Oddball unisaw guts question

Recently picked up a 1951 vintage Delta Rockwell unisaw and am going through it before putting it in service.
In my small shop I will be welding in addition to woodworking
and we all know that sawdust and sparks don't play nice together.
I want to fabricate a blade shroud for the unisaw to catch most of the dust as close to the source as possible.
On my saw, there are two threaded holes that look like prime candidates for mounting a shroud of this type (they move with the blade). They are shown in the following picture--they are center to the picture (one above the other) and the circular area around them has been faced flat.
http://www.drizzle.com/~dantzler/dropbox/saw3.JPG
My main question is can any one tell me the thread spec for these holes? Secondary to that, if any one has done this before (I know folks have since I humbly admit to not coming up with the idea on my own) would you have any suggestions on implementation?
Some of my thoughts...
I would prefer not to put any more holes in the saw cabinet. Most likely I'll run some kind of flexible duct (maybe even shop vac hose) from the bottom of the shroud out the cabinet and to a good shop vac now (and maybe dust collector later). I could fab the shroud out of mild steel, but that would make me slightly nervous because I shudder to think what would happen if the thing ever came loose. I may take this as a good excuse to start doing aluminum TIG and make it out of 6061.
Thanks for helping me brainstorm.
Jeff Dantzler Seattle, WA
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I just dug all the crud out of these holes and by chance happened to have a 5/16" x 18 tpi bolt lying around so I figured that part out.
Would still be interested in any input regarding the blade shroud.
Cheers--Jeff
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If you are trying to get the shroud to tilt with the blade can you use the spliter mount bolt hole? I know all the safty freeks are going to say something about not using a splitter. If you post on the wood working group you will get a bunch of messages. The Unisaw is a REAL nice machine, I will be selling mine in a few weeks, I am about done with my kitchen.


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wrote:

I personally think you're too concerned about the combustion issue. If you stand at that saw ripping as fast as you can with no ventilation in a closet and have someone else welding at the same time you MIGHT be able to cause a flash fire. I think with minimal ventilation you would not have a problem.
As far as the shroud goes, the two holes are for a small shroud that basically keeps pitch off the elevation gears. On the older style cabinets I've seen, a slanted false bottom is installed in the bottom of the case that is slanted towards a hole cut for the vac system. I suppose to reduce the amount of dust that was able to accumulate, you could do the same thing but higher in the cabinet.
Mike O.
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On Sun, 26 Feb 2006 16:49:54 -0000, Jeff Dantzler

They should be 5/16-18 thread. They are used to mount a sawdust deflector that must have been removed from your unit. The deflecter is to route the dust down and in the direction of the blade travel so that it does not come out of the insert opening.

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I have an imperfect dust collection system on mine an old unisaw .I made an improvised dust shoot for the interior terminating at an elongated hole in the side of the base . the dust collection system [2HP grizzleguts] is plugged in there .
the front ventilated cover has been replaced by an unvented one and caulked, the base is also caulked to the floor the table is sealed underneath with either duct tape or expanded foam ["stuff"].and lastly I have drilled as many holes as I can get in the insert .
It does gets a lot of the dust generated by the blade but not all , probably as much as any other solution ......
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I have an imperfect dust collection system on mine an old unisaw .I made an improvised dust shoot for the interior terminating at an elongated hole in the side of the base . the dust collection system [2HP grizzleguts] is plugged in there .
the front ventilated cover has been replaced by an unvented one and caulked, the base is also caulked to the floor the table is sealed underneath with either duct tape or expanded foam ["stuff"].and lastly I have drilled as many holes as I can get in the insert .
It does gets a lot of the dust generated by the blade but not all , probably as much as any other solution ......
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Thanks to all who replied.
This will be an interesting project, but I think I can come up with a good solution.
Jeff
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On Sun, 26 Feb 2006 16:49:54 -0000, Jeff Dantzler
[...snip...]

[...snip...]
I just picked up a copy of Sandor Nagyszalanczy's book "Woodshop Dust Control". There on page 177 it had a picture similar to what you are talking about, specifically for contractor table saws. He does describe in a couple of paragraphs just what he did, but there is only 1 photo from the top and you can't see how it is mounted. Anyway, it might be worth a gander at your local library.
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Thanks Jim!
Jeff
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