SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492024-03-28T16:04:15-06:00SparkFun ElectronicsCustomer #928140 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #928140urn:uuid:f61f1309-1e3f-e69b-64d0-7e7e3b0573ad2017-04-01T12:13:42-06:00<p>Does anyone know the thickness of uarm's parts,because i'm not sure ,i note that uarm's parts have a different thickness ??? thanks for answering me.</p>
Customer #525619 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #525619urn:uuid:e06dfa4b-8868-673d-1f91-203825b497242015-04-21T07:13:50-06:00<p>Just in case you missed it -- that's almost half an inch. Not really usable for anything beyond a toy.</p>
phenoptix on ROB-13286 - uArm - Desktop Robotic Armphenoptixurn:uuid:c7108e14-2863-2c42-4f5a-ffbf21b8cddb2015-03-27T19:20:53-06:00<p>So you'd want a robot arm kit, at a lower price point, possibly made from acrylic? I have to say I like your style!</p>
uArm Team on ROB-13286 - uArm - Desktop Robotic ArmuArm Teamurn:uuid:9e14c957-5cbe-5532-0710-4a482c6dd77c2015-03-25T04:42:12-06:00<p>Thanks for your advice. Pricing a product, we need to consider many different aspects, including cost on manufacturing, structure, materials, labor, operation, marketing..etc. Also the quantity is an important factor in affecting the cost and this will affect the price of product. The price is fixed based on these after serious consideration.
For the stepper motors, we are doing the test about it. We are also trying to lower the cost and price. Thanks!</p>
uArm Team on ROB-13286 - uArm - Desktop Robotic ArmuArm Teamurn:uuid:e71e3708-f9ae-db0b-1a8b-aa82a72361512015-03-25T03:45:30-06:00<p>Thanks for your advice! We can't agree more about selling the unassembled kits. But what we think over is the difficulty of the assembling. The previous acrylic version needs almost 5-6 hours to do the assembling and during the assembling we also find many steps which are difficult for people to access. So we do want to make some parts together and make the assembling easier, and that's the real reason why we change the materiel to the aluminum. Now it only needs less than 2 hours to make it, but there are still some steps which are not easy enough and we are trying to improve it. We will provide the unassembled kit as soon as we get everything ready.
What's more, we are always keeping trying to provide our consumers the cheapest products with the best quality. Currently the quantity is not large enough, so it indeed cost us more to get the parts with best quality. Anyway, now we have several engineers who are good at these and trying to improve it. We are sure that we can offer better products with lower price in the future.
Many thanks for your advice and we will try to do our best as always.</p>
Customer #474258 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #474258urn:uuid:eebc38df-5487-b3af-c620-24a7031fe7392015-03-24T19:57:33-06:00<p>Will the metalwork be sold separately? I'd like the option of incorporating the electronics myself-</p>
Mr Electrical on ROB-13286 - uArm - Desktop Robotic ArmMr Electricalurn:uuid:6dd4377c-78df-841f-3e4f-f146a9ca37f52015-03-24T14:33:55-06:00<p>It's interesting that you guys are selling fully assembled units. The reason folks buy stuff from Sparkfun is that they are looking to make things; common sense would say that a majority of folks would want to assemble something like this as well. The main benefit of buying something like this instead of making everything from scratch (beyond convenience) is that most folks don't have the correct machinery or workshops to do it themselves.<p>I would very much like to see (and would VERY likely buy) an unassembled kit that included good servos for a decent price. The current $400 price point is a bit much - if you cut the costs of assembly and just shipped a box of parts, you could sell it for $200-$250 and likely get a few more folks to buy it. I could very easily order/commission all of these parts for around $150 end cost from local sources (ie, non-bulk/non-ebay pricing) - the $400 price tag just seems a bit much to save a bit of errand running.</p><p>The more folks that purchase it, the more feedback you will get, the better the product becomes, the MORE folks purchase it.....the cycle goes on and on. I'd love to see robotic arms take off like RepRap and 3D printers have. But, the only way to do that is to make things accessible at a software level AND at a price point.</p><p>One more thing that the uArm Team might consider are geared DC motors with small encoders in place of hobby servos. The end cost is going to be about the same, but you are able to tailor your acceleration curves (WOOT PID LOOPS!) much more easily to reduce backlash and your precision and repeatability increases dramatically. Hobby servos are easy, but not great for larger robotic systems.</p><p>Edit - Somehow, I missed the picture with the unit next to the $2 bill. There is SERIOUSLY no reason this should cost $400. There is also no reason it needs to be made out of aluminum for something this small. Acrylic would work just as well. Don't get me wrong, the aluminum is nice, but a bit overkill structurally speaking. A well programmed acceleration curve would nix vibrations out the window.</p></p>
Customer #525619 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #525619urn:uuid:530d577b-ade2-a800-7d95-1f46ef945bf42015-03-24T06:51:25-06:00<p>Suggestion: Price it at $99. That's still a bit much for a toy, but such as the nature of these DIY robotics. $399 is simply silly for a toy. I could see $199 or $249 if it used stepper motors with a positional accuracy closer to 1mm.</p>
uArm Team on ROB-13286 - uArm - Desktop Robotic ArmuArm Teamurn:uuid:38ccfa9b-98b3-4446-d41d-f1956fdcc6c82015-03-24T05:11:08-06:00<p>Thanks very much for your advice. There is no doubt that the precision of uArm is not good or even worse compared with the industry robot arm. And also the performance of the servos is not the best in the market. But the point is that industry robot and uArm are two different things. Although accuracy is not the most primary appeal in uArm, we also do a lot of work to improve it (decreasing the backlash in the gearings, using cnc to cut the holes and etc.). For our target customers we think , the easier to control, the better, and the more funny to play with it , the better. So we develop the mouse control, leapmotion control and learning model for the uArm and all of them are very easy to use and bring people a lot of fun.
As it is known that every coin has two sides. Although the tail with the electronics can make the wires whip on the desk, but when uArm lifts something heavy in the end-effector the tail will play a very important role in keeping the balance of the uArm.
Thanks for your advice again and it means a lot to us! If you have any other suggestions, please feel free to let us know.
Thanks!</p>
uArm Team on ROB-13286 - uArm - Desktop Robotic ArmuArm Teamurn:uuid:b5010da1-d08b-6236-441f-f574f6c353382015-03-24T03:56:49-06:00<p>It is 10mm.</p>
uArm Team on ROB-13286 - uArm - Desktop Robotic ArmuArm Teamurn:uuid:8df4e99d-e40e-6bff-7eeb-2b9c9b62765e2015-03-18T06:40:34-06:00<p>Really sorry for the inconvenience! Please send your address and phone number to info@ufactory.cc, and we'll send you the servos for replacement.</p>
Customer #525619 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #525619urn:uuid:0bb39844-ad48-66d1-2ba2-25c284df816a2015-03-14T09:35:07-06:00<p>I've seen this in action on EEVBlog. The accuracy is necessarily lousy -- determined by your PCM resolution and the quality of the servos. The worst engineering miss on there was the connectivity -- the USB and power plug into the electronics "carriage" and whip around your workbench.<p>I see no more than $100 in parts there, so the price is ludicrous. It was bad enough on their kickstarter, but this is seriously deranged.</p></p>
iandees on ROB-13286 - uArm - Desktop Robotic Armiandeesurn:uuid:d30a60ec-d6d2-4903-0f37-e1b0eb2eb61c2015-03-13T10:13:32-06:00<p>I should have waited and bought it from you guys ;).</p>
SimonRafferty SFX on ROB-13286 - uArm - Desktop Robotic ArmSimonRafferty SFXurn:uuid:8238528b-5620-7c66-27b6-e73abf3bd8552015-03-09T13:53:18-06:00<p>You can add a feedback wire to any servo easy as. Inside there is a potentiometer, turned as the servo moves. Just connect the middle pin on the pot to your analogue in. Generally the pin will vary between 0 & 5v over the servos range of movement.<p>I suspect the 'feedback' servos are just off the shelf servos with the wire added. Making your own means you can use servos of an appropriate size / torque.</p></p>
JopieK on ROB-13286 - uArm - Desktop Robotic ArmJopieKurn:uuid:f5827ee7-1c60-6d55-f3bf-c95e70fae9fd2015-03-08T04:43:04-06:00<p>If it could be a bit more precise one could maybe use it for DIY PNP applications.</p>
Hackberry Jake on ROB-13286 - uArm - Desktop Robotic ArmHackberry Jakeurn:uuid:ddf0e52c-4324-3de8-24a4-8ba6117ee3b32015-03-07T16:55:20-07:00<p>Assembly is the funnest part!</p>
Customer #539573 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #539573urn:uuid:33266074-6840-0ec5-cb82-a741b62d8d192015-03-07T05:37:53-07:00<p>Does anyone know the positional accuracy of this arm? Thanks.</p>
Customer #342551 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #342551urn:uuid:c63f4854-9666-80b8-a895-4eea36e1c6b42015-03-06T20:20:26-07:00<p>will you sell the arm alone??
(no electronics)</p>
Customer #496749 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #496749urn:uuid:a39582ea-f6e8-cecc-abf6-c9d4bf4310542015-03-06T20:17:14-07:00<p>I was thinking, and I think that you could implement the coffee gripper (http://www.gizmag.com/versaball-robotic-gripper/30442/ has a good example). But my question is whether the pneumatic systems are compatible with it? If it was, then you could switch to grabbing objects that aren't flat.</p>
Customer #658289 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #658289urn:uuid:3d63ab7e-bab1-b69a-e7a5-54fc3986db262015-03-06T18:36:57-07:00<p>can you buy a mechanical end-effector (gripper) also?
can you vary the amount of suction</p>
Customer #658289 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #658289urn:uuid:980070d1-de0c-e879-93b4-af754b01910b2015-03-06T18:31:22-07:00<p>Hi sparkfun robertc etc, the reason i will buy from you is the support. appreciated, there's always glitcches, problems..</p>
ThomasCouey on ROB-13286 - uArm - Desktop Robotic ArmThomasCoueyurn:uuid:86b19214-cfc6-b3cf-db8a-5b2e65659b6b2015-03-06T18:10:09-07:00<p>PickledDog is right about the feedback wire.</p>
PickledDog on ROB-13286 - uArm - Desktop Robotic ArmPickledDogurn:uuid:798ffdd1-9171-7e78-4d33-01df57918d5f2015-03-06T13:12:29-07:00<p>I see these servos have a 4th wire which, from reading the code, is hooked to an analog pin. These must be "analog feedback" servos. In this case, the 4th wire is connected to the internal feedback pot, allowing you to read the servo's position with analogRead.</p>
Vitor Henrique on ROB-13286 - uArm - Desktop Robotic ArmVitor Henriqueurn:uuid:0bdc98d8-2ae3-7225-548a-ba4004d7c5282015-03-06T13:08:02-07:00<p>Despite I laughed a lot of Robert's answer, <a href="https://learn.adafruit.com/analog-feedback-servos/servos-as-input-devices" rel="nofollow">this</a> is one way to do it!</p>
RobertC. on ROB-13286 - uArm - Desktop Robotic ArmRobertC.urn:uuid:765fe3e4-fbfd-e22c-6862-47d9ee1fdf322015-03-06T12:07:26-07:00<p><a href="http://i.imgur.com/ZhTwj09.jpg" rel="nofollow">Here's</a> an explanation.</p>
Nunzio on ROB-13286 - uArm - Desktop Robotic ArmNunziourn:uuid:158e0995-474a-08b8-bf28-c3f24f594d152015-03-06T10:46:07-07:00<p>How Arduino is capable to understand and reverse record and play servo positions while they are detached?</p>
RobertC. on ROB-13286 - uArm - Desktop Robotic ArmRobertC.urn:uuid:f89b0dae-faaf-404a-f207-69afdaf0841a2015-03-06T10:28:14-07:00<p>We don't have any replacement parts, but we stand behind what we sell. If you have an issue with a product bought from us, we'll take care of you.</p>
MatthewR on ROB-13286 - uArm - Desktop Robotic ArmMatthewRurn:uuid:6a1f2544-5dae-c495-efe4-a0d8861118ea2015-03-06T09:05:17-07:00<p>(*edit: what DonW said)</p>
DonW on ROB-13286 - uArm - Desktop Robotic ArmDonWurn:uuid:70b4a72b-5d1f-48c7-6a27-7bbbfc3b21492015-03-06T08:58:28-07:00<p>Sure looks like that in photo 3, the side view. I imagine it's both for counterbalance when the arm is extended and to insure a constant range of motion for the cables & vac tube.</p>
iandees on ROB-13286 - uArm - Desktop Robotic Armiandeesurn:uuid:dbe0ca9b-7d1d-0113-d9d7-1b22ddbfda242015-03-06T08:27:08-07:00<p>I bought one of these on Kickstarter and they shipped bad servos. I've tried to reach the supplier via their support channels to no avail. Does Sparkfun have any replacement parts for this robot or are you just selling the arm kit?</p>
Customer #19855 on ROB-13286 - uArm - Desktop Robotic ArmCustomer #19855urn:uuid:3db0cbd6-47d0-5de9-0fcb-7921a3c69c962015-03-06T06:24:09-07:00<p>Is the electronics chassis really held up in the air? Or am I just getting tricked by the photography angles lol. If it is, I wonder if it's just for aesthetics or serves as a counterbalance of some sort.</p>