when you prg. in mastercam your tool paths are from the x0/z0 of the part not the machine.

it doesn't know the distance from your machine home to the part z0.

because your tool offsets will be different.

the way that i do it is post out the prg. with the g10's at 0.

then when you set up the machine

you find your work shift value with a qualified tool. then manually edit in that value into the prg.

unless you know the exact distance from the home to z0 on the part ahead of time. this is the easiest way.

HTH Ken

yes in the tool path parameters make sure that the "linerize helix" is unchecked.

also in the control definition on the arc setting page it should be set to allow helix's

HTH Ken,

alt-s also works if you have geometry over surfaces. with the surfaces shaded it always

wants to grab the surface not the line or arc. i put the unshading icon on my tool bar

just so i don't have to touch the keyboard.

HTH Ken,

http://www.atimetals...ace Mills I.pdf

 

attached is the cutter information we received. as you can see the whole bottom edge is a radius, and we were trying to use this to finish mill a part

look on page 10 of your link it shows the cnc program radius size ie; a bull style em

HTH Ken,

i use negative when i have to allow for plating build up. just put in a negative value of

the plating thickness and undercut the part by that amount. really saves on having

to redraw a wire frame for plating allowances.

HTH Ken,

i'm not a post guru, but in your string you call smo8_1 for the "M83". and capture this in "used_coolent"

but in the pretract you are looking for "smo8_2" for the "M84" call

HTH Ken,

I have already used an indicator in the spindle to locate drills and boring bars. I am looking for a device or technique to put turning tools on center. I like KH012's idea. It is so old school.

thats me old as the hills. started cranking handels over 30 years ago.

but i still get excited watching the chip fly!!!!

i have looked for a device to put the tools accuratly on center on a slant bed but havn't found it yet.

Ken,

if the tool is a drill ect. an indicator in the spindle is the most accurate way.

for turning tools if you need to be exactly on c/l then take a light face cut on

some soft mat'l look at the tip it leaves, no tip your on center.

if the tip looks like a dome or volcano then your probably above center.

if the tip is a post then you are probably below center.

adjust -y- up or down till theres no tip.

HTH Ken,

axelzu , care to share what your solution was?

Ken

don't know about the ultem but we used to cut alot of carbon filled peek. the only thing that would

last were diamond coated tools or cbn inserts and boring bars. with reg. carbide the tool wear is drastic.

like offsetting .0005/.001 per part just to hold tol. speed and feed arn't the problem just tool wear.

HTH Ken

take a look at the post for the MILL2.SET for the set up sheet. i followed how this post buffers the depths

and puts them in the setup sheet. then i copied that buffering into my post. had to add an extra variable

for the output in second buffer. this does it per tool. not a table at the begining. but you should be able to add it.

the mpaster post already does this but adding another variable to captue the value might help

HTH Ken

Ken another idea is to leave the part long for a center that can be removed after you have done all your work. We did this for years on long small diameter shafts and helped us to achieve our SFM and keep the shatter down. Yes another operation cutting off the false center, but in the long run much quicker and easier than fighting them without one.

we also do this alot when the part allows a sacraficial end to be removed later.

thanks

Ken

Hi Ken,

 

Do you use the VNMG holder for that insert (vngp-330)?

 

Thanks

yes it will load in a vnmg holder. the holder is for any 35 deg insert regardles of the rad. on the insert

HTH Ken

on long shafts like that we have good luck with a vngp-330 insert .007 rad.

depending on how the fin. looks after the rough tool you may have to do a rough and fin. pass

with the small rad. insert.

to get rid of the chatter the rpms might have to be slow like you ended up (s1000 f.002).

when that doesn't get it some times we will rough and finish the shaft in sections from the front

to the back.

the chatter will determine the rpm. you can almost never get it into the correct sfpm for the insert

good luck

Ken

we have good luck with the "iscar sumocham" drills in 6al-4v going 2.0+ deep in 1 shot with high press coolant.

they have drills in the range you need.

HTH Ken

glad to help

Ken

valenite lists one in the catalog, part # s20u-mvxnr-3 , vnmg-332 insert / 117 deg lead boring bar 1.25 shank

HTH Ken

I have run into this prob. some times with the tool size. say a 3mm em (.1181).

it will try and round up and down the .00005 rad. value of the .0001.

i change the tool size to an even # (.1180) and re generate. this usually cleans up

the prg.

HTH Ken

I recreated my threading tools as a custom profile. then i was able to shift the x/z point so

that the verify would look right.

HTH Ken,

We calibrate all the probes at all orientations biweekly, but our cmm is in a climate controled room

that stays at 68 deg. The cal. takes about 2 hours to run. We will cal. more often if needed ie. dirty

probe or inconcistant results.

If you don't have a stable temp. or are probing dirty parts then you may want to do it more often,

but usually just a quick cal. on the first or primary probe in the morning will be ok.

HTH Ken,

it shouldn't be any greater then the differance between the largest dowl pin size and

the smallest hole size for a basic true position call out. then you can add maximum

or min. mat'l modifiers to the GDT block for the hole size and dowl pin size.

HTH Ken,

(Also check your soft jaws to make sure they are not tapered. Also check to make sure there is no corner radius in the bottom of your jaws pushing on the part.)

we sometimes use a dovetail cutter to under cut the fillet in the jaws to prevent the part lifting off the jaw.

Ken,

if you are using a threading cycle the the feed is based on theads per inch. you have to figure that out first.

but since you have multiple leads your "TPI" is greater per lead.

say your cutting a 1/2-20 thread then the tpi is .050, but if the thread has two starts then the lead is .100 per start.

with 16 starts you have figure the advance for one revolution then multiply x 16 to get the lead for one thread.

then convert this to the tpi that you need.

HTH Ken,

if the part shape allows it I generally try and do all the roughing and drilling with a high vise torque on the part.

then add an "M0" to retorque the part for the finish tools. this is usually on a part by part basis but we do it

on all types of mat'l. thin walled alum. can be really fun like prg. an arc to cut a straight wall to compensate

for the part flex in the vise.

Good Luck Ken,

it probably has to do with the clamping pressure of the vise. the vise compresses the part at the base, then you cut it.

when you release the part from the vise it springs back.

the only way we have found to get rid of this with kurt vises is to use very lite torque for the finish cuts.

on some of our parts we are down to around 25 inch lbs. or less.

(edit) you might try adjusting the screw on the movable jaw on the vise. you can tighten it up

to get less movment or slop in the jaw.

HTH Ken,