Bridgeport power knee lift

I spent most of the day on the BP. This one has very few hours on it and is a pleasure to use, especially with the DRO. Although it's a pleasure, it's
not fun like my old BP with it's "Kentucky windage". However, cranking that table up and down a hundred times sucks! Is there a power way to do this? I've never seen one. A power draw bar would be my next wish. Am I getting old?
(I made a bunch of complex parts that look like they were investment cast and well within .001")
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Gardner wrote:

Servo, and their competitors all make power feeds thatare meant to be fitted to the z axis.
Check the tool catalogs.
I use an Align brand one on a Milltronics milling machine, and it has worked very well exxcept when the table is raised against the spindle, at which point you are looking for a replacement gear.
Cheers Trevor Jones
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Gardner wrote:

I bought a gizmo on ebay that you drive with a 1/2" electric drill motor, fits in place of the knee handle. Poor man's power feed, works just dandy. Don't know if that guy's still in business, great item.
GWE
--
Posted via a free Usenet account from http://www.teranews.com


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
They also sell air powered ratchets (not the $19.99 HF ones, bigger ones) that may work. Hey, maybe even $19.99 one will work.
i

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 18 Apr 2007 23:48:14 GMT, "Tom Gardner"

====see http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberB749 http://cgi.ebay.ca/150-LBS-Z-AXIS-TRAVEL-POWER-FEED-BRIDGEPORT-MILLING-NEW_W0QQitemZ330076690600QQcategoryZ12581QQcmdZViewItem http://www.use-enco.com/CGI/INSRIT?PMAKA07-3695&PMPXNO41200&PARTPG=INLMK3 http://www.use-enco.com/CGI/INSRIT?PMAKA 5-6411&PMPXNO227509&PARTPG=INLMK3
http://marketplace.soyfeed.com/Grinders/New-150-lbs-z-axis-travel-power-feed-bridgeport-milling / http://bbs.homeshopmachinist.net/showthread.php?t 609&page=2 google on <z-axis power-feed bridgeport> about 2500 hits
Unka' George ===============When we are planning for posterity, we ought to remember that virtue is not hereditary. Thomas Paine (1737-1809), Anglo-American political theorist, writer. Common Sense, ch. 4 (1776).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'm installing the HF z-axis unit now (purchased it 12+ years ago). I'm installing it for the same reasons, just too much work to crank.

feed units. I have the servo unit purchased through enco. Pricey (about same price as 15 years ago), as I have a Wells-Index mill. For a few more $s they sent an simple to install kit customized for my mill, good instructions (only complaints with the Servo brand is, very small control range on the .9 turn potentiometer from off to, too fast, it does not have any feed back velocity control for the selected setting, also it is not controllable for a very slow feed rate). As for the HF unit, it has the Bridgeport shaft adapter included (I did not see this pictured in any of the other Z-axis links). It is for a shaft end that has 3/4"x16 threaded end for the "crank engage "pawl" nut. This adapter is machined to fit over the 5/8" shaft where the crank handle would be. Looks like you thread this onto the Bridgeport shaft, and drill and pin it. It also comes with a stand that will mount on the machine, that the power feed then mounts too. Also has hardware for the limit switch install. In all pretty complete kit of components. I'm making a whole new shaft from the bevel gear out, it will mimic the Bridgeport shaft arrangement. Looking at the 150 inch pound vs 135 in. lbs. unit, the motors are universal (meaning they can run on DC or AC power) but the control electronics are SCRs and require AC power to work. The 150 in.lbs. unit is full wave, where the 135 in. lb. is half wave. This makes the low end speed control sloppy on the 135 in.lb. units.
Anyone out there have an improved controller design or links to someone who has worked out a nice control circuit?
As for the draw bar. I made a new one that used a 3 inch diameter by 2 inch long cylinder of steel round stock. I lightly knurled this. This serves as my Nut that I drive by hand to tighten the R-8 collets, I use a throw out bearing from my 1981 Datsun B210 clutch. I have never had the R-8 tooling slip with hand tightening. I made a whole new drawbar shaft from 7/16" O2 drill rod, At the top of the spline drive I made a replacement thrust nut much larger to accommodate the throwout bearing diameter.
Ignator
On Apr 18, 8:21 pm, F. George McDuffee <gmcduf...@mcduffee- associates.us> wrote:

see http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberB749 http://cgi.ebay.ca/150-LBS-Z-AXIS-TRAVEL-POWER-FEED-BRIDGEPORT-MILLIN ... http://www.use-enco.com/CGI/INSRIT?PMAKA07-3695&PMPXNO41200&PART... http://www.use-enco.com/CGI/INSRIT?PMAKA 5-6411&PMPXNO227509&PART... http://marketplace.soyfeed.com/Grinders/New-150-lbs-z-axis-travel-pow ... http://bbs.homeshopmachinist.net/showthread.php?t 609&page=2

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snip-----

You serious? If so, you're not challenging your mill much. I've had 1" end mills pull out after serious tightening of the drawbar, roughing aluminum. Having worked in the trade, I'm not shy about taxing a machine's ability.
Left hand spiral end mills are made to prevent pullout under load. It's a serious problem when you tax a machine's ability.
Harold
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I dry cut most everything, so I'm doing very light cuts, relative to money making production. I know, use coolant, just makes a mess of the floor and my shirt.
I have used the water pump pliers on it a couple of times, but for most cutting I've done it's not been a problem. I never use the R-8 Collets to hold end mills, my used mill shows multiple signs of this in the table surface. Nice little ramps.
I think a thrust ball bearing should be used in all draw bars. I built one for the horizontal Rockford mill that's drawing in a B&S#9 taper. Now this taper can really hold.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snip--

Chuckle!
Ok, that makes sense. I agree, lube tends to be a little messy, but you can brush apply and improve surface finish tremendously, plus it prevents chip welding. That's a real problem when machining aluminum, particularly 6061- even in a T6 condition. Using a brush, you can keep the edge damp without all the splattering, although you still get some. If you haven't tried, give it a go when you're struggling with finish.
Harold
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Gardner writes:

Besides the power feeds others have replied about, consider making it an axis on a CNC upgrade.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Am I getting old?
Hell yes------and it has nothing to do with the Bridgeport. ;-)
Harold
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

But you took better care of yourself..as I would have had I known I was to live this long.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Still suckin' on them smokes, eh?
H
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Addicted...sister Pat and I are both in the process of convincing ourselves to quit. We are under a whole lot less pressure now. This month I bought a new(er) Toyota fork lift, contracted to have concrete and stone work in the parking lot and dropped $25k on the roof. Five years ago I would have had to finance any one of those projects and I just paid cash for them all. A VERY foreign feeling for me.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Understood! That's a ton of money to part with, but you have my respect for being able. We've paid cash for so long I can't remember when I last charged anything--------although, to be honest, I really can. Bought a boat in early '77, financed about half of it. Paid cash for everything since then. EVERYTHING! We collect interest now, we don't pay it. Sure as hell makes a difference in how far your money goes when you aren't tossing half of it on interest. You get some super deals with cash, too.
Forget the smokes. Listen to some great music------I like the baroque.
Luck with quitting. I really do understand how hard it can be. Cheer sister Pat on for me as well. You folks can do it. My father tossed his smokes after using them for something like 30 years. Made the decision to quit and did it, just as fast as that. Never looked back, but we're known for our strong constitution.
Harold
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Ditto, the tempo is very conductive to creative thinking. I'd rather be creative than smart any day!

It's friggin expensive too! Thanks for the vote of confidence, we'll get there!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'd think the money aspect would make the decision much easier. But then, I'm one hell of a lot tighter with the buck than most folks.
H
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Apr 2007 05:57:35 GMT, "Tom Gardner"

Hi Tom,
Smoked for several years myself. Thought it would piss off the girlfriend I had at the time (she smoked, hoped she would quit), wrong, we both ended up smoking...
It took me a few tries, but I quit and it doesn't bother me a bit anymore, other than now the smell stinks :)
Just do it, you'll be a lot better off. Lost my good neighbor last month. He was diagnosed with terminal lung cancer (heavy smoker) and inoperable brain tumors last November. Docs gave him 18 months, he only lasted five. Just 56 years old... We want you around here (the Rec) to hassle for many years to come. QUIT! If I can do it you sure as hell can.
--
Leon Fisk
Grand Rapids MI/Zone 5b
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm due, I have cut down 1/3 and found a few tricks that help.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 Apr 2007 05:57:46 GMT, "Tom Gardner"

One of my "tricks" was to bum them from friends that still smoked when the urge got the better of me (bars were the toughest, stay out of bars :) They knew I wasn't being cheap and every so often I would buy them a pack, replacing more than I ever bummed anyway. I found that if I had to ask somebody for a cig I smoked a whole lot less. If I had a pack, I would smoke them all...
Food for thought, it helped wean me to the point I could just give them up.
--
Leon Fisk
Grand Rapids MI/Zone 5b
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.