Adapt-A-Roll question about that ridge on the bottom.

[shalom_septimus]

<p>The Adapt-A-Roll 620 was manufactured in three sizes: 4x5, 3¼x4¼, and 2¼x3¼. They never made one in 3A size that I know of (3¼x5½).<br /><br>

So, I happen to have two Adapt-A-Roll 620s in 4x5, only one of which I particularly need. I was thinking of converting the spare to 3A format to use with a Premo #8. This would require narrowing it by around a half inch, and lengthening it by about the same. <br /> <br /> (I would probably find a local machine shop to do this for me, rather than attempt it myself.) <br /> <br />Narrowing it would be fairly easy; simply mill off a quarter inch, more or less, from each side, until it matches the original Premo film-pack holder. The "wings" are hollow; it shouldn't be much trouble. <br /> <br /> Lengthening it might be more of a hassle. My first thought was to have them drill and tap a couple holes in the end and screw on a piece of aluminum bar stock, but then I took another look at the thing and had an idea. <br /> <br /> There's a ridge on the bottom side that stops it when sliding it into a Speed Graphic. If I were to mill that off, the holder would slide in another half inch and bottom out in the Premo. (It has a piece of wood at the end of the channel, which the SG does not.) <br /> <br /> So my question is: Is that ridge necessary for anything <i>else</i> besides stopping the holder from sliding in too far? Like a light trap or something? Because if so, I could probably get them to attach a similar ridge at the extreme end of the wider part, but if it's not needed, I wouldn't bother. <br /> <br /> (Tried posting this at graflex.org but didn't get any answers there, so I figured I'd try here. Thanks in advance.)<br /></p>

[dan_fromm2]

<p>The film holder's ridge and the mating groove on the back are a light trap.</p>

[tony_lockerbie]

<p>As Dan says, the extended ridge on all roll films is there as a light baffle.</p>