Xicoy Electronic C.G. Balancer
07-22-2015, 01:58 AM
#176
Just curious. How do people feel about making the CG exactly spot on, no falling to the side of nose heavy just in case something is wrong? For a 3D plane, I am not so much worried, they have a wide range of latitude but a scale warbird on the other hand, it is pretty sensitive to anything tail heavy. With the use of a kit like this, I am afraid to be precisely wrong and not sure I should worry about it.
Last edited by wfield0455; 07-22-2015 at 02:02 AM.
07-22-2015, 05:25 AM
#178
Well I returned my first unit and got a replacement set......still finding that one side of the model is 4lbs heavier than the other. This is not right.
Im biting the bullet and purchasing a calibrating weight set...................that being said, what a PITA product!!
Im biting the bullet and purchasing a calibrating weight set...................that being said, what a PITA product!!
07-22-2015, 06:07 AM
#179
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Sadly, mine is going back for a refund.
The first set of weighing scales were really faulty but Gaspar was very quick to send me a replacement set with no quibble. The new scales are almost as bad, the same weight put on all 3 sensors gives 3 very different weights, the difference between the lowest and highest being 110 grams, or 4 ounces, with a 6kg weight. One of the scales from the first set I had would give a difference of nearly 2lbs in weight just by moving the wheel 2mm to the side. I have 3 postal scales I got from ebay for just £5 each (approx $7.50) including postage and they agree with each other to within 2 grams.
It's time to give up, which I am sad about because the device is great and the angle sensors have made setting up big tailplanes and elevons etc so easy, but when 0 out of 6 weight sensors can be trusted.......
The first set of weighing scales were really faulty but Gaspar was very quick to send me a replacement set with no quibble. The new scales are almost as bad, the same weight put on all 3 sensors gives 3 very different weights, the difference between the lowest and highest being 110 grams, or 4 ounces, with a 6kg weight. One of the scales from the first set I had would give a difference of nearly 2lbs in weight just by moving the wheel 2mm to the side. I have 3 postal scales I got from ebay for just £5 each (approx $7.50) including postage and they agree with each other to within 2 grams.
It's time to give up, which I am sad about because the device is great and the angle sensors have made setting up big tailplanes and elevons etc so easy, but when 0 out of 6 weight sensors can be trusted.......
07-22-2015, 06:15 AM
#180
If a postal scale can hold calibration why can't these? It baffles me. Great concept, but if you can't replicate the good idea into manufacturing consistantly it is dead before it's out of the box.
07-22-2015, 07:05 AM
#182
So far we had only 1 scale returned out of over a hundred sold.
07-22-2015, 01:04 PM
#185
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If that is the case, then I will take it, gladly. However, my track record shows that if one is going to be sent out that is bad, I get it. I hope all others that are reportedly bad are simply ones that are not being used properly and education fixes the problems.
07-22-2015, 01:46 PM
#187
I apparently got a set of the good ones also. After hearing of the issues others seem to be having I decided to order a 2Kg calibration weight from Amazon. All 3 of my scales are consistent to each other within .04 lbs (.6oz) which while not laboratory quality certainly seems good enough for our purpose.. When powering the unit with a freshly charged 2S Lipo, they don't seem to drift noticeably over a 20 minute time period either. As I recall, on most of the planes I've checked the CG on, a difference of 50 grams only changed the CG a mm or 2 and it's hard to get accurate measurements to calculate the CG from that are much better than that. I'm not looking for an exact CG but rather to ensure that it's within a safe window, so that I can fine tune it based on flight testing. This unit seems to work perfectly fine for that..
07-22-2015, 04:02 PM
#189
Why would you assume it was meant to be powered with weight on the scales? I always assumed the scales would need to be zeroed before use so I set the scales out close to where they will be used with nothing on them, power up the unit and press the TARE button in the weight menu. I then carefully place each scale under a wheel and press the CG button. I guess I've always just checked that everything was properly zeroed before using any digital scale.
07-22-2015, 04:15 PM
#190
Really? Maybe that is why mine didn't work. I always powered the unit up and then placed the jet on them. Oh and I must be the only one who returned one lol. I've already gotten refunded for it.
07-23-2015, 01:31 AM
#192
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So when Olivier Nicolas of Ultimate Jets is having to dismantle, match, rebuild, and recalibrate them all, and still rejecting 10% of them, it's because he can't use them properly and needs education? When Gaspar told me that there had been a number of faulty sensors in a batch, it was really just me misusing them and needing education, not that the manufacturer confirmed that there were some faulty ones? You have managed to be very rude and insulting to a number of people.
Last edited by HarryC; 07-23-2015 at 02:13 AM.
07-24-2015, 01:13 AM
#194
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I may have discovered the cause of my weight sensors giving random readings even immediately after calibration. It seems that due to a tiny error in design calculation or manufacture, the top case may be rubbing against the base or the pcb and thus affecting its readings. It also explains the huge difference in readings caused by moving the wheel slightly across the top of the sensor.
If I am right, then a tiny change of less than 1mm in the position of the bolt hole in the base is needed.
I really like this device and the angle sensors so I don’t want to return it for a refund, I want to make it work. I spent a lot of time last night carefully calibrating the sensors but one of them never quite weighed the correct amount by a few grams, and another sensor would over weigh by several hundred grams then not return to zero by a long way, then tare it and it would under weigh by several hundred grams then not return to zero by a long way, tare it and it would over weigh by several hundred grams, and so it just repeated that cycle.
Inside the unit is the measuring beam which is bolted to the base at one end and bolted to the top cover at its other end. Therefore the position of the holes in the beam, base and top cover determine the position of the cover relative to the base. If you turn the sensor upside down and look at the narrow gap between base and cover, on mine the gap is not even all the way around, at the end where the top cover is bolted to the beam the gap seems to go to zero. I can’t slide a piece of paper around the narrowest point of the gap so the gap is less than the thickness of paper and may go to zero, and I can also feel the paper snagging something. That something turns out to be the pcb inside the unit which not only sits ever so slightly proud of the base unit meaning it has more chance to rub against the cover, but at both ends of the pcb is a very small spike sticking out which gives it another chance to rub against the cover.
I very carefully sanded the edge of the pcb flush with the base including getting rid of the tiny spikes, then applied pressure along one end of the beam to try and push it away from the closed end of the gap as I re-tightened the base bolt, but it is manufactured very precisely so if it moved it was fractions of fractions of a mm. But it was enough! I can just about get a piece of paper to slide through the gap and now the sensor weighs exactly the calibration weight, returns exactly to zero, and does it over and over again.
This would also explain why some of my sensors give a huge difference in weight just by moving the wheel a couple of mm. The top cover is bolted at one side to the beam with a washer in between which means the position of a weight on the cover can rock the cover ever so slightly and thus affect the gap at the narrow side and thereby change the pressure of the interference between cover and base/pcb.
I will see if I can mill or file the hole in the base by about 0.5mm to make it a slot so that the beam and therefore the top cover change position by just enough to ensure a gap all the way around, and I will remove the proud edge and spikes of the pcbs to make sure they don’t touch and interfere with the top case.
If I am right, then a tiny change of less than 1mm in the position of the bolt hole in the base is needed.
I really like this device and the angle sensors so I don’t want to return it for a refund, I want to make it work. I spent a lot of time last night carefully calibrating the sensors but one of them never quite weighed the correct amount by a few grams, and another sensor would over weigh by several hundred grams then not return to zero by a long way, then tare it and it would under weigh by several hundred grams then not return to zero by a long way, tare it and it would over weigh by several hundred grams, and so it just repeated that cycle.
Inside the unit is the measuring beam which is bolted to the base at one end and bolted to the top cover at its other end. Therefore the position of the holes in the beam, base and top cover determine the position of the cover relative to the base. If you turn the sensor upside down and look at the narrow gap between base and cover, on mine the gap is not even all the way around, at the end where the top cover is bolted to the beam the gap seems to go to zero. I can’t slide a piece of paper around the narrowest point of the gap so the gap is less than the thickness of paper and may go to zero, and I can also feel the paper snagging something. That something turns out to be the pcb inside the unit which not only sits ever so slightly proud of the base unit meaning it has more chance to rub against the cover, but at both ends of the pcb is a very small spike sticking out which gives it another chance to rub against the cover.
I very carefully sanded the edge of the pcb flush with the base including getting rid of the tiny spikes, then applied pressure along one end of the beam to try and push it away from the closed end of the gap as I re-tightened the base bolt, but it is manufactured very precisely so if it moved it was fractions of fractions of a mm. But it was enough! I can just about get a piece of paper to slide through the gap and now the sensor weighs exactly the calibration weight, returns exactly to zero, and does it over and over again.
This would also explain why some of my sensors give a huge difference in weight just by moving the wheel a couple of mm. The top cover is bolted at one side to the beam with a washer in between which means the position of a weight on the cover can rock the cover ever so slightly and thus affect the gap at the narrow side and thereby change the pressure of the interference between cover and base/pcb.
I will see if I can mill or file the hole in the base by about 0.5mm to make it a slot so that the beam and therefore the top cover change position by just enough to ensure a gap all the way around, and I will remove the proud edge and spikes of the pcbs to make sure they don’t touch and interfere with the top case.
Last edited by HarryC; 07-24-2015 at 01:25 AM.
07-24-2015, 09:04 AM
#196
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So when Olivier Nicolas of Ultimate Jets is having to dismantle, match, rebuild, and recalibrate them all, and still rejecting 10% of them, it's because he can't use them properly and needs education? When Gaspar told me that there had been a number of faulty sensors in a batch, it was really just me misusing them and needing education, not that the manufacturer confirmed that there were some faulty ones? You have managed to be very rude and insulting to a number of people.
I am not going to tell you how to feel, that is yours to own. I certainly didn't mean any disrespect.
Andy
07-24-2015, 09:10 AM
#197
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I have just come back to the device after 24 hours, and all three sensors are still showing the correct reference weight to the exact gram so I feel that I have solved the problems that mine were having.
07-24-2015, 08:58 PM
#200
Harry,
I tried a little of what you did (not to the same extent) with trying to get the gap even. It turns out the sensor was just bad and the guys from Ultimate Jets replaced it at JOK. The wife is out of town so tomorrow I'll bring the jet in the house and try the balancer out again, maybe even on the dining room table.
In the mean time I did the maiden and it was perfect from the hang balance.
I tried a little of what you did (not to the same extent) with trying to get the gap even. It turns out the sensor was just bad and the guys from Ultimate Jets replaced it at JOK. The wife is out of town so tomorrow I'll bring the jet in the house and try the balancer out again, maybe even on the dining room table.
In the mean time I did the maiden and it was perfect from the hang balance.
