Hello,

After following the Phlatprinter Development for a while I've decided that you guys are having too much fun and I want to join in! I've added myself to Mark and Trish's waiting list and am anxiously awaiting the Phlatprinter Offerings once the changeover to inhouse MDF fab is complete.

My main use for the machine will be to cut 6mm depron or FFF but I would also like to be able to cut out light ply and balsa. I'm currently considering a MK1 with the Y Axis Belt mod, acme Z axis mod, and rotozip mod *or* a MK2. I was originally leaning towards a mod'ed MK1 but have noticed that several MK1 owners have now upgraded to the MK2 machine.

If anyone has any opinions on MK1.5 vs. MK2 phlatprinters I would love to hear them (pros and cons of each option).

I've already ordered the following to get a head start on the electronics portion of the build:

Easy CNC 4 Axis Driver Board
3x Vexta 266-02A Steppers
24 V 6.5 Amp DC Power Supply
Parallel Port Cable
Shielded 4 Wire Stepper Cable
3x 4 conductor connectors

Mach3 and the Phlatprinter Overlay are installed on my desktop and I watched the Phlatscript Tutorial Videos. All of the electronics should arrive this week and I will connect everything up to verify everything is working OK.

 

I have a MK1.5, but if I were buying a new one I'd definitely go with the MK2. It has all of the really good modifications that we did to the MK1.5's, plus some others that Mark thought of, AND it's going to get even BETTER after M&T have completely moved the machining in-house.

 

MKII, not just for the speed and accuracy, but the ability to cut full sheets of depron at 27 inches wide. I would have the MKII by now if I hadn't gotten laid off.

 

Ditto what Dorsal said. Also, I haven't checked the prices, but the MK1.5 might cost as much as (or close to) the MK II by the time all is said and done and you don't have to worry about figuring out how to do this or that mod.

Tim

 

Dennis, Jeff, Tim, rcav8r & Shaun,

Thank you very much for sharing your thoughts on the MK1.5 vs the MK2. I'm leaning towards the MK2 right now but am a little concerned about the relative size of the unit. It appears to be significantly larger than the MK1. Very capable but large. I guess it could probably be scooted over to the side of the garage when not in use and wouldn't take up too much space.

Regards.

Ben

 

Ben, since I don't own both I can't give you comparative measurements, but during the 3 days at the Toledo "Weak Signals" show I was in the PhlatBoyz booth a lot and it never seemed to be that much larger than my MK1.5. Yes, it looks very impressive, but my machine is sitting atop an old rolling microwave stand and the two setups seemed very similar.

 

Dennis,

That is good info given that you have seen both in close proximity at the show. Thanks.

 

My two cents.... MKII if you can afford the extra cost. In the long haul it will be money well spent.

My MK1.5 belt modded unit has been working faithfully for what, maybe 3 years now? I dunno, time seems to slip away, but it has a significant amount of hours on it none the less. Maintenance has been minimal and while the unit serves my purposes, handling full 27" sheets would really be nice!

The MKII was a result of watching the MKI grow and it has incorporated all of the things we learned from the MKI.

Do yourself a favor and go all the way with an MKII. You just can't go wrong with anything Mark and Trish bring to market. They put their heart and soul into their efforts and it shows.

 

You guys are comparing the old machines. I would think the Mk1, assuming it is still offered, would get some major improvements. Can you sign up for a mk1 on the wait list? I got no more info then you guys, so I am not hinting at anything. :?

-Kwok

 

Kwok, I believe the "new version" of the MK1 is the MK2, and the MK1 will remain as it was when we bought ours.
( At least, that's the way I would prioritize any revisions or upgrades to anything I was producing and selling, especially if one was the 2009 model and the other was from 2010. )

 

Mark and Trish,

Thanks for the update. MKIII!!! This is good because there is no decision about which machine to get now. I'm excited to see what you guys have come up with. Anxiously awaiting news on the new machine.

Somewhat unrelated question for you guys. Can the Phlatprinters damage themselves with an errant travel command or do the steppers just drive into a stop and miss steps? I know heavier servo driven CNC machines have limit switches to prevent the machine from damaging itself if the travel cal gets messed up and they drive into the end of travel at full speed. Just curious if end of travel limit switches are beneficial in this size machine or not.

 

I don't use limit switches, some do. If you are using the vexta steppers you really wont need them, a monster stepper would power a gantry right thru the side.
I have smacked the sides multiple times before the belt mod and it will just stall the stepper motor. The only damage mine ever gotten was a mod I tried that basically tore the Z axis apart.

 

I have limit switches installed, but not for the machine's safety. As Jeff says, using the Vexta steppers will give you more than enough power to drive the machine and cut foam / wood / plastic, but it won't tear itself up if it hits the limits of travel.
The most important limit switches I have installed are the ones for Y-Home and Z-Home (X-Home is meaningless). These 2 switches allow me to command to "Ref All" and the cutter will -first- retract to the switch (down below the material) then slowly come up until it just releases the switch (Home for Z), then it will bring the Y-axis toward home until it trips its limit switch, then slowly back off until that switch is released. Then it sets my DROs (Digital Read Outs) to 0,0,0. When that task is done, my Y and Z axes are within 0.001" or 0.002" of the same place, every time. That's cool!
I also have a switch at maximum Z travel and at maximum Y travel, but I have never tripped them unless I was manually jogging the head to test they still worked. They do, but for all they have been "needed", I shouldn't have bothered installing them at all.

 

Jeff and Dennis,

Thanks for the info. That makes sense. Without the home limit switch implementation for Y & Z is the homing operation done by manually jogging the machine to the desired home position in Y & Z using Mach3? I'm guessing before executing the g-code you would jog the Y and Z axis to the desired home position and then execute the file. Is this correct? With the Ref All command and the YZ home limit switches this is done automatically and repeatability within 0.002" or so if I understand your previous post.

Sorry for all the questions. Interesting stuff for me.

 

Ben, you've got it exactly correct - I just thought manually jogging the axes back to Home was too much bother. If you ever forget to "Home" the head before starting a file, Mach presumes you have, and treats the starting position as if it was 0,0. Nothing disastrous happens, but you will throw away that piece of foam and load another one that hasn't been sliced to useless chunks. (Now, how do I know that?)
Actually my 0.001" - 0.002" estimation is just that. Now that I have a good dial indicator, maybe someday I'll take the time to precisely measure the accuracy of the "Home" command. BTW, my machine can't use the "Home" button for some reason (maybe it's the way my SmoothStepper interacts with the EasyCNC controller, I don't know) so I use "Ref All" and it works perfectly.
ymmv

 

Dennis,

Good to know. Wasted foam can be expensive if its a full sheet of depron.

Ben

 

On my Mk 1.5 (belt on Y) I have home and limits on Y and Z as well, and I have had them trip when the stepper looses steps. When they trip, everything stops including the dremel, thanks to the relay board it's plugged into (I'm using EMC, not Mach, so your mileage may vary). I feel better ducking out of the shop for a second knowing that if things go "pear shaped" things will come to a halt without my direct intervention.

 

ttranband,

Sounds like a good idea in the event something goes awry.

What limit switches are you guys using and what is a good source?

 

rcav8r, it sounds like you have the toggle switch wired so it bypasses the limit switch, if the toggle is closed. Is that correct?
That sounds like a smart idea!

I think these: http://www.mpja.com/prodinfo.asp?number=18085+SW are the ones I bought.

 

I'm using microswitches from one of the CNC suppliers on eBay, maybe CNC-guy. Same sort of things that are in arcade machine buttons, but with screw terminals instead of spade lugs, and they can be wired normally open or normally closed. I have mine set for normally closed so that if a wire should break things will stop (easy adjustment in EMC). The Z limit switches are on the sides of the Z gantry and travel with the dremel. I had some old black nylon wing hold-down sets that never made it into a model, so I used them to allow for fine adjustment. The Y limit switches are on the bottom of the Y gantry and hit the ends of machine screws that are mounted in the cabinet sides - again allowing for fine tuning of the limit position. I lost about 1/2" or so of travel by mounting my drive belt rollers inside the cabinet, so the limit switches ride on the side "under" the idle roller (left end of the gantry) and don't cost me any more lost travel. Having all the switches on the moving gantry allows the connections to run through a single length of "surplus" Cat-5 cable (1 pair per switch, even though I could have them sharing the common lead).

In addition to the safety stops, having the limit switches allows easy automatic homing of the axes with repeatability of position that is more precise than I can measure with my cheapie Harbor Freight dial indicator.

 

rcav8r, dorsal & ttraband,

Thanks for the limit switch info. I'll have to order some soon.