Film-Tech Forum ARCHIVE: Converting to 1/2" spindles

This is topic Converting to 1/2" spindles in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Martin McCaffery (Member # 37) on 01-11-2004, 01:06 PM:

Has anyone had any success converting 5/16" reels to 1/2"?

I'm switching over my reel arms, and just bought some new hour reels. I still have some 20 min Goldbergs I'd like to be able to use. Is it easier and cheaper just to buy new (or used) ones, or can the conversion be easily done?

Posted by Gordon McLeod (Member # 33) on 01-11-2004, 01:48 PM:

If they are the cast alumionum 2000' reels the centre can be bored out by a machine shop

Posted by Steve Kraus (Member # 476) on 01-11-2004, 01:50 PM:

If they are the house reels with the steel center can't that just be driven out and replaced with a larger one? I often tap on mine to recenter them so it seems like they'd come out easily enough.

Posted by Greg Mueller (Member # 17) on 01-11-2004, 02:06 PM:

Typically the 1/2" reels that I use have "drive dog" holes, unlike the 5/16 the use a keyed shaft. You can knock out the adapter in the cast reels as suggested, but you also have to drill a slightly larger that 1/4" hole so the drive dog pin will fit into it. Maybe they make keyed shaft 1/2" units but I've never seen one.

Posted by Gordon McLeod (Member # 33) on 01-11-2004, 02:14 PM:

On the cast reels since he does say 2000' house reels have a recesed area around the insert that the drive dog will line up with and drive
The only reason I sujest get a shop to do it rather than drilling it out is that the key will grab your bit and probably make it drill of square and that will give you a wobling reel
Never had any luck pressing out the insert as it was pressfitted in in the first place

Posted by Scott Norwood (Member # 30) on 01-11-2004, 06:46 PM:

The older Goldberg cast reels do not have the drive dog "notch," so this may be a problem. The newer reels do have it, even if they also have 5/16" keyed shafts.

Personally, I hate the 1/2" shafts. Unless you _always_ run 6000' reels or have a huge pile of large-shaft reels, you may want to think twice about switching. In theory, the 5/16" shafts are more likely to get bent or otherwise damaged, but I've never seen this problem myself, even at places that usually run 6000' reels.

Posted by Steve Guttag (Member # 268) on 01-11-2004, 10:16 PM:

Sorry Scott...I can' t back you up on that one...if you run 6K reels...go with 1/2" (12.7mm). As to the difference between the 5/16 and 1/2" Goldberg cast reels is not only removing the insert but there is a 1/2" bronze insert that should be placed in the hole...I don't like the 1/2" 20 min. cast reels...

Some reel arms/projectors allow for a reasonably fast change between the various spindle sizes and this is really the way to go.

Steve

Posted by Brad Miller (Member # 2) on 01-11-2004, 11:34 PM:

I'm with Scott here. I've yet to see a bent 5/16" shaft and having to ALWAYS wind film over onto 1/2" house reels is a major pain in the butt. I use 5/16" for everything and have yet to have a problem.

Posted by Daryl C. W. O'Shea (Member # 1303) on 01-12-2004, 01:09 AM:

I'm with Steve. I have seen enough bent 5/15" shafts to know that 1/2" for large reels are necessary. Usually it's the takeup arm shaft but if you've got short operators a bent feed arm shaft is more common.

Since you have to wind the shipping reels onto large reels anyway, the winding everything over thing is pretty much a non-issue. Sure you'll have some film come in directly from another theatre on 5/16" shaft 6000's, but that's life.

Of course if you're only using 2000' reels 1/2" shafts aren't necessary.