what kind of machine would i need to produce pieces like in the picture?
i want to manufactor parts for rc-cars. ive gotten quotes for these peices to be made professionally, lets say 1 company wanted around 40$ a piece, another company wanted 20$ a piece... im not willing to let these people rip me off. If anyone could direct me to a machine that would be able to produce this, it would be greatly appreciated
http://img8.echo.cx/img8/3572/machine3wl.jpg (http://www.imageshack.us)

You will need a cnc mill. I don't think those quotes are out of line at all.

All but the flat one there will require multiple setups, that middle one there a fixture has to be made to hold it while those holes are drilled. Figure a couple hours programming and verification time plus setup and stock cost. Plus tooling cost. Plus polishing or chrome, whatever finish those parts have on them.

20 bucks a piece is cheap.

That is unless you tell them you want 50,000 of them then I'm sure the price will drop.

If you want a machine to do parts with that quality finish, and in quantity start looking at used VMCs, ie: Fadal, Haas, Okuma, etc etc. they start at about 15k for an old machine on up to the millions. Figure a few thousand in tooling, a few thou for the software, coolant, phase convertor (unless you already have three phase power).

You may also look into a used converted Bridgeport or clone, in working condition maybe 3-4-10 k depending. Ebay will give you some ideas of what is out there.

That first, flat one could be done on a little router based CNC. For the others Nervis1 one right. Even if you have the machine to do them yourself, the programming time, set up, deburring, polishing etc will lead to your time being about 0.03c/hour for these $40 parts.

Do you like machining as a hobby, or do you like RC cars as a hobby?

MUCH better idea than a machine that will cut them in aluminum (which is going to be high $)

Machine that will cut foam, then build yourself a little home foundry. Can be done for less than $25. Cut the pieces in foam, then cast them.

what do you mean cut them in foam then cast them?

We do lost foam casting for the aircraft industry. It is also how toyota motors are done. The basic process is simple:

1: Cut your shapes out of foam, add runners and sprues
2: Cover the foam with a refractory shell
3: Bury the part in loose sand and vibrate to pack the sand
4: Pour the part
5: break off shell and cut off sprues

There are several advantages to this over simply machining the part out of a chunk of aluminum. First, for the home hobbyist, you only need a CNC machine capable of cutting foam. These are realtively easy to build, as opposed to machines desingend to cut aluminum, which are much, much mroe expensive. For the professional shop, thre is a decrease in tool costs, since an end mill used only on foam will last nearly forever, and they are much, much cheaper than standard endmills (we commonly use bits for a dremel, just make sure you measure the actual bit you are going to use and input it in your tool library). Machining time is also much lower.

In either case, your materials are going to be cheaper, since aluminum ingot is much cheaper than billet. Lost foam is a little more labor intensive, but for the home hobbyist, it is probably a more logical process from a cost standpoint

thank you for your response but i have no idea what any of this means, i am a extremly handy person but i know 0 when it comes to this stuff.
Can you supply me with some pictures so i can get a better idea of what your talking about.
1: Cut your shapes out of foam, ??add runners and sprues??
2: Cover the foam with a ??refractory shell??
3: Bury the part in loose sand and vibrate to pack the sand
4: Pour the part?? LIQUID ALUMINUM??
5: break off shell and cut off sprues

http://www.backyardmetalcasting.com/index.html

try this one out

You'll find lots of info on casting here (http://www.backyardmetalcasting.com/).

Bear in mind though that a cast part will still require machining and the surface quality and mechanical properties won't be as good as a machined from stock part.

Nikolas

Edit: Miljnor beat me to it by 2 minutes...

its all those years of typing! :D

thank you for your response but i have no idea what any of this means, i am a extremly handy person but i know 0 when it comes to this stuff.
Can you supply me with some pictures so i can get a better idea of what your talking about.
1: Cut your shapes out of foam, ??add runners and sprues??
2: Cover the foam with a ??refractory shell??
3: Bury the part in loose sand and vibrate to pack the sand
4: Pour the part?? LIQUID ALUMINUM??
5: break off shell and cut off sprues

Sorry.

In a greensand mold, sprues are the tunnel that you pour the metal into. They are connected to the part by a runner. In lost foam, the sprue is just an extra piece of foam stuck on there that sticks up out of the sand. You pour your metal down that to fill your part, then you cut it off later.

Refractory shell....the foam is coated with something that can take the heat form the molten aluminum without breaking or burning. We use a ceramic product whose name escapes me at the moment, but I could find it if you need it. Most guys at home use drywall mud thinned in water.

Yes, liquid aluminum. you melt it in a furnace. Any idiot can do it (there iwll be those who tell you it is difficult or impossible, it is nothing), and do it cheaply. Check out the page the other guys linked. There is some pretty good info there for somebody new to the craft.

Bear in mind though that a cast part will still require machining and the surface quality and mechanical properties won't be as good as a machined from stock part.

The finished part MAY require machining, and if suface quality is a consideration, that can be taken into account and corrected for. Lost foam is comparabe to lost wax as far as surface quality possibilities. If you know that surface finish is a consideration, you can treat your foam and end up with something that you really only have to run through the polisher for a mirror finish.

You are correct about mechanical properties, though. Any casting is going to have different mechanical properties from a machined part. For what is being done here (the parts at the top), it should not make a difference. Our shop has cast mounts for jet engines, and they do fine. The important thing is to rememebr when you are designing your part to consider the properties fo cast aluminum as opposed to billet, and make sure you adjust for that in your design if need be.

20$ a piece... im not willing to let these people rip me off.

You've got to look beyond the 1$ worth of material, and I'd say that's a fair price.

Small mill $30,000+
software $10,000
tooling $10,000
support equiptment $10,000
(air, measuring equtp., etc)

You've got a $ 60k investment right there. Plus all the usual business expenses, utilities, overhead, employees, insurance, bus. license and paperwork, accounting, office supplies/staff, taxes, etc. etc. etc.

Ok, you've got that for a business expense.

PLUS
Programming 1-3 hrs.
jigging and fixtures 4-5 hrs.
trial and test parts 1-2 hrs.
at 65-75$ an hour....

You can amotize those costs over as many parts as you'd like. If you want one part, thats about 650$ right there....All for about a 5-10 minute cycle time...

For the DIY'ers, what's YOUR time worth?

Oh, if your looking into casting, your're gonna have to still machine those A-arms. Unless of you go 30K$ for die casting tooling. Oh, and polish.

Sorry for the rant, but I'm a shop owner and hope to inform folks why parts cost what they do.

Oh, if your looking into casting, your're gonna have to still machine those A-arms. Unless of you go 30K$ for die casting tooling. Oh, and polish.

That depends on your casting process and tolerances required. Those could be used as cast if you used either lost foam or investment if the tolerances do not have to be closer than .005. As far as polish, 30 seconds w/ an 8" wheel woudl hadle it. Casting has come a long ways.

Sorry for the rant, but I'm a shop owner and hope to inform folks why parts cost what they do.

I quoted a guy some parts AT COST one time (friend price) and he blew a gasket when he saw waht it was going to cost. He ended up coming back a few days later and apologizing when he got some other quotes and realized how low mine actually was. We have 7 million dollars woth of equipment. SOmebody has to pay for that. Everythign cost money, form equipment to tooling to zip ties. None of that stuff is free, and it has to be built into end prduct pricing. The shop that quotes prices without taking these things into account will not last long.

This is why I generally do not like to deal witht h epublic. We have contracts with boeing, cessna, and lear. They understand such things, and I havenever had any of them whine about cost as long as it is reasonable.

Regarding casting, you may be able to use a zinc alloy which melts below 1000F instead of aluminum. Ingots can be had from here:

http://www.eazall.com/diecastalloys.aspx

Chris

(chair) You see... I am not the only guy that has these rants about "actual" parts cost through an established shop.
I get complaints about how expensive parts are and I am 1 of the least expensive shops here.

Those prices originally given are "lunatic fringe" cheap for 1-offs
:cheers:

Thinking the same thing Dar, I don't think I could make those a arms for 20 bucks. Ought to get em made before the shop owner changes his mind!

If you're just looking for a few pieces then it's best to pay for someone with the machinery to do the work.....if you want to mass produce them...then there are many options.....

like pay someone else with BIGGER machinery to do the work.

sorry, just could'nt resist. :D :D

I'm not flaming, just a scarstic and cynical shop owner that's heard way too many "that's way too much, I'll just do it myself" replies from people.

(chair)
Those prices originally given are "lunatic fringe" cheap for 1-offs
:cheers:

I kind of thought the orginal post was amusing - if I could get complex (multiple ops) stuff like that made for $20, I'd have to seriously look at selling everthing and getting serious about golf.......naw, i like making making metal chips more.

it just highlights the different paradigm between knowing not just what goes into making something, but also what goes into even getting to the position of being able to make something, compared to standing there with a little hunk of metal with a few holes and wondering if I'm being ripped off.

A very aptly put perspective - Mcgy

Hello -

I doubt anyone would make very many of these for you for $20 each. No way. After they made the first 5 or so they would realize thay screwed up and jack up their price closer to your $40 per piece price. If you figure all of the steps mentioned by NERVIS1 and figure that most shops are going to get at least $55 an hour, you can see that $40 is, well, actually a bit LOW.

It's not that these are extremely complicated - the costs are associated with machine time. Close tolerance machining of smaller parts is time consuming. Add the fact that they are aluminum and you have a lot of experienced machinists would likely shy away from suggesting machining from solid stock as an option to production of more than a handful of prototype parts. Cutting aluminum with small tooling is relatively slow - you can only cut as fast as the tooling will allow, and in the case of smaller tooling, the depth and number of flutes prohibits aggressive cutting - carbide or HSS - you just can't push but so hard on smaller tools.

These parts are suited for high speed machines - with high spindle speeds - but you'll pay a premium for time on those machines as NERVIS1 said. I am not saying it can not be done on conventional equipment - of course it can. But not for the price you want - not if the guys in businiess to make money that is. If you can find a shop to subsidize your parts, please let me know. I would be interested in talking to them!

Like most, I can think of a host of ways to make these things but it depends on many, many things. BUT - unless you are making hundreds or thousands, it will cost you.

How many parts of each are you looking to make?
What type of aluminum? 6061? 5052? 2024? 7075?

Extrusion with fixtured, secondary machining is an option for high volume and probably the best way for quantities above maybe 300. Die cost would be about $1200 per piece (or so), and 500 pound minimums are typical.,,lots of places in the northeast US are hungry for work.

Laser cutting from plate then secondary machining is an alternative, but still expensive.

Lost mold Casting such small parts would likely not be very efficient. Sorry - I just can't see it. Investment casting - maybe with some volume.

NERVIS1 had all the right answers. Fadal, Haas, Okuma machines could crank these out all day long, but they don't give them away and they aren't free to operate.

Holy crap, I hope you plan to make alot of parts if you plan to make castings of them. Machining a part is the most expensive way to to make something but if you only need a few hundred or less it is your only option, 40 - 20 dollars per piece to make the parts that you showed is not outrageous. A small retrofitted vertical mill could make your parts, or even, if you were feeling creative you could use a manual mill with a rotary table but this would be slow. All of these opinions are my own and certainly not the end all and be all - all spelling and grammatical errors are exclusively my own.

On the contrary. Lost foam is by far the most cost effective option for most short run items.

For the items in question, you would order foam of the correct thickness, gang cut them 50-100 at a time, have your chipsweeper spend an hour assembling your tree and coating it, then into the fluidized sand bed and hot metal down the pipe. If you wanted 1 or 2 of each, casting and machining would be roughly the same price because with the lost foam you have virtually 0 tooling costs, and very little time. For 100 of them you are only looking at 20 minutes of machine time (you can cut foam at 300 IPM on a $3000 mill). Building the tree is next to nothing and is not skilled labor, and then you have to pay for ingot stock for the casting, fuel for the furnace, and a man to pour it (which IS skilled labor). then cut the parts apart, etc...

In the rough, meaning they would have to be polished by the end user/customer, 100 of these could be cast @ $6-$12 each and you would still turn a profit on it.

If you only wanted 4 each, though, they would run much more ($15-$20 each) cast.

Crikey!!! I can't even buy the Aliminium for that let alone cnc mill them. It costs $896 for 10mm (3/8) 1,200 x 2,400 mm sheet where I live and that changes in price about as fast as Stainless Steel does. Buy the parts and be happy with a quality product as they look beautiful and have been finished with care.

Just to chime in. That 20-40 buck seems fairly reasonable. Without seeing the scale of the item and tolerances.

I tried to have some parts made in the past from cad drawings. I couldn't find any machinists that were willing to touch the parts. The few that did quoted me around 1500 dollars to build it.

With that said, I decided to make them myself. Almost 2 years later, I have a mill, lathe, most of the parts to make it cnc, and a new16x20 workshop. I still haven't made the parts and have almost 10k invested. Now I'm saving up for an eletrician to power my workshop, which will be another 2.5k.

Just to put things in prospective.

In retrospec, I should have changed the design and tolerances for a re-quote. Of course, at half the quoted price, I still wouldn't have been able to make the item and sell at a profit.

Now that I have the machines, I find myself thinking of lots of neat things I want to make.

Assuming I ever get power. (lol)

*side note*

Anyone a licensed eletrician in Arkansas that wants to work for Beer and donuts?

*grins*

I was in Arkansas (Conway, Springdale, and North Little Rock) 3 weeks ago. I would have wired your shop for free if you would have taken me to Mc Clards for lunch.

Lol,

Well I wish that it would have been that simple.

I'm having to deal with the pain of having a "service upgrade". House is older than I am, running on a 60amp meter face. Looking to have it upgraded to 200 amp, 100amp for house and 100 amp for building, with sub panel installed in the shop.

Due to new wiring code. I think I'm looking at an external panel on the house to hold any new wiring and to act as a feed for the existing dinky inside panel.

So mustbenu, make sure that your location has the proper power requirments. Assuming you decide to get into the world of machining.

All of the nickle and dime requirements eat you up.

Mc Clards....hmmmm....must be a strip joint or a BBQ joint....

The best BBQ ribs I have ever eaten ...brought back 3 bottles of their sauce 'ol Billy's favorite BBQ place

If you think that you are being ripped off then you should machine them yourself. For around $250,000 you should find yourself well enough equipped to machine your parts sucessfully. I think that once you are making them yourself you will find that at $40.00ea. you were really not being "ripped off".
Personally, I would not get anywhere near that job for less than $60-$65 ea.

"Almost 2 years later, ..."

"Where there's a will, there's always a way"..my daddy used to say. But he never said it was going to be easy.

I am just recently getting myself back into toying with machining after a 25 yr leave of absence. So far (and I'm afraid to look at the real numbers) just to set up with a mill/drill, a lathe, supporting equipment and tooling I'm already into $12k+. At least I started with work already lined up and there isn't much ($) left after making the payments.

Not to discourage anyone from persueing the trade but one thing that hasn't been mentioned here is the fact that everyone of you guys that know what your doing spent a LOT of time as a chip sweeper...you get my drift.

Rome was built with a chisel and hammer. I remember seeing this one old guys turbo fan jet engines that were about a foot long with unbelievable detail and accuracy, the compressor fans were incredible (I wish I had the link), and somewhere along the site he says it was a real paindoing all that work with his SHERLINE CNC mill, because he had to re fixture the big parts so many times. Unbelievable work. The quality of the tooling is very important regarding the finishes. You can spend 65.00 on a 3 inch endmill, or you could spend 1500.00. The machine envelope is the only real limitation, and how well its adjusted and set up. That and the operator experiance of course. How fast you need to produce them, and how much work you are willing to do are the variables.

So, I'm basically agreeing with everyone, as far as your parts, its 300.00 min and 65.00 an hour around here.