Van's Air Force
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Final Drill using Reamers, pros cons
- Thread starter Jskyking
- Start date
Are you talking about the countersink holes for the skins? It's better to use a drill bit. I've read not to use a reamer because a perfectly round hole allows the rivet to possibly rotate with vibration. So in this case it's actually better to use the less precise drill bit.
1001001
Well Known Member
I use reamers wherever I can. Cleaner hole, less deburring. It doesn't make a perfect hole, but it's better IMO.
I use reamers whenever I can. I will second Mike though, them double margin drill bits are sweet! I'm using them exclusively now for drilling initial holes. Heck I like reamers so much I usually drill to 43 and them ream to 40 (assuming it's not prepunched of course).
swisseagle
Well Known Member
I had a lot o micro cracks after dimpling, when using reamers!
Looks like there is a bit of heat generated and this changes the characteristic of the material.
The cracks are visible after dimpling, but you need a magnifying glass.
For sure I was lubricating and was using low RPM.
Had to replace the center section ribs due to this.
Looks like there is a bit of heat generated and this changes the characteristic of the material.
The cracks are visible after dimpling, but you need a magnifying glass.
For sure I was lubricating and was using low RPM.
Had to replace the center section ribs due to this.
I used #40 and #30 reamers extensively (but not exclusively) on my prepunched holes. Neither drills nor reamers generated any heat that my fingers could feel and unless the aluminum is way too hot to touch, the temper and material properties are unchanged. I suspect micro cracking after dimpling has more to do with the deburring bit and chamfer than the reamer or drill surface finish inside the hole.
To the OP, do some test holes using a drill and also a reamer and a good deburring bit. Examine the holes with a 16x magnifying glass. I think you'll find the reamer results in a better surface finish.
Scott Hersha
Well Known Member
I used piloted reamers in most pre-punched holes in all three airplanes I?ve built. No cracks, and the hole was cleaner and easier to deburr without taking too much material off. Never had a crack, holes were clean, results were good. If I wouldn?t have had these piloted reamers, I would have used a drill bit and not thought twice about it. I think some people get in to trouble when they over deburr the holes, hence the reamer requiring less aggressive deburing. I don?t think there?s anything wrong with either method.
Gotta upsize a hole anyways, mind as well be a reamer in my mind. It also gets the added benefit of less deburring. That being said, I wouldn't hesitate to simply use a drill bit if that's all I had; however, reamers don't cost much more and I have found they last a heck of a lot longer.
