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Best speed (rpm) for #30 and #40 reamers?
- Thread starter designerX
- Start date
captainron
Well Known Member
Reamers normally run at lower RPM's than drill speeds, so a cordless drill would be a good choice. You can use an air drill with a good teasing trigger, and higher speeds won't bother the smaller diameter 30's and 40's. Always make sure the drilled hole is within a few thousandths of the reamer dia., and NEVER turn a reamer backwards in the hole. If you are going through thicker stuff, a little Boelube can't hurt. Always use lube on steel parts.
ge9a said:
They will enlarge holes with less burring than a drill bit. The downside is that you need to be very square on the pre-punched hole as they are less tolerant of misalignment than drill bits are. Your work will also be slower because they want to be turned at very low rpm.
You can buy them from any of the tool houses. I got mine from Cleaveland. Maybe six bucks? Pretty cheap, anyway.
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I doubt you have a motor fast enough to exceed the recommended cutting speed of 100 SFM in Al. Most of the holes in the kit are pre-punched to within a few thousandths of the finished hole diameter. If you are creating a pilot hole it should be within 1/64" (.015) of the finished hole size. 2800 RPM is fine (what I use) if you are comfortable with it but 1500-2000 RPM will give you a nice hole (100 RMS or better). #30 and #40 drills can be run as high as 6000 RPM and regularly are in composite/aluminum materials and this is also what the Winslow Nut plate drill motors turn. Proper technique is to stop the reamer and pull it straight out of the hole to avoid bellmouthing the hole, although few do this. I wouldn't say I'm an expert but this is generally what I do on the F-22 program. Most of the small motors we issue in the C-130/F-22 program are 2800 RPM. I've got Quackenbush setups reaming holes at over 1.250" diameter that are running 450 RPM with .001" IPR feed rate. Also, bear in mind that CNC routers will turn 1/4" bits at over 20,000 rpm while profile routing parts at incredible feed rates and get good surface finish. Just go with what you like and check the hole finish when you're done! Hope this helps -- Les
clevtool
Well Known Member
Speeds and Feeds
Les is right turn them like you would a drill with the #30 & #40 sizes. If your drill is of a quality that it tends to vibrate at the higher speeds, you will then need to slow it down, but if the bearings are holding the end of the reamer true then wind it up. Be careful with the feed rate though and let it cut through the material rather than pushing it through too fast. Look for chips not dust.
Others are right too about larger size reamers and needing to turn them slower. The larger diameter the outside of the cutting tool the lower rpm you need to achieve that 100 SFM (surface feet per minute) because the cutting edge is traveling further across the material in each revolution. You can do the math or use a table to figure it out for each size in any material, but the easy way is to look at the chips and keep them in between curls and dust.
Mike
Les Dial said:
Les is right turn them like you would a drill with the #30 & #40 sizes. If your drill is of a quality that it tends to vibrate at the higher speeds, you will then need to slow it down, but if the bearings are holding the end of the reamer true then wind it up. Be careful with the feed rate though and let it cut through the material rather than pushing it through too fast. Look for chips not dust.
Others are right too about larger size reamers and needing to turn them slower. The larger diameter the outside of the cutting tool the lower rpm you need to achieve that 100 SFM (surface feet per minute) because the cutting edge is traveling further across the material in each revolution. You can do the math or use a table to figure it out for each size in any material, but the easy way is to look at the chips and keep them in between curls and dust.
Mike
2-3,000 rpm may be acceptable for for a tool held by a machine or when already placed in the hole. But the first time you spool up your drill motor to x-thousand r's and try to insert the reamer and it grabs and/or wallows out the hole, I bet there'll be some swearing happening.
Just something to consider.
2 cents based on having created many oblong holes, sliced fingers, broken bits, and considerable swearing
Just something to consider.
2 cents based on having created many oblong holes, sliced fingers, broken bits, and considerable swearing
Bryan:
2000-3000 RPM is what I'm watching people do right now at work. The trick, I think, is to not start the cutter prior to inserting it in the hole. As to it being angled, that is just technique. Use a reamer bushing if you need one. (Remember though, Drills will fit reamer busings but reamers will not fit in a drill bushing.) I also discussed it with the guys in the Van Pool (All A&P's) and they all agree that the high speed is better. Still, you need to do what works best for you!!
2000-3000 RPM is what I'm watching people do right now at work. The trick, I think, is to not start the cutter prior to inserting it in the hole. As to it being angled, that is just technique. Use a reamer bushing if you need one. (Remember though, Drills will fit reamer busings but reamers will not fit in a drill bushing.) I also discussed it with the guys in the Van Pool (All A&P's) and they all agree that the high speed is better. Still, you need to do what works best for you!!
