What's new
What's new

I have a 2023 DNM5700. Is the coolant/chip management really supposed to be this terrible?

xnewmanx

Aluminum
Joined
May 19, 2016
Preface this by saying, I don't know what I'm doing and I am not a trained machinist.

I was using a haas in my garage shop for a couple years and "upgraded" to a DNM5700.

I mostly cut aluminum. Some steel. I cut plastic one time.

It has a left side discharge LNS turbo chip conveyor.

My complaints:

The very first time I ran it I didn't turn the chip conveyor on. I was sitting at the machine watching it run and about 40 minutes in the coolant stopped flowing. I walked around to the back of the machine and the entire sump had emptied on the floor and flowed down a nearby drain. Chips (aluminum) had built up on the conveyor belt, which somehow allowed all the coolant to just flow onto the floor.

I now run the conveyor any time the machine is on.

However, the chip conveyor sits flush with the top of the coolant tank and a LOT of coolant spashes on the floor. If I wipe up the floor clean, in less than 2 hours I will have a 3 foot diameter puddle and a small pile of chips. The distributor claims this "isn't right" but also has no suggestions on how to fix it short of making some sort of close off with rubber and tape.

The collection pan at the conveyor discharge will fill so full of aluminum chips that I have to scrape it out twice a day. If I had to guess I'd say about 25% of the chips wind up having to be manually scraped into the chip bin. The pan in my haas i probably had to scrape out 10 times in 2 years.

The coolant pump sits in it's own little area and has a weird box filter, then a fine screen behind that. If I forget to clean that screen every couple hours, the pump will run dry.

I recently had a part with a 70 hour run time, so I pulled that small screen out. But earlier today the pump shut off even though the tank was full because the inlet to the pump got clogged. Now I am paranoid that I have to be right here on top of the machine because the coolant could shut off at any time...

At this point I don't know what to do, because I'm spending an hour each day just scooping chips when I used to be doing other stuff. Not to mention the floors in my shop are now WAY dirtier and need to be mopped every week just from all the coolant splashing everywhere. Also, I should mention that I usually run the machine for less than 5 hours a day.

The distributor is trying to sell me a 20,000 dollar filter conveyor, but I'm not certain that's going to solve my problem, and it's also 1/5 of what I paid for the machine just to handle the same chips that my haas handled fine with just an auger for 2 years.

The machine seems decent enough otherwise. Here is a recent project I made on it:
 
Dang dude, we went from "I don't know what I'm doing and these chip thingies are weird" to "but check out this sick turbskie I made for funsies" in a couple of paragraphs. That's friggin rad.

I don't know your machine, but chip management is a plague that few machines answer really well. Do you have a mix of a lot of big chips from the roughing and then a lot of really fine chips from the surfacing ops you're doing that are blocking your filters?

Can you take some pics of your conveyor layout?
 
Here is under the machine. This was just cleaned 5 hours ago.


IMG_2244.jpegIMG_2243.jpeg

This is all I have run.

IMG_2245.jpeg
 

Attachments

  • IMG_2241.jpeg
    4.7 MB · Views: 20
  • IMG_2240.jpeg
    3.4 MB · Views: 15
  • IMG_2239.jpeg
    4.2 MB · Views: 18
  • IMG_2237.jpeg
    4.8 MB · Views: 18
  • IMG_2238.jpeg
    5.3 MB · Views: 18
Last edited:
Sorry for the screenshots. The pictures would not upload otherwise for some reason...

Here's the side of the machine

IMG_2249.png

I had cleaned this screen before I wrote the first post. It looks like this already.

IMG_2248.png

Here are all the chips that have gone into the catcher at the coolant discharge area of the conveyor

IMG_2247.png

These are all the chips that have made it into the bin via conveyor.

IMG_2246.png
 
I can confirm that the chip/coolant management on the DNM5700 is horrendous when paired with the LNS Turd-o chip conveyor. I have no idea why so many MTB’s continue to deliver machines with those conveyors, they are awful. I understand it’s an expensive pill to swallow, but if you can justify the cost of a Hennig CDF conveyor I highly recommend them. We have one on a DVF5000 that has been issue free for over 2 years. Haven’t had to pull the sump to clean out chips since we installed the Hennig CDF unit. IMO, if the machine is making you money, it’s worth it to not have to worry about chips building up/clogging things up. On top of the reduced maintenance time/cost of pulling the sump to suck out all the chips that made it past the conveyor and filters into the “clean” side where the pumps are.

Might be worth asking if your sales rep can help you work out a good deal on a new conveyor setup, since the machine can’t do what it’s intended to do because of the terrible chip conveyor that they paired it with.
 
Vern has been trying to tell you to trap those fines before they get down to the conveyor. Fine aluminum chips will float on any foam in the coolant and get carried overboard. Not excusing the machine but, those chips can be a challenge. Is that from hours of ball-contouring those surfaces?

dd0j8bdp0gi81.jpg
 
Former Doosan/DN employee here.
@LockNut on here, is a current employee, as well.
The aluminum fines you're creating are (obviously) the cause, so upgrading to a better conveyor will get rid of the majority of issues. I dealt with quite a few customers who swapped out the standard conveyor for a Mayfran or Hennig. Money well spent. The LNS is a general purpose conveyor.
There are M codes and Keeper Relays for the conveyor and augers, so that they run whenever the machine is cycling.
 
I also recently installed a new DNM5700. Seeing this makes me glad I sprung for the filtering conveyor (LNS Turbo MH140). That being said I find the Doosan to be MILES ahead of the Haas for chip management.

Agree with the other posters, you need to make bigger chips, or replace your current conveyor with a filtering conveyor.
 
Last edited:
a paper filter chip conveyor system would definitely alleviate a lot of those issues. as others have said, i've found the base LNS chip conveyor on doosans to be pretty fkn horrible.

Yeah, that volume of ultra fine alu. chips will challenge a good drum filter but if it has a good backwash it will probably be ok. Paper band would be best, but expensive and higher maintenance...
 
Yeah, that volume of ultra fine alu. chips will challenge a good drum filter but if it has a good backwash it will probably be ok. Paper band would be best, but expensive and higher maintenance...
what makes you say that paper band are high maintenance? i've found that to be completely opposite.
 
In my experience a good salesman asks how much aluminum you'll be cutting with the machine. It's widely known you need a better conveyor than standard to deal with what you have going on.

I'd be all over who sold you that machine as is, presuming they knew your use case.
 
what makes you say that paper band are high maintenance? i've found that to be completely opposite.
Higher compared to a drum filter I meant.

I had a Cromar drum filter on a machine that cut a lot of aluminium and in ~10 years of running it the only time I had to do anything to it was when an operator dumped a massive bundle of stringy stainless swarf into the conveyor in one go and caved in the filter panels on the drum...
 
Higher compared to a drum filter I meant.

I had a Cromar drum filter on a machine that cut a lot of aluminium and in ~10 years of running it the only time I had to do anything to it was when an operator dumped a massive bundle of stringy stainless swarf into the conveyor in one go and caved in the filter panels on the drum...
i've mostly had experiences with KNOLL paper band systems and they have been silly simple. just replace the paper element once every couple months and keep it topped off.
 








 
Back
Top