The shafts are standard drill shafts so I'm going to assume the answer is no.
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The shafts are standard drill shafts so I'm going to assume the answer is no.
As Gary said, I'm quite sure they're mass produced shafts for drills that Ewan puts flats on.
Could you not extend the shaft by tapping a suitably sized steel tube (12mm OD) with a 3/8th thread and tightening it hard onto the end with a bunch of loctite?
If thats the case then I will just extend the shaft with Ellis method. Might even be better as then I can support it at the other end.
Gary and Ellis are correct, the gearboxes would be almost twice as expensive if the shafts were completely custom. As it is they are made in batches of tens of thousands for cordless drills and the only modification is the machined flat along the 12mm section.
Hi Ewan, how come you're not at the champs this year? Weren't you working on something big and tracked for last year?
On another note, what grease do you use in your gearboxes?
Final year of university, in the middle of writing my dissertation at the moment about this thing:
https://lh4.googleusercontent.com/-c...0/IMG_2782.JPG
Lithium grease is best, there's quite a few eBay sellers with tubes or tubs of it.
:S
A Chewing Simulator!
Yeah, you get a bit of a push in a subject direction depending on your supervisor's area of expertise, at Bristol at least.
Blimey, I didn't know Wrigley's were that underhand. Why don't they employ someone?
Students are always viewed by big business as being free/cheap labour to research stuff.
No that's not it, it's for medical research purposes which falls under research grants rather than private investment. As such my name will be on any published papers that may arise from it in future.
aha nice, and it will be useful when you get old, could use it to chew your food for you!
In an unconventional fashion I would like to announce that from June 12th all GR02 motors sold will come with an external bearing kit free of charge and a discount offered on shaft mounting hubs. There will also be special rates offered for purchases of four or more motors together. Consider this an incentive to leave off motor orders until after this date if they aren't urgent, something that would help me at the moment, busy as I am!
24V 550 Motor (Optional) Recall
A number of users have reported manufacturing issues with the 24V 550 motors, in some cases with the motor brushes and on one occasion with the bearings. Unfortunately these are problems that weren't seen during my own testing, indeed they do not affect all of the motors but (it would appear) a large enough proportion that I have decided to offer a recall to anyone who wants it
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The options available for previous motor customers are either
1. Replacement 18V HRS550 motor(s) with a lead/connector option to match that of your original 24V motor purchase. These can be sent within the UK free of charge (possible fee for international shipping) and you will not have to return your 24V motor(s). The motor pinion can be either 9T or 15T
2. A refund of the 24V 550 motor value (£8.90) upon return of each motor
In both cases please contact me directly with your name, original order ID and replacement/refund option if you would like to claim. Also if you have any questions please PM or email me.
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I am hopeful that this will be a more satisfactory resolution than dealing with individual motor problems as they arise. It probably goes without saying that I shan't be using this motor supplier again!
Hi Ewan, been following the issue with the 24v motors. I bought a couple of motors some time ago which I have not used yet. (I did actually try them out on a power supply to check they work, which they did) I took a closer look at the brushes today as Gary had pointed out the problem seems to crop from this area. It seems the brushes are mounted incorrectly, from the photos it's clear - they seem to be 90 degrees out of phase, and contact with the commutator is just on two points. I noticed when I tried them out that they sparked quite a lot, could have something to do with this?
Attachment 3681Attachment 3682
Hi Chris. Yes you're correct the brushes have been the cause of most of the problems. For the majority of motors operation has been fine until either heavy loading or impacts which have bought the brush quality issues to light. In most cases the brushes have been visibly fine from a contact and angle perspective but have not handled high operational stresses at all well. Here's a side-by-side view of a set of the 24V brushes by the brushes of a 12V HRS550, spotting the quality differences is not exactly trivial except for those motors which have had a poor contact angle to start with (which may actually include yours by the sounds of it).
Attachment 3683
Please do email me if you'd like to claim your 18V motor replacements or to send back the 24V motors for a refund as discussed in the previous post. Most previous customers of the 24V motor have now done this.
Probably it was just a problematic batch, as from your photo both look fine in my eyes. I'll email you Ewan, better not risk using them and swap for the 18v, btw - excellent aftersales Ewan;)
Agreed. Great service. I'll put a word in to say that the 18v motors are a reliable replacement - they stood up perfectly to 3 fairly hard consecutive events: the champs, Yeovil and then four quite brutal rumbles at Colchester. Any we burned out were purely due to the gearbox issues we experience. Our robot runs hard enough for it to be impossible to keep the wheels tight, and the nature of the weapon is such that it is constantly bucking and bouncing, and the motors are as new. We will be buying more.
I thought I would give Ewan some support and say my GR01's have been fantastic :) Will definitely buy much more from Gimson's in the future inc. linac's, accessories and all sorts. Keep up the good work Ewan!!
Dangerous Dave
Thanks for the kind words guys, it's appreciated!
Replacement motors arrived, thanks Ewan
collected my actuator from the post office today as post missed us on wed, quick postage and very well packaged
the actuator allot quicker than i was thinking it would be and very powerful, oh and thanks for the diodes they will be very useful
ewan i don't suppose you do spare gears for the gla-s as ive managed to shred mine in testing :cry:
Yes I should have a set, email/PM me with which gear failed. Incidentally that's the first time I've known those gear to fail; did you stall the actuator up against an end point or apply a >230kg load?
oh brilliant thanks :)
i was lift about 40kg ish but i will change the mounting points of the lifter and move it nearer to the from to decrees the strain on it,
I've just had a look at your test video (self-righting one), it looks like a 6:1 (or more) mechanical disadvantage which would have given >230kg at the actuator for a 40kg load at the end of the arm. Changing the pivot may be a good idea, (or alternatively you could just make sure you don't lift 40kg!)
i measured it up and worked it out its a 5.75-1 so yeah very close estimate
The GR02 gearmotors are now back in stock with new lower prices and a free external bearing kit supplied with every motor
http://www.gimsonrobotics.co.uk/GR02...gearmotor.html
Any questions, please let me know
Some of you may have noticed that prices for a number of our items have gone up recently, this is to take account of 20% UK VAT which is now applicable to all Gimson Robotics sales except those received from outside the EU, or those from VAT-registered businesses in countries except the UK. One item that will remain at the same price for now is the GR02 gearmotor, something we have been able to achieve due to savings made down the supply chain.
Quick question are gimsons still going? I put an enquiry in but havent heard back and when i look at ewans profile he hasnt posted since august 2013 and his profile doesnt say when he last visited this forum
I think you can buy a few linacs or the high geared motor, but the GR02's are gone. No longer available.
I put an enquiry in for a actuator
Hi Ade,
Still going, please try emailing again as your message must have slipped through: http://www.gimsonrobotics.co.uk/contact.html
Hi ewan. Thanks for reply. will do now
Hi ewan. Still struggling to get a reply. I have pm'd you directly as i need a question answering before i can place order. Thanks
Hi Ady, not sure why that is, noone else is having problems with our message form or email at the moment. Have just replied to your private message on the forum.
Cheers ewan its probably me. Checked my spam folder on email too