped out the Y axis e-chain so I could reverse it. I thought I might be able to save 6-7 feet of the 2 core cable used in the e-stop circuit. Then I realized that if I reversed the e-chain, I would use more 4 core cable used to run the motors. Anyway, I think everyone will need to order more than 35 feet of the 2 core e-stop cable. Mine ended up short and if I don't splice on some extra, I'll have to mount the control box on my table like Hugo.
  #80  
Old Sat 10 November 2007, 20:36
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Good note Doug.
FYI
A great source for "cut as much as you need" is from Skycraft Surplus in Orlando, Florida. They have a website and do mail order. They stock many 4/6/7/9 core chainflex/olflex and others for cable chain use. It all starts in the .43/ft range and goes up.
  #81  
Old Sat 10 November 2007, 21:27
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Thanks Sean. Luckily, I have enough cable to get out of the bending zone so if I need to splice some cheaper stuff in, I should be okay.
  #82  
Old Sat 10 November 2007, 22:51
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
By fixing the cable chains on the drawings, I can now also start to give accurate cable lengths. A huge mistake is to cut the motor cables into 4 equal lengths - there is a big difference in the cable to the x-motor nearest the control box and cable to the z-motor.
  #83  
Old Mon 12 November 2007, 17:06
Doug_Ford
Just call me: Doug #3
 
Conway (Arkansas)
United States of America
Today, I added the cables to my machine which is built to cut 49 X 97 inch sheets of plywood. In order to calculate how long to cut the cables, I took alot of measurements. I figured new builders could use this information when placing their orders so that they don't order too much or too little.

My recommendation is that a new builder wait until he has the table, gantry and car built and the e-chain installed so he can take his own measurements. He should also thoroughly understand the E-stop, pause and resume circuits so that he can mentally walk through the process of routing the cable. It isn't complicated but it also isn't as simple as it may seem. I routed my E-stop circuit incorrectly and I wasted some wire that I now have to reorder.

**IMPORTANT**: The cable lengths I'm showing below are from the point where THE CABLES ENTER THE MACHINE. That is the point where the e-chain is anchored to the table. If you order your cables without adding the distance to the floor, across the floor to the wall and up the wall to your control box, YOUR CABLES WILL BE TOO SHORT. You must decide how far the control box will be from your MM and how high the box will be on the wall and add that to your order. Also, ensure that you include in your measurement the distance inside the box to the component to which you will connect the cable (relay, Gecko, Terminal, etc.).

- Stepper motor cables. Each motor is connected directly to its Gecko drive in the control box using a 4 core cable.

Z-axis motor - 18 feet 6 inches + distance to control box
Y-axis motor - 18 feet 8 inches + distance to control box
X-axis motor (front) - 16 feet 6 inches + distance to control box
X-axis motor (back) - 7 feet 6 inches + distance to control box

- Router motor cable. The router is connected to the relay in the control box. You only need one of these two core cables. Its length is 18 feet 6 inches + distance to control box

- E-stop circuits. There are two E-stop switches under each E-stop operator (or button). One switch is connected to a circuit that shuts off the contactor. You need a separate 2 core cable for this circuit. The other switch is connected to a circuit that uses the PMDX breakout board to perform the stop. The wires for that circuit are part of the seven core cable. The other wires in this cable are for the pause and resume circuits. Both the 2 core cable and the 7 core cables are the same length overall and may be routed along side each other.

Both the 2 core and 7 core cables will be divided into three pieces:
  • The first cable will be 7 feet 6 inches long + the distance to your control box. That cable will run from the control box through the X-Axis echain to the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM.
  • The second cable will be 9 feet long and will run from the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM through one of the gantry tubes to the E-stop/Pause/Resume box mounted on the gantry on the front side of the MM.
  • The third cable will be 11 feet long and will run from the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM through the Y-axis echain to the E-stop/Pause/Resume box mounted on the car.
Be sure you connect the E-stop switches in series.


Please make sure you give yourself some additional wire so that you have working room to strip and make connections to the switch terminals.


If you are building a machine that cuts larger sheets of plywood, you will need to change these lengths.
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