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"D" holes in chassis

PostPosted: Thu May 14, 2009 3:24 pm
by JimB
Another newbie question: how do you produce the "D" shaped holes for such items as binding posts and fuse holders? Or would round holes be OK? I would think that if you tighten them sufficiently with a lock washer that they would be secure enough?
Thanks
Jim

PostPosted: Thu May 14, 2009 3:34 pm
by Geek
Hi,

Unless it's a "must have anti rotation" safety thing, I just use round holes.

I used to scrollsaw or dremel the "D" holes and it took too darn much time.

And a D-hole punch cost WAY more than a regular hole punch.


Cheers!

PostPosted: Fri May 15, 2009 7:26 am
by JimB
thanks Gregg!

PostPosted: Fri May 15, 2009 8:36 am
by TomMcNally
If you want to make some really nice holes for your
1/2" binding posts and fuse holders - grab a Greenlee
Chassis Punch on eBay ... well worth it. A twist drill
tends to distort the chassis, and a UniBit, although it makes
a nice hole, is risky if you push too hard and go one
step past where you wanted to be. (Voice of Experience)

By the way, one of those black metal drill guages from the
hardware store is great for sizing bits and parts ... you can
test fit the parts in the gauge and find the best fit bit.
I like it because some of the imported parts have an odd
size, and it makes it easy to get it right.

PostPosted: Fri May 15, 2009 1:29 pm
by battradio
Hi ,

I lucked into a 1/2 D and 5/8 D chassis punch with four other round punches for $25.00 over on the ARF forum a month ago. Just used the 1/2" D punch for the first time a couple days ago , it nice to to have to hold the fuse holder or binding posts to keep them from turning , but at $169.19 new from Mouser , stick with a round 1/2 Delton chassis punch for $22.79 from Mouser . If you only need one or two punches ebay may be the way to go , but the shipping charges add up fast if you buy from several vendors . Also buy radio punches not conduit punches a 1/2" condiut punch is not 1/2" in diameter .

Mark

PostPosted: Sat May 16, 2009 10:19 am
by EWBrown
A half-inch conduit punch is really 7/8 inches, and a 3/4 inch conduit punch is actually 1 1/8 inches. The size referred to with conduit, is the internal diameter of the conduit "pipe".

One nice feature of the conduit punch sets is that the drive bolts (3/8 inch and 3/4 inch) have ball-bearings, so that the rotational friction is significantly reduced.

I bought a lightly-used 4 piece conduit punch set last year, and the largest punch is just the right diameter for the James 6113 and 6115 OPTs' terminals.

/ed B

PostPosted: Sat May 16, 2009 3:56 pm
by Geek
battradio wrote:I lucked into a 1/2 D and 5/8 D chassis punch with four other round punches for $25.00 over on the ARF forum a month ago.


Lucky score! (lol)

Fleabay can be good for those. I netted all my Greenlee's for every tube socket I could use there for under $100.

Cheers!