Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Actually, I would probably get one of the thinner, lighter oils to use on aluminium and general lathe work. Even without GST, the Rocol was $36 so you definitely got a good offer. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Thu Jul 02, 2015 6:40 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
DIY Lipo armour
I have been interested for years in using soda bottles as an alternative to heatshrink tube to protect battery packs. I recall several people (possibly Glen?) tried this in the past with mixed results.
I came across this video today:
https://www.youtube.com/watch?v=WKfID-i41sc
and that gave me an idea. If a rectangular mould just a little larger than your Lipo pack was made from MDF, the bottle preform could be blown into a shape just right to slip over the pack.
Trim off both ends, insert the pack and heat shrink to size. The bonus about this is that the preform is not expanded very much, so the wall thickness will be double what it is in a soda bottle and therefore very strong. The preform bottles are about $1 USD so I ordered some from Amazon for a test. If that works, the technique could be used in other areas, maybe battle hardening motors or electronics, even encasing an entire antweight. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Last edited by Nick on Fri Jul 17, 2015 1:29 pm; edited 1 time in total
Fri Jul 17, 2015 8:49 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Ahh, the good old Nicad days . I'm hoping that the custom moulds will be much more durable than the usual lipo shrink coating. My other idea is to make the rectangular mould a bit bigger so that the pack can be wrapped in foam and then fitted inside the bottle so you have built-in shock protection. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Fri Jul 17, 2015 10:21 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
Leaving some room spare would be a decent idea, the lipos seem to swell a bit under heavy load and go back soon after. Anyone else noticed that?
How are you gonna expand the bottle blanks? Maybe it might be better to build a small vacuform machine and just use some PET sheet. Lots of hobbyist prop makers and what not have done it. Doesn't look too hard really. Seems like you would need to make two piece aluminium molds then blow heated air in through the blank otherwise? Could be tricky. _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Fri Jul 17, 2015 1:11 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Check out the video - the guy just uses compressed air injected thru the bottle cap and uses a piece of pipe as a mould. I figure its much easier to use compressed air as I have the compressor and there are no sealing problems like you would have in vac forming. I figure on making a simple box mould from MDF or ply and wood screws. It might be an idea to pre-heat it with a heating gun to get the plastic right into the corners. A one piece mould should work as the plastic will become fairly flexible as the wall thickness goes down. It might not work as well as it does in my head, but its cheap to try and could improve bot reliability. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Fri Jul 17, 2015 1:28 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Dumb machinist question:
Does anyone know what sort of grease gun to use on these small grease nipples?
I'm sure the answer is embarrassingly obvious but I can't find anything that works. the only grease gun I have doesn't seal around the nipple and grease goes everywhere but into the bearing . _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sat Jul 25, 2015 9:57 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
The little can with the flexy nozzle works for me - just cut a slot in the end end.
Auto resizing. We are still living in the year 2000. _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Sat Jul 25, 2015 11:30 pm
Don Experienced Roboteer
Joined: 21 Feb 2010
Posts: 355
Location: Gladstone, Queesland
just an oiling point,like glen just use the little oiling cans
Sun Jul 26, 2015 9:00 am
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
yah, normally use oil in those not grease.
We don't cut anything on them just push them against the ball and it pushes it in then squirt oil in until it comes out somewhere. _________________ Mechanical engineers build weapons, civil engineers build targets
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. I'm hoping that the custom moulds will be much more durable than the usual lipo shrink coating. My other idea is to make the rectangular mould a bit bigger so that the pack can be wrapped in foam and then fitted inside the bottle so you have built-in shock protection.
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