[webgeek]

Hi all; I got my NM-200 a month or two ago and I've been so busy getting everything I need for full-on production that I've not had a chance to post a review. I think I can sum the entire thing in one word though - wow!

Back Story
Simply put, I love this machine. A little backstory will help explain where I'm coming from. I'm an absolute beginer when it comes to machining but I've always loved the idea of doing it myself. I came up with the idea of making parts for hobbiest in the various hobbies I play around with - RC, robotics, etc. I converted a little Sieg X2 into a CNC machine and quickly learned the basics and that I liked it. I designed up a few parts and found I'd have no trouble selling them. I decided to take the risk and I got a business lease to pay for everything. That brings me to ordering the machine.

Ordering
So my machine is slightly different than most of the S2's out there. I got a one-off machine from Khai - it has the S2 electronics and spindle but has part of the S1 frame so the spindle at lowest extension is still a good 5+ inches from the table. My only reason for getting this machine vs. a new S2 is that this was the last machine Khai had in stock. Ultimately this probably proved a mistake as it still took quite a few weeks to actually get my machine and the height of the spindle is a huge annoyance (my biggest one by far). I got the included computer, stand, coolant, 4th axis electronics (though not the rotary table itself), and a few spindle extender things.

I chose the Novakon over the Tormach for a couple of reasons. The first was the increased table travel which I ABSOLUTELY LOVE. The next reason was Novakon pre-sales support. I called Tormach 2x and Novakon multiple times. Khai is a customer service guru - prompt callbacks when I had to leave a message and just consistently pleasent to deal with all around. Tormach on the other hand was just not that helpful or even that friendly in the end.

Delivery and Setup
The machine is big. I had NO clue how large it would be until I actually saw it. It comes in two large crates, one that contains the base and one that contains the rest. It was reasonably well packed with foam and the like. Lots of people have talked about much of the set up and the manual shows this in great detail. I'll simply add that the foldable 2-ton engine hoist from Harbor Freight is NOT large enough to really manage this mill. That's what I used and it was a horrible nightmare I'd not wish on anyone. Actually getting the mill in my garage and on it's base was a terrible ordeal and very frustrating. I've already told my wife I'll never move from this house as I can't move the mill again.

The mill itself worked right out of the gate. Plugged it in, hooked up a monitor, keyboard, and mouse then turned it on. Everything worked first try. The mill tram is quite good initially as was the overall accuracy. The only thing that gave me any trouble was the coolant system - one of the tubes was far too large and didn't fit through the hole in the cabinet. I ended up doing some tricky routing with PVC instead. Additionally, a couple of bolts and nuts were missing so I had to snag them at the hardware store. All of them were for the coolant shroud though so no harm.

Good
The mill has many good points, it seems very rigid though I don't have a good way of telling how rigid with the small work I do. It has a huge amount of travel - particularly huge when compared to anything in it's price range. It's accurate, powerful, well-designed, and well-constructed. The electronics cabinet is a wiring work of art. Adding the superb support from Khai makes it an easy choice and one I believe I'd make again.

Bad
The coolant system is pretty whimpy and inconsistent - sometimes the flow drops off a bit for no reason I can tell and even when it's at it's best, it's not as powerful as I'd like. At best it barely puts out enough oomph to wash away the chips. Additionally the coolant tub is just too small to let the machine run consistently. I plan on replacing the tub with a large Rubbermade-style bin that can hold a good 5 gallons. If the pump is too whimpy long term, I'll replace it with a good pond pump as well.

The spindle drawbar is too short as well - strangly so. It works, but I wish it had a good couple of turns of threads more.

Modifications
Since the huge majority of my parts are cut from .09" to .125" aluminum, the first thing I did was to create a tooling plate 24" x 15" with 1/4" tapped holes set 1 1/2" apart. I then mounted this plate on two 8" Enco vises that I mounted on blocks to raise above the table. I hate having to raise the vises but this is the price to pay for the huge z-axis clearance.

Then I created a tall "enclosure" using PVC and shower curtains to contain the splash from the coolant. This actually worked out far better than it sounds and looks pretty good in the end. It was both inexpensive and quick to make while keeping all the mess totally inside. I'll take some pictures if anyone is interested.

Next on the list is a PVC keyboard/mouse/monitor tray - almost done with this one. After that will be a tool holder for the quick change tools I use most frequently.

Summary
I love this machine and would buy it again. Today was the first chance I've had to really try and run a significant job on it and it came out flawlessly. The job took about 3 hours and ran unattended (40k+ lines of gcode). It was a trial run for my production layout and looks like it will work great - the machine appears to be a huge success. Novakon, for Christmas I'd like an ATC to go with my great machine

Thanks!

-Mike

[JoeBean]

Restricting the mouth of the coolant nozzle will up the pressure and less volume will flow, with the result of more consistency and increased effectiveness. Realized this after some aluminum chips partially blocked the nozzle.

Also, aiming the mouth so it's spraying towards the drain, and not away from it (ie from left to right, and not the more natural right to left), speeds up draining and lessens starvation at the pump.

Still, the pump is a weakpoint. I'm thinking of getting a cheap cdedicated ompressor and hooking up a mist system with venturii vacuum in place of a pump.

[JoeBean]

I just read you fid the drawbar too short. Others had problems with that with the original NM-200. but mine was fine, if not longer than I'd like. How much thread engagement do you have? (length, or turns)

[webgeek]

Hi Joe - I just did the restricted trick as well as pointing to the outlet and it's still not cutting it. The pump is pretty wimpy even at it's best. It works great for 20 minutes or so and then the flow really dies out. I can't tell why it's dying out because there appears to be coolant in the tank still. I've been able to get my production runs down to about 170 minutes each but I need it to be full on strong that whole time or the chips REALLY pile up. I'm thinking of using one of the "dirty water" Harbor Freight pumps - something like this one and then putting it in a nice big bucket. That's how I made the coolant system for my Sieg X2 and it worked very well. As long as I don't pump coolant faster than it can drain, there is no problem with really blasting the bit. BTW: the reason I don't want to run air is the compressor is so danged noisy (even the "quiet" ones get loud) and I run all of this in my garage at night. Thanks!

-Mike

[iGAK]

Mike,

My drawbar was too short until I called Khai and found out I had assembled it wrong.

Actually the spindle drawbar is one of the best features of the Novakon NM-200 Pro Series 2 CNC mill. To assemble the drawbar, first put the thick washer onto the drawbar, then put the drawbar into the center of the spindle. Finally install the special locking nut to the top of the spindle and over the top of the drawbar. The drawbar is now locked to the spindle and can no longer be removed from it without first removing the special nut use to secure the drawbar to the top of the spindle. In other words, you must install the drawbar before you install the special nut to the top of the spindle. This ingenious setup allows you to remove and replace a quick change tool from the NM-200 CNC spindle in under thirty seconds by using the Novakon supplied wrench and ratchet with an eight point 14mm socket. With this setup, a dead blow hamer is not required to remove tooling from the spindle -- Holding the spindle with the lower wrench and using the rachet with the eight point 14mm shocket to turn the drawbar counter clockwise about a half of a turn will pop the tool collet loose from the spindle -- See pictures below.

[webgeek]

Ha ha! You (iGak) posted basically the same thing Khai emailed me this afternoon! I just checked and you are right, I have the drawbar on top of the retaining nut. As I've been using quick-change tooling it hasn't been too much of an issue and I've not had to bang on the drawbar to loosen anything yet but it's still a nice feature and now things engage MUCH better - thanks much for posting that!!

-Mike

P.S. I'll edit my review in a few minutes to remove that complaint as it no longer exists

[JoeBean]

Keep the "lock" nut open by a couple turns as it's not necessary to have it fully closed. That way just backing off the drawbar releases whatever's in the spindle.

[webgeek]

Yup, very slick setup. It wont let me edit my original post anymore so I'll just say that the spindle drawbar complaint is no longer valid - mea culpa!

-Mike

[CROSSHATCH]

Well what did you mill!

[webgeek]

Ha, the big run is this weekend. I'll upload actual pictures after that. I need to properly level out my fixture plate first and secure it down better. It's BADLY out of level as the way I raised the vises is only kinda accurate. I'll replace it in the future once I get the whole machining pipeline flowing properly.

I just finished building my own coolant system using the pump I linked above. Only problem is that with enough flow to keep chips good and away the little strainer starts to block. Since the pump can handle debris up to 3/16" (which is bigger than anything I cut) I've removed the little strainer for this initial set of tests. Think I might just need to make a better strainer or a second drain on the other side in the end. It's clearly still not an ideal solution. The new pump could easily overfill the entire coolant tray if the drain blocks for more than a few minutes. Any suggestions here?

I have attached a screenshot of what I tested with this weekend. That is a partial part of 3 orders. I just sold 30 orders this week so I really need to put the spurs to the machine. One trick I've learned with Visual Mill using drawings from CAD is to create those little washers you see in the image in CAD where you want your fixture tie-downs to be. Then you can use them to drill holes in the blank sheet of material and bolt it down to the jig. It's quite hard to organize and lay things out in Visual Mill but trivial in a good CAD package so I lay all of this out against a helper model that matches my fixture plate.

Additionally, the little "L" shaped thing at the top is used as a home point for all operations. Visual Mill is good at moving everything around to make a box of stock around parts and giving you a home point. I had no end of trouble getting it to use the home point where I wanted it though so I made that little indicator inside of CAD and it becomes a part of the assembly I use in Visual Mill. Then I just tell VM to use the upper left of the geometry as the home point and I'm golden. Since the fixture plate is used (but not exported) as part of the CAD assembly, everything lines up perfectly every single time. Works great. I should probably create a little tutorial on this as it was a lot of painful trial and error to figure it out and I didn't see anyone else explaining it already. Would this be useful to the community?

Thanks!

-Mike

[CROSSHATCH]

Can't wait to see how those come out.

Remember to post Speeds, Feeds and DOCS

[Krenovian]

Additionally, the little "L" shaped thing at the top is used as a home point for all operations. Visual Mill is good at moving everything around to make a box of stock around parts and giving you a home point. I had no end of trouble getting it to use the home point where I wanted it though so I made that little indicator inside of CAD and it becomes a part of the assembly I use in Visual Mill. Then I just tell VM to use the upper left of the geometry as the home point and I'm golden. Since the fixture plate is used (but not exported) as part of the CAD assembly, everything lines up perfectly every single time. Works great. I should probably create a little tutorial on this as it was a lot of painful trial and error to figure it out and I didn't see anyone else explaining it already. Would this be useful to the community?

Thanks!

-Mike

Mike,
I'd love to see a tutorial on this technique if you have the time. Seems like a real time and frustration saver.

Curtis

[kvom]

I've had the same issues with the coolant pump. One thing I needed to do was shorten the feed tube to the minimum needed (this reduces the weight of the coolant in the tube). I've also found that when the flow wimps out, stopping and starting the pump seems to restore the pressure. I was looking at replacing it with an immersion pump in a rubbermaid container as other have done, but couldn't find one here with a 220V motor that I could control with the stock wiring. I didn't want to mess around with any wiring so I've letting it be. In any case I don't let the mill run unattended so I can manage with it the way it is (for now).

I also have the tall column, but use a cast iron tilt table to raise my vise(s).

[Resendiz]

T handle L ratchet locked in the spindle head. How to unlock spindle head so I can release the T handle L ratchet