#robotics Logs

Feb 26 2020

06:34 PM SpeedEvil is now known as Guest34276
10:56 PM goppo_: hi
10:56 PM goppo_: anyone know what the typical bend tolerance is for aluminium right angle brackets?
10:57 PM Tom_L: https://www.custompartnet.com/calculator/bend-allowance
10:58 PM Tom_L: depends on the alloy and temper
11:02 PM goppo_: right
11:03 PM goppo_: basically i'm trying to make a right angle aluminium part where a motor mount will be fixed. if i were to have the plate bent, the tolerance will be 1mm. but i guess the only alternative is to use a right angle bracket
11:03 PM goppo_: but i fear the tolerance may be even greater
11:04 PM Tom_L: get some right angle extrusion instead
11:05 PM goppo_: Tom_L yeah i've thought about that, but i'm trying to make the part as thin as i can because it is to be fitted in tight space
11:05 PM goppo_: it's actually the base for a motorised linear guide
11:06 PM goppo_: and the unit itself is rotated by a motor
11:06 PM Tom_L: i've got some pretty thin extrusion i use for different things
11:06 PM Tom_L: like 1/16" or thereabouts
11:07 PM Tom_L: maybe thinner
11:07 PM Tom_L: probably 3" T
11:07 PM Tom_L: just depends what you have access to
11:08 PM goppo_: this is what the unit looks like now: https://imgur.com/a/3NwWT7F
11:08 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/local_stock/1.jpg
11:09 PM Tom_L: i can usually find just about anything i need :)
11:09 PM goppo_: nice
11:10 PM Tom_L: the way your part is, extrusion may not be an option due to the length
11:11 PM Tom_L: bending aluminum will weaken it especially if it's T material (tempered)
11:11 PM goppo_: yeah
11:11 PM Tom_L: why not steel?
11:12 PM goppo_: the current design uses 1/8" aluminium plate
11:12 PM goppo_: not sure if that's good enough
11:12 PM goppo_: Tom_L i'm trying to reduce the weight because the servo that drives it isn't that big
11:12 PM Tom_L: unless it's O material it's likely going to crack
11:12 PM Tom_L: but then you'd have to temper it
11:13 PM goppo_: i was thinking of using 6061
11:14 PM goppo_: i guess i could look into using steel if aluminium's too weak
11:15 PM goppo_: but do you think i should have the angle part bent?
11:16 PM Tom_L: i welded mine http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Assembly/Z_Motormount2.jpg
11:16 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Assembly/Z_Motormount3.jpg
11:18 PM Tom_L: why the separate piece behind the motor?
11:18 PM goppo_: nice
11:18 PM Tom_L: why not make that all one piece?
11:18 PM Tom_L: then add some triangles on the side for support
11:18 PM goppo_: Tom_L that's for attaching the servo arm
11:19 PM goppo_: a disc, in this case
11:19 PM Tom_L: k
11:19 PM goppo_: the red piece
11:19 PM Tom_L: got it
11:20 PM Tom_L: what cad is that?
11:20 PM goppo_: it's solidworks
11:20 PM Tom_L: i've played with it a little
11:20 PM Tom_L: mostly use catia
11:21 PM Tom_L: does assemblies better
11:21 PM goppo_: maybe i could replace the bend with triangles
11:21 PM Tom_L: if you have room
11:21 PM Tom_L: does it rest on the bolts at the far end?
11:21 PM goppo_: i've played with catia just a little
11:21 PM Tom_L: if not you may need the support
11:22 PM goppo_: my school gives us an educational copy of SW so i thought i'd use it when i still can :)
11:22 PM Tom_L: i took some catia classes
11:23 PM goppo_: oh, the bolt is part of the linear guide
11:23 PM goppo_: the 4 copper spacers are meant to slide left and right
11:23 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/practice_drawings/
11:23 PM Tom_L: a few of the things we did
11:23 PM goppo_: and this hole thing is meant to be supported by the servo's pinion
11:24 PM goppo_: not shown here
11:24 PM goppo_: it's going to be on the left of the red disc
11:24 PM Tom_L: gettin late here
11:24 PM Tom_L: heading to bed
11:24 PM goppo_: thanks
11:25 PM Tom_L: what school?
11:27 PM goppo_: university in sydney. my major's actually computer science, but they offer solidworks to us as well :D
11:27 PM goppo_: for 3 months... :(