Re: Fisher 1 October 14, 2015 11:30AM |
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Re: Fisher 1 October 14, 2015 01:05PM |
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Re: Fisher 1 October 14, 2015 07:59PM |
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Re: Fisher 1 October 15, 2015 03:34AM |
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Re: Fisher 1 October 15, 2015 04:28AM |
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Re: Fisher 1 October 15, 2015 06:22AM |
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Re: Fisher 1 October 15, 2015 06:51AM |
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Re: Fisher 1 October 15, 2015 09:30AM |
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Re: Fisher 1 October 15, 2015 10:31AM |
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Re: Fisher 1 October 15, 2015 11:54AM |
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Re: Fisher 1 October 15, 2015 01:41PM |
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Re: Fisher 1 October 15, 2015 02:17PM |
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Re: Fisher 1 October 15, 2015 07:46PM |
Registered: 11 years ago Posts: 12 |
Quote
droftarts
I have answered Ian separately by email:
We would really like to understand how they have broken. We haven't had any breakages in 6 weeks of testing! Please could you consider, and give me some feedback, on the following:
1. Please send me a picture showing how they have broken. Send any other pictures that may also be appropriate.
Pictures to follow in daylight.
2. I understand that they have broken around the ball mount - which end? Carriage or effector? Or is it consistently one end (ie close to the hex, or round hole)?
I had only got as far as assembling the carriages. I put the screw through until it just came to the outer edge, then carefully popped them over the ball and tightened by a turn or two on each rod. I then carried on building the effector, but heard a 'pinging' sound after about 10 - 15 mins - that was the arms breaking. the second set went within minutes of the first, then a final set went as I was looking on the forum.
3. Rod assembly: Where the rods assembled correctly, with the laser cutter kerf angled outwards? This causes the hole through the rod to be a different size on each side of the rod. The rods should have the 'small hole' side in contact with the steel ball. Using the 'large hole' side may cause the rod to interfere with with the screw that the steel balls mount on. I don't particularly think, if it is broken at the ball mount, it's to do with overtightening the screw into the arm; more likely it is catching on something.
I followed the instructions on the site ' sharp edges should go together'. I don't trust my eyes completely, so I was feeling for a sharp edge.
4. Was the effector moving at the time (either moved by hand or under power)? Could they have hit anything (eg cable tie holding wiring) or binding on the carriage or effector? Did you check the spacing between the outsides of the balls on carriage and effector (56mm)? Did you put extra washers in, when you assembled the carriage and effector parts, that would cause the arms to interfere with the carriages or effector?
The effector was not attached - I haven't got that far yet. It was just sitting on the bench waiting for the next parts to be fitted.
6. Environment: Is the place you're building your printer particularly cold, possibly causing the acrylic to be more brittle than normal? Have the rods been dropped on a hard surface, that may have cracked them?
Building in the living room - normal 18 - 22 centigrade. I don't recall dropping the arms at all. Just popped them out of the laser cut sheet and pulled the plastic sheet off, then stuck them together.
Any information you can give us will help!
bgkdavis - I think "Most of us have broken arms" is a bit of an overstatement. We would have been sending out hundreds of replacements, and we're not. Changing to other rods brings it's own problems (exotic materials, expense, multiple parts, getting the length and fit correct, etc) whereas if we can finally get to the bottom of how to produce them without breakage, there would be no need to go to these extremes. Our design aims to be accurate, easy to produce, simple to assemble, reliable and cheap!
With regards to this final quote, I can see that your arm design allows for a large degree of movement around the ball because the points of contact are top and bottom. There might be constraints in the range of movement with the traxxas style mount.
I use the traxxas style arms on both a 3DR and a mini Kossel without issue, but I think there is something to be gained from having the rods pivot about the top and bottom as opposed to the left and right sides.
Ian G
Re: Fisher 1 October 15, 2015 07:56PM |
Registered: 9 years ago Posts: 443 |
Re: Fisher 1 October 16, 2015 03:06AM |
Registered: 9 years ago Posts: 155 |
Re: Fisher 1 October 16, 2015 05:24AM |
Registered: 9 years ago Posts: 34 |
Quote
droftarts
I have answered Ian separately by email:
We would really like to understand how they have broken. We haven't had any breakages in 6 weeks of testing! Please could you consider, and give me some feedback, on the following:
1. Please send me a picture showing how they have broken. Send any other pictures that may also be appropriate.
2. I understand that they have broken around the ball mount - which end? Carriage or effector? Or is it consistently one end (ie close to the hex, or round hole)?
3. Rod assembly: Where the rods assembled correctly, with the laser cutter kerf angled outwards? This causes the hole through the rod to be a different size on each side of the rod. The rods should have the 'small hole' side in contact with the steel ball. Using the 'large hole' side may cause the rod to interfere with with the screw that the steel balls mount on. I don't particularly think, if it is broken at the ball mount, it's to do with overtightening the screw into the arm; more likely it is catching on something.
4. Was the effector moving at the time (either moved by hand or under power)? Could they have hit anything (eg cable tie holding wiring) or binding on the carriage or effector? Did you check the spacing between the outsides of the balls on carriage and effector (56mm)? Did you put extra washers in, when you assembled the carriage and effector parts, that would cause the arms to interfere with the carriages or effector?
6. Environment: Is the place you're building your printer particularly cold, possibly causing the acrylic to be more brittle than normal? Have the rods been dropped on a hard surface, that may have cracked them?
Any information you can give us will help!
bgkdavis - I think "Most of us have broken arms" is a bit of an overstatement. We would have been sending out hundreds of replacements, and we're not. Changing to other rods brings it's own problems (exotic materials, expense, multiple parts, getting the length and fit correct, etc) whereas if we can finally get to the bottom of how to produce them without breakage, there would be no need to go to these extremes. Our design aims to be accurate, easy to produce, simple to assemble, reliable and cheap!
Ian
RepRapPro tech support
Re: Fisher 1 October 16, 2015 01:13PM |
Registered: 9 years ago Posts: 82 |
Re: Fisher 1 October 16, 2015 03:10PM |
Registered: 9 years ago Posts: 155 |
Re: Fisher 1 October 16, 2015 05:37PM |
Registered: 9 years ago Posts: 443 |
Quote
Martoh
Droftarts, why did you put cap head screws for the effector balls ? The new effector is printed for hex head and then you don't need allen key.
Re: Fisher 1 October 16, 2015 09:42PM |
Registered: 11 years ago Posts: 12 |
Re: Fisher 1 October 17, 2015 09:08AM |
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Re: Fisher 1 October 17, 2015 12:50PM |
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Re: Fisher 1 October 17, 2015 05:14PM |
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Re: Fisher 1 October 18, 2015 12:43AM |
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Re: Fisher 1 October 18, 2015 03:34AM |
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Re: Fisher 1 October 18, 2015 03:51AM |
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Re: Fisher 1 October 19, 2015 03:33AM |
Registered: 10 years ago Posts: 14 |
Re: Fisher 1 October 19, 2015 03:47AM |
Registered: 11 years ago Posts: 14,685 |
Quote
wmacm00
Just need the New SD image to be released to get it running, as i tried the beta SD image, but the new extruder drive is the other way round, so filament going the wrong way...
Re: Fisher 1 October 19, 2015 03:49AM |
Registered: 10 years ago Posts: 14 |