Diving head first

[steveyb4342]

Hi everyone Im new to this board and just as new to CNC machineing. I am quite interested and Im amazed one can be built by a hobbiest! This being said Ive decided I want to dive in head first and try and build one. I know my way around a few tools, I build boats and I just rebuilt a car. I was wondering if there are any step by step books I could read? Im not up on all the technological terms so maybe a "CNC building for dummies" book? lol. Im looking to build a CNC mill capable of milling aluminum regularily also it must be able to mill a piece of aluminum about a 30" {wide} by 40" {length} by 25" {tall} block of aluminum. Can this be done? How much would it cost roughly? Im toying with this idea right now and Id really like to do it if money allows. By the way I have some experience with manual mills. I realise this is a big undertaking but itll be fun and I have time to spend on it.

Thanks Steve

[epineh]

Hey Steve welcome to the Zone!!!

Not too sure about a book for learning to make a machine, but everything you need is somewhere on this forum... that might not sound too helpful but my tip would be to read read read.

If you have milling experience you will know that you need a rairly rigid machine, the more rigid the better if you intend to cut aluminium, you COULD take smaller cuts but it sounds like you want to chew on a fairly good size chunk of stock.

There are free plans on this site to build look for Joe's 2006 machine or JGRO's machine, though I don't think they will suit your needs for cutting large pieces of aluminium, but might be a good "first" machine.

Be careful, these things get REALLY addictive.

Good luck

Russell.

[steveyb4342]

Hi epineh! Thanks! Yes I do have miling experoence and I know this is gonna be a handful to try and make. It wont matter too much if I have to take smaller cuts I dont mind if it takes a long time. Yea I will look into as much reading on this forum as I can I will also look into those plans. I wonder if I can change them around a bit and maybe beef them up a bit to do what I like? hahahaha I imagine it could get addictive it sounds like fun! I want in! lol


Thanks Steve

[ger21]

Originally Posted by steveyb4342 also it must be able to mill a piece of aluminum about a 30" {wide} by 40" {length} by 25" {tall} block of aluminum. Can this be done? How much would it cost roughly?

What exactly do you need done to that big piece of aluminum?
Anythings possible, but this would be a very ambitious project, probably requiring a well equipped metal working shop and a lot of time and money.

Sure, you could build a simple lightweight machine, but you'd be looking at machining times of several days with that much material. Unless you're just looking to engrave.

[steveyb4342]

Well at first I just want to screw around with a bit smaller stuff but eventually Id like to try making an aluminum engine block. It will be primitive at first but as I try to do more things I eventually would like to do a nice one. I dont mind if the cutting times are in the range of a few days, heck I dont mind if it takes a week. Time honestly doesnt bother me at all, the question is can I do it? I have access to a mill, lathe, drill press and MIG welder if needed. Plus a bunch of tools. How much money do you think I will be looking at to build a bare bones machine that will do the job I want? Remember I dont care how long the cutting times take. Also if that works I wouldnt mind trying to cnc some cylinder heads again they would be quite primitive at first but who knows?

Thanks Steve
PS: It may be smarter to start with the heads first either way.

[ger21]

I don't even want to guess a $ figure, but I will guess and say it's not really feasible. I've never seen anyone build a machine from scratch with the ability to pull that off on that large of a scale. I've seen some small machines that could build a much scaled down version, but nothing on the scale you're talking about.

[steveyb4342]

Ok, well if I cant do it with a block could I do it for heads? I really want to cnc my own engine pieces lol. Then the stock would only have to be about... 10" {wide} about the same length a bit shorter an about 5" tall. Those are maximums. I actually want to try and cnc most of the parts for an engine. If I can Id also like to try a crankshaft, valves, rockers, pushrods, connecting rods and pistons. Maybe even a camshaft? How close can the tolarences be made on a cnc? For example a piston could be as close as 4.030 etc. Any suggestions? This just seemed to be the way to go cause I like playing with engines etc and this would make it a lot cheaper and I think building a cnc machine would be very fun and rewarding. I also am amazed watching them work.

Thanks Steve

[epineh]

For what its worth, I am interested in much the same thing, only on a smaller scale. My thinking is that I will need a small CNC mill, with coolant, to make heads, covers, brackets etc. Also a CNC surface grinder for the cranks and cams, small scale again, but I am hoping I can use CNC control to make the journals easier to machine.

Also a CNC lathe for pistons, sleeves etc. Now I am not saying any of this is impossible, just quite a task, and I would hate to think of the cost (in case the wife finds out, I'm starting to think she can read minds...)

Another option is to buy an already setup machine, something like an CNC'd X3 might suit your needs out of the box. I would go that way but that would mean selling my fishing boat - Noooooooooooo!!!

As for accuracy, my router is accurate to 0.01mm, I'm not sure of what that is in inches, but it is good enough for what I need. Here is the build log if you want to see what I went through to make it :

http://www.cnczone.com/forums/showthread.php?t=22101

Cheers.

Russell.

[steveyb4342]

How much would this "already setup machine" cost? Assumeing you could get good enough at it you could make parts and sell them to try and off set the cost. Of course it would be on a small scale but eventually Id imagine youd have no trouble breaking even maybe even make some money? Personally I would just like to experiment doing it with CNC and try to make my own engines as much as possible and who knows maybe try to offset the cost by doing some work?

Thanks Steve

[philbur]

Hi Steve,

A bit on the ambitious side I think.

The cost of the machine tools necessary to build a worthwhile multicylinder engine will run into many 10 of thousands of USD’s (second hand) and that's before you CNC them. The man-hours involve, from "know nothing" scratch to finished engine, would be approximately half a life time. As a minimum you will need a large mill, lathe, cylinder grinder and probably a surface grinder. For a block that size the mill alone would probably weigh something in excess of 5 tons and that a bit on the small side. CNCing it will probably cost you USD 10,000 plus. Should I go on?

Regards
Phil

Originally Posted by steveyb4342 How much would this "already setup machine" cost? Assumeing you could get good enough at it you could make parts and sell them to try and off set the cost. Of course it would be on a small scale but eventually Id imagine youd have no trouble breaking even maybe even make some money? Personally I would just like to experiment doing it with CNC and try to make my own engines as much as possible and who knows maybe try to offset the cost by doing some work? Thanks Steve

[steveyb4342]

point taken. I didnt plan on building a whole engine right off the get go. I start with valves maybe then try rockers etc etc. I guess Ill just continue with my manual milling ways. Thanks anyways. ...... Now to try and make 8 identical intake valves for my test bed 305 on a manual lathe. This could be interesting lol.

Thanks Steve
PS: I appreciate all your help I just wanted to know how feasible it would be, I thought the block would be hard, never imagined that hard.

[epineh]

Well I for one am seriously thinking of selling the 'ol fishing boat and getting something like an X3 already CNC'd like this :

http://www.syilamerica.com/product_h4.asp

Also a small lathe, this will fill my motor making requirements, as I mentioned I am only going to make small motors, most likely single cylinder 4-stroke, but multi cylinder is the dream.

I am not intending to make back any money on these motor's, the support side alone would be a nightmare, just something to have a little fun with.

Russell.