Building a CNC router

[rcrabb]

I believe Jeff still owes us a video. Anyone agree?

[HomeCNC]

Thanks Phill.

Yes! Thank goodness for feed rate overide

Rcrabb, My cousin has filmed a cutting project but his digital editing PC has broken down. He is building a new one before he can finish my movie. I will let the group know when it's done.

[HomeCNC]

Well I have my first video on my website. It is just a sample that my cousen Dan did to play with his editing software. It is not the finished one. This file is LARGE!! 48 meg. Only download it if you have high speed internet.

http://www.homecnc.info/router-movie.htm

[kong]

Wow, awesome! Watching that machine cut is inspirational!
But...if your cousen doesn't mind me saying so, there were too many effects on the video and not enough routing, sorry! You can tell he know's what he's doing though!

*/kong has run away/*

[HomeCNC]

I already told him that I said that it was fine for the introduction, but when the cutting starts to hold back on them. The next one he does will try to do that. What he want to do is make a video that is going very fast to show the work being done and bring the speed back to normal at key places. This way people can see the entire carving being done in a few minutes.

Also I told him that people like to see the motors and feed screws turning as well.
He is having fun! You know that the song in the introduction part of the movie is his creation. He is playing all the different instruments and put all the tracks together to create the song.

[bcromwell]

Any new videos yet???

[HomeCNC]

We just did another tape session on Sun of last week. 12/14/03

He is going to do another one.

[balsaman]

I liked the first video but agree that the effects were somewhat annoying. A flashy intro is ok but then get down to business...

Eric

[cncadmin]

What software did you use to make that video?

[Mr.Chips]

Super Video!!!!!

I too would like to see more of the motors, shafts, belts, you know the meat and potatos of the business ends.

Hager

[HomeCNC]

What software did you use to make that video?

I think he used Adobe Premiere Pro.

I'll let you all know when the next one is ready.

[barbwirebi]

Jeff

Where did you get your Torid transformer?

Im looking for 36vdc 20amp minimum

Thanks
Bill
Bill

[HomeCNC]

www.plitron.com

They have many to choose from. Just remember that you get two transformers in one toroid. So if you want 36VDC @20 amps purchase the 25VAC output at 10 amps. If you want 30 amps output get the 25VAC 15 amp toroid.

[barbwirebi]

Thanks Jeff
I am considering "Pilitron PN# 117016201
with output of 25V @ 20 amp toroid

Will this be able to give me 36VDC @ 40 amps ?

I will be also running a simultanious 4th axis

Thanks so much
Bill

[HomeCNC]

Yes in deed! Make sure you calculate the proper Capasitor for 40 amps. Oh I'll do it here.

40 amp * 80,000 / 36 VDC = 88888.88 so get a 90,000 uF cap.

[keithorr]

.

[HomeCNC]

I want to try my hand at a 4th axis on my router. Below is my CAD design. I'm going to make the spindle fit my 9X20 lathe chucks. The 6" bison is shown on the drawing. Of course it's servo powered. I'll use one of the 360 oz/in servo's I have.

[HomeCNC]

I need to design the tail stock next. And then of course make the parts.

[steveald]

Hi Jeff,

I like the 4th axis, unfortunately I have built my gantries too short. Maybe on machine #3

I have a couple of questions for you.

I am looking at getting a Plitron 55VAC 13.64A transformer with dual outputs to run 2 servos. Is there an advantage to connecting the outs in parallel and having 2 drives share the 27.28A available? Or would it be better to use one output per drive? I was thinking that both outs in parallel would allow one drive access to any current not used by the other drive, and I don't think that would be true with one drive per output.

Also, with a servo rated at 1750rpm and 120V running at 77V, am I only limiting my speed? The way I understand it, the torque available is pretty much constant up to the rpm rating and dependant on the available current, and the available speed is dependant on the voltage of the P/S, so I should be able to run at approx 1100rpm with 77V. Am I on the right track here?

I want to use geckos, but if I need the 120V I will have to use Rutex, so I'm in a holding pattern trying to figure all this out. Any insight would be greatly appreciated.

Thanks

Steve

[HomeCNC]

It is an advantage to connect the output in parallel. Think of the amps like a large pool of available power. All your servos will draw from this pool. If one servo is not using much that leaves more for other servos to use.

You should be fine at 77 VDC. You will never get the 1750 rpm of the servo motor anyway. Remember you will need to deliver steps from the PC to generate your speed. The servo can only go as fast as the step rate delivered to the drive. If you have a very low count encoder then you may be able to get the rated RPM but if you have a 250 - 500 count encoder then NO WAY!