[corydoras]

I just started building my 2nd machine, and it is to be a servo powered cantilevered design.

The servos are Sanyo Denki BL Super on the X and Y axis, and stepper for the Z axis, due to weight reduction.

Just finished the framework and the gantry, but still need to make the z akis and the belt transmision for the Y axis.

The X axis ia a Parker/Hauser linear drive HPLA 80 with a 4:1 reduction on a planitary gear.

The Y axis are 2 x 25mm THK linear guides and are to be belt driven.

Working area for the mill are gonna be 1850 mm x 1200 mm and approx 70 mm on the z axis

Here are some pictures from the build, and theres gonna be more.

Please feel free to comment the construction and keep em good ideas coming

[Glidergider]

Wow, that's a cool design. I hope you have an overhead crane installed above it. It must weigh a bunch. The cantilever design will be very conveniently and provide lots of access to the cutting materials. Is this really a wood cutting machine, or do you plan another type of cutting head planned? The design makes me think of a plasma cutter. Its going to be a nice machine, no matter what kind of head you have installed.

[corydoras]

Its gonna be a wood maschine, and the machine is made into severel parts that are boltet to make movable and to make it fit trough my basement doors.

Its not as heavy as it looks, but plenty rigid fo my kinda work.

The gabtry weighs aprox 120 lbs but I can move it on the linear guides with my little finger.

Yes the cantilevered design makes it very accessible.

Thanx for the comments

Cory

[walter]

Hey that looks cool!

[Glidergider]

Cory,
Just curious, what kind of work, professional wood carving or is this a hobby machine?

[corydoras]

Just a hobby machine, needed something bigger and better than the first one I made.

http://www.cnczone.com/forums/showth...ght=angel+2000


Painted tha parts and are going to start making the z axis now, as I wait for my timing belts and pulleys to arrive

Cory

[cabinetcraft]

Good luck on the cantilever design. Make it a stiff as possible and then double that times 2. We have a large cantilever router at work from Europe and it does OK until you get out towards the end of the Y axis and then the quality of the cut starts to go down. I'm used to 3/4 red oak at 500 ipm+ but not on this one armed bandit as once your past center on the Y axis there is too much flexing and everything goes to H**l. Make it very rigid and then some. Looks really good though, what you going to use for a spindle?

[Glidergider]

There are thousands of guys who would love to have your first cnc machine. Very nice. This second one is going to be even bettter. I have the JGRO for about 2 months now, and I already want a bigger cnc.

I see you are a RC airplane guy. Do you cut molds with your cnc? Someday, I plan to do that, but of course I'll have to expand the cutting table first.

[corydoras]

Did a test run on my x axis today (the parker/hauser linear drive)
Jogging back and forth with me STANDING on top of the carriage......about 180 lbs....and no problem at all.

I have a 4:1 planetary gear on it and i jogged at about 12000 mm/min

Hopefully this will be enough to convince me that my 120 lbs gantry will runn smoothely on rapid moves.

Will post more pictures as the build progresses

Cory

[corydoras]

Well here are some more pics from the build.

Got the x and the y axis in place and have done some test runs aon 65000 mm/min....man that is fast...and will of course not be able to cut at that speed, but the rapids are fun.

Video coming later today.

Not completely happy with the gantry motion some small vibration and backlash....hmm I am using AT-10 timing belts and 4:1 planitary gear..

Cory

[Glidergider]

Looks like you could build seats on top of that gantry, charge $5 and give a pretty exciting ride on that thing. I'd pay. Wow, I'm impressed with the speeds.

[corydoras]

Thanx Glider..

Mabye I´ll use it for that if it doesn´t get accurate enough.

Maby I´ll have to rebuild the gantry....its awfully heavy an maby not as rigid as I hoped for.

Here is a video of some movements at 50000 mm7m

http://youtube.com/watch?v=3MoU7KRB1AA

enjoy, and please comment

Cory

[Glidergider]

Wow, the speeds. Hope the flex is within your limits. I saw another guy build a cantilever here in the zone. To solve his flex issues, he spread the rail base out. This effectively reduced his X travel.

[corydoras]

Not much progress on the build, due to very nice weather

Started building the electrical cabinet,and doing some work on the z-axis.

One question I keep asking myself.....if this so called "one armed bandit" doesent get rigid enough.....does anyone have any idea of how to reinforce it or drawings for a new gantry?

I have have about 20 meters of aluminium sized 80x40 mm about 3mm thick that i can use for a new design.

Would it be possible to make another linear rail on the other side and still have the timing pulley on one side?....or will it yaw?

Keep em good ideas coming ...pleeeease

Best reg
Cory

[zippy]

Where's the lack rigidity? Is it the bearing interface or resonance in the square tube? It looks like you have way more experience then me and better tools etc... but I saw a reference in the polymer concrete monster thread and then found and read a PhD thesis about controlling the vibration in steel tubing he tested lots of methods and published the data so if its vibration in that long arm I think that could help you. It looks like something that long would ring like a bell. I'll see if I can hunt up the link.

[zippy]

I went back it looks like the beam is an extrusion so I don't know if this will help but its a good read.

http://www.mech.utah.edu/~bamberg/re...e%20Design.pdf

[corydoras]

Thanx for the links Zippy, but the Cantilevered design is is stopped!!!!!!!!!!!!!

I figured out after many nights of no sleep, and to many hours constructing that I was never gonna be satisfied with this design.

I ran some circles, and the accuracy of start and stop pos where fine, but the circels cut edge was a little bit "wave shaped", and that was on the inner pos of the beam....dear not think of how it would be on the end...

This was only making a 2 mm cut in plywood

I started rebuiding the machine yesterday, and are moving to the traditional gantry/portal design.

The main frame is almost ready, and the gantry is due for tonight, but some problems occured,....the cabinet for the lectronics was designed for fitting under the machine, but with the moving gantry and the servos and pulleys underneath there is just not enough room.

I think Ill put the cabinet under the workbench in the shop.

The cutting area was a little rediced due to reconstruction, and are now1800x1150x250 mm, but I think it will have to be enogh fo now, but i still have 2 pc of THK rail lying aroud so if i ever want to enlargen it, it coud be 3600mm for the x axis, but no room in my shop for that.

Ill post some photos of it soon, if anyone are interested in following the build

Cory

[Glidergider]

Cory,
Good luck with the rebuild, but I know you won't be needing luck with your kind of skills. I'm envious of your large table and super fast speeds. Once you get the gantry redesigned, it will be an awesome machine.

[corydoras]

Thanx Dave,

Hopefully, it will be as accurate as I want it, I am also thinking of making a low vacum bed for my 4" balsa sheets when starting to cut some wing ribs, and one for my depron sheets to make some indoor models.

As you may have understood, my other passion except cnc is rc model airplanes,....and correct me if I´m wrong......your nick sommhow tells me that this takes up some of your spare time as well

Cory

[Glidergider]

Yup, I do RC gliders. Although I will admit, this CNC gig has put a serious dent in my flying time. I'm the president of the North Alabama Silent Fliers. We are a a small AMA club that is devoted to RC sailplanes.

I'm real interested in your vacuum bed design. I will be needing that too. About a week ago I cut my first set of balsa ribs using a .032 Down-cut bit. Here's a link to my pictures.
http://www.cnczone.com/forums/showpo...&postcount=196
http://www.cnczone.com/forums/showpo...&postcount=198

Can you discribe in general terms how you plan to build the vacuum bed?