Build Your Own Arcade Controls Forum
Software Support => Automated Projects => Topic started by: rockyrocket on March 08, 2013, 08:27:42 am
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Hi, so I have a rotating set up that uses a 6mm pololu mount (http://www.pololu.com/catalog/product/1083) on the motor shaft, but alas the grub screws are not coping.
Having my screen at an angle is producing too much torque through added friction from the lazy susan bearing not being flat and over time the mount fails.
The soft alu mount is not designed for this much abuse so my question is can anyone sugest an alternative mount for a 6mm shaft?.
So far adding a bigger grub screw and jbweld has not worked and I may try "adjusting" it onto the shaft with a vice, but really I need a more suitable solution.
Thanks in advance.
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Im not sure. 6 mm is not very big, but Im sure it can be done.
How about it guys? Put your thinking caps on.
Could you maybe go with a bigger lazy susan type bearing that would take the side load off the motor shaft?
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Yes maybe a better qualty bearing is needed.
I have an 9" lazy susan now, so going up in size is not the issue its more that the incline allows the loose bearings to collect at the lowest point of the channel producing resistance, when laid flat the bearings run fine.
Wonder if a more industrial ring type bearing exists maybe from a ofice chair or something?.
Will have to think on some more.
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Does the motor shaft have a flat spot? If not, consider adding one. ;D
You could also try grooving both the shaft and mount, filling in the grooves on both sides with jbweld, then putting together with some of the grooves aligned.
When the jbweld hardens, it will act as a key and not allow anything to slip. (kinda like a makeshift splined shaft)
I have a set of those Pololu pololu mounts that I plan to use in a 360 degree wheel driving setup.
Glad to know about this issue ahead of time!
Not sure what exact bearings you have, but for a few projects I've flushed thick oil out of them with thinner oil to get them to spin easier.
Last time I think I used PB Blaster to flush the old gunky oil out.
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Thanks for the ideas badmouth,
Yes the shaft has a flat already that the grub screws key onto - I have a spare unused mount so am thinking that the with the bad one I have nothing to loose by distorting the mount into the flat of the shaft in a vice, but I think the polulo mounts alu is too soft for the hard steel shaft but hey whats to loose?.
I am into bicycles and once a local frame builder made me a custom drivetrain part that was bonded together with a high strength red locktight ( i think) so maybe that may help or I could make some kind of shim for the mount or tap a thread into the shaft maybe?.
I have time to come up with a solution as at the moment its not top of my to do list, but saying that I will look into alternate bearings right now and thinking about it I pass a business that I think make bearings so maybe thats an avenue.
One other idea is to use a drill chuck on the motor shaft and then attach the monitor mount to that some how.
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I originally tried a lazy susan, but wasn't happy with the slop in the rotation. I ended up using a robotics turntable:
http://www.vexrobotics.com/vex/products/accessories/motion/276-1810.html (http://www.vexrobotics.com/vex/products/accessories/motion/276-1810.html)
After I got it, It wasn't quite as tight as I had hoped, but in the end I have been happy with it.
Here is a video:
MAME Rotating Monitor Mechanism (http://www.youtube.com/watch?v=C--HMmH1BNo#)
In the video, the monitor was pretty flat, but since then, I moved it up to a much steeper angle, and the turntable has no problems.
Justin
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get out the drill press and bore the shaft. Lose the grub screw and use a cotter pin. Cheap fix and worth a shot. Which bearing are you using? I've been hunting for a cheap sleuth bearing but they don't seem to exist.
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Thanks guys for the input, and the timing is just perfect as last weekend I redid this but am still not sure if it will hold.
My fix at the moment was to use the other pololu mount as you get two and to tap a slightly bigger grub screw into it, but the cotter pin idea would of been much better and I have plenty here from bicycle breaks.
If that fails then I now have some other ideas mostly gleamed from using the search term "6mm shaft coupling" that brought up items like this (http://comparerc.com/#!/product/188212/mj4706-collet-prop-adapter-for-6mm-shaft-m8/) aswell as other items used in CNC`s.
Infact as an experiment I think I will order this (http://www.ebay.co.uk/itm/320913918480?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649) right now just to see how suitable it is.
@GoYouSalukis I really like that bearing so may well go for it!, and Le Chuck my bearing is just a generic lazy susan from the bay and would work just fine if it was flat - just not at an angle.
Not sure what a sleuth bearing is and my google skills are failing me.
On a side note the VEX site from the turntable link has some fun looking toys in it.
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My bad. Slew bearing. Like on a windmill. Stupid auto korrect
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My bad. Slew bearing. Like on a windmill. Stupid auto korrect
Ah I see :) .
So after I walked away from this I realised that your method is by far the best solution so have also just ordered this (http://www.ebay.co.uk/itm/370526929063) steel mount to use with a pin, thanks.
And then ofcourse the friction from the bearing will be null.
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So, google + slew bearing = this image - crikey!.