mhackney's 3D Printers

[mhackney]

I've been working on controlling the hot end and bed temperatures from Mach.
Surprisingly, there are really no out of the box products that do this. I am
using an Arduino that talks to Mach via Modbus - same as Andy's Velleman
interface. However, I built a simple circuit that uses a MOSFET to power the
heater and another to read the thermistor. There is a really nice PID open
source library for the Arduino that the RepRap controllers all use. I'm using it
too. Here's a photo of the prototype:



The MOSFET is the boxy looking thing at the lower left of the breadboard. This
is only a single heater-control circuit but there will be two to control the hot
end and bed. There will also be 2 MOSFETs to control two fans - one for extruder
cooling and one to cool bridges. The Arduino has plenty of horsepower and I/O
capability to do a lot more if needed too. I might have Mach controlled LED
lighting for instance. Or maybe an extruder feeder.

At this point, I am ready to put together the complete circuit and finish the
Mach interface.

cheers,
Michael

[jerbro]

I like the lighting control idea. Yes, please. : )

Jeremy

[mhackney]

That would be pretty neat!

I got the rest of the materials to finish the hot bed today too. So I should be able to get that together now - especially since I have some "free" time

Cheers,
Michael

[Rescue35]

Sorry to hear about the work predicament but I'm glad it is already starting to look better.

I managed to get Mach3 to move mine today. Just need to get the extruder to run and I may be in business.

Couple of questions I couldn't see the answer to in your pictures.

1:Which two diodes are you jumping out on the 3 axis board?

2:How are you grounding the EZstepper to the parallel port ground?

Keep up the good work.

On a side note there where a few pieces of missing hardware in my kit besides just the 2 12" of 1/4-20. I was missing 3 1/4-20 nuts and a 10-32 nyloc nut (which I had on hand) as well as 4 3mm bolts. I am not complaining as $2.50 at the hardware store had me set on everything. I just want people to be aware.

[mhackney]

Rescue35,

1) the diodes are the 2 small components at the position in this photo. Simply bridge the pads with solder or use a short wire jumper.



2) I actually removed the ground to the parallel port and simply use the 2 grounds (the middle two pins) on the four pin connector to the EasyDriver. Stick with that.

As for some of the missing parts - did you get four 1/4-20 Nylon lock nuts? These are used on the Z axis screws to retain the gear at the bottom rather than using four 4-20 nuts on each side. That freed up the 1/4-20 nuts I needed.

cheers,
Michael

[Rescue35]

Thanks,

I received enough nylock 1/4-20 nuts.

I got the diodes taken care of and I already had the ground pins like that. Still no joy. The test gcode I was running didn't have an "A" axis so I fixed that, nothing. Jogging "A" via hotkey, nothing. Both lights for the "A" axis are always on, on the 3 axis board...never even a flicker. I used the same settings in Mach3 as you did for all axis.

I rechecked all my connections to and from the ezstepper board. Nothing ever changes and I'm at a loose.

[cornbinder23]

Thanks,

I received enough nylock 1/4-20 nuts.

I got the diodes taken care of and I already had the ground pins like that. Still no joy. The test gcode I was running didn't have an "A" axis so I fixed that, nothing. Jogging "A" via hotkey, nothing. Both lights for the "A" axis are always on, on the 3 axis board...never even a flicker. I used the same settings in Mach3 as you did for all axis.

I rechecked all my connections to and from the ezstepper board. Nothing ever changes and I'm at a loose.

What are your port and pin settings for the A axis motor?
I loaded the seemecnc .xml for mach and had to change the ports for the extruder. IIRC I had to set the step pin to 16 and dir pin to 17, It was set to step pin 9 and dir pin 8.

Hey Michael hows everything going?
I am currently doing some "slight" upgrades to mine when I have a spare second or two, I was not impressed with how much it flexes with rapid movements on the X.
Now, I know that those full speed movements are only happening when the extruder is not printing and just traversing to the next point, but I just cant help myself.
I havent even printed anything yet, just got it together and talking to mach, and now its back in pieces. lol
Going to get it just right before I start learning the printing basics
I see sooo many printer build threads popping up I might just focus on getting mine done and then post some pics and vids, I will keep track of all the mods though.
Keep up your courage Michael!

JTCUSTOMS

[Rescue35]

Thanks cornbinder,

That was the problem. I had to reconfigure a lot of the original SeeMeCNC xml setup.

Now that I have that done I'll try printing something tomorrow.

[mhackney]

Rescue35, I was going to tell you the same thing! I discovered that about the Mach profile too. It will be updated and documented in the electronics manual I'm writing now.

JTCustoms, things are going well. I did determine that my 3 axis board has a problem though on pins 16 and 17. I may have done something jumpering the optos or diodes, I can't see anything odd but who knows. I used a single axis driver to replace the EasyDriver that has lots of umph. The stepper now holds great when energized but was still missing steps. Then I noticed that it did that even without filament. And it would go one way then the other when stepping a jog key.

Cheers,
Michael

[Doubleoh9]

I posted awhile back right after I built the H-1. Now I've made a few improvements so i thought I would put some pictures up. Mods include:

Frame extended to allow a heat bed.
Heat bed with Vellman control.
Linear bearings on all axis.
Ball bearings on belt pulleys.
PVC pipe filament holder.
Aluminum table.

With the linear bearings, the axis move with near zero resistance and now belt tension can be higher to reduce backlash.

Jim

[mhackney]

Great mods Jim. Can you use the stock linear rods with the linear bearings? Did this also increase your Y travel?

cheers,
Michael

[Fastest1]

I had seen Chris Muncy extend his also to accommodate the heated bed. Just as I got my frame put together, I saw that. So down to HD for some all thread. Nice job.

[cornbinder23]

I posted awhile back right after I built the H-1. Now I've made a few improvements so i thought I would put some pictures up. Mods include:

Frame extended to allow a heat bed.
Heat bed with Vellman control.
Linear bearings on all axis.
Ball bearings on belt pulleys.
PVC pipe filament holder.
Aluminum table.

With the linear bearings, the axis move with near zero resistance and now belt tension can be higher to reduce backlash.

Jim

Nice mods, I like the new mounts on the x axis, it gives good access to the hot end , I will be making new mounts for the linear bushings that showed up yesterday for my H1
On the Velleman controller did you just jumper out R6 to run the heat bed?
And are you running the everything off on power supply?

JTCUSTOMS

[cornbinder23]

Great mods Jim. Can you use the stock linear rods with the linear bearings? Did this also increase your Y travel?

cheers,
Michael

They appear to be 8mm rods, which is what I am upgrading mine to
It doesn't effect the Y axis on mine. I will be making my new mounts probably out of plastic as I have a mess load of 1" thick UHMW and EPDM
I want to keep it as light as possible.
I also picked up a little box for all the electronics.
I am not sure how many amps the heated bed will pull, might need a little more power supply.

JTCUSTOMS

[Doubleoh9]

Thanks guys.

The linear bearings I bought are for 8mm rods, so the stock rods don't work. However, the larger 8mm rods fit in the stock 90 degree clamps if you loosen them up completely. I was going to make new clamps, but these work. I turned down the ends so they would fit in the lower plates that hold the Z axis lead screws.

For the Velleman, I jumpered R6 and put a 4.7k in R5. R5 was trial and error to get the board to stay on til it reached full temp. I'm using the stock thermistor that comes with the kit. For ABS you can just turn the thing on without a thermostat because it only gets up to about 110c. I wanted the thermostat for lower temps. With R6 jumped, I can get the bed perfect for PLA.

I bought a new 550 watt power supply that has 2 separate 12 volt circuits. I suspect you could run everything off the stock supply, but I haven't measured total current. My stock supply died after a few days and long before I got the bed.

Jim

[Doubleoh9]

Forgot to mention that travel remains stock...with slightly less in the Z because of the bed height. My z travel is now 5.125"

[mhackney]

Thanks for the info. I'm looking at linear bearings to use in my next printer. Planning a home brew in aluminum a similar to a CNC router with a moving gantry.

Cheers,
Michael

[Rescue35]

Well over the weekend I managed to get mine sort of functioning. I noticed that ReplicatorG wasn't producing Gcode for the A axis that Mach was looking for to run the extruder. Slic3r did no problem.

I think it is jumping on the X axis belt as the head slowly creeps toward the left.

The worst of it is that other than a little blob I couldn't get anything out of the extruder. It is getting hot, 240 degrees at one point via mechanical thermometer. The thermistor had popped out of its hole again. After letting it cool I removed the nozzle and it was full of a clear plastic when I was running black. Then it hit me, that must have been my teflon tube at one point. I will have to pull the entire hot end off to find out for sure whats going on.

[mhackney]

That's correct Rescue35 - ReplicatorG the standard version does not support Mach gcode. The guys at SeeMeCNC have a special version of ReplicatorG. But SeeMeCNC is now supporting Slic3r and that is what I am documenting in the manuals. It suppers Mach natively now.

Jumping is typically caused by the belt rubbing on the idler rollers because they are tightened up too much and can't spin. Check all of the X idlers.

It sounds like you overheated and melted the teflon tube. You have to be careful with the thermister - it needs to be siliconed in place so it can't short or pull out and cause an overheat.

cheers,
Michael

[rpovey]

I managed to print two test cubes before irreversibly blocked my teflon tube. I've ordered more.
In retrospect I think the extruder was slipping on my prints, and I wasn't getting a consistent amount of plastic, I'll calibrate it with the hot end in place next time to verify it's not slipping.

You have to be careful not to get it too hot, I'm pretty sure this was my issue as the heat soaks into the body of the hot end, the plastic in the teflon tube gets soft and the extruder creates a nice perfectly fitting plug inside the tube.
I think the answer is to run as cool as you can obviously still managing to extrude and have it stick.