[Nissan20det]

Okay that makes since... Although I did think to make deeper cuts you would just slow your feed down(jog speed). And you would be able to make deeper cut right?

[TiagoSantos]

That only works up to a point.. You need a decent chip load (the amount that the cutter removes with each flute, on each revolution) to keep cutting, otherwise the cutter starts rubbing instead. Rubbing leads to chatter, hot tool, chip welding.. Not good!

The correct chip load doesn't depend on depth of cut.. So a smaller or a deeper cut can have the same chip load, but a deeper cut will cause much higher deflection in both the tool, and in the case of the smaller machines, the machine itself. Deeper cuts also need more horsepower (again, since the chip load doesn't change, but there's more of the cutter in contact with the piece).

I'm only a newbie myself, so if any of the more experience guys feel I'm talking non-sense, please feel free to correct me, but I think I'm not far off the mark

[Nissan20det]

Makes since....so does a wider diameter tool have the same effect? Since the surface area is greater on the cut, would you be sacrificing depth and speed? But I guess it could even out though, shorter depth but more surface area.

[TiagoSantos]

yeah, it would be a similar effect.. On smaller machines though, using wider tools creates other problems - horsepower related mostly. The bigger the tool, the more horsepower you need.. The piece of aluminum in relation to the tool is sort of like opening a jar lid - the bigger the diameter of the lid, the easier it is to open (more leverage..). The bigger the tool, the more power you need to keep the material from stopping the spindle.

There is no easy way around it, the speed or ease at which you can make a part depends heavily on how rigid the machine is, and the power of the motor. It's always a compromise, but obviously not all of us are going to spend 70 grand on a Haas, so it's all about how much of a compromise you can live with It's all relative, a $2000 CNC sherline can be as good a deal as a $12000 Tormach or a $75000 Haas, the price to performance ratios are probably about the same.. But some people NEED a Haas (or bigger!), some are ok with a Sherline and others are somewhere in between!

[Nissan20det]

Okay this is pissing me off lol.. I am testing out some CAD and tool path programs.. I'm using TurboCad right now and I'm trying to figure out how to rotate a 3d piece I made. Alright so not just a pan rotation but how to rotate the piece in its relation with XYZ.... It's a round thing I made, But it does not sit flat in the cube its slanted?!?!?!? Like this [/] not this [ _ ] How do a square it up?????? can you do this in Turbocad/CamBam/Cut3D???

[Fastest1]

Select all and rotate? If you are considering any production or work in steel, pass on the Sherline or A2Z. Yes it could be done but you will want bigger immediately. Been there done that. Not knocking the learning experience they will provide and prototypes could be done, possibly. Keep your eyes open, watch Craigslist machines do pop up pretty often. Projects being abandoned are always around, learning what you will need is the issue.

[Fastest1]

Yes you can rotate a part in CamBam, the others I don't know about but would expect they do.

[Nissan20det]

Okay .... How lol

[Nissan20det]

Your not understanding what im talking about..... My object is not square with the X and Z axis.... so if L represents X and Z axis. And _ / | represent my object. my object sits like this L / it should sit like L | or _ not /.. so I want to rotate the objects relation to the XYZ axis. I'm not just looking to rotate the object to see the other side.

Also I'm Making some stuff of Google Sketch up. Have any of you figured out how to export to DXF in the free version... I tried like 8 different plugins and nothing seems to work. I really like sketchup it takes me a tenth of the time to make stuff, So I would love to be able to use it.

[BAMCNC.COM]

Have you looked at YouTube for tutorials? That's how I learned Rhino.

[Fastest1]

Okay .... How lol

Are you using CamBam? Select all of your geometry in the column on the left, select all or shift, enter. Then at the top there is an option to rotate. This is not pertaining to the view, this is for moving the geometry within the space. Btw IIRC there will be 2 ways to do it. 1 is by coordinate and the other by selecting a pivot point and dragging with the mouse while watching the coordinate window in the lower right corner.

[Fastest1]

Select all, edit, transform, rotate.

[Nissan20det]

Sweet! Thanks......

[handlewanker]

Hi, it seems that the lesson about going for the cheapest tart you can pick up and buying her a diamond ring to make her look a million dollars is what you are contemplating with that fiddly little mill thingy.

As soon as you find it's short comings, IE in the cold hard light of day when the honeymoon's over...LOL, having "invested" in the cheap shortcut method, you are now stuck with something that you will have to get rid of at less than half price....you can always build on something substantial, but not on a cheap substitute....... you just cannot take the family car onto the Indianapolis 500 track and hope to survive.

The analogy of the camera is a prime example of the path to take......buy the most expensive lens and the cheapest box to tack it onto......the lens makes the photo, the box is just something to impress your friends with.....digital cameras are a bit more complicated now when you apply this formular, but the lens is still the prime factor for quality photos.

My preference would be to buy the best but cheapest mill, very preferably second or more hand, so you get the quality of the build but not the price for the gleam of the paintwork on a new cheapie.

The oldie but goodie will need refurbishing in the screws and drives, but you're going to rebuild a cheapie anyway, so what's the diff....if after you cut your teeth on the oldie rebuild and it lacks what you want, you can still sell it on Ebay and get your money back as it has reached bottom already.

Without too much mechanical knowledge the chances of a success is probably 100 to 1 against you....you might cobble the lot together, but with CNC, the smallest amount of slop is a recipe for disaster.
Ian.

[Nissan20det]

So your saying buy a used item never new

[cjsamples]

Nissan,
I think what he is trying to say is to get the best bang for your buck is to buy used until you know more about your final choice. Since you are going to cnc the mill, you will be eliminating the bulk of things that might have troubles from a previous user. Granted, gibs and the main parts might have some wear, you will be bypassing the buyers depriciation once the crate is open. Once the car leaves the lot, it is worth a whole lot less.
Since you are still open to what your final products will be, the size, work area, and machine requirements are still in an open field and have not been set. By buying used, you can get a taste and see how far you want to go. Hit craigslist and see if there is anything that might be a good candidate for a CNC conversion. Buy a little bigger than your current plan and you will have room to grow, and hopefully put a little money to the side for the final purchase. Or end up deciding it is not for you and resale your used purchase for almost what you spent.
Most people get into this for business or as a hobby. Determining if it is a business or hobby will point you in the right direction. If you have a product that will return your investment, buy the best you can afford. If it is a hobby, buy the best you can afford to spend on a hobby. A hobby might turn into a stream of cash flow, but it turns quickly from a hobby if that happens.

That said, I have a used bridgeport wantabe and two lathes, all from craigslist or ebay. Machines I would have never bought new as mine is a hobby. Learned alot from them and still learning every day. CNC just amazes me and I am fascinated with the things that can be done. Think machine porno. Aircraft mechanic by trade, photography and machining is my hobby. I will be buying a machine for my hobby soon to CNC because I think it is cool. No need of it other than to make cool things for photography and any other thoughts that come to mind. Maybe I will find a product along the way to make and sell and cover my cost, maybe not, but I will have fun along the way.

Chris

[awerby]

While there are some things in favor of purchasing used machinery, I'm not sure I'd recommend it to someone who has "no idea" what he's doing. Just choosing a good used machine takes some experience; there's a lot of machinery out there that was used for one production operation its whole life and has severe wear on part of the ways and screws that's difficult or impossible to repair. And while retrofitting machines is an enjoyable pastime for some, for others it's a big nightmare, especially if they don't have the facilities or skills required.

The Original Poster expressed more interest in making auto parts than in working on machines. While the original machine he indicated may have been small for his needs, going to the other extreme and embarking on a major retrofitting project on an old industrial mill may not get him much closer to his goal anytime soon. Finding something that has a clear path to CNC, with parts that are available and a plan that's been followed successfully by others would probably be preferable, at least initially. Getting something that will be making parts in short order, even if some parts he might want to make are too large for now, sounds like a better option than having him invest his budget in a big old clunker that will remain an inert pile of greasy parts for the foreseeable future.

Andrew Werby
www.computersculpture.com

[cjsamples]

Good points Andrew, not knowing anything about machinery could run him down the wrong path. Mentioning car parts and RC car and planes makes one think it is for both business and hobby. In reading his postings it does sound a slight bit of the "gee whiz" factor. Knowing I have that factor playing a part in my future purchase I am looking at the G0704 or one of the 45 class machines.
Both of these have a clear path to CNC and would give him plenty of room to grow. Cost wise, I see the G0704 the cheaper path with a faster return on investment. Having a wealth of knowledge here to read and proving solutions to common problems along the way. I think a person can get into this for less than $3000 and probably under the $2500 mark with smart purchases. I think the G0704 is in my future, with phase 1 cnc conversion using an old pc I have sitting around the house.
Hopefully this discussion will help him decide.
Chris

[handlewanker]

Hi, the big problem is seperating the wheat from the chaff.......if you don't know the difference you won't be making any bread you can sell.

Machinery is made with a price tag, and the newness guarantees you are paying for the degree of gloss on the paintwork, the shipping and handling, and the markup all down the line.

What can you get with a budget of "not over $1000, preferably less".

With that sort of money I wouldn't even be thinking CNC, maybe a South Bend oldie for some hobby work weekends, and it would cost more to CNC that than your budget twice over.

If the desire is to go CNC just for the exercise, then the budget will be wasted as the end product will make nice wirring noises but not very seriously.

My only advice is, if old is out and new must be, do the research as to what is REALLY capable of achieving the modest requirements you anticipate, forget about NOW, cost the outlay for a package, save like for your first car and go for that target.......any other plan is a waste of time.

Sometimes sacrifices have to be made, like selling one piece of equipment to fund another etc.

You will go into debt with CNC anyway, once you start amassing the various tooling you MUST have to achieve CNC capability.

Pity you don't know how to drill a hole in a piece of metal without a manual.
Ian.

[MrWild]

I'm sorry, I honestly don't think CNC milling/machining is for you. I don't mean this in a bad way, but before you spend a penny, you should spend six months reading all the manuals and information Hoss tossed you. You are not going to be able to do anything quickly with a toy mill. Seriously, expecting a Taig clone to make parts you can sell at a profit isn't going to make you much money if it takes three to five hours to do something a real mill can do in fifteen minutes. Telling you that the next step up (an X2) will take only .010 depth of cuts in steel isn't getting through to you about the problems you will face.

Having a $1,000 budget won't even get you in the door for a real machine and tooling. Even if all you work with is aluminum and all you make are badges, you will be spending a huge amount of time baby sitting the mill. Thinking you can program a part and walk away expecting everything to go right, is an accident waiting to happen. The smaller/weaker the mill is, the more time it will take to machine something and the longer you will have to sit by it nurturing the cut.

You say you are a performance car mechanic so I'll try to give an analogy of the problems you face. When you upgrade a motor, change the CPU, add a turbo, whatever, you make the changes with quality parts. You don't increase the power 50% and stick a stock clutch in the motor. Drivers want to heel/toe the gas and brake while banging gears, so you put in a much better clutch without counter weights and heavier duty springs to make up for the extra torque and horsepower. It gets er done.

The toys you are looking at is like taking a stock Yugo and entering a race at Road America. You might bounce around the track during practice, but once the flag drops, you will be bouncing off everyone's front end repeatedly as they lap you. You might add a K&N air filter, and stingers on the exhaust, but you're still racing an anemic under powered turd. Hopping up a Taig is the same thing.

If you lived close, I'd take the time to teach you what you need to know, but again, the knowledge doesn't happen turn key over night. It takes money to make money, just like performance doesn't come cheap. If all you really want to do is dink around the winter months, by all means get a toy and play with it. Upgrading once you see just how much a boat anchor a toy mill is, will cost much more in the end than if you went with quality at the beginning.