PDA

View Full Version : Snow in the UP



Gary Campbell
10-12-2011, 05:19 PM
Maybe not, but it looks like it. This could be a show and tell item, but since the design and material were not mine, I didnt post there.

A ShopBotter and now friend and customer from Toledo, Rick Wyatt brought up 4 sheets of 3/4" cast acrylic sheet that he was having problems cutting on his PRT. We found that there was a section of the file that, when changing from one area of cutting to another, restarted a fresh cut, and the max depth of that pass was about 5/8". Needless to say, pushing a 1/2" ballnose full width that deep into plexi is beyond what the PRT could handle.

We will send the file into Vectric to see if this is a settings or software glitch. Finished product will be an edgelit acrylic ships wheel just under 8' in diameter. 2 of these were cut with a tiled toolpath using Aspire 3 into 4 sheets of material. I was able to cut each sheet in about 4 hours at 6ips, XY and 5 Z. Made a lot of snow as early in the day humidity was low and I didnt run the dust collector.

Photos below show the blowing and drifting snow and an earlier smaller version of the product, both lit and unlit.

Gary Campbell
10-12-2011, 05:51 PM
One more pic.... showing chipload on the acrylic (Plexiglas) sheet.

jimboy
10-12-2011, 06:27 PM
Well Gary, you’ve invented something new…snow that you can vacuum . So what spindle speed(rpm) did you use? Did you have any melting? And was it fun-just kidding.
Jim

Gary Campbell
10-12-2011, 06:35 PM
Jim...
Sorry... I thought I posted that. 13K rpm with 4 flute ballnose. 6/5 XY/Z No melting. Checked bit when it sounded a little noisy near the end. 114 degrees

MogulTx
10-12-2011, 08:08 PM
Nice. You rock, Gary!

I have done a little work in acrylic and plexi- but never got good flakes like that. I was getting a powder on the plexi - a grainy powder. I was using a two flute end mill, and I can't recall my depth of pass... but I think I was traveling 3-4ips at about 16Krpm. (PRS Standard w/ PC router). Depth of cut was probably around .1". I didn't plunge deeply, because I use DS Tape to hold it down, and clamps near the edges. ( No vacuum. Yet.)

I will have to see if I have a four flute to work from... ( And I need someone who is a plain individual ( not a PhD) to explain how one really uses that dang chip load calculator!!!) I would enjoy seeing that nice of a slice coming off my work!

Thanks for sharing.

Monty

Gary Campbell
10-12-2011, 09:30 PM
Monty...
I have heard a lot of info on a chipload claculator, but have never looked at one. After a while you get a feel for a good staring spot and fine tune from there.

Rick brought a piece of material that we used to test move speed and rpm. I test by setting rpm and move speed at my best guess and increase move speed til it sounds right. Then edit file so that ramping is proper for feed. Then play a little with rpm to fine tune.

Your machine will be different than mine, as the HSD 5 hp is a hoss. You should be able to get near the same chipload at 3 ips with a 2 flute.

RickWyatt
10-13-2011, 09:33 PM
Hey Gary!

Thanks again for your expertise, hospitality and conversation.

I sincerely appreciate you being able to run this job for me.

I have thrown together a quick video for everyone to see a PRS Alpha running they way it was meant to run... Completely dialed in with max feeds and speeds creating a perfect chipload. Gary truly knows his stuff.

http://youtu.be/XK10nC2u_QE

By the way... if any fellow "flatlanders" make to the U.P.... you have to try the "Pasty"..:)

Rick Wyatt

Gary Campbell
10-13-2011, 09:49 PM
Rick...
You are most welcome.... the pleasure was mine. Cant believe that video was taken with a cell phone. Production was pretty good too.

Thanks again for the work.