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View Full Version : Bah! I'm going crazy! I'm never gonna get my tripples done in time at this rate



Billy Golightly
05-22-2006, 07:20 PM
Well I've ruined the SIXTH piece of 3/8 aluminum plate this afternoon trying to mill out the pieces for my tripple clamps. %^$#%$@%#@%$#@ Man I just want to freakin smash something. I THOUGHT after the last 4 I had my angles and stuff figured out, so I remade a new template and I used it this afternoon and Its still all screwed up albeit not the same way it was but its still not right.

Riddle me this!:

I have a paper template the exact dimensions that my clamps need to be (I checked before I did the first trace, and I just checked it again every single angle and which way possibly). I placed this template on the aluminum plate and traced it out with a black ultra fine point sharpie black magic marker. I then went right across from it and traced out another one with the exact same paper and sharpie. I then put this in the mill and spend probably a half hour or better on setup ensuring that when I travel the length of the bed I follow these lines exactly and do not get wider or shorter at one end then the other. More or less, making sure I follow the lines exactly. With both pieces I do this. Now, I make the first pass and check it, everything is good. I change posistions and re-setup on the next line to mill another 30minutes or better of setup time. I re-dial in and check everything one last time even after it has been tightened down on the bed. I keep a very close eye on how the end mill is traveling the line and it never goes out of spot. I move the bed the length of my cut by hand and without using the powerfeed. I carefully watch the endmill stay exactly on the line from the start point all the way to the end. I then cut off the motor, un bolt it down from the bed and promptly let out the biggest string of cuss words I've used in a long long time. The thing is so cattywompass and out of shape I cannot believe it. It is 3/4 of an inch taller on one side then the other just liek the first one, HOW?!?! Both pieces were off the exact same amount in the exact same places, but when I traced them out they fit the template perfect, and the template IS correct. What in the blue hell is going on?:mad: :mad: :mad: :mad: :mad:

Muddy200x
05-22-2006, 07:57 PM
Somone give the man a beer! QUICK

That's pretty much the reason I change my cerreer from a machinist to a welder. Less stress as a welder. Less brain work too, and if you mess somthing up its easier to fix. Haha. BTW, What type of mill are you using.

Billy Golightly
05-22-2006, 08:08 PM
Its an old Enco mill (Bridgeport clone) that HAD a 2 axis DRO. That *Edited**Edited**Edited**Edited* the bed on me yesterday.

03 ORANGE SHEE
05-22-2006, 08:20 PM
i think its the operator:lol:

Billy Golightly
05-22-2006, 08:25 PM
No disagreements there...not much I can do about it though :lol:

Muddy200x
05-22-2006, 09:01 PM
Ouch, I was going to say "I hope it's not an Enco." Haha... We have 2 old Encos at my work. All the machinist there hate them. I was talking to an old machinist one day and accidently called the Enco a Bridgeport and in return ended up getting this long shpeal about the differences between the two brands. Ive used both of then since then and totally see his point. I'm not saying that yours is as bad as the ones at my work, but if it is, I would say it's the machine. :D

erectordale
05-22-2006, 10:17 PM
your jibs could be worn badly as i had this with my lathe and had too re-scrape then back too tolerance

knsmodels
05-23-2006, 09:03 AM
How big of a cut are you taking at one time?? Are you generating to much heat causing it to distort?? Whenever cutting something out we always roughed it out then rechecked the template before final cuts where made....just a thought.....:wondering

Billy Golightly
05-23-2006, 09:52 AM
I'm taking the full width of the end mill, and the thickness of the plate deep. It might be to much...I dont think I'm overheating the plate because I can handle it with my bare hands when it gets done. Spindle speed is about 240rpm since I do not have a coolant setup.

staceyl200
05-23-2006, 10:01 AM
Have you got the locks on the bed on in the axis that you are not using and the axis that you are using just put a little bite on the lock as this will help if the cutter decides to climb and if your gibs are worn

stacey

Billy Golightly
05-23-2006, 10:12 AM
Stacey, I think thats my problem...this mill does not have a bed lock for the forward and backward (I believe thats the y axis right?) and I'm having to travel such a long distance that I have to travel the other direction (x axis). I've been trying to hold the other axis I'm not using by hand and keep it from crawling. This was eaiser to do when the DRO was working because I could zero out and if it moved even a half a thousandths I could tell and correct it before it moved much.

I did some more checking on the pieces this morning and I might be able to salvage them provided nothing else goes wrong.

staceyl200
05-23-2006, 11:18 AM
In the future you could make your own locks ,,all you need to do is drill and tap exactly where the gibs are and use a couple of bolts or buy locking handles from a hardware shop and use those ,, because thats all that they are basically . Just be carefull as the knee of the mill is cast iron and is quite brittle. Hope this is of some use ,,Good luck on the tripples!! And lets see some pics

Cheers
stacey

knsmodels
05-23-2006, 12:33 PM
To me that sounds like to much of a cut especially without coolant........I think the aluminum would heat up and cool down pretty fast as far as being able to handle it when done......What diameter cutter??? Good luck with it.....

honda250sx
05-23-2006, 01:59 PM
Speeds and feeds are very important. Use the almighty internet , there are some nice charts out there. Myself i am a machinist. The company i work for makes custom hydraulic cylinders to customers specs. I see your taking the length of the bed cut at the depth of the plate 3/8? Taking the depth of the plate would be fine if you had a .750 or greater diameter endmill. And thats at perfect speed and feed. Your maximum depth of cut is half the diameter of the endmill. Of course this differs from what type of tooling your using. Coated endmills, carbides and so on.

Secondly how rigid is your setup? Are you machining with the knee all the way up? Possibly the quill all the way down? Do you have parallel's underneath the workpiece? Is it clamped sufficently?

Aluminum is one of the easiest metals to machine. Get yourself a squirt bottle, fill it with household red kerosene. Kero, is an excellent lubricant for machining aluminum. It can become gummy and lock that cutter up in a nice ball of crap in a few minutes. Also pick up your speed. Way to slow. What type of cutter are you using? How many flutes?

Get yourself setup nice and rigid. Have the quill all the way up. Use the knee of the machine to bring the workpiece up and touch off. Pick up your rpm. Remember a quite machine is a happy cutter. Your looking for a good chip, use the kero freely. Take lighter cuts


PM if you have questions!

Jeff
HDM HYRDAULICS
250sx customizer