A question for the machinists in the crowd

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Vonz90
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A question for the machinists in the crowd

Post by Vonz90 »

So, what would be the cheapest/best CNC machine to do some low volume stuff on the side (aka that would fit in a garage). I am contemplating doing some stuff that I don't think anyone else is doing. The requirements would be:

1. Capable of making something the size/complexity of a monolithic AR upper (not what I am thinking about, but similar level of complexity/size). Also, what if the size was only that of an regular AR uppper, does that give more options?
2. Relatively easy to maintain.
3. Fits in a garage comfortably (three car garage, but I put cars in 2/3 of so it would fit comfortably in a 1 car size area).
4. Would not need to be high volume, auto feed or anything like that.
5. Needs to be stand alone (I obviously do not have central cooling water) and would need to work on 240V maximum.
6. I know a couple of CNC programers, so I could get help with that side of things. However, easy to work with in that realm would be a plus.

As part of my job, I've actually spec'ed out and bought CNC's for production a couple times, but since I'm not looking to spend $500K+ of my own money, I have no idea what is out there.

Thanks in advance.
Precision
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Re: A question for the machinists in the crowd

Post by Precision »

I don't know squat about this topic, but it is quite interesting to me so I began looking. A little googling later...

HOLY Crap that shit ain't cheap.

http://www.littlemachineshop.com/produc ... C+Machines

@ $5000, 7000 and 9000

http://www.tormach.com/product_pcnc_main.html

@ $9000

Wow. I want your toy budget. :D
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D5CAV
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Re: A question for the machinists in the crowd

Post by D5CAV »

I have friends who have a Tormach. It's made in either Taiwan or China IIRC. They seem pretty happy with it.

They do some prototyping for their business, so it's paid for itself vs. going out to a prototype house for machining work.

I've talked to them about using it for some light spare parts machining. They are OK with it, but want me to get checked out and buy the bits.

1. The bits aren't cheap, especially if you want to do steel, so for the parts I want, it's more cost effective to pay a smith to make them for me.
2. I would need to spend about a week with them to learn the machine, and I just don't have the time.

They had an old Bridgeport Mill, probably 1960s era, that was replaced by the Tormach. That mill went to another friend, who I'm not as close to. I'd probably be more comfortable playing with the Bridgeport than the Tormach.

IIRC, they just gave him the mill in return for removing it from their garage without damaging anything. I think it weighed about 2x as much as the Tormach.

You might look around for used manual mills instead.
None are more hopelessly enslaved than those who falsely believe they are free.” Johann Wolfgang von Goethe
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Darrell
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Re: A question for the machinists in the crowd

Post by Darrell »

I am reminded of amateur astronomers who learned the old school way--get a good basic scope with clock drive and setting circles, and a sky atlas. Then proceed to learn how to operate the scope and find your way around the heavens. OR the new school way--get a computerized goto scope with all the bells and whistles, GPS, etc., plug it in and go. That scope will do everything but walk the dog. However, the owner will never learn the sky, how to operate the scope and find what they're looking for, etc.

I recently mentioned in another thread that I'm doing a project for work, including a lot of machine shop stuff. We have a good Bridgeport mill, and a large Jet lathe. All manual, not even any digital readouts, just dials. I am (re)learning a lot along the way. I don't get to do it enough to be really good at it, but I'm miles ahead of where I was when I began the project.
Eppur si muove--Galileo
tfbncc
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Re: A question for the machinists in the crowd

Post by tfbncc »

The Sieg X2 mill (same one sold by Harbor Freight, Grizzly, Micro-Mark, et al) is probably the most popular home milling machine available under $1000.00. The good news is that tooling and spare parts are available everywhere as well as good CNC kits. The bad news is that the mill needs "tuning" to get it to work at it's peak capabilities. Another good benefit is that there is almost always a coupon available for Harbor Freight for 20% off which will save you a chunk of change. Look for sales around the holidays as well.

Comparison Chart of Mini Mill Vendors

I used to own a Sieg X1 micro mill, the next size down. But even though it was about 2/3 the size of the X2 it still weighed 90 lbs. So be aware that you will need a really strong bench to bolt the mill to.

Other small mills available would be the Sherline and Taig models. Sherline has gotten to be pricey in the last few years due to popularity. Taig, while small, has a 1/4 hp motor with their CNC ready mill.

Taig Tools
Sherline Products

The most cost effective mill would probably be a Sieg X2 for under $600.00 then add a CNC kit available from several different vendors for about $500.00
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Vonz90
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Re: A question for the machinists in the crowd

Post by Vonz90 »

Just to clarify, if I do this, the intent would be as a side business kind of thing. I'm an engineer not a machinist and not going to turn myself into one. So the thought would be something that can run relatively independently past the development stage, even if I had spend some time/money developing fixtures and jigs to do it. (Understanding that setup and flipping, etc. necessary unless spending a lot more money for automatic part handling and pared machines etc.

Like a little 3 - axis CNC with a turntable or 5 - axis if that makes more sense. Since I would be designing the stuff, so I could taylor the design to what I had available to make it to some extent.

If the mini mills will do that, I'm game, but I would not want to dive into something unless I have a semblance of the right equipment.
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HTRN
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Re: A question for the machinists in the crowd

Post by HTRN »

Precision wrote:HOLY Crap that shit ain't cheap.
Pocket change. The 4th Axis that's sitting on a dolly at work cost 55 grand. You really don't want to know what the machine it goes in costs.. Hell the going rate for a nice clean Bridgeport Series I is around 8 grand from a dealer these days.
D5CAV wrote:1. The bits aren't cheap,
1) They're not "bits", they're endmills. "bits" are those funky drills that are used in "bit and brace".
2) Endmills can be had cheap on ebay, from shop cleanouts, inventory reductions, etc. 20 bucks for endmill is cheap. You want to see pricey? Go look at some of the specialty stuff, like single flutes made for plastic, or better yet - thread mills. Case in point - one of the idiot minions forgot to close the vise today, and destroyed a threadmill that cut 1"NPT. Replacement cost? 260 dollars.
HTRN, I would tell you that you are an evil fucker, but you probably get that a lot ~ Netpackrat

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Darrell
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Re: A question for the machinists in the crowd

Post by Darrell »

And this is just one example of why knowledge of basics and background are important.
Eppur si muove--Galileo
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HTRN
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Re: A question for the machinists in the crowd

Post by HTRN »

Good rule of thumb: for every dollar you plan to spend on the machine, plan to spend an equal amount on tooling(and I don't mean consumables - vises, superspacers, chucks, tool posts, collets, etc all cost money, in some cases, large amounts of it.). I'm not even going to get into what metrology is going to cost...
HTRN, I would tell you that you are an evil fucker, but you probably get that a lot ~ Netpackrat

Describing what HTRN does as "antics" is like describing the wreck of the Titanic as "a minor boating incident" ~ First Shirt
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D5CAV
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Re: A question for the machinists in the crowd

Post by D5CAV »

HTRN wrote:I'm not even going to get into what metrology is going to cost...
This guy has a lot of metrology.

https://www.youtube.com/watch?v=1Ufes_zrZmg

He makes rebarreling a mauser look pretty intimidating.
None are more hopelessly enslaved than those who falsely believe they are free.” Johann Wolfgang von Goethe
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