Mailing List flyrotary@lancaironline.net Message #3569
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: Mill/Lathe tools
Date: Mon, 6 Oct 2003 21:32:23 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Ok Mike
 
    I understand the points you are making and since you have been there and I have not can hardly argue otherwise.  While I certainly agree there may come a time when if  that #%^$@#  machine had 1/2" more mill head clearance........  But, given my needs, I would probably then just farm out that particular job.
 
    If you can afford the biggest and best and have a need for it, how could anyone argue against it.  But, until I can justify (hummmm wonder what project would justify a Bridgeport?)
 
You have provide a lot of sound advice for anyone consider a machine tool and the list has benefited from you experience and viewpoint. 
 
Thanks for taking the time
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
----- Original Message -----
Sent: Monday, October 06, 2003 9:16 PM
Subject: [FlyRotary] Re: Mill/Lathe tools

"My 20 year old Chinese drill press, cutoff saw and band saw do not have on bit of plastic on them and are ugly, but despite being abused for close to 3  decades just keep on working."
 
    I totally agree with you on these specific machines, Ed. I have, and the museum also has, a chinese drill press and chinese bandsaws. Superb acurracy is not the hallmark of these types of machines, so close is just fine in this case. I would also advise most folks to get a Chinese bench vise and a Chinese bench grinder. They are quite sufficient and I would not advise anyone to buy anything else for home use.
    Drill presses especially are subject to SEVERE abuse in most shops. I wouldn't buy a used one unless I knew its condition and could give it a thorough going over. That said, I'd trade my chinese one for a good (key word being GOOD) 40 yr old used Clausing drill press in a split second! I use the mill as a drill press if any degree of accuracy at all is required.
    When talking the high end machines, like mills, lathes and such, I stick by the "bigger is better" motto. I have experienced firsthand the frustration of trying to work on a very small piece that missed fitting in the machine by a fraction of an inch too many times. It still happens, even with bigger machines, but not nearly as often.
    Your machine is a LOT better than that crappy Smithy I had. It has a lot more room on the table, and under the spindle, but the basic design isn't far removed. The extra rods no doubt help keep the head from twisting, but they are simply not comparable to a cast iron box, 15x15" square with 2" thick walls. THAT'S how a milling machine MUST be made to prevent chatter and flexing of the column. You also will NEVER find yourself saying, "Gosh I wish I didn't have this much extra room under the spindle, or travel on the table." It's like too much horsepower on a plane... you don't HAVE to use it all, but when you need it, it sure is handy.
    I remember the day that 12,000lb, 24x72", 25hp American Pacemaker lathe showed up at the museum. I thanked the guy profusely for the donation while secretly asking myself..."What the HELL am I ever going to do with THAT??!!"
    After I had that machine all hooked up and cleaned up, I chucked under my breath the day I was using a cutoff tool to take the top off a Mazda air conditioner dryer to make a burp-bottle for the 13B. The power was WAY overkill for the job and the machine was MUCH bigger than you would think necessary, however, I could fit the entire dryer into the hole in the spindle, so I only had about 2" sticking out past the chuck jaws. No wobble, no hangups, no problems. There was not another more perfect machine to do that little simple job. Sure beats trying to take it off with a pipe cutter or hacksaw. Welding it back up will be a snap as both sides are already straight and the cut is as clean as if it were done with a surgeon's scalpel.
    Another example showed up a few weeks later when a buddy's bandsaw had the idler wheel bearing gall up. It was chinese, so the bushing was metric. He needed it bored out to 1" so he could go down to Motion and get a $0.25 bronze bushing for it, instead of trying to custom order the metric one (I also had to make him a new shaft as it was shot, too). The wheel was 14" in diameter. I chucked it up and was finished with the job sooner than I could have found a reamer, set up the drill press and then had it bounce all over the place and end up with the resulting hole triangular or pentagonal due to slop in the spindle. I bored it 31/32 and then used a heavy boring bar to finish the ID. Final fit was within .0005" Without that machine, it would have been a PITA and the bearing fit would have been sloppy.
    When I found the Van Norman #6, I thought I would NEVER need a bigger mill. I soon realized how limited even it was. I jumped at a chance to get a Van Norman 22L, with nearly twice the travel and table size. It is much better, but it's huge. I would probably have turned it down if it had been offer to us before I realized the shortcomings of the #6.
    Buy as big a machine as you can fit in your shop. Buy a bigger machine than you think you will need. Buy an old used American machine before you buy a new import (if you can afford new American machine, more power to you!). Buy a floor machine instead of a bench machine, unless the bench machine has the original cabinet or stand with it. Buy a lathe first. Buy a BIG lathe (you will be glad you did). Get somone who knows what they are looking at to go with you if you don't know what you are looking for, especially on used machines. Don't be afraid to spend as much or more money on a used American machine, they hold their value extremely well. A Bridgeport mill or South Bend lathe that costs $2000 can be sold tomorrow for $2000. A brand new import machine that costs $2000 is worth $1300 tomorrow, if you are lucky.
    If a 3in1 fits your needs, is the biggest thing you can fit in your shop, and is the most expensive machine you can afford, by all means get one! It is better than a soupspoon and an icepick for removing metal! I promise you, though.... The first time you just can't fit that little part in your machine and you have to take it over to somebody else, who puts it in his Bridgeport with room to spare, and then cuts it like it was mozzerella cheeze, taking a 1/4" at a pass and leaving a mirror finish with the checkerboard crosshatching from the cutter, you'll be in the market for a good mill. Been there, done that.  Mike C.
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