I'm a dreamin' on buildin' a homemade barfeed for my Hardinge CHNC...
The part that concerns me at the moment is the bearing on the outside end of the unit. I'll be extending the spindle hole tube two or three feet longer. Make a solid base bolted to machine. Then a bearing to support said tube from whipping. Probably 1.25" O.D. My lathe runs 5000 RPM max. What bearing should I use?
A common-as-dirt sealed or shielded 6206 (30mm ID) or 6207 (35mm) would be fine at 5000 RPM, and be cheap to boot. If space is tight a thinner section bearing (600X, 1600X, etc.) would also work, but probably cost a bit more.
Ned Simmons
First of all..will this be a pneumatic or weight powered bar feed? Or are you using a bar puller?
Gunner, who knows a bit about bar feeds
"The importance of morality is that people behave themselves even if nobody's watching. There are not enough cops and laws to replace personal morality as a means to produce a civilized society. Indeed, the police and criminal justice system are the last desperate line of defense for a civilized society. Unfortunately, too many of us see police, laws and the criminal justice system as society's first line of defense." --Walter Williams
At least I'm not burdened by knowing what I'm doing
I don't have floor space for a real bar feed. I'm thinking of making the spindle hole extra long. Then I could just slide in a long rod and use a bar puller. Or, slide in bar, put in a hockey puck piston, put air rotary union on end. Apply air pressure when needed to push piston ahead. I'm still a dreamin' on the best way to retrieve that pistion when its all the way against the chuck.
Better ideas?
P.S. Thanks for those PCB drills. I'll be using the broken ones for practice on my recent purchase, a single flute Deckle style grinder, this afternoon. Damn, too many of them are too nice for this!
Karl
======================= You may be getting a little too elaborate if you are using a bar-puller.
Where are our screw machine people? Sounds like he is looking for a stock tube. 5k rpm may be higher than they will stand however. Anyone got a big Brownie stock tube for sale?
Basically these were a piece of pipe on two stands [front & back] in line with the spindle. Made lots of noise, especially with square and hex stock. Some people would put a large rubber hose inside the pipe to muffle the noise.
Unka George (George McDuffee)
There is something to be said for government by a great aristocracy which has furnished leaders to the nation in peace and war for generations; even a democrat like myself must admit this. But there is absolutely nothing to be said for government by a plutocracy, for government by men very powerful in certain lines and gifted with the "money touch," but with ideals which in their essence are merely those of so many glorified pawnbrokers.
Theodore Roosevelt (1858-1919), U.S. Republican (later Progressive) politician, president. Letter, 15 Nov. 1913.
Greetings Karl, My home made bar feeder uses a rotary union and air to push a piston that pushes the stock. I use different size pistons for different size stock. The reason for this is so there is always sufficient stock in the collet to take the machining load. This prevents the stock from being torn from the collet and breaking things. If the pusher is a larger diameter than the stock there will always be the maximum amount of holding power. The pushers are tapped in the back for 3/8-16. I use a piece of all-thread that I stuff into the tube and screw into the pusher to retrieve it. The tube has a quick disconnect on it so that the rotary union is fast and easy to remove. I made the custom quick disconnect retaining part just like the typical one for an air hose. Three balls and a spring loaded sleeve that slides over them. I use a regulator to limit the air pressure pushing on the stock so that it doesn't slam into the stop. I usually end up using the side of a tool shank for the stop. I have a mounted a valve between the regulator and the rotary union to turn off the air when it's time to remove the union and pusher. This way it doesn't fly out when the quick disconnect sleeve is drawn back and smack me in the face. ERS
There were broken ones? I gave you some extras, but if there were more than a couple, Ill stuck replacements in an envelope for you. I made sure you had a large percentage of carbides, hence your package went over the 1 pound rate by .04 pounds. Some of the ones that may appear to be broken are alleged to be 2 flute endmills, according to the guy I got em from, some years ago. Used for cutting traces on PC boards and laying out new pathways.
Did they arrive in good order? I figured shipping them in the padded envelope would be ok..but..I was nervous about it.
If you are space limited..just use a bar puller, its very easy as of course Im sure you know. As for putting the hocky puck piston back..when you load the bar with the new stock..it pushes the piston back. Just be sure to put an inverted cone in the face of the piston to keep the stock centered under pressure and high speed.
Gunner
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
Ive got a number of bar feeders for sale. Some 12' and some 6'. Most are Vanco brand. I bought 8 complete sets from a company a few months ago.
Gunner
president. Letter, 15 Nov. 1913.
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
I am "VERY HAPPY" with those PCB drills. Thanks. Your check is in the mail. (One of the three GREAT LIES. The other two are,"Of course I'll respect you in the morning". And, "I'm from the government and I'm here to help you")
"The Kid", my 23 year old, is right. You can quickly make an engraving tool, small grooving tool, etc. out of a PCB drill with a deckle type single flute grinder.
Damn Eric,
I thought I had an original idea. How did you copy me before I even made it? Because I stuffed the CHNC in the corner, it going to be easier to load bars from the back of the lathe. I'll just use allthread to snatch that piston back.
You missed several Great Lies..
"I only want to put the head in, really" "I promise not to cum in your mouth" "I did not..have sex with that woman..Monica Lewinsky..."
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
According to F. George McDuffee :
I agree.
That is not too different from what I've done. I've made a wooden (2x4) cradle to hold a 1-1/2" PVC pipe at spindle height several feet from the end of the spindle.
"Large" workpieces (e.g. 1" or 3/4" go directly in the tube.
A second tube has a pair of PVC caps fitted, and a much smaller PVC pipe glued into holes bored in those caps. This one I use for 5/15" down to 3/16" or even 1/8".
One end of the tube is pulled up close to the outboard end of the spindle, and the other end is secured to the cradle by a short bungee cord passing over it.
When I'm using the smaller one, its end sticks into the outboard end of the spindle.
It isn't nearly strong enough to bend the workpiece back straight if it ever gets bent, but it keeps the end from ever getting far enough off center to make it possible for the bend to start.
It does not have to be very long, because my source of bar stock delivers 6' lengths. If I were using something longer, I would have two or three cradles along the length, and for the double-walled tube, I would add some stiffening disks every two feet or so.
And I feed just by gripping the stock between the outboard end of the spindle and the end of the support tube to get it started -- then I pull it by hand from the working side of the spindle, and use the stop on the bed turret to push it back as I lock the collet.
Enjoy, DoN.
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