Rich too Posted August 22, 2012 Author Share Posted August 22, 2012 I did it, spun two of the adpaters in a drill slowly and they are both clearly out of true. What causes this - perhaps the prop? i'll have to ream another and try that. any problem with running it with just the tip of the adapter and spinner out? as i said there are no vibrations. Rich Quote Link to comment Share on other sites More sharing options...
cagey Posted August 22, 2012 Share Posted August 22, 2012 Dickster, have you turned the prop over slowly, with the motor held rigid and measured any out of alignment at each blade tip ? Do this on several different props to be certain. That'll let you know for sure if the drive is off centre. If you have access to an engineers lathe, this can be trued up easily. As for balancing, believe me this is a must, regardles of whoever says otherwise, an out of balance prop can wreck an electric motor in a very short time, the bearings go first then they vibrate about in their mounts enough to become a loose fit = one knackered motor. Seen it happen, so don't ignore the balancing even if it only takes a tiny smear of cyano to achieve. Quote Link to comment Share on other sites More sharing options...
John Miller 4 Posted August 23, 2012 Share Posted August 23, 2012 Hi Dickster With the greatest of respect putting it in a drill and spinning it, will only tell you that it is rotating. A drill is not nearly accurate enough. I agree with cagey, the only real way is to hold the motor rigid and check the motor shaft with a D.T.I. while it is rotated by hand. If all is O.K. then you can turn your attention to the driver, if this is out then I would venture to suggest that the mounting face is not square to the bore, of course it may be the motor case is not square to the shaft, but I suspect this not to be the case. You need a Model Engineer friend to help if you cannot access the equipment yourself. The forces involved in an out of balance prop can wreck bearings in the blink of an eye, well almost. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 23, 2012 Share Posted August 23, 2012 I totally agree an out of balance set up, can do a lot of damage. I would be very surprised if the prop, as supplied, is the problem. Since obtaining a static balancer, I have been surprised how accurate even cheap propellers are. Dickster seems to be looking for gross errors. I believe if the motor is held firmly at the mounting face, then using a DTI on a firm base, the source of the problem would be soon identified. Such an arrangement may not necessarily be adequate to obtain definitive values, but good enough for gross errors. I do however remember that it is very possible to statically balance, yet the object to be out massively dynamically. Quote Link to comment Share on other sites More sharing options...
Mal Quelch Posted August 23, 2012 Share Posted August 23, 2012 Hi all, This may not be the same problem but i have had spinner run out also. Not only with this type fitting but also with collet type. Using APC `style` Electric props. In my case I found that when tightening the prop the raised prop size (8x4 10x6 etc) on the front boss , being on one side, stopped the spinner tightening up level. The prop ran true but the spinner appears off centre. Might be worth a look ? All I did was face the lettering off level and it was fine. You could try tightening say a nut, or stack of washers in place of a prop and see if it changes anything? Simple I know but worth checking. Mal Quote Link to comment Share on other sites More sharing options...
Rich too Posted August 23, 2012 Author Share Posted August 23, 2012 I know I should try and get hold of a DTI to be sure. Mal, thanks, i have inspected the prop but I will look at that also. Rich Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 23, 2012 Share Posted August 23, 2012 Although not as obvious or providing a numeric value, a simple fixed pointer, which the items are rotated past works. In that run out can be visually seen. An assessment of how much is a matter of judgement. You can see 0.005" without to much difficulty. Given you are looking for gross errors, it is not an issue. As has been suggested, observing if there is any propeller run out is a good staring point. Quote Link to comment Share on other sites More sharing options...
Pete B Posted August 23, 2012 Share Posted August 23, 2012 It's just a thought but I've encountered, on a Turnigy motor, an instance where the supplied adaptor did not seat properly over the front end extension on the motor (the bearing housing). It was not possible to tighten the adaptor to the front of the motor with the bolts. Whether it was because the adaptor had not been machined out enough to fit over the extension or not, I don't know, as I was planning to use a collet adaptor anyway. Just a thought....... Pete Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 23, 2012 Share Posted August 23, 2012 It is that sort of thing Pete which I think Dickster is looking for. Normally I am amazed how accurate the assemblies are, but every so often, I am disappointed. Quote Link to comment Share on other sites More sharing options...
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