[fkaCarel]

Thanks for the forensics. Making a worm gear with screws. It's a good idea, but as there are norms for threads and norms for gears, It would'nt pass nowadays. And looking again, it is a bit vulnerable. I can think of a number of people I know, that would unthread/unworm it just by being near.

[Adobe Machine]

Next step is turning the ends of the X axis ball screw.I have done a few of these and before you could buy just any acme screw, had to make a few of those also. I learned ( right or wrong) to make a soft jaw for the lathe chuck to center the ball screw in the chuck. This method also gives a good grip on the very hard ball screw. One of the more imortant things is to keep the ball screw and cutting tools cool. Even with carbide tooling and a rigid set up, lack of coolant, to much rpm or too aggresive of a cut will kill the tooling in a hurry, then that begins pushing the ballscrew away from the tooling , which makes a funny looking shaft.(done a couple of those )

I start by cutting the ball screw with a cut off saw and lots of water, this is high carbon steel,if you get the end you are cutting hot,it brings the carbon to the surface, making it difficult to use tooling for drilling a center for the live center.

Next step is make the soft jaw, used some scrap 6061 t-6 round stock, bored to .631 ( actual advertised major diameter ), then turned the O.D., that is pictures # 1 and 2.

Taking the piece to the verticle saw I find center and mark, align square and cut the jaw down the center. (pictures 3 and 4 ) not shown is cutting the jaw off the round stock.

pictures 5 and 6 show turning the ball screw after alingment in the chuck, drilling a center hole for the live center. Again,its slow .136 rpm ,chuck and .05 doc with lots of coolant.

I'm turning the simple end now and must get the the screw to .495 for 5.6 inches from the start, as the apron has a bored hole of .5 of 3.1" long.The simple end bearing has a bore of .4725, will turn that area to .4723 as i want a slip fit only.The rest of the simple turned end is for a small ,knurled knob, 1/8th key and a 7/16 nut.

Unfortunatley, if it was not for medical appointments I could get something done,but the rest of this week is toast for playing in the shop as I gotta go to the VA and sit around and grumble with the rest of the vets. Good care, just long lines..


Adobe (old as dirt)

[Adobe Machine]

here are the pictures

[Adobe Machine]

more pictures

[Trapper14]

great work adobe! nothing like those action shots

[Adobe Machine]

1st I wish to thank the staff at CNC Zone ffor un-screwing my screw up in starting this on the wrong forumn Thank you

Trapper 14, tis for the kind words..note I have tried to access your new lathe page as listed above a few times..I keep getting a message tht it is overloaded..is there another way to access..I'm sure all of us would like to see your new lathe..can you post the pics here ?

Adobe (old as dirt )

[Kipper]

Those " T " slots were machined at manufacture for the Taper attachment.
I checked them for parallel to the Z axis ways and they are spot on. They are an odd ball size so I made 4 "T" nuts( 4 came off the machine ) and they will support the bearing blocks for the Z axis ball screw.Pretty handy ,huh.
Thanks for the comment.

Adobe (old as dirt)

Thanks for that and I like the email notifications for this thread Keep going and never stop Sir :tiphat:

[Adobe Machine]

Finished the X axis ball screw end,front and did a test fit.Had to nudge the shaft in the bearing using the palm of my hand.Possibly should have used some 120 grit crocus cloth while in the lathe at high speed to polish a little more, as I wanted a loose slip fit. Pulled it out , no marks on the shaft so I recleaned the shaft and bearing I.D., oiled the shaft and it seemed to slide in easier. Gonna leave it alone.

Got tired of cutting the hard steel,its slow and gets boring,besides spending 3 days at the V.A. hosbital getting poked, punched and supplying blood, I wanted to have a little fun. Decided to make the Manuel X feed handle
( used only to position with the servos "off").

The handle's main diameter is 1.5", but there are two more steps, one at 1.3" and the last one at .8 inches. As you can see I knurled the main diameter with a small diamond pattern knurl.

1st picture is my "other lathe",a 17"x60" Le Blond Regal, purchased at auction in posssibly 1986-87.The lathe was used then, but in reasonable shape.Lots of my emloyees have operated ( and hurt ) this lathe, but it did a good job untill we began going to cnc in the mid 90's,as a lot of our work was big shafts for minning and construction equipment. The company who bought me out was not intrested in any manual equipment, so I got to keep this lathe also. The lathe gives a nice finish, and I can hold decent tolerances as long as I use dial indicators and take my time.When I get close on the O.D.,just switch to tenths indicators. Will be glad when the Pratt Whitney is CNC'd and operating!
Picture 2, taking a .250 cut off some scrap 6061 T-6 round stock
Picture 3, final cut on the major O.D.
Picture 4, shows the 3 steps finished
Picture 5, knurling the major diameter ( Yes, for those who know, that is a knurling bar for one of the turning centers sold with the business.it had a damaged shaft, I repaired and made a sleeve to fit in my tool holder, works excellent, minimal cost.(Just could never throw any thing away ! )
picture 6-7 shows the knob finished and installed. I think it is small enough and will not get in the way...Have had handles etc grab my apron just a couple of times.
The Z axis position handle will stay, it is clutched, to disengage, you only have to pull out the small knob in the middle.

Next is the very criticle rear fixed bearing X axis turn on the new ball screw, the tolerances on this is measured in tenths, and this ball screw did not get much softer even after I was under the lead portion, so it will be a slow go tomorrow.

Adobe (old as dirt)

[Adobe Machine]

A question for the experts:I'm a bit of a KLUTZ with a computor..( well really a BIG Klutz)..I had to hire a next door neighbor to help me set up a net work so that I could use the CAD in my home office and send the CAM G code to the shop and my retro fitted Tree Mill.We were unable to get it to work correctly as WiFi, ( 4 different wireless routers etc )and then just did a hard wire through the ceiling, has worked great, never lost a program. We think that the problem is the house and shop have a steel roof ( fire protection, live in a heavly forested area.idiots and lightning start lots of fires in this state)
Any way my neighbor built a computor for the Tree machine and used Win 2000 XT, as he said its a stable program.Have had no problems and use the Mill every day,my longest program being over 21,000 lines with no faults.There are no other programs installed on this machine except Desk CNC and Vector CAD /CAM from IM Service.Some how he has it programmed so that everything is turned off when Desk CNC is running,so there are no pop ups or updates etc, while running the mill.
Now I have a new laptop that my children got me for fathers day with xp etc, I wanted to use it to run the lathe I'm converting, but have seen several comments in the CNC Zone to the effect that may be this is not the best thing to do ? Will use the same combo of Desk CNC and Vector, but even my neighbor is unsure about using with XP, says he can install the same 2000 xp,which is fine .The lap top came with a lot of programs I will never use.
Just what are your recomendations? Use the Lap Top as is ? Convert to Win 2000 ? Just install extension and use the mills computor ? Neighbor said we will have to seperate (partition? ) the two Desk CNC programs, as there are different values for the machines, and do not want one program to overwrite the other.? What would you do ?
Really appreciate the advice and help !

Adobe (old as dirt )

[FPV_GTp]

WOOOOOOOOOOOOOOOO Adobe Machine , nice work

cheers

[Adobe Machine]

Machining of the x axis shaft, supported (fixed angular bearing end ), which will also be the driven end.

This was a PITA.. the shaft did not seem to lose any hardness under the "threads", although the threads disappeared at .500 ( see comments below), still seemed as hard as the 1st cut at .631..any way turned the bearing portion to .472-. and 2.35 in length.I tried to fit the fixed bearing pack @ .472 ,but it got real grumply, not what I wanted , so very carefully reduced .0005 and re-tried. I do not like cramming the shaft on angular thrust bearings..should be a gentle slip fit..not loose ..not overly tight.If you expand the inner race at all, they seem to quickly lose their accuracy...I have in the past machined to recomended specs and ended up having to "push" expensive bearings on shafts (using methods I would rather not discuss in front of NC Cams) and they quickly failed ..Expensive lessons, so I have learned to look at all specs as a starting place..and I measure the bearing I.D. and compare to specs..will admit its better now than 30-40 yrs ago, but still I use a little" Kentucky Windage" and feel to fit.


(comment ) At a measured .502 , I got worried as I began seeing the threads on one side of the shaft still remaining ( like a shadow) and 180 deg on the other side, pure virgin metal.I decided that .002 out of round would be unacceptable on this short of shaft , as it would tend to bind when turning. I assumed the manufacturer ( Rockford) was accurate to tenths on the core of the shaft. so I took a pass of less than .0007 and all the shadow went away, so did not throw the shaft in the waste basket...remains to be seen
if there is any curl or bounce in rotation.

Finished the bearing surface, liked the bearing fit ( just pulled the tail stock back, did not upset the set up.) turned the area to be threaded to .469, then turned the driven pully area to .406 ( more why later).

Threading: The first secret to threading is the math..really simple , but sooo many times I have seen this simple math overlooked, not understood, really f... up, and it usually ruins hours and hours of work on producing a complex shaft ( which this IS NOT).. any way, Rockford Ball Screws reccomends
( and sent a nut and lock washer ) a thread of .469-32..Okay, major diameter is .469, how do we figure pitch diameter and minor diameter ? I go to the little blue book ( Machinery hand book) and have to referance .500-32 as the closest we can get page 1649 25th edition)
.500
minus (-) .469
_______
= .031
Subtract .031 from the published Minor diameter (d3) of .500 which is .463
(forget the tenths in minor diameter, round up, its hard to measure, and I will take ten good machinests, measure minor threads and get 10 different answers, same thread) that equals .432 which will give enough room for the proper nut and will take the torque.Pitch diameter listed @.500 is .497, so subtract the .031 and you have .466, that will be about correct after debur..in fact just exactley what it turned out to be as measured .
Threading
Picture 1. Start your cross slide at 29.5 degrees..this is a must and important!
Picture 2. Align the tool post ( and tool holder ) to 90 deg to the Z axis centerliine..I keep it to (+ - 0003 over 2") takes a moment. but is important so that you are not cutting the following thread .
Picture 3 .Since this is a "re-set up" ( removed the shaft from the chuck and fixture) its imperative to check / correct run out. I'm lucky as the chuck is pretty new and tir is almost "0", so little correction is needed.
Picture 4 and 5 . This is the 5th pass, most I could take was about .0010
per pass..stuff is just hard. But with a 32 thread, any 8 numbers on the scale work ! So my job was realitive easy..I did use a dial indicator for exact depth, and one for travel on the Z ..Crank and go !
Picture 6 Threding the nut on after deburr..was not loose, not grumply, I'm buying it.

Last picture. A shot of the ISCAR insert for a 32 external thread..Makes life a lot easier using the right equipment and cutters..you can not duplicate this cut with out the right cutters..really neat under CNC control.

Next: Modification of the X axis ball nut flange, attaching to the already made carrier etc.

Thanks

Adobe (old as dirt )

PS guys still in a quandrey about the computor to use..any help ?

[Adobe Machine]

X axis ball nut flange modification: Not much room here, so I took the compleated ball shaft, used recomended torque for the preload on the fixed angular mount bearing, un-loaded the primary ball nut ( at least the one attached to the flange ) and began to modify. I just hate to cut up manufactured items, but could not modify the cross slide, so modified the flange to FIT. You can see in picture 1 , I just drew up the demensions in Vector and cut the ball nut flange to the specs needed to fit. Unloaded, I inserted the ballshaft in position, installed and torqued the angular bearing housing & installed the carrier to the cross slide base.I then loaded the 65 balls into the nut housing and installed the return tube loaded.The cross slide had been tightned so the cross slide would not move real easy, I backed the now loaded ball nut and flange to the cross slide/ball nut carrier to "tight" against each other and marked the 1st fastner with a center punch of the correct size (.266), then got to unload the balls and return tube.( I modified one of my wife's plastic containers and used the lathes casting to support, so all the balls fell into the containers)
Next was to drill and tap the carrier ,1/4-20...cleaned up everything and reassembled, including the ball nut, tightned the one fastner and moved the asembly through the full range of motion..No binding, real smooth..begining to feel a little better..some of the panic is easing as to having turned the shaft off center.. Everything tight, I center punched holes # 2 and 3, ...again unloaded and removed everything..( This is being real difficult in a wheel chair and trying to keep my back upright...this took two days, and some help from my wife..no one got mad !..)
Drilled and tapped the other into the carrier. At this point I realized how important the face to face relationship is on the the carrier and ball nut flange...I had read some comments by Walt @ SGS about ball nut flange to carrier relationship, and how if a little bit off could bind the ball nut...IE screw up the smoothness of the ballshaft/ballnut.I really do not know how to "scrape In" this surface, but figured ( may be wrong !) if both surfaces were flat, would stand a better chance of proper alingment.
So,I coated the 2 surfaces with blueing, heavy , and let dry. Then taped some 600 grit paper to a flat surface and began working the pieces untill all the blueing disappeared...they look flat, and on the granite stone show no light..took some time, hope I did the right thing..
In case there is some binding, I drilled and tapped 4 holes 5/16-18 in the carrier and installed set screws...that way if it is necessary to change any relationship on the ballnut flange/carrier , I can loosen, tighten, fine tune etc ..this may be "overkill"( hope ) as everything so far has indicated that the assembly is dead nuts..but you never know !
Picture 1 &2. Modify of the flange, using my Tree CNC retro fit

Picture 3 . My way of making the flange and carrier flat to each other.

Picture 4. View of empty primary ball nut attached to carrier after lapping.

Picture 5. The fixed angular bearing and fastners, ball nut (preloaded) and carrier assembly, X ball screw shaft and manual X axis knob.

Both the ball nuts must be empty to assemble and then loaded in Situ

Tomorrow...Install and test,

Thanks,

Adobe (old as dirt )

[swoolhead]

The lap top came with a lot of programs I will never use.

Just uninstall all the junk that shipped with the PC, most of it you dont need.

Just what are your recomendations? Use the Lap Top as is ? Convert to Win 2000 ? Just install extension and use the mills computor ? Neighbor said we will have to seperate (partition? ) the two Desk CNC programs, as there are different values for the machines

This would be the best option, separate the disk into two partitions (use something like partion magic to shrink the current partion) and install a second instance of XP (Use XP, it as stable if not more so than 2000 Pro) that you only use with the CNC programs, this will allow you to install what you like in to your normal every day partitions and not have to worry about the stability of the system (i.e. background tasks like AV stealing CPU cycles) while your machining.

I'm sure other will chime in about running CNC from a laptop, but I have no experience with that, but can't see why it would be an issue if you disable all the power management in the BIOS and se the XP partition to Performance/no power management.

Whats the make and model of the Laptop?

Stephen.

P.S. Nice work BTW, I have a similar sized lathe I'm looking at converting over the winter and your posts have been most helpful!

[Mcgyver]

that is a beautiful lathe. only the best ones weight in at 3200 lbs for 12x30!

[Adobe Machine]

Swoolhead: Thanks very much for your comments, called my neighbor/ computor guy and he knew exactly what program you have mentioned.
What type of lathe are you going to convert ?


Again Thanks.

Mcguver: Thank you...they also made a 16X 60 that uses all the same parts in the gear head,apron and cross slide that weighed a hefty 5500 lbs.These lathes are very stable, just real nice to operate.Too bad we let the Machine Tool Industry go overseas,but it looks like we are losing a lot more manufacturing every day.

Adobe (old as dirt)

[Adobe Machine]

Swoolhead: Sorry, missed answering your question: The laptop is an Acer, Aspire 3000 with XP, 1.8 GHZ, 448 MB of Ram. Thanks

Today was assembly of the X axis ball shaft, double ball nuts, ball nut carrier,
fixed Angular bearing housing and ball shaft lubrication:
!st, I emptied the balls out of the 2nd ( tension nut) ball nut, and assembled the shaft to the angular bearing mount ( not in the machine) .then from the rear inserted the shaft ( whew !) and fed into the two empty ball nuts with the tension hardware in between.(This really sounds bad,but can not think how else to explain.) I loosley attached the angular bearing mount finger tight.Then began to load the empty ball nuts. I had some .0002 oversize and loaded the front attached ball nut , and at the same time loaded the tension nut with standard balls.

I loaded both ball nuts at the same time, did not take long at all. Assembled the return tubes, but on the front ball nut return tube I had to reduce the circumferance on the small allen head # 4 fastner to clear the attaching bolt
(pictures).

At this time I torqued all the fastners. I am a firm believer that a clean, lubricated fastner, properly torqued, will clamp the parts correctly, with out warping and possibly damaging the bearings.Unless there is extreme vibration I do not use locktight.

I set up the tenth dial guage and checked for backlash..none 0 ,but this is not cutting or loaded , so will find out when I begin making chips. The action is smooth, I can feel the extra load of the tension ball nut, but is not prohibitive. I took my battery powered drill and chucked up to the shaft and ran the carraige back and forth for 30-40 minutes pretty fast to see if the ball nuts accumulated any heat..none...then rechecked the backlash and again just not any..hopefully will stay that way.

Next was assembly of the cross slide cover, which I drilled and tapped to accept a 1/8th pipe and installed the oil fitting. At this time I'm doing all the oil lines in soft lines,when finished and I know what the exact routing is , will install 1/4 ID stainless .There will be many changes on routing ect, and the stainless and SAE fittings are just to expensive to be changing around. At least that is how I build my Hot Rods, saves lots of money and frustration to do in soft lines 1st.

Picture 1: Ball nuts installed and ready to load.

Picture 2:Ball nuts loaded and return tubes on.

Picture 3 and 4: Closer pictures of the assembly..you can see the allen head fastner that had to be modified. ( not bad, change order , just charge the customer O.T.)

Picture 5 and 6: Torqueing the fastners, used an x pattern and kept checking for possible bearing bind or roughness..none .Started at 25 lbs and worked up to 66 lbs in increment of 20 lbs .

Picture 7: Installed ballscrew cover and oil fitting,

Picture 8: Completed front view.

Next, will build the Z axis bearing mounts , turn that shaft and attachments to the ball nut flange ( which I do not have to modify, Yea..) but wife has dibs on my body the next three days..wants to go look at "nature" in the white mountains..well, ok it is pretty but I would rather be in the shop !But I started that argument before and LOST ( big time ).

Adobe (old as dirt)

[swoolhead]

[QUOTE=Adobe Machine;197735]What type of lathe are you going to convert ?
[QUOTE]

I have a Colchester Triumph 2000 (about 10x30) I'm going to have a bash at converting.

My bigest problem at the moment is I don't think that the channel that the x-axis screw runs in is going to be big enough to allow me to fit a ball nut in, so I am going to have to find a way to hang the nut off the end of the cross slide and extend the screw out the back. Though this does have the advantage of allowing me to hang the servo under this and save a bit of space

Once I have cleared my garage up so I can get to the lathe, I'll take some mesurements and pics and start my own thread on the project.

Stephen.

[Adobe Machine]

Neato, that looks like a substantial lathe to start with. The x axis channel on mine, as you can see, is just real close, but was real lucky that everything fit. One of the forumn members, pstockley, has started a Hardinge TFB lathe retrofit, and he is doing the same thing you are talking about..in fact I remember that he had drawn it up in CAD, rendered and everything in maybe July, of this year. Might take a look, give you some ideas,seemed like a real professional retrofit.

Was looking at your all of your pictures, impressed with the blonde riding the rocket ! Seriously that lathe looks similar to my Le Blond, in fact the coolant piping is exactly the same. Also what nice home you have, looks like a home built right here in the USA.

Thanks

Adobe ( old as dirt )

[asuratman]

Hi Adobe,
Can your converted cnc lathe cut thread? I found on the other thread that they could not cut thread. Thanks. Asuratman.

[Adobe Machine]

Yes, purchased a program from www.imserv.com, called FG4L. covers all US and metric plus odd ball..Fred Smith developed this really easy threading program that requires you to "fill in the blanks" hit the button and the G code is developed..Does require an encoder at spindle speed. Note: I'm using Desk CNC, and that program was written for it,but call them at 248-486-3600 to see if other controllers will work.
I did use the G code generated by this program,edited and transferred to a friends turning center and he commented it was better than his high dollar program, he was kinda bummed out .

The ability to thread was one reason I elected to convert the lathe to CNC, as I'm unable to stand any time at all, and manual threading requires you be right there !

Tooling and set up are still very important, CNC or manual. The above link to imserv. also has a short tutorial on threding..

Good Luck !

Adobe (old as dirt )