Why buy a mill with no chip conveyor?

ranchak · Jun 19, 2016

I'm looking to get another VMC, one thing I have noticed is that there are a number of VMCs that don't have chip conveyors. Is this primarily a cost issue when purchased new or is there something that I am overlooking. I have machines that have chip augers and I realize they are not 100% efficient, but it seems like its better than shoveling. The machine I am currently considering is a Daewoo DMV4020. Nice machine, but no conveyor. Just thought I would put this out there and see what the general consensus is.

Needshave · Jun 19, 2016

Cost and space are the only two reasons I can think of not getting one. In my opinion they are worth the cost and space unless you have work that makes very little chips.

ranchak · Jun 19, 2016

Agreed on the space issue, but it certainly can't be that costly of an option when purchasing new. You would think the time savings would beat out the cost savings.

Ziggy2 · Jun 19, 2016

ranchak said:
Agreed on the space issue, but it certainly can't be that costly of an option when purchasing new. You would think the time savings would beat out the cost savings.

Depending on the quality of unit but most of the quality filter conveyors offering TSC with a high pressure pump system will be in the area of $25-40,000 depending on unit capacity. These will have at least 3 coolant pumps,a tank that is sized at least 4X the total GPM rating of the system, bag filters for screw pump protection, electrical controls, chip conveyor and some sort of primary filter, usually a rotary drum.

The problem is that the cost of these units have a minimum price level that is based on total component cost, not capacity, making the small units relatively expensive in comparison to the machine cost, especially in the sub $125,000 machine price range. If a company is putting in a cell of 8 Brothers Rapidos, they will definitely be purchasing filter-conveyor systems for each machine. If it is a small shop purchasing their first Brother machine and are on a budget, the money is going to go for tooling and fixturing. Can't fault the reasoning, just plain economics and how much they can afford.

Usually the company that installed an 8 machine cell with filter-conveyors is running 24-7 and by the time they get new machines, the old ones are pretty well run out and probably not well maintained. The single machines owned by small shops are the ones that end up on the market that are worth buying used and these are the very machines that originally not purchased with the filter-conveyor.

Here is an example:
Barnes International, Inc.

WILLEO6709 · Jun 19, 2016

ever had to dig out a busted onveyor? overloaded it and jammed it up to the point the motor would not pull it? conveyors are not all they can be cracked up to be sometimes.

Jashley73 · Jun 19, 2016

2 reasons come quickly to mind.

1- Protoype shops, where the spindles don't get much above 30% uptime, and because of that, and the general nature of the work, they don't generate a lot of chips. In this case, it's not worth it for them to get a conveyor - the money would be better spent on tooling, a probe, or CAD/CAM software.

2- Some shops might cut 99% aluminum, some 90% steel, and others a mix of everything. In each of these scenarios, a single conveyor to cover all won't work great. So for that reason, the builders will offer the "base" machine without a conveyor, so that the buyer might buy a conveyor more tailored for their use.

fpworks · Jun 19, 2016

I have a friend who has three five axis Okumas...all they do is make little holes...sometimes pretty deep. (along with the other things associated with making holes, such as threads, ports, snap ring grooves, counterboring, etc.) Cycle times are often 20 minutes per part, and they run two shifts/day. No chip conveyors and they simply empty the chip pans once a week.

Mike1974 · Jun 20, 2016

Jashley73 said:
2 reasons come quickly to mind.

1- Protoype shops, where the spindles don't get much above 30% uptime, and because of that, and the general nature of the work, they don't generate a lot of chips. In this case, it's not worth it for them to get a conveyor - the money would be better spent on tooling, a probe, or CAD/CAM software.

2- Some shops might cut 99% aluminum, some 90% steel, and others a mix of everything. In each of these scenarios, a single conveyor to cover all won't work great. So for that reason, the builders will offer the "base" machine without a conveyor, so that the buyer might buy a conveyor more tailored for their use.

That is true, but often times, IME, that saved money is just not spent at all. :nono:

Even in a prototype shop it sure is nice to not have to bail chips!

Depending on the system, belt vs auger, the auger is only halfass effective anyways (single) so in that case it might not be worth the money period, as you still need to shovel chips to the front/rear of machine to get them into the auger.

edit: I would ask the same question about the probing package. :confused:

I know not quite apples to apples as to the effectiveness to cost ratio, but still... If someone questions why the extra cost of a probe system they have obviously never used one!

DDoug · Jun 20, 2016

Mike1974 said:
That is true, but often times, IME, that saved money is just not spent at all.
Even in a prototype shop it sure is nice to not have to bail chips! Depending on the system, belt vs auger, the auger is only halfass effective anyways (single) so in that case it might not be worth the money period, as you still need to shovel chips to the front/rear of machine to get them into the auger.

Mike, my take on it is this, a prototype shop might need to completely 100% clean out the machine between materials.

Inconel one day, magnesium the next day, mild steel, brass, bronze, and so on.

So anything other than a clean smooth chip pan can't be cleaned very well.

Click to expand...

machtool · Jun 20, 2016

Ziggy2 said:
Depending on the quality of unit but most of the quality filter conveyors offering TSC with a high pressure pump system will be in the area of $25-40,000 depending on unit capacity. These will have at least 3 coolant pumps,a tank that is sized at least 4X the total GPM rating of the system, bag filters for screw pump protection, electrical controls, chip conveyor and some sort of primary filter, usually a rotary drum.

The bloke has only asked about a chip conveyor? He never mentioned TSC even once. When did we turn chip extraction into a Phd of filters, pumps, bags, protection & controls.

Dupa3872 · Jun 20, 2016

IMO It's all about base price. They get you in the door with the base price often very attractive then you start adding on options. HAAS has a great base price and as you have seen us talk over and over lately once you start building a quote and adding in the options you need.....almost everyone needs they are not the bargain they once were. It's all sales tactics nothing more.

Make Chips Boys !

Ron

david n · Jun 20, 2016

It comes down to how the buyer is using the machine.................as mentioned prototype shop. Sometimes you will see machines come out of tech schools with no chip management. I know of a shop that machines tiny little plastic parts. All they use is a dust collection system for chip evac. Graphite machining is another area where no conveyor would be needed. Or sometimes it is some management idiot that tries to save a buck, "We don't need no stinkin' chip conveyor." And wonder why a few years down the road when they can't sell the machine for as much as others on the market that have conveyors.

WILLEO6709 · Jun 20, 2016

I have machines with and without conveyors and my observations are as follows:

If the method of getting the chips to the conveyor sucks, why bother. Case in point, I have some HMC's with massive flood washdown ( designed for aluminum) and in aluminum it works great..... in steel... well how heavy are the chips?

on augers: if you have long drill chips don't screw around with augers, its faster to sweep the machine out with a broom than spend an hour a week untangling scrap from the auger.

If you have method to get the chips to the automatic conveyance out of the machine its a godsend, otherwise give me a corn broom, a shovel, and a heavy steel dustpan.

CarbideBob · Jun 20, 2016

One needs low pay, entry level jobs to sort out the 16-18 year old kids and see if you want them.
Around here by law they can't run machines but they can sweep, mop, clean coolant tanks, and shovel chips.
How they do these things gives you an idea if you want to spend serous money bringing them up the ladder.

Once you have a machine or as I have seen many times, 40 machines and workers sitting because the chip conveyor is broken.........It can become a very critical part of the process.
Good idea in lots of places, an extra failure point you don't need in others. They will break and/or jam a lot and it seems always at the worst possible time.
........And then there is the employee who wants a break and "accidentally" drops a wrench or hammer in with the chips.

For production mostly a good idea and if a rollout you really should have a spare waiting in the wings as this is a high failure rate item.
Bob

Ziggy2 · Jun 20, 2016

machtool said:
The bloke has only asked about a chip conveyor? He never mentioned TSC even once. When did we turn chip extraction into a Phd of filters, pumps, bags, protection & controls.

The OP was looking at a used machine and was asking why would a used machine be offered without a chip handling system. I gave my explanation why I see new machines purchased without any chip handling system.

The problem is one of economics. The low end priced systems are only marginally better then shoveling. Nothing wrong with augers but they have their limitations and do not have the coolant flow capacity to address proper chip removal from the cabinet with continuous flood coolant.

When you start adding all of the things required to make a system that will handle chips well and without shoveling, it gets complicated and expensive. Often the chip problem is not worth the expense of a coolant-chip handling system. It is all a function of what the original purchaser of the machine needed.

Most chip extraction applications utilize flood coolant to move the chips within the cabinet and flush them into an auger or conveyor. This creates a problem in that the coolant system needs more capacity, pressure and flow, to handle the extra required coolant flow.

There is no right answer for this problem. Many times, the shovel is the best economic solution for low chip volume applications. Machine owners that have larger needs can and will justify the expense of the added chip handling system. Sometimes parts require special finishes that mandate high purity coolant filtration and yet the total swarf produced in a week on a 24/7 auto load machine might fit in a 5 gal. bucket but the application justifies the $40,000 chip handling system.

It is all a question of what the end user needs and can afford.

ranchak · Jun 20, 2016

Wow, way more replies than I expected. I can see both sides here and I would have to assume economics wins out more times than not. I guess if the price is right I can do without the conveyor.

Captdave · Jun 20, 2016

When we started out it was 75% about limited space and 25% cost. Now we have ample space and I could care less about the cost of an effective conveyor, amortized over the life of the machine its peanuts. I still do a lot of prototyping and short runs in our first VMC a Hurco VM-10 and I'm always on the look out for a used conveyor. I hate cleaning out a machine!

URGuys · Jun 20, 2016

Jashley73 said:
Prototype shops, where the spindles don't get much above 30% uptime, and because of that, and the general nature of the work, they don't generate a lot of chips. In this case, it's not worth it for them to get a conveyor

Ding, ding, ding. We have a winner.
Of our two current machines, one has the angled bottom so chips slide to a bin with the coolant and for the most part it works on a machine that takes tiny cuts. The other machine has a conveyor that I use once a week if I'm really taking off material; or once a month if I'm hardly using the machine. For the extra 4' of space used by the conveyor it's not worth it.
I'm pretty sure the next mill we purchase won't have a chip conveyor because of the budget and space issue on something that is very low in the list of importance.

FYI: the quotes we've received, conveyors start between $4-6k. Then go up from there depending on coolant blast on them, etc.

Comatose · Jun 20, 2016

Even in, say, a high production multi-speedio cell, the input stock might be an extrusion or a MIM part that needs a bunch of 2-56 holes drilled and tapped, plus a couple surfaces faced .01"

Not a lot of chips in that case, why add complexity to the system?

If you're moving a lot of metal, sure, but not everyone and everything is.

adama · Jun 20, 2016

I think it also comes back to part design, more than a few of us don't just whittle everything out of some large block of alu.

Anyone thats delt with nylon and a screw conveyor on a lathe never makes the mistake a secound time!

Why buy a mill with no chip conveyor?

Cast Iron

Aluminum

Cast Iron

Stainless

Diamond

Titanium

Stainless

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Diamond

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Stainless

Diamond

Diamond

Diamond

Stainless

Cast Iron

Titanium

Aluminum

Titanium

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