that's the same size as a standard potentiometer..

basically i have a shit ton of knobs that we're going to paint. i need to build racks to hold the parts and the easiest way to hold them (if i can find this rod stock) would be to just weld some tips to some existing racks.

something like this is what would work, but i need like 10ft of just the splined part.. i guess at worst i could order a bunch of potentiometers and cut them up..

1/15/2010 10:36:49 AM

Why can't you just use regular rod or threaded rod a bit smaller? It just has to hold them, not spin, right? As long as you don't turn it upside down they'll stay.

1/15/2010 10:49:02 AM

worried that by getting something large enough to hold them well the splines might get bent down when we send them through the oven.. it may not be an issue but we thought if we could find some something like this to work it'd be easier and less headaches in the long run

oh, and no they can't really spin around or anything when being sprayed.. we'll have probably 15 rows or so of them at least and if they're spinning overspray from one row would fall on the row below it and we'd have a lovely mess

[Edited on January 15, 2010 at 11:17 AM. Reason : asdf]

1/15/2010 10:56:40 AM

Would a snugly fitting wood dowel work? I have tried to find spline stock before and its a pita. I believe most of the companies that make it do custom orders.

If you did just get a bunch of pots why cut them up instead of just mounting them as-is? (other than having more for paint to stick to...)

another alternative might be small rubber tubing over a steel pin, that way it would grip the knob but not hurt the insides.

are they plastic knobs?

[Edited on January 15, 2010 at 11:29 AM. Reason : d]

1/15/2010 11:29:15 AM

yea they're plastic

first order is for a million of them painted

so, yea..need something that will not give us problems. mounting whole pots might work fine actually..

1/15/2010 11:38:24 AM

crikey!

another idea, this is reaching some, you could get some small steel tubing (mcmaster-carr has this), say, oh, 7/32 OD, .015 wall, or whatever size is just under the ID size, and then crush the tube a little bit at a time til its snug in the knob. I don't think you want to do that a million (or how ever many the racks hold) times though...

so maybe you could get some drill rod that will fit nicely. It comes in a huge range of sizes... What is the spline ID? If you have an extensive drill bit set, see if a knob will fit appropriately on the shank of one of them and get that size rod for your rack. If its a +.002 fit or so I don't see it damaging the knobs...

1/15/2010 11:53:01 AM

yeah i think something like that is what we'll end up doing.. i'm trying to keep tooling costs down bc we're competing with China mfg's where they aren't having to buy any tooling currently. i also have to consider how difficult it is for line workers to put these parts on the rack though and how easy it will be for the robot painting them to blow them off the rack.. the splined shaft seemed like a pretty ideal "tip" to hold the part since it'd be super easy to load parts on to and hold them pretty firm at the same time without messing up the splines of the plastic part

I think we're gonna do 250 per rack and do about 50 racks. That should fill our line up and would let us do about 50,000 in a shift or so. damn things have to be dirt cheap unfortunately

1/15/2010 12:31:44 PM

You should include a bullet and a handgun in your budget for the poor sonambitch on the assembly line that has to put a million knobs on a million splined shafts.

If you had a funnel with a T-shaped spout that shakes them you could just dump the knobs in and they'd come out aligned sideways. Put 10 funnels in a row and have plunger bar push them all onto a rack row of spindles. An inverted parallel Pez dispenser. The spindles would have to be tapered as in your photo so the knobs could spin a bit as they slide on...simple cut stock would be a pain to align.


[Edited on January 15, 2010 at 11:12 PM. Reason : .]

1/15/2010 11:04:05 PM

CTD in that assemblers future.

1/15/2010 11:12:31 PM

Edit:
If you had a funnel with a T-shaped spout that shakes them you could just dump the knobs in and they'd come out aligned sideways. A worker could then just slap a rack in sideways.


Getting these knobs to line up automatically on splines will be difficult I think, especially if the splined stock isn't tapered on the end like your photo. How bout just welding a bunch of bolts to a rack, then coating the bolts with plastidip or something so they stick in the knobs tight.

1/15/2010 11:36:55 PM

while it looks like a decent idea on paper i don't see it working.. you have no idea what these knobs even look like or how they're shape. they aren't standard guitar knobs or anything..they just happen to fit on a standard pot shaft.

also, only half of the order is for knobs.. the other half is square buttons that won't be going on this shaft

and..they load small parts like this all day, everyday.. they'll be aight

1/16/2010 11:36:57 AM

something like this? it doesn't look like the have 6mm major diameter though, maybe try calling them? https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=992&GroupID=206

have you tried calling a local tooling builder? they might know where you could get it.

[Edited on January 16, 2010 at 4:30 PM. Reason : .]

1/16/2010 4:29:37 PM

hmmm that could be what i'm looking for. will call them on monday

and yea our usual tool shop is coming in next week so i was gonna ask them but figured i'd look first and see if it was common or not..

[Edited on January 16, 2010 at 4:32 PM. Reason : asdf]

1/16/2010 4:31:38 PM

would 6mm hex stock work?

1/16/2010 4:36:12 PM

6mm hex would probably do more harm than good.

1/16/2010 4:39:31 PM

then 5mm

1/16/2010 7:57:44 PM

so what'd you do

1/31/2010 11:34:04 PM

didn't get the job

2/2/2010 3:30:58 PM

that sounded like a bitch anyway

2/2/2010 4:50:26 PM