Looking for CNC Mill Part I

[gjahnke]

delrin blocks sliding on CRS would be better. Even better than that is see if you can find chrome plated steel rod. They use it for hydraulic cylinders. It works GREAT

[kfong]

Hey everyone,

Ran across this http://www.woodpeck.com/14ttrack.html#492
I think it would make a good cheap alternative to the rollerbearing slides. There is some up and down slop, but the side to side looks good. If mounted to the side for the x axis. The gantry could be used to apply side pressure.

Kin Fong

http://www.embeddedtronics.com/

[amirgeva]

I checked the local prices of various pipes and I had an idea.
I'm wondering if it has potential, or am I way off.

Aluminum pipes are cheap and very smooth but not strong enough. Would filling the hollow core of these pipes with steel, possibly gluing or welding, make it strong enough ?

[delphi7x10]

Originally posted by amirgeva
I checked the local prices of various pipes and I had an idea.
I'm wondering if it has potential, or am I way off.

Aluminum pipes are cheap and very smooth but not strong enough. Would filling the hollow core of these pipes with steel, possibly gluing or welding, make it strong enough ?

Amirgeva,

How about a lenght of hardwood dowel? If it was a tight fit, and pinned at the ends, with epoxy smeared in first, that should give it the strength. The only problem that you might have with it is the bearing would flatten it. BUT if you used the delrin bearing idea that should not be a problem.

[uscra112]

I tried using ractangular oak ways, sanded very smooth and oiled, with plastic pad bearings.

Too much static friction - positioning accuracy stunk.

Stick to metal unless you're using Cranky's roller wheels.

[amirgeva]

I think Delphi was referring to using the dowel to strengthen the aluminum pipe, not as the rail itself.
I will probably use either that or a steel rod. This is for the Y axis, using a block of delrin as a slide.
On the X Axis, I will use a steel pipe and rollerblade bearings.

[kfong]

I don't think Oak would make a good slide, it just does not have the smoothness of metal and rather difficult to true, plus there is a hardness factor that's what bearings need to ride on. Using an aluminum channel and delrin slide would be much smoother. They use this setup for woodworking and the friction created seems quite minimal. For cutting balsa, I see no reason why this wouldn't work, and getting less than 1/16" seem quite plausible.

Kin Fong

http://www.embeddedtronics.com/

Originally posted by uscra112
I tried using ractangular oak ways, sanded very smooth and oiled, with plastic pad bearings.

Too much static friction - positioning accuracy stunk.

Stick to metal unless you're using Cranky's roller wheels.

[Tiramisu]

Hello,

I am getting ready to try cutting my first 3D object on my router. I settled on using Rhino and Meshcam for the gcode. I was planning on just cutting Ownes Corning pink foam for now. What kind of bit would be the best for cutting this type of material?

Thanks

[RJG]

I'm still researching this CNC thing and trying to finish up a couple of other projects befor starting my machine. It would be a big help if you could give me you opinion on the following control board:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3805692679

What are its strong points?

Weak points?

Thanks,

~~RJG

[balsaman]

Originally posted by Tiramisu
Hello,

I am getting ready to try cutting my first 3D object on my router. I settled on using Rhino and Meshcam for the gcode. I was planning on just cutting Ownes Corning pink foam for now. What kind of bit would be the best for cutting this type of material?

Thanks

Use a ball endmill, I would say.

Eric

[Ali Kat]

Hi Guys,

I've just about got through reading the entire thread and I'm amazed at the information that's out there. I'm hoping to contribute a few posts in the near future but first off I'm ooking for some advice:-
I have a s/h stepper controller setup using a SMC 1500 card with 3 off NEMA 23 motors, built in power supply etc. It runs OK with PCNC but I don't have the pinout info to try it with other software. Does anyone have any experience with the SMC card and TurboCNC or similar?

[Ali Kat]

Hi Guys,

I've just about got through reading the entire thread and I'm amazed at the information that's out there. I'm hoping to contribute a few posts in the near future but first off I'm looking for some advice:-
I have a s/h stepper controller setup using a SMC 1500 card with 3 off NEMA 23 motors, built in power supply etc. It runs OK with PCNC but I don't have the pinout info to try it with other software. Does anyone have any experience with the SMC card and TurboCNC or similar?

[rtreadway]

I just like to say hello to everyone I’m looking forward in learning CNC Milling, from what I’ve read so far is that there is a deep pool of knowledge in this group.

I will be using John C. Kleinbauer’s. Design (The Brute). I will try not to annoy everyone with the same questions that I’m sure was asked a thousands times.

Looking forward to this new endeavor.

Rodney

P.S. Sorry about posting a new Thread. . .

[GenesisCreation]

Here's a link to a nice milling machine:

http://www.scaled.com/services/new_cnc/index.html

I wonder when John will have a set of plans available for a system like this?:)

[crankorgan]

I tapped the largest group with my designs. More expensive machines and designs are a crowded field. I have seen several aluminum frame style router companys go under. From time to time you see their machines on Ebay. Some have design flaws. Even though they are made out thick aluminum using expensive linear bearings they flex due to over extending an axis. Going for a couple of extra inches of cutting area seems to be the downfall of designers.


John

[GenesisCreation]

Yes I agree you have plans suited to meet the needs of most people. I purchased a set of your 7th Sojourn plans and that should do everything I need.

It would be fun just to be able to watch Rutan's machine in operation though. Looks really awesome. My previous post was a feeble attempt at humor, and also to share something to inspire others to build their machine. ;)

[Ali Kat]

Keep taking those "sense of humour" pills, Cranky :D

Nick

[uscra112]

Aww, that Rutan gadget is just a toy compared to what you find in the big aluminum airframe parts shops. Gantry mills 35 feet WIDE x hundreds of feet long. 3 or 4 spindles, 100 HP each. They have 50 HP chip extractor vacuums on each spindle sometimes. Eat yer hearts out, guys!

[crankorgan]

Originally posted by Ali Kat
Keep taking those "sense of humour" pills, Cranky :D

Nick

Only if you buy a spell checker :D

[Ali Kat]

So how do they spell "humour" in other parts of the world?:confused:
Nick

[DICKEYBIRD]

Humor, y'know, like color? Tyre = Tire :) Bonnet = hood, wing = fender, boot = trunk, cold spark plug = hard, soft = hot.

Funny, innit? 2 countries separated by a common language. ;)

[Ali Kat]

Sometimes I wonder why we let you look after N. America for us when I look at what you've done to our language!!:confused: Then I look at the postings on this thread and realise that you guys have come on a long way!!!:D
Seriously, you're right, Dickeybird - half the fun of this CNC thing is figuring out what exactly you're referring to:rolleyes: My Zeus tables are getting well thumbed converting that "inch" business into real measurements.:)
Which leads me on to a question - has anyone had success using both metric and imperial leadscrews / threaded rod on the same machine? Is there software that can handle this "mid atlantic" problem?
Nick

[crankorgan]

Originally posted by Ali Kat
Which leads me on to a question - has anyone had success using both metric and imperial leadscrews / threaded rod on the same machine? Is there software that can handle this "mid atlantic" problem?
Nick

My take on this is.... A stepper steps in even amounts. Full step=200 step per revolution and half step=400 ETC. So it would be nice if you use a leadscrew that gives you a step that in inches is .00025 per step or something that is usable. If you use inches a 20 turn per inch leadscrew or a 10 turn is a good idea. Other leadscrews add errors. People worry about backlash and torq. Then they pick the wrong leadscrew and get a second set of problems. If you don't know what you are doing go with a 10 or 20 tpi leadscrew. Those 4tpi surplus leadscrews just lkook like a bargain.

The same goes for metric. You want each step to be an even amount. You know you are in trouble when you find yourself entering .000277777 into the program.

The software can be switched between metric and inchs. The software will round up or down to the closest distance. More turns on the leadscrew or microstepping will reduce the error.


John

[jihlein]

I just finished building a CNC foam cutter and electronics for a friend, and I've built a set of drive electronics (HobbyCNC) for myself to drive a router. Been following the discussions here and collecting a lot of great info.

I've looked at John K.'s plans and think the Phoenix would suit my needs. My only question is what is the Z axis travel range? My intended use is RC airplane parts, at some point in time I might want to try a 3D fuselage plug. If I could get 24"x9"x3" travel, that would be great.

On the software side, I've been playing with KCam. It seems to drive my electronics/motors fine. Are there any other software packages I should look at? DOS packages are out of the question as I've only got Win2000 and WinXP PCs available. Might look for a used laptop that I can put Win98 SE on with all the CNC type apps, but I'd rather concentrate on the machine itself for now.

Thanks in advance,

John Ihlein
Albuquerque, NM

[crankorgan]

John,
Cutting out a 3D part 36" long requires a very fast machine. Using a 1/8" bit it would also take hours. Phoenix was designed for cutting larger balsa parts. It can be made longer.

John

[jihlein]

John,

Agreed, the 3D part would take a very long time. The parts I'm interested in are small, primarily fuselage pods for discus launch gliders or small electrics, probably not much more than 12-14" long.

JI

[crankorgan]

JI,
As long as you understand how long it would take. Using a precut block of material and letting the machine put in the motor-battery and servo compartments is the answer. I get surfboard and windsurfers who can't grasp that fact a 1/8" bit would take forever. Surfboard companies use hotwire to cut the inner foam shells. I finally got to see this on Invent This on Tech TV. CNC is not the answer to everything.

PS It might have been "Guts and Bolts" on the History Channel where I saw the surfboards being cut with a hot wire.

John

[nismo240]

Are any of these stepper motors applicable to CNC?

http://www.allelectronics.com/cgi-bin/category.cgi?category=400600&type=store

This one seems like the best fit...

http://www.allelectronics.com/cgi-bin/category.cgi?category=400600&item=SMT-67&type=store

nismo240

[crankorgan]

Building a machine around the motors is a bad idea. Design the machine first. Before building the machine decide what you need it for. If you answer seveal things, then I will tell you, you will need more than one machine. Work from the cutting bit out. Router? Dremel? Other? How strong does the machine have to be to hold these spindles? What do you want to cut? How big a cutting area. Most people buy tiny cheap motors and expect them to drive a 4' X 8' machine. There are no simple answers in this hobby. It all depends on what you are trying to do.

[ninpofox]

Nismo240,

The motor you list, CAT# SMT-67, is good for small machines. I bought a case of these when they first hit the surplus market. I used 3 of them on my 12" x 24" wood routing machine and 4 on my 24" x 36" hot wire foam cutting machine. I recently purchased another case for 2 new machines I'm building for a friend. The new machines will be the same size.

[coffeemug]

Dickeybird, that sure is a whole new level of model building you have going.

P.S. -I used to fly out at Millington '89-'92. Got sort of spoiled on the good weather and longer flying season.

[nismo240]

Nismo240,

The motor you list, CAT# SMT-67, is good for small machines. I bought a case of these when they first hit the surplus market. I used 3 of them on my 12" x 24" wood routing machine and 4 on my 24" x 36" hot wire foam cutting machine. I recently purchased another case for 2 new machines I'm building for a friend. The new machines will be the same size.

What controller are you using to drive the steppers? What softwate do you use for routing??? foam cutting???

nismo240

[sdfine]

ninpofox,

Did you find a good deal on the case lots of these? I'm interested in picking up a case for a CNC basics class I'm putting together.

Thanks

[ninpofox]

Nismo240,

I'm using the design for the MM2001 boards for both the foam cutter and wood router. You can find the design and documentation at this site:

http://gm.cnc.free.fr/index_en.html

I made my own printed circuit boards and purchased components from various suppliers for my first 2 machines. I thought I would save some money and time by buying kits for the next two, but I'm pretty disappointed with the service and product I received from CNC Hobbies. I just received an order I placed 4 weeks ago and there was a few errors in it. You can find them at this website:

http://cnchobbies.com

If I build any more machines, I will either do all of the work myself or try Hobby CNC. You can find them at this site:

http://www.hobbycnc.com/driverboards/driverboards.htm

As far as software goes, I like the GMFC for foam cutting. You can find it at this site:

http://gm.cnc.free.fr/index_en.html

The wood routing software I use was created by a friend of mine for a gantry style scribing machine. It's very basic in function and I will most likely use something different in the future as I want to do some 3D work.

I highly reccommend the CNCZone website:

http://www.cnczone.com

There's a lot of great information there.


Sdfine,

I bought a case (box of 10) of these from an electronics surplus in Dayton quite a while back. If I remember correctly, I paid around $100 for the case. They don't have these anymore, but All Electronics does. That's where I got my second case for $150. I didn't to ask for any kind of quantity discount.

I hope this helps.

[amirgeva]

I worked on my design, got the MDF, painted it. Got the delrin, which I was planning to use for both the nut and the bushings to slide on the polished stainless steel pipe that I got.
I then went to a workshop to machine the delrin blocks for precise holes and a guy there was throwing away parts of an old drafting table. I scavenged two linear slides. :) One is 3 feet in length (24" movement range) and one is one foot (7" movement range).

But now I need to redesign everything :(

My original plan was to make a moving gantry, similar to the Phoenix, but I will probably change it, now that I have a 24" movement Y axis that is rock solid.

Any suggestions?

[DICKEYBIRD]

Dickeybird, that sure is a whole new level of model building you have going.

P.S. -I used to fly out at Millington '89-'92. Got sort of spoiled on the good weather and longer flying season.

Well thank you for the kind comment coffeemug. :) Were you referring to a picture or something earlier in the thread?

The Millington Barnstormers are having an r/c - u/c funfly May 1 & 2....I'm hoping to be there. Good club!

[coffeemug]

I was reading something at the beginning of the thread, saw the picture of your mill and was really impressed. My scroll saw will never look the same :) -I didn't realize my post would show up many pages later.

I live up in Duluth MN now, so the first event I can fit in at that latitude will be the S.M.A.L.L. event in Maumelle (in June.)

[durone]

Take a look at www.profili2.com/eng/default_pannelli.htm
now Profili softare have a new panel management function with ribs placement, mill diameter correction, cutting line break and Gcode output.
You don't need any more to use 3 or 4 applications, Profili + your Gcode emulator is now enough.

ciao
Stefano

[DICKEYBIRD]

I was reading something at the beginning of the thread, saw the picture of your mill and was really impressed. My scroll saw will never look the same :) -I didn't realize my post would show up many pages later.

I live up in Duluth MN now, so the first event I can fit in at that latitude will be the S.M.A.L.L. event in Maumelle (in June.)Thanks! By the way, the S.M.A.L.L. event is now held in Burns Park in North Little Rock....see ya there! :)

[Coligny]

Hello cranky

I have a total weight of 6.5 kg on my x-axis, I have a 4 amp, 2V motor to drive it (about 70 mm diam.), it should be strong, it goes through a 3 mm pitch rod, from your experience, you think the inertia will be to big? Will my motor be strong enough? :eek:

[Coligny]

Hello Stefano

Good to see you on this forum, so you will be building a cnc router at last?
I am from South Africa, and have a registered version of profilli, I would like the pro version though, but will you ship a cd to SA?

Regards

Coligny Marloth

[crankorgan]

Hello cranky

I have a total weight of 6.5 kg on my x-axis, I have a 4 amp, 2V motor to drive it (about 70 mm diam.), it should be strong, it goes through a 3 mm pitch rod, from your experience, you think the inertia will be to big? Will my motor be strong enough? :eek:

I build prototypes for testing. I learn from them. Your question is impossible to answer. Why? You left out your friction coefficient. Is you axis using antigravity? Bearings? Drawslides? 4amp 2 Volt Stepper? Servo?
My design? Your Design? Ask me something that can be answered. :D

Cranky

[Coligny]

I have roller bearings in nylon housings running on stainless tubes. very little friction, moves when i touch it lightly, yet, when cutting, i am worried that the change of direction might have to much inertia. Lets assume my motor is stronger than average, is 6.5 kg very heavy for a x axis? (the y and z axis is on a moving gantry)

thank you

Coligny

[crankorgan]

[QUOTE=Coligny]I have roller bearings in nylon housings running on stainless tubes. very little friction, moves when i touch it lightly, yet, when cutting, i am worried that the change of direction might have to much inertia. Lets assume my motor is stronger than average, is 6.5 kg very heavy for a x axis? (the y and z axis is on a moving gantry)

You still did not say Steppers? or Servos? Lets just say you are using steppers and TurboCNC. There is an acceleration/deacceleration setting in the program.

John

[balsaman]

You will be fine. As John says, you can adjust the accel easily to suit your setup.

Eric

[Coligny]

Thanks,

I use steppers, and a very nice program called NINOS, I will check on the acceleration/deacceleration setting in the program. I will post a photo soon, to get more comments on my design.

Regards

[amirgeva]

Here's a picture of my completed X Axis. Hooray :)

I also found a reasonably priced source of linear bearings (about 10$ for 20mm ID, length 45mm)
Given that they are not very long (only 45mm), is using 2 of them for the Y axis ok or are 4 required?

[balsaman]

Show us a picture of them.

Eric

[amirgeva]

Although this is not the specific product the store I found carries, they look very similar to this:

[amirgeva]

Here is how I was thinking the bearings (light green) might be used.

[rodair]

I would suggest a brige (space them a bit) but for sure they're nice.
Roger B.

[amirgeva]

Do you mean space them as in the following picture?
This is obviously more solid, but requires 4 bearings instead of 2. :(

[rodair]

Yes

[durone]

Hello Stefano

Good to see you on this forum, so you will be building a cnc router at last?
I am from South Africa, and have a registered version of profilli, I would like the pro version though, but will you ship a cd to SA?

Regards

Coligny Marloth

I'm making a partnership with an italian builder of CNC machines.
It's going to build a modeller series of its professional CNC (no parallel port driving, but true gcode interpretation by the control board!).

Write me at my private address info@profili2.com to have more info about the Pro version.

ciao
Stefano

[DwarfSmith]

Just dropped my letter+check in the mail to Cranky, now to wait, for my plans so i can start, been reading this thread for a while, finaly have the budget to build the machine
**runs out to see if they arived yet :) **

Brian
aka
Dwarfsmith

[bps]

Also the older rotary engraving machines that are computer run can make nice 2 axis cnc's. The will generaly run on proprietary software but can accept file generated through conversion software to do special shapes. Limited to thin soft aluminum, balsa or plywood though. Just a thought. Nice plans and ideas here though.

JEB :D

[jihlein]

Here's a screen shot from Kelly Cam after completing a CNC cut. Does anyone know what the 3 gray X's indicate? When the X's appear, the computer also beeps. I've looked thru the online help, but no mention of these X's is made. FWIW, my copy of KCam has not been registered yet.

As my machine is not quite yet finished (lead screws have not arrived), I haven't produced a part with this file. I have run the motors with the file, a from watching and listening to the motor response, it "looks" as if they are moving correctly.

http://rib gc.jpg

Hope the screen shot is above this text, not clear on how to add images in this new software.

Thanks in Advance,

John Ihlein
Albuquerque, NM

[balsaman]

Do you mean space them as in the following picture?
This is obviously more solid, but requires 4 bearings instead of 2. :(

The increased cost will be worth it since it will make the machine actually rigid enough to be functional. This is no spot to try and save a few dollars.

Eric

[amirgeva]

Balsaman, you are correct that saving a little with the result of a disfunctional machine is not a good idea.
The reasons for my original question were:
1. You get more travel range without the bridge
2. I've read a lot of stories of people who had overkills in various parts of their machine (I believe your rails are an example, although they were free)

So I was just making sure I wasn't going to spend extra for no good reason.

[Jojje]

The rod is self-locking and it's easy to adjust.

[shedkid]

HI mr dickeybird ,new to this game of cnc canyou put me straight ,converting my mill to cnc got a couple of motors and all belts and gears, even the computer rigged up in wokshop but what interface board did you settle for,did you build a psu for the steppers and one for your interface,and did you find it easy the programming bit "G code etc"
cheers for now BAZ :confused: :confused:

[balsaman]

The rod is self-locking and it's easy to adjust.

I am worried the corners of the bearings will wear grooves in the rod. Very little contact area there...

Eric

[Jojje]

You can buy them with small or big radius, or with a 45 deg. corner or a V-notch in the middle or...??? Or you can mount the bearings in a small angle. My bearings radius = 0.3mm. I'm not so worried and you can adjust it very easy.

/// Jojje

[crankorgan]

There are three things wrong with the design. 1.The play in the bearings can't be ajusted out. 2. The bearing is performing a slight slicing action as it rides in the bar. 3. The bar needs to be of a smaller diameter which adds flexing to the system. But if you are doing light cutting and you keep the axes short it will work great.

John

[Jojje]

Hello John!

1. Yes it can, only turn the screw in or out.

/// Jojje

[Jojje]

Here's a test I did just now.
The rod is 20 mm and the bearings is 12 mm.
It works fine for me ;-)

/// Jojje

[crankorgan]

Hello John!

1. Yes it can, only turn the screw in or out.

/// Jojje

The two bearings will deflect together and the play will not be nulled out. You are talking about bearing to rod play. I am talking about the play in the bearings. A high quality bearing will fix this problem. Most bearing system have bearings at right angles to each other. This allows the bearings to be preloaded against rails. The more you preload your design the faster it will fail.

John

[longhair]

Please forgive my ignorance, but I question why you would position the bearings as they are in the above picture. It seems to me that you would be further ahead to have the bearings on the rod with in the X and Y axis.

The scenario above is putting a side load on the bearing which it more than likely wasn't designed for and would eventually wear a groove in the rod.

I may be way off base, but that is what appears to me.

Pete

[TimKoene]

HI group,

After reading through this whole sea of words I have decided that I will build one too. (I decided that long before reading this, but I thought I'd give you guys some credit :p )

I have some neat stuff lying around in my basement which I am planning to use for a full gantry mill setup of about 80*60 cm.

Parts found are:
2 100cm long matching pairs of 1"*1" heavy duty aluminum box tubing.
2 60cm long 1" diam sections of high quality steel tubing.
1 150*60 flat piece of solid oak from our old kitchen.
4 high quality linear slides which look like drawer slides but are much more smooth and precise.
4 new and factory square pieces of MDF with a cutting top finish, 60 cm long and 20 cm wide.

This is my plan:
-Use the large box girders as main rails, ridden on by skate bearings after the aluminum is polished.
-Make the Y-axis supports out of 1 or two pieces of thick and heavy wood
-Use then 2 steel tubing to make the y axis from, from where the z-axis carriage runs on the tubes by means of 12 rollerblade bearings. (two on the horizontal plane and one above.)
-The z-axis will most likely be made out of the linear slides, two of them.

Will this make for a nice setup if everything is smooth and properly made? What could I expect of it?

With regards,

Tim Koene

[jihlein]

Here's a closeup of a gantry machine my Dad and I are building. Needs lead screws, limit switches, and finishing of the z axis motor mount. Can you tell he's a retired mechanical engineer?? :D

John Ihlein
Albuquerque, NM

[armandolunar]

Saludos,
Los felicito por tan exelentes comentarios sobre las Maquinas CNC, me gustaría saber donde conseguir los planos de los aviones para hacerlos con estas máquinas y si es posible, donde conseguir los planos de las diferentes máquinas.
Disculpen que no escriba en ingles, pero, no lo domino mucho.

Gracias y Saludos.

[~PK]

Well thats just great. I've been quietly congratulating myself for getting to the end of this thread (took 4 days), when up pops this this little beauty "en espanol" - which is about my limit. What if all the answers to my CNC questions are contained therin? How am I supposed to know whether "exelentes comentarios sobre las Maquinas CNC" means "don't spin the motors until you've finished building the machine" or "hook the white wire to the resistor" :confused:

Anyway:
I've just ordered the plans for the Brute from John, as well as the Piker board. I'm aiming to end up in the "one half of one percent group", as I've already sold the finished product that I'll be making with the CNC mill that I .. er.. don't have yet :) . Nothing like a little financial motivation to see you through.

I'll be aiming to build this as quickly as possible, with pretty much no deviation from the plans. I need to start shipping finished product by the end of the month, so this time around it's KISS.

I will make time to take plenty of pictures and keep you updated though.

Cheers
Peter

[TimKoene]

"exelentes comentarios sobre las Maquinas CNC" means something along the lines of "Excellent comments on the construction of a CNC machine"

But that's just an aside I guess :P

[armandolunar]

Good Night,
Excuse me my English, I´m interesting about construction of CNC machine, and i need plan of this and i need plan about any airplane building with this.

Thank.

[~PK]

Good Night,
Excuse me my English, I´m interesting about construction of CNC machine, and i need plan of this and i need plan about any airplane building with this.

Thank.
Hi Armando,
I've just bought plans for a CNC machine from John at http://www.crankorgan.com. His machines seem to be a very popular choice on this board. He only supplies his plans to customers in the US or Canada - mainly because it is hard to get the materials he uses in other countries, but you will find lots of useful information at his site.

Peter

[armandolunar]

Thank Peter,
do you have plane of airplane building with this machine?

[~PK]

Sorry, No.

As Austin Powers says ".....that ain't my bag baby" ;)

Peter

[uscra112]

My $0.05 worth - Jojje's design will wear the rod fast - too small of a contact area between rod & bearings.

The bearings will survive, for a while.

A common type ball bearing can take a lot of end thrust. There are "radial-thrust" ball bearings that will take even more. The problem with Jojje's setup is that the thrust is all concentrated on one side, so the ball-to-race clearance is zero only adjacent the contact point. Thus the balls cannot share the load - only the one at the contact point gets any. Hence the bearing itself will be unhappy. Now the bearing size is way bigger than is needed to carry the load, so it'll probably work for a while.

There are industrial linear-guideway systems that use v-grooved ball-bearing wheels running against the corners of a square rod. For light loads, a round rod would do as well.

[bgriggs]

I just completed the new 4 axis chopper board from HobbyCNC. I took pictures and will comment in another thread about the build. The board worked right off with no problems. This is only my second electronics project :D .

[FRAMEDnLV]

which board did you get from hobbycnc? Is the new board (pwm) or the one with the power resistors?

Chris

[Wolfrick]

Gentlebeings,

I've worked my way through the entire thread, and I feel like I've served an apprenticeship in CNC!

Many of the questions I had about hobby cnc have been answered, and I have a new appreciation for what has been accomplished. I wish I had been part of this from its beginning; I'd certainly be farther along in my own plans than I am now.

Cranky John, thank you for your help and support. I hope I never have to ask you another question :) Other 1%-ers: Thanks for sharing your successes and more importantly, sharing your mistakes! It takes a lot of guts to admit your errors, and even more guts to post a detailed color photograph of them. My hat is off to you all. Thank you for all the mistakes I might not make now :)

I'll post my progress as I get up to speed. John, look for my order soon, maybe today.

~Rick Berry aka Wolfrick

[Doug Blackmon]

I just noticed yesterday that HobbyCNC had a new board, anyone care to discuss the differances between the boards.

Pros, and Cons if any.

Thanks,

Doug

[FRAMEDnLV]

The new board is a different chipset. It regulates the current. I have been testing the same chip. It is much better than any of the 3 amp unipolar drivers.

Chris

[bgriggs]

I just posted a thread about the new HobbyCnc chopper. I built it in about 3 hours including photos and Fear factor.

http://www.rcgroups.com/forums/showthread.php?t=231646

Bill

[SFT2]

I tried to read the entire thread, really, but after 5 hours and 1000 messages I just couldn't take it anymore :)

I've been slowly working on a CNC router/mill thing for years, pretty much since I bought my vertical mill, but the main stopping block has always been the software. I use Solid Edge Origin for CAD and 3d modelling, which isn't particularly good at writing DXF files it seems. It makes GREAT drawings, though. The actual CAM software has been the big problem, though. TurboCNC looks perfect. Problem 1 solved.

Next problem, the motor controller. I have the schematic for a 3 axis step/direction controller, but I am absolutely HORRIBLE at making PCBs. However, I do have the hard part of the controller in my grubby little mitts right now :) Sitting in front of me, as I type, are 11 Allegro UCN5804B stepper controller ICs. 1 per axis is needed, so I have enough for 3 full machines and a couple of rotary tables. If there's anyone out there that can make the PCB I'll trade ya 4 of the ICs for one.

3rd problem, the spindle. Not an issue. Nice thing about a Sherline is that one set screw holds the head onto a round pin. I'll just knock up a duplicate pin on the lathe (which will be CNC eventually) so I can use the Sherline head when needed. I also plan on building a much higher RPM head myself using tapered roller bearings and quite possibly a pneumatic turbine. Translation: an evil die grinder ;)

Last problem is finding steppers that will handle the job and not cost a fortune. Anyone know of a good source of NEMA23 frame motors?

My plan is for a gantry machine that can handle 12x36 stock, so I'll need roughly 14x38x4 travel. I'm not concerned with the rigidity of the machine since most of it will be very heavy wall steel tubing welded in fixtures with the slides built separately and bolted on once the steel has been welded and trued somewhat. Then the slides can be aligned and life will be good. I had originally planned on linear bearings riding on 1" centerless ground stainless rods for the slides, but lack of affordable bearings has changed that a bit. Now I think I'll use some good, shielded bearings in V grooved aluminum wheels. Since the gantry is going to be very heavy I want to support the slides every few inches. Hmm... maybe some heavy aluminum I beam would work better. The grooves on the wheels could ride on the edges of the top web of the I beam and the axles could be mounted in eccentrics to give adjustability.

Yes, I tend to ramble on.

Anyway, if anyone has any comments, sees anything wrong, or can help with any of those problems, please speak up :)

[HobbyCNC]

Have you looked into Hobby CNC? Driver boards, cnc packages, plans, etc.

Dave Rigotti
www.hobbycnc.com

[SFT2]

No, don't think I'd seen your stuff before. Looks like it could be a good option, though. Looks like your controllers use the same IC as the schematic I have, too, so I know it'll work for what I need to do.

[SFT2]

It suddenly occured to me that I can solve another of my problems with a slightly different machine and the same electronics and software. I need a plotter. I'm thinking about a couple of drums roughly 3" drums about 8" between centers driven by a stepper and timing belt to move the paper under the pen, then hold the pen and it's axis in a single axis gantry. The whole thing could be mounted to a wall to save space. I originally planned on using the roll of paper as one drum, but since it would very rarely be the same diameter as the output drum there would be problems. Hmm... maybe drive the drums with rubber friction rollers that actually move the paper instead of the drums?

[uscra112]

It's been done. Plotters generally dont have the power to carry much of a spindle, though.

[SFT2]

Oh the plotter won't have to worry about a spindle. A much heavier, stable machine will deal with that. The plotter will just be to replace the current print and tape method of generating plans (which sucks for a bunch of reasons). Wonder if there's any software out there that could handle using a 4th axis to rotate a turret with different color pens. Overkill, but would be nice.

[kfong]

Here is a professionally made bipolar chopper board, just add electronics from Digikey. Saves you the trouble of making it yourself and it's a proven design.

http://www.embeddedtronics.com/microsteppld.html

Kin Fong

I tried to read the entire thread, really, but after 5 hours and 1000 messages I just couldn't take it anymore :)

I've been slowly working on a CNC router/mill thing for years, pretty much since I bought my vertical mill, but the main stopping block has always been the software. I use Solid Edge Origin for CAD and 3d modelling, which isn't particularly good at writing DXF files it seems. It makes GREAT drawings, though. The actual CAM software has been the big problem, though. TurboCNC looks perfect. Problem 1 solved.

Next problem, the motor controller. I have the schematic for a 3 axis step/direction controller, but I am absolutely HORRIBLE at making PCBs. However, I do have the hard part of the controller in my grubby little mitts right now :) Sitting in front of me, as I type, are 11 Allegro UCN5804B stepper controller ICs. 1 per axis is needed, so I have enough for 3 full machines and a couple of rotary tables. If there's anyone out there that can make the PCB I'll trade ya 4 of the ICs for one.

3rd problem, the spindle. Not an issue. Nice thing about a Sherline is that one set screw holds the head onto a round pin. I'll just knock up a duplicate pin on the lathe (which will be CNC eventually) so I can use the Sherline head when needed. I also plan on building a much higher RPM head myself using tapered roller bearings and quite possibly a pneumatic turbine. Translation: an evil die grinder ;)

Last problem is finding steppers that will handle the job and not cost a fortune. Anyone know of a good source of NEMA23 frame motors?

My plan is for a gantry machine that can handle 12x36 stock, so I'll need roughly 14x38x4 travel. I'm not concerned with the rigidity of the machine since most of it will be very heavy wall steel tubing welded in fixtures with the slides built separately and bolted on once the steel has been welded and trued somewhat. Then the slides can be aligned and life will be good. I had originally planned on linear bearings riding on 1" centerless ground stainless rods for the slides, but lack of affordable bearings has changed that a bit. Now I think I'll use some good, shielded bearings in V grooved aluminum wheels. Since the gantry is going to be very heavy I want to support the slides every few inches. Hmm... maybe some heavy aluminum I beam would work better. The grooves on the wheels could ride on the edges of the top web of the I beam and the axles could be mounted in eccentrics to give adjustability.

Yes, I tend to ramble on.

Anyway, if anyone has any comments, sees anything wrong, or can help with any of those problems, please speak up :)

[lsippell]

After a couple of months of reading all the post, I'm finally getting started!
I just today received from Hobby CNC's Dave Rigotti's new chopper board and components.

I also picked up an old reel type lawnmower sharpening machine to use as the base for my machine. It's giving me the x-axis to start building from (47 inch of travel). The rails are 1.5" tool steel with a center support. The carriage rides on 5 bearings, 4 on one rail in a V pattern and one mounted vertical in the other rail. Mounting two test indicators, one on each rail, I get only about .0002 deflection on the carriage. The carriage is about a 25# casting, but only needs about 1 or 2 oz. of pressure to get it to move.

Louis Sippell

[crankorgan]

Oh the plotter won't have to worry about a spindle. A much heavier, stable machine will deal with that. The plotter will just be to replace the current print and tape method of generating plans (which sucks for a bunch of reasons). Wonder if there's any software out there that could handle using a 4th axis to rotate a turret with different color pens. Overkill, but would be nice.

Plotters are made with different color pens. The plotter lifts off the paper and it goes and gets a different color pen. The problem with plotters? The used ones only work with DOS-Windows 3.1 and some with Win 95 and 98 if you are lucky. The drivers for the older plotters won't work under the newer versions of Windows. Plotters take a long time to draw what a regular printer can do in seconds. But a plotter can be used to draw on Balsa-leather and metal.

[bgriggs]

Anyone have a used Minimill they are willing to part with? If so PM me with you cost and location. Any of the clones will work (Harbor Freight, Homier,


Bill

[xdissent]

well i just started reading this thread around 8am and at 12:30, im still going! im in the process of building a brute, and im really glad i stumbled across this thread. i just googled "helium inflated airplanes" and found myself here. imagine!

just kidding. but seriously, this has to be some kind of a record. so much helpful information! keep up the good work everyone. rock on

handsome greg

[Gary Blaylock]

Hi everyone,
I have my router almost finished, just have to mount the router itself. I mounted a spring loaded pencil to my Z axis so that I could learn how to set up the software. I'm using Master5 because it seems to run much smoother than Kcam.

I have two questions:

(1) Has anyone had any experience with Mach2? I'm thinking of purchasing this instead of Master5. It's only $50. more. :confused:

(2) When I do a drawing in Acad and save it as a .dxf file, I import it into Master5. How do I set my Z axis. Do I zero my Z axis by touching the bit to the work piece? How do I set the depth of cut and the height the bit will rise when traveling? Same question with importing a .txt file which was run through Ace Converter.

Thanks for all the help, :)
Gary

[balsaman]

Hi everyone,
I have my router almost finished, just have to mount the router itself. I mounted a spring loaded pencil to my Z axis so that I could learn how to set up the software. I'm using Master5 because it seems to run much smoother than Kcam.

I have two questions:

(1) Has anyone had any experience with Mach2? I'm thinking of purchasing this instead of Master5. It's only $50. more. :confused:

(2) When I do a drawing in Acad and save it as a .dxf file, I import it into Master5. How do I set my Z axis. Do I zero my Z axis by touching the bit to the work piece? How do I set the depth of cut and the height the bit will rise when traveling? Same question with importing a .txt file which was run through Ace Converter.

Thanks for all the help, :)
Gary

Mach2 is newer and better, but requires at least 500 mhz and 1 ghz is probably better.

The z hieght is set in the software. In Ace you can select a z offset. Go here for instructions on Ace: www.dakeng.com

I am not sure how it's done in Master 5, never tried it.

Eric

[amirgeva]

OMG, I just spun the motor. Am I doomed? :p
I finished the X Axis completely, and had to make sure I have no surprises before moving on with putting together the rest.
Attached is a picture of the car vacuum tube coupling.

[HobbyCNC]

Tell us more about your setup! Driver board, voltage used, etc.

Dave Rigotti
www.hobbycnc.com

[amirgeva]

Dave,

As you probably know, this is your "80oz-in 12V" kit. :)
The power source is a modified PC power supply.
The voltage setting for the motors are the default that comes with the kit (can't remember the exact figure).

I just need to figure out how to measure the resonance frequency so I can make a good ramp up profile for the motor (I'm writing my own software).