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Tapered Reamer question

B

Brambo

Well Known Member
Tapered Reamer

After reading about problems with the nose gear becoming loose in the engine mount socket, I decided to try using a taper pin. Following the instructions of the Jim Ellis artical on installing a taper pin http://www.matronics.com/wiki/index.php/Nose_Gear_Strut , I find that the taper reamer doen't seem to be working. I first started using a ratchet, turning slowly and using plenting of cutting oil. Then I tried a electric drill at slow speed. Still no apparent progress. Is there a trick to this or is it just going to take a LONG time? If someone out there has used these taper reamers before, any suggestions would be welcome.

Bill Rambo
RV-7A
 
Are'nt these legs tempered? If so, it may be hard if not imposible to do this.... If not, it should work, just go slow and clean the reamer often. Make sure you are turning the reamer the correct direction.
 
reamer

Jim Ellis says that it is not difficult. You might want to send him a private message or wait for him to respond here when he sees this thread. Perhaps he has some hints.
 
Most taper reamers are designed to be used by hand. Use a good two bar tap wrench and do it by hand.

I used a Brown and Sharpe taper on my RV-3 gear legs and trashed one reamer by not applying enough pressure initially. If you don't start it cutting right away, you'll dull it in an instant and it will never cut. Could be the problem you're encountering. I tried again with a new reamer and it worked perfectly. Should not take long at all. After drilling the holes, reaming was the easy part.
 
Most reamers have straight flutes, so they do not self feed at all. It takes a lot of pressure to get them to cut. If you were able to drill using the S size drill, you should be able to ream it without a problem. Remember, a taper reamer is cutting the entire depth of the hole, when you are getting close to being finished, unlike a drill bit that cuts mainly at the end.
 
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Bill,

When you ream the hole for the pin I found that the reamer would often turn but not cut. You must hold firm inward pressure on the reamer while you're turning for it to cut. It seems, if you ease up on it, debris gets under the cutting flutes and prevents good contact with the stock. When this happens remove the reamer wipe it clean with a lightly oiled rag and clean the hole...then try again. Firm inward pressure and a slow steady turn seems to work best. You can "feel" the reamer cutting when everything is just right. Do not try to use a power drill...it just spins the reamer in the hole.

Sometimes a small burr will form on the edges of the reamer flutes. Use a small flat stone on the inside edge of the flutes to remove them if they occur.

Also don't use too much cutting oil...this seems to cause the reamer to loose it's "bite" on the metal.

Good Luck!
 
I like the concept of a tapered hole that can continually be tightened, but I've given up on a source for the pins. Even AS wont stock them because ther is not enough demand. Others have $75 minimum orders.
 
I used to service lots of machines that used taper pins to hold components in place.
Rule #1 with any reamer: NEVER turn the reamer backward in the hole. Keep enough pressure on the reamer to keep it making chips. If you are not making chips the metal being reamed may be too hard to ream with the tool you are using, or the reamer may be damaged by someone turning it backward in the hole. As long as you are making chips, the reamer is doing it's job. When you see it making chips at the small end of the hole, your tapered hole is finished. Drive the pin firmly into place.
 
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I have a tapered pin holding my "Aviaiton Products" full swivel tailwheel on. I had a 3/16" bolt (AN3) shear off in a rut at Van's Homecoming in North Plains. I changed to the tapered pin shortly after that when I got home.

I had NO problem using a tapered reamer to make the 3/16" hole larger using my Dewalt battery drill.

I now have over 2,000 hours on the airplane. The tapered pin has been in place at least 1,800 of those hours.

The reamer and pin both came from Aircraft Spruce. They had them in stock 8 or 9 years ago when I purchased it.
 
Taper pin source

I've ordered some pins through a local supplier- They ordered 10 and required me to purchase 5 of them. I expect them to arrive next week- I'll post when they come in- I'll have several to sell and I'll post supplier's phone #.
 
Last year I turned some lengths of 8620 steel on my lathe with a taper attachment and made some taper pin stock. The AN taper is actually a Brown and Sharpe #2 taper, which is 1/2" per foot IIRC. It wasn't too much trouble to fit taper pin stock, mark it for the length required, turn a shoulder on it and thread it 10/32.

Use lots of cutting oil, turn slow with lots of pressure. Reaming tapers is a slow process but once you are there it doesn't take much to miss the mark. Never back out the reamer by turning it backwards.

Taper pin reamers are about 1/2 the cost if you buy from Travers tool or MSC than they would be from AC$. Just be sure its a B&S taper, not a Morse taper.

Regards,
Bob Japundza
RV-6 flying F1 under const
Indy
 
Jim Ellis,

Your Wiki calls for a number 3 reamer, but a number 4 pin. Is that intentional? It allows us to start with a smaller drill size, but it would seem to require more finish reaming.
 
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