Latest Core XY build photos

[Jetguy]

https://www.flickr.com/photos/90025904@N04/sets/72157649795398404/

[hugues]

Beautiful !

[fredini]

I am very excited to try this out! :)

On Thursday, April 23, 2015 at 12:32:13 AM UTC-4, Jetguy wrote:

https://www.flickr.com/photos/90025904@N04/sets/72157649795398404/

[New3dGuy]

Have to say it looks nice, love custom built items.

looks pretty rigid and secure as well. prints are pretty clean as well

[Jetguy]

Thanks for the kind comments. This one has taken a little while to work out, simply because I'm trying my best to only use off the shelf parts with minor mods so that this design can be more easily copied and built by more folks.

[adam paul]

Where did you get the dc/dc ssr. I have ordered 3 from Amazon, all three fault on. They were not fotek, which I have used for dc/ac.


That's a great looking build.

[Jetguy]

Sorry if that wasn't clear, this is an AC 120V 600 watt heated bed. This thing heats "instantly" !

I do and have used DC to DC SSRs? I'm wondering if you have a problem with just how it's wired? Also, I did make a mistake myself and almost ordered a resistance controlled one (nice for some applications, just not this one).

Just saying, I doubt they are bad, it's either wiring or some other aspect of the system (or just the wrong SSR). I know that's not the answer you want to hear.

On Thursday, April 23, 2015 at 8:04:27 AM UTC-4, adam paul wrote:

[Jetguy]

Also, just a note or two on the Z axis.

This is following the 3 leadscrew design using Zen Toolworks TR8x8 upgrade parts for their 12inch mini mills. They go for about $45 each and come with nice Delrin anti-backlash nuts. I don't use the anti- baklash part because the shear weight of the bed on this + the drag of three leadscrews is a bit overkill.

So all three leadscrews are driven by a single motor and belt. I use 36T pulleys at the rods and an 18t at the motor for a 2:1 ratio giving the motor the torque to lift that heavy bed. TO compensate, I set the stepper driver for the Z axis so that it's in 1/8th stepping mode, not 1/16th like the others basically reversing the 2:1 ratio. This allows this printer to use 400 steps per mm on Z axis just like every other normal MakerBot and Makerbot clone.

Since I know Fred has a few original Replicator-Dual printers, he can literally take an SD card file for any of his Replicators and it will print on this machine. Now granted- due to quirks with Makerware's starting gcode, those prints won't center in the build area, but because this printer is bigger than the Replicator series- it will fit and will be printed on the build plate. Rep-G and S3D prints will center because their start.gcode uses the homing offsets and thus the print is auto centered.

It's little details like that that are going to help out Fred long term. Again, the fact that in a pinch, he can literally take an SD card out of his other Replicator Dual that might be having an issue and he's got a pressing job that must be printed- just slap it into this and it prints it. Obviously, you want to try and use a custom profile sized for the machine, but on the technical level and the way the extruder and everything works- from a software perspective- this is just another Replicator clone that happens to have huge build dimensions.

[Jay Raxter]

Jetguy,

A few questions...

Where are you getting the 20/20 from? Isn't there a guy on the web who's DRASTICALLY cheaper than most? 

Maybe I missed this..but are you using an aftermarket mightyboard replacement? (you said Fred could just use his R1dual files)

I also see YOU are using Gino pads too...Jeez...was I the only one who missed seeing these? Scott just told me about them...

Thanks

Jay

[Jetguy]

This printer is a mix. I ordered from Amazon a bunch of whatever brand of 20mm extrusions in 8 foot sticks. This is where I kill Prime shipping. I'm the reason it went up because I order big stupid stuff that must cost them an arm and leg to ship- let alone ship 2 day express.

In the past, I had ordered a bunch of precut 610mm length ones from Adafruit. Even if I paid a little more, I like supporting them. One of the few companies that has ridden the maker movement well and stayed true to the maker community with open source and still reasonable pricing and service from NYC. For that, they deserve my money.

So here lies the rub. The 8 foot sections from Amazon- yep, some non-standard stuff that insert nuts barely drop into and will not fully rotate 90 to lock. So they still work, but it's just not as easy to rapid prototype because you have to remember to insert nuts prior to bolting everything together and plan ahead. I actually found that the non-insert flat nuts work better- but again, a pain because you MUST plan ahead.

Of course the Adafruit stuff is top quality and everything works as expected.

Now I could go to other folks, I could even get Misumi-precut to length. It's just what I used and why I did so.

[TobyCWood]

OMG... So nice! How much???!!! Hey.... why not quit that job of yours... lets startup a company!!

You can be the next ... Bre Pettis! Ouch... sorry...

On Wednesday, April 22, 2015 at 9:32:13 PM UTC-7, Jetguy wrote:

https://www.flickr.com/photos/90025904@N04/sets/72157649795398404/

[TobyCWood]

The extruder assembly... hey... was that an Aliexpress buy???  I'm seeing "Mk7"s and "Mk8"s that look exactly like this assembly for around $40 on Aliexpress these days. I was wondering about them. The steel tubes looked a bit long in the photos.

[Jetguy]

A little more- $49 on Amazon Prime, but yes, same thing as you are likely looking at. http://www.amazon.com/gp/product/B00SLL9OO8/ref=gno_cart_title_0?ie=UTF8&psc=1&smid=A7Y75ROU9VMVI

Here's the problems with that as is.

#1 junky PTFE lined thermal barrier not even machined for a heat break

#2 Thermistor is glued into the heater block

#3 Motor is a little higher current than I care for to reach max torque. They are rated at 1.68A VS the typical MakerBot style motor at 0.84 A.

#4 heatsink has a minor cutout at the bottom edge that limits conduction making the stock heatsink worthless IMO. But hey, they are using a PTFE lined hot end- so cooling was a joke anyway.

Reality is, I would spend just as much money to get a David's 3 in 1, then still need to buy a drive gear, and then still get a bunch of hotend stuff from QU-BD just to make what I have now.

I really do like these and the main frame is threaded M6 and is a great heatsink in and of itself. So attach a good MakerBot or equivalent thermal barrier tube, reuse the heater block after removing the thermistor, add the magic brass nut and use a QU-BD heatsink from the pile and it becomes an exceptional extruder.

That's my frustration. I have to buy parts from all over the planet- throw half away, mix and match as required and then and only then do I get what I after in the first place.

I wish somebody would get the hint and just copy one of my extruders as completed and mass produce them. 

[New3dGuy]

JetGuy, have you ever looked at 80/20 They make extruded Aluminum in both Fractional and Metric sizes, sell all kinds of hardware as well as share plans and ideas of things to build with parts list (BOM) and all.  Also do tubing as well.

a couple of people in my design class used there products to do their final project. Also provide their products for design by having 3d content to download for design means.

[Jetguy]

I use 80/20 on my larger printers so I spread the "wealth" of my major hardware purchases.

[Andrew (Libre3D)]

Very impressive. I see the 3dhacker test model is nicely done. Jaw dropping tech here!

[Dan Newman]

On 23/04/2015 10:46 AM, New3dGuy wrote:
> JetGuy, have you ever looked at 80/20 <http://www.8020.net/> They make

The couple of times I looked at using 80/20's products, I found them on
the expensive side. (More expensive then, say, Misumi.) Particularly
their brackets, plates, and t-nuts. I think their extrusions were
maybe a little more cost-competitive; it was the other components which
weren't.

Dan

[New3dGuy]

I heard 80/20 was high, they sell through distributors, like Grainger & McMaster Carr

Also seen tslots.com &  MiniTec Framing Systems, LLC

I like that you SPREAD the wealth, nothing wrong with that.  have you found anyone to have better quality and fitment vs another ??

[Jetguy]

80/20 stuff is nice in the 1.5 inch size I use on larger printers. Faztek is a very acceptable brand compatible with 80/20 1.5 inch sold on Amazon and often way cheaper.

Whatever brand Adafruit is selling of 20mm extrusions is great stuff, I really like the profiles and have used all the brackets and plates. Also, I love the drop in T-nuts and screw packs.

Conversely, whatever brand this last batch of 20mm extrusions I got from Amazon is horrible, the slot is too narrow. 

But it's all decent quality, most are not that different and you can more or less swap parts and brackets between brands. What I find is that one brand may have a unique bracket or attachment and so you buy that from them and use cheaper parts from other suppliers. But like I said, you kind of have to roll the dice and test because it's not a guaranteed compatible item between any 2 brands.

The big thing is factoring in shipping and time from ordering to door. For me, I have limited free time. I need the parts on time to maximize the time i do have when building something. Also, always order more than you need. And sure, there are days that McMaster and Grainer have stuff I need, but usually I find it elswhere, cheaper and faster.

[Ryan Carlyle]

I really, really like the XY and Z motion stages. Very nice use of standard brackets and simple plate stock. Looks clean and parts procurement shouldn't be hard at all. You could probably kludge together all the special structural pieces with a cordless drill and a hacksaw/dremel if you had to. 

Nice looking print cooling fan too. 

[Jetguy]

Thanks, that means a lot coming from a fellow builder.

And yes, that fan BFB0312HA (12V version) from Digikey is the same one SeeMe CNC sells. It is a double ball bearing blower 1.46 cfm which is perfect.

I just had 3 more come today and I'm switching every printer I own to this setup. It's very lightwieght but perfect airflow.

[Ryan Carlyle]

What rails are those? HIWIN clones?

[Jetguy]

3 x MR12 MGN12 Miniature Linear Rail Slide 400mm + MGN12H Block for 3D Printer

http://www.amazon.com/gp/product/B00QQLZATS/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1VPX6Z58UA6YU

Note that the "H" series block bearing is the longer version and you really want those. You can find cheaper on Ebay and other places.

[Ryan Carlyle]

Yeah, HIWIN clones. Typical Delta build parts. Hadn't occurred to me to get a three-pack for a CoreXY though, that's smart.

How's the rigidity of the X-bridge? I'm guessing most of the strength comes from the rail itself and the aluminum plate is for interfacing?

[Jetguy]

Aluminum plate provides rigidity in the X axis direction- thus eliminating the common ringing we see in long dual rod axis.

[New3dGuy]

The more readily available the parts, and OFF the SHELF items the more feasible it is to build...

I agree with Jetguy, waiting for parts to arrive, or wondering when sucks !!

I am an Amazon Prime user, sure they eat tons of shipping cost on me as well...  but I get my Money out of it NO QUESTION...

I was really impressed with the offerings from MiniTec Framing Systems, LLC BUT no pricing, have to ASK for a quote on what you want, but they will CUT and machine anything they sell per your specs 

[Petr Ptacek]

Hmm, how long are these bearing blocks compare to regular bearing blocks? It is neat to use just one instead of two. It looks so simple ...

Also, how thick is that alu plate? Does it provide any support for rail what so ever or it is there just for X axis rigidity?

[Jetguy]

As with any "I" beam, or in this case "T" beam, there is some rigidity added just by shear nature of the shape. This particular "shape" is optimized in the lateral direction VS vertical direction.

Compare MGN 12 C VS H  http://hiwin.com/html/extras/mgn-c_mgn-h.html

[Jay Raxter]

Jetguy

So those are about 15-3/4" long (400mm)? 

After mounting that would yield what? 14" of travel?

Are they rigid enough to only need one per axis? Would they support multi-head or removable head devices (laser, extruder, light mill head)?

Thanks

Jay

[Jetguy]

You get about 13 inches (330mm) of travel on 400mm rails. That's always going to be true. Your carriage has length so you have to subtract that from the 400mm. No matter what you do, everything ends up taking more space than you plan.

Are they rigid enough to only need one per axis?

I would say only if using a single MK8 direct drive. You might jump up to 15mm rails for heavier heads. 

No way would I even consider milling on anything this light. This is literally the tradeoff between speed and light weight VS massive slow and heavy for milling.

All of my laser cutters minimally use 15mm rails and that's just swinging a super lightweight laser lens, mirror- but they also are much larger spans so again it all comes down to the right size for the job.

You may not agree with me, I'm not fans of all in one machines. Safety is a huge factor and all this laser stuff is going to give you guys Cataracts. Seriously, you guys are bathing your eyes in UV laser light with no protection or reflections. This is illegal- although I'm amazed how weak the enforcement has been of late. When I got into lasers, you are required to file with the FDA just to purchase them- let alone put them into a machine. FDA controls radiation and since laser are high powered radiation in light spectrum, hence controlled. How the hell they are being imported and the FDA is sleeping on it is beyond me.

Then we get into milling dust and that's just obscene in something you later want to print in or worse- laser optics.

[Ryan Carlyle]

Yep, the people making the multi-bots don't seem to have even the slightest idea about laser safety. They're just unbelievably, insanely dangerous for stray reflections hitting your eyes.

[John Gelnaw]

On Friday, April 24, 2015 at 11:44:50 AM UTC-4, Ryan Carlyle wrote:

Yep, the people making the multi-bots don't seem to have even the slightest idea about laser safety. They're just unbelievably, insanely dangerous for stray reflections hitting your eyes.

Remember:

[Jetguy]

All I could think of is it must make this sound when working https://www.youtube.com/watch?v=IQ-HeEhE5nY

[New3dGuy]

Nice I like that sign

should also protect Lost Eye as well !!

or is this a cheap alternative to laser eye surgery  ??

[fredini]

Check out my writeup on visiting Jetguy this week to see firsthand "where the magic happens"!

http://thegreatfredini.com/2015/05/02/the-maestro-of-3d-printer-building-jetguy/

[Andrew Mazzotta]

Awesome!

[New3dGuy]

Nice write up and love the pictures...

looks like it is a Printer Surplus !!  So every square inch is occupied by a printer it seems !!  Thought I saw what looks like a kitchen or formerly a kitchen.  Love his dedication, commitment, and support of the 3d Printers !!

[James Armstrong]

Fredini, nice write-up. It was nice meeting and spending some time with you here. I just printed my first 3d scan of my son (thanks for the intro and help). I think we counted near 18 printers in the panorama photo I took (no telling how many are upstairs).

- James

[fredini]

James- 

Great meeting you too! I had a blast and wished I could have stayed longer. Coming home, its like every other 3D printer I ever owned was a toy in comparison! I've been putting the Big Boy through its paces and its amazing! First prints here: 

http://thegreatfredini.com/2015/05/05/first-pri-t-on-jetguys-big-boy-corexy-3d-printer/

Thanks Jetguy!

[Joel Mongeon]

Those prints look fantastic! When can the test of us buy a genuine Jetguy core XY printer ;)

[New3dGuy]

Nice Prints....

thanks for sharing 

[Dan Newman]

On 05/05/2015 4:45 PM, Joel Mongeon wrote:
> Those prints look fantastic! When can the test of us buy a genuine Jetguy core XY printer ;)

Let's use Fredini's pictures, some old Kickstarter copy, and launch a (fraudulent) Kickstarter
campaign!

Dan

[Ryan Carlyle]

I'd suggest we start a legitimate Kickstarter campaign, but ugh, who wants to deal with order fulfillment.

[Fred Kahl]

I'm totally ready to liquidate my replicator stock and start building these things. This printer is amazeballs!

On Tue, May 5, 2015 at 10:20 PM, Ryan Carlyle <temp...@gmail.com> wrote:

I'd suggest we start a legitimate Kickstarter campaign, but ugh, who wants to deal with order fulfillment.

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http://theGreatFredini.com

http://Scanarama3D.com

[DonaldJ]

Order fulfillment might not be too bad if it's sold ONLY as a kit, with a fixed, limited quantity (10? 50? 100?).  And NO followup support. You get the parts, a BOM, instructions, and perhaps an amusing assembly video.  That's it.  Very exclusive, very chic.  Not cheap.

For an extra $50 you get a dandy personalized "Jetguy Labs" label...

[Petr Ptacek]

ROFL. So spot on!

[Jetguy]

I'm glad this drummed up so much interest. Honestly, this is nothing "that special". Between myself, Dan, Ryan, and a few others who have massively contributes design ideas, we all are working on the same basic elements. 

Dan's latest here is not far off from this http://www.thingiverse.com/thing:612857

It's just a matter of building around what parts you can source.

My design is focused around Adafruit parts just because it's easy and I happen to have huge respect for the company.

Dan's is a Misumi based build and is just as good.

On Wednesday, May 6, 2015 at 8:46:36 AM UTC-4, DonaldJ wrote:

[Jetguy]

Also, we can give "factory tours" at an additional cost. 

[James Armstrong]

But you have to go through the "clean room" blower facility to get all the dirt and contaminants off first before taking the tour. Right now all Jetguy has rigged up is a garage entrance with a blower producing gale force winds generated by a jet turbine. Ear protection is optional. 

[Dan Newman]

On 06/05/2015 6:39 AM, Jetguy wrote:
> Also, we can give "factory tours" at an additional cost.

Does that include a ride around the warehouse in a powered golf cart?

Dan

[Andrew Mazzotta]

I found a golden ticket in my PLA roll. Jetguy wanka factory tours it says :-)

[JB]

I found a golden ticket in my PLA roll. Jetguy wanka factory tours it says :-)

 with a FREE blow on the way in?

[Dan Newman]

On 06/05/2015 7:29 AM, Andrew Mazzotta wrote:
> I found a golden ticket in my PLA roll. Jetguy wanka factory tours it says

And he found some oompa loompa's in the streets of brooklyn. They even
had some MBI severence pay ;)

Dan

[Brandon Andrzejewski]

I'm having a fun time imagining using Skype as a kit build aid, with half the 3DPTTR group in a Skype call building up "Big-Boy" kits.  First finished cal cube wins the Wonka tour!  =P

[JasonB]

Do you think it would easily scale up to 500mm rails, or even 600mm?  Perhaps 20x40 all around and some U-channel aluminum rather than a flat plate would be useful for the x beam.  I want to fit three extruders on it, not necessarily increase the bed size.  But I wouldn't want to lose any print area either. 

[Jetguy]

500-600mm as is is pushing the "sag" factor. Add 2-3 extruders and a totally different setup is required.

Sorry, being honest- that's just how it works. I have a design for that but it switches to much heavier components. Cost isn't that much higher, but then it's heavier and less portable.

It will be based in this old frame but all new CORE XY system to replace the older Ultimaker crossing http://www.thingiverse.com/thing:177934

[Jetguy]

Basically, the gantry switches to the same thing used on the giant core XY , a camera slider http://www.amazon.com/StudioFX-Bearing-Camera-Slider-Stabilizer/dp/B00BOGOT4M/ref=sr_1_1?s=photo&ie=UTF8&qid=1430940086&sr=1-1&keywords=camera+slider

[Jetguy]

OK, guys, so here's one for you.

The clone of the one I just built for Fredini has a bed heater pad from QU-BD that I got a long time ago. Fred's machine has a 600 Watt 120V bed and uses an SSR. I also smartly put a thermal fuse in line and mounted directly on the heater pad with Kapton tape in case there should ever be a thermal runaway event, fuse blows long before the bed ever even reaches 150C. This is because again, the heat pad is sandwiched via a cork pad and wooden base pressing the "sandwich" up against aluminum heat spreader. The thermistor is sandwiched on the top side sensing the heat pad, but also the aluminum plate directly. 

This printer is identical construction, the difference is that the heater pad in this printer is DC and is measured at 2.6 Ohm and rated for 24V roughly around 200 Watts. I also use a DC to DC SSR on this printer to handle the load. The PSU is a genuine Meanwell 24V 350 Watt rated unit. These are generally a little better built and this one looks spot on from the inside. However, the instant I kicked in the heated bed, I heard a dull thud. Nothing bad happened, the PSU was still putting out power, the bed was heating- although I stopped. What immediately concerned me was I touched the PSU on the DC output rectifier side which was rapidly heating up even though now the bed was totally off (per looking at the SSR).

2 theories. Either the diode array has failed and is dumping heat inside the PSU

or

The SSR is shorted and even though I think it's off, it's heating the bed.

[Jetguy]

OK, so SSR seems failed ON. Not surprising, it's a MOSFET and that's how they fail.

Hooked up an Ammeter in series with the bed and PSU- pegged it on the 20A rating.

So, while a fail- I'm blown away at the Meanwell PSU which I had mistakenly assumed failed. Not sure what was failed in the heater pad because the external wiring is all open and obvious.

Measured bed now and it's 1.0 Ohms?? It was 2.6?????? I have no idea what is happening. It's an all sealed silicone unit with attached cord. No soldering or anything. 

I can say this- PSU rated for 14.5 A just took probably 25A and NEVER kicked out. It was getting hot- but NOT failing.

25A rated 60V DC to DC SSR is obviously toast and is shorted. The output terminals read 0.6 Ohms according to the meter.

SEE KIDS- this is why we say put extra safety in your circuit. DO NOT TRUST ANY SSR. It's fine to use them, just know that if it fails= heater stuck on. There must be a secondary thermal safety.

Again, bed failed, changed resistance or something.

SSR rated fine for the current should have even handled the overload since it's 25A . 1 ohm plus the wiring and connectors and even the failed SSR is 1.5 ohms. The meter told a different story and while rated for 20A, obviously the circuit is slamming over 20A. Again, amazed the PSU took it like a champ!!! Go Meanwell!!!!

[Jetguy]

Ok, so switched to 12V 30A rated Meanwell assuming this was meant to be a 12V bed.

Current draw is 14A

SSR, even blown, it smoking hot. Bed is heating so the heater is working and the bed is heating

OK, bypassed SSR and now circuit is just 12V PSU, Meter, and HBP. Current is an astounding 16A!!!!!

Hmm, short of a relay or custom FET, not sure how anyone used these QU-BD parts. Bed is running 16A@12V or 192 Watts

The 24V fiasco has to be pushing almost 4X more. No I didn't measure it wrong, this seriously changed resistance the first time used. I measured it 3 times before connecting and building this thing.

[Jetguy]

OK, so for S's and G's i opened up the SSR.

Output device is an NEC C2751 http://html.alldatasheet.net/html-pdf/438982/ISC/2SC2751/54/1/2SC2751.html

It's rated at 15A and a peak of 30A. The fact it's an NPN and not a MOSFET as i had predicted is interesting (maybe only to me).

It is blown and is currently conducting 0.6 Ohms.

So, word to the wise, This Fotek (I'm no calling these FU-tek because they must think this is OK) is NOT rated for 25A on the face.

SSR-25 DD

However, searching the web, I cannot find any reference to this SSR on any Fotek site. They only make DC SSR of 5 and 10 Amp rating????

Just saying, double failure today.

SSR is junk at best and potentially counterfeit and even if not, the rating is not to be trusted given the "find out what's inside test".

[adam paul]

I have seen a story or two on the fauxtek ssr's on the internets. Can you go a further in detail on the thermal fuse arrangement, are there pics on your flicker?

[Ryan Carlyle]

Jetguy, you should check the bed heater for hot spots or ridiculously uneven heating, it may have internally shorted when you powered it up. 

Wouldn't be the first time QU-BD sent 12v parts instead of 24v, but resistance shouldn't change unless something broke...

[Jetguy]

That would be the "right" thing to do.

So far, all I can figure is it really was a 12V bed and my other 12inch bed really is the 24V bed. How and why it read higher resistance before being actually used is a mystery but I'm seeing even heating.

The bigger problem at hand today is building a suitable control circuit for this bed (since I have it, it might as well get used) and given it loads to an astounding 16A on a 12V source, some careful thought needs to go into the switch (MOSFET) that controls this.

So i dug into the parts drawer and here's what I got:

IRFZ44 - 35A continuous

FQP50N06L - 35A continuous

From mightyboards- removed AQV252G SSR (trick little opto-isolator and FET module rated at 2.5A max)

So the opto-isolator is ideal to invert the low side switched output of our mightyboards. Simply use the correct value resistor in series and all you are doing is lighting an LED inside the opto.

The output then drives the gate of the larger main current FET and you now have an opto isolated switch capable of some serious current without blowing sky high.

[Jetguy]

So today, in the "Ugly but works" category (Quick note for those really looking, the red wire is actually ground return to the PSU, not +12V. The black wire is the return from the HBP and the other side of the HBP is directly to the PSU)

parts count from "the pile":

FQP50N06 FET

~3K resistor pulldown across the gate. (just picked a random resistor lying around)

-Hidden in the heatshrink is a 100 Ohm resistor feeding the gate

AQV252G- Opto-isolated mini SSR. (removed from a mightyboard bypassed safety circuit)

Pin 1 is 12V from the mightyboard

Pin 2 is switched HBP ground output from mightyboard through 1.7K resistor to limit current through the LED inside

Pin 3 NC

Pin 6 is connected to pin 1 thus 12V from the mightyboard

Pin 5 is the output of 12V driving the gate on the FET.

She get's warm, borderline hot but is cranking about 16A across it. Heck all the #16 wiring between it and the PSU is getting warm, so for it to get midly hot means even junkbox parts can work.

[Jetguy]

Best part is, the mightyboard is seeing all of a 12/1700 + whatever drop across the LED or maybe all of a 5-7 mA load on the HBP connector.

That VS the brutal 16A actual load that would burn the connectors on the mightyboard in a second (8A rating on a good day).

I know, too geeky for some of you. But it's been a while since my engineering degree that I had to play the numbers game, but not just that, you take what you have in the parts bin- grab all the data sheets, ask yourself what might work, crunch some more numbers and then test it with fingers crossed.

Sure, guys who can sit at work and order from the latest parts listing have it easy. Just order whatever you engineer. To work backwards from "this is what I got" (good, bad, or crappy) and work forward- that's when life gets fun.

The thing is, high power on 12V is best avoided. High power = high current. Current is unforgiving. It WILL find the weak point in the chain. It will smoke a connector, an IC, and even a wire if you aren't 100% up on your game. I dare say low voltage high power is more dangerous than medium voltage (120V wall power). Sure, wall power can shock you if you get careless but it's a tad easier to control and currents are nothing to speak of. This high current stuff is a pain in the rear.

[Ryan Carlyle]

Any chance a mechanical relay would work for this? (I can't remember if it's a PWM controller or just bang-bang.)

[Jetguy]

At this current, a relay might weld the contacts and thus be constant on. James has this problem with his high current bed and an auto relay. It's stuck on him before.

The FET is taking it no problem.  Longer term plan is to chuck this 12V version out the window and go to a real 120V and SSR version.

Considering the long prints and so forth, abusing PSU, wiring, connectors, and a control device just doesn't seem reliable.

The worry, concern, and headache aren't worth trying to maintain something that want to blow itself up constantly.

While 16A may not sound astronomical, even the wiring gets warm here. One loose terminal and bam- it gets away from you quickly.

[Petr Ptacek]

Depends on relay. Good Allen Bradley power relay can handle it just fine, they are usually rated for 10E8 operations, 4 ops/sec. They are not cheap though.

[Dan Newman]

On 08/05/2015 3:41 PM, Jetguy wrote:
> At this current, a relay might weld the contacts and thus be constant on.

+1

That's my concern as weel. You can get high current relays and put in a
snubber circuit as well, but I suspect the relay alone will cost more than
a good SSR. (A RC snubber circuit is probably less than a dollar; a diode
snubber maybe a couple of dollars?)

Dan

[Kurt @ VR-FX]

Great fuckin pic JetGuy - us being right next to the train track! Gotta love the noise!!!

Sent from my iPhone

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[Kurt @ VR-FX]

Glad u relayed that same story here after our chat the other night! Just crazy Electrical Shit!!! 

Sent from my iPhone

[Ryan Carlyle]

Hmm, yeah, 16A doesn't seem like much, but it's a lot for DC. (AC arcs extinguish at zero-crossings.)

Really ought to go for an SCR/thyristor type system for this stuff when you get into high power AC. I wonder if there's any way to get a Mightyboard to control an SCR instead of PWM'ing a relay?

[Joseph Chiu]

> (AC arcs extinguish at zero-crossings.)

Aren't contact bounces over a much shorter period?  It would be effectively DC during the time interval in question, I would think.

--

[Ryan Carlyle]

On Saturday, May 9, 2015 at 8:46:54 PM UTC-5, Joseph Chiu wrote:

> (AC arcs extinguish at zero-crossings.)

Aren't contact bounces over a much shorter period?  It would be effectively DC during the time interval in question, I would think.

It's more about the maximum length of time an arc can be sustained after breaking contact. Look at something like a household circuit breaker -- they regularly trip on ~20A of inductive load without any lasting damage. Part of that is rapidly pulling the contacts apart and having serious heat dissipation to resist arc damage, but it also helps that 60Hz AC will typically only arc up to 16ms or so. DC can sustain arcs for a pretty long time if the contacts are close together. 

[Kurt @ VR-FX]

Well - not so fast - as I know its a lot of work for JetGuy - as I was
speaking to him on the phone about it.

But - like other mentioned - a KS Proj might be pretty cool...

-K-


On 5/5/2015 7:45 PM, Joel Mongeon wrote:
> Those prints look fantastic! When can the test of us buy a genuine Jetguy core XY printer ;)
>

[Kurt @ VR-FX]

Jeez JetGuy - some VERY Interesting info below - and based upon that - I have no idea how some of these guys are making the machines that do IT ALL - like I saw at the 3DP show - the video to upload shortly - of a system that swaps in Extruders Heads vs. Milling Head vs. Laser Head vs. - Kid you not - a Frosting print head or even a Pasta print head!

-K-

On 4/24/2015 11:09 AM, Jetguy wrote:

You get about 13 inches (330mm) of travel on 400mm rails. That's always going to be true. Your carriage has length so you have to subtract that from the 400mm. No matter what you do, everything ends up taking more space than you plan.

Are they rigid enough to only need one per axis?

I would say only if using a single MK8 direct drive. You might jump up to 15mm rails for heavier heads. 

No way would I even consider milling on anything this light. This is literally the tradeoff between speed and light weight VS massive slow and heavy for milling.

All of my laser cutters minimally use 15mm rails and that's just swinging a super lightweight laser lens, mirror- but they also are much larger spans so again it all comes down to the right size for the job.

You may not agree with me, I'm not fans of all in one machines. Safety is a huge factor and all this laser stuff is going to give you guys Cataracts. Seriously, you guys are bathing your eyes in UV laser light with no protection or reflections. This is illegal- although I'm amazed how weak the enforcement has been of late. When I got into lasers, you are required to file with the FDA just to purchase them- let alone put them into a machine. FDA controls radiation and since laser are high powered radiation in light spectrum, hence controlled. How the hell they are being imported and the FDA is sleeping on it is beyond me.

Then we get into milling dust and that's just obscene in something you later want to print in or worse- laser optics.

On Friday, April 24, 2015 at 10:48:07 AM UTC-4, Jay Raxter wrote:

Jetguy

So those are about 15-3/4" long (400mm)? 

After mounting that would yield what? 14" of travel?

Are they rigid enough to only need one per axis? Would they support multi-head or removable head devices (laser, extruder, light mill head)?

Thanks

Jay

On Thursday, April 23, 2015 at 7:52:20 PM UTC-4, Jetguy wrote:

3 x MR12 MGN12 Miniature Linear Rail Slide 400mm + MGN12H Block for 3D Printer

http://www.amazon.com/gp/product/B00QQLZATS/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1VPX6Z58UA6YU

Note that the "H" series block bearing is the longer version and you really want those. You can find cheaper on Ebay and other places.

On Thursday, April 23, 2015 at 7:48:48 PM UTC-4, Ryan Carlyle wrote:

What rails are those? HIWIN clones?

On Thursday, April 23, 2015 at 6:37:16 PM UTC-5, Jetguy wrote:

Thanks, that means a lot coming from a fellow builder.

And yes, that fan BFB0312HA (12V version) from Digikey is the same one SeeMe CNC sells. It is a double ball bearing blower 1.46 cfm which is perfect.

I just had 3 more come today and I'm switching every printer I own to this setup. It's very lightwieght but perfect airflow.

On Thursday, April 23, 2015 at 6:07:53 PM UTC-4, Ryan Carlyle wrote:

I really, really like the XY and Z motion stages. Very nice use of standard brackets and simple plate stock. Looks clean and parts procurement shouldn't be hard at all. You could probably kludge together all the special structural pieces with a cordless drill and a hacksaw/dremel if you had to. 

Nice looking print cooling fan too. 

[Kurt @ VR-FX]

OMG Oh Great Fredini - that Fuckin' print is AMAZING!!!! Just seeing the main piece of the woman - the shots of it as it was Printing - F'ing Awesome!!!

-K-

On 5/5/2015 7:24 PM, fredini wrote:

James- 

Great meeting you too! I had a blast and wished I could have stayed longer. Coming home, its like every other 3D printer I ever owned was a toy in comparison! I've been putting the Big Boy through its paces and its amazing! First prints here: 

http://thegreatfredini.com/2015/05/05/first-pri-t-on-jetguys-big-boy-corexy-3d-printer/

Thanks Jetguy!

On Saturday, May 2, 2015 at 10:28:51 PM UTC-4, James Armstrong wrote:

Fredini, nice write-up. It was nice meeting and spending some time with you here. I just printed my first 3d scan of my son (thanks for the intro and help). I think we counted near 18 printers in the panorama photo I took (no telling how many are upstairs).

- James

On Saturday, May 2, 2015 at 9:04:50 PM UTC-4, New3dGuy wrote:

Nice write up and love the pictures...

looks like it is a Printer Surplus !!  So every square inch is occupied by a printer it seems !!  Thought I saw what looks like a kitchen or formerly a kitchen.  Love his dedication, commitment, and support of the 3d Printers !!

[Jetguy]

GRRRR.

So, I thought I'd try out a different FET since Amazon had some nice ones http://www.amazon.com/gp/product/B00AKTLO4M/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Like a moron, I solder the brand new "FET" into the circuit just as the one before because these all have the same pinout and nothing changes.

I think nothing of it, plug it in and instant smoke.

Now, I go back over to figure out what went wrong- I look and I soldered in a  L7912CV voltage regulator- as if it was a FET. 

Ok, so did I grab the wrong part on the bench? Hmm, no I pulled directly from the bag directly from Amazon labeled  IRL7833. It's ALL L7912 3 pin TO220 NEGATIVE voltage regulators that "look" like FETS.

So then I look at the second bag and HMM, 2 pin TO220 devices- clearly diode arrays, not FETs. They don't even look like FETS- they are 2 pin devices.

Tip of the weekend---- check devices actual part numbers before assuming they are what they said they are.

You go punching 12V at 16A backwards through a 3 pin regulator rated for 1A- it's going to give off that bad electronics smell in a fraction of a second. It' would be funny if that's what I trying to do- some good old destructive demonstrations- but I kinda wanted this circuit to work.

[Petr Ptacek]

We have good days and we have bad days. And then we have those special days ...