Looking at Pegasus 12

[uncle_bob]

If you buy the nuts and the rod for an Acme setup separately, keep in mind that there is more than one Acme thread out there. Some are far more common than others. Your best bet is to get the nuts and rod from the same guy at the same time.

[tsteever]

Anything special or specific about the collar on the bottom?

Do you have links to the files you printed?

[uncle_bob]

The adapter / coupler that attaches the Acme rod to the stepper ( = collar on the bottom?) is the main problem with this approach. If it does not line up the center of the motor shaft with the center of the threaded rod, you are right back to troubles. That is where getting an integrated stepper / rod really shines (there is no possibility of offset). Depending on where you buy the parts, it may actually be just about as cheap. It gets the couplers out of a very crowded part of the printer andmakes the conversion easier.

[BLKKROW]

The adapter / coupler that attaches the Acme rod to the stepper ( = collar on the bottom?) is the main problem with this approach. If it does not line up the center of the motor shaft with the center of the threaded rod, you are right back to troubles. That is where getting an integrated stepper / rod really shines (there is no possibility of offset). Depending on where you buy the parts, it may actually be just about as cheap. It gets the couplers out of a very crowded part of the printer andmakes the conversion easier.

I contemplated using integrated stepper motors with the 8mm acme thread. However, I couldn't find a company that sold them in the proper length for a decent price. After searching for a few weeks, I thought about the assembly of the integrated stepper/acme thread and realized the mounting for the motor would need to be modified. If you recall you first install the motor bracket getting it straight and in the proper place. You then have to tilt the motor in just the right way to slide it up and into position.

Using a integrated motor/thread system wouldn't work in this manner. To do this, I have two options, the first would be to CNC out one side of the aluminum bracket, so I can slide the motor and threaded rod in easily. The other option would be to print a bracket that can warp over time.

So I decided to go the easy route and use the flexible collars. However, I have plans to install the following couplers: https://www.amazon.com/Wangdd22-Coup...o+8mm+coupling

This will make the Z Axis nearly as rigid as the integrated motor/thread, while making it easy to install.

I will put my files up on Thingiverse sometime soon for those who want them. They are only a prototype and I plan on changing things are time progresses.

[uncle_bob]

If you get rid of the coupler and mount the nut right, I believe you can keep the motors in the "normal" location for the non-Acme thread rod driving motors. That's what they did on the i3 MK2. Worst case would be a printed spacer between the motor mount and the "chassis". I'm not sure if you could mount the nuts *below* the lower X arm, but you might be able to. That would make the required length of Acme rod a bit easier to find.

[BLKKROW]

Here are the files I used:

https://www.dropbox.com/sh/lp88ldb90...2iL5Ph0ya?dl=0

Again, these are Beta designs and may have issues. I am testing them out currently.

[augerpro]

So my buddy bought the Pegasus and we're in the middle of the build! Couple questions:
1) why use the springs on teh heat bed? Does the underside of the heat bed need insulation for the heat bed itself, or just to protect the metal bed and mechanicals? We've been thinking this over and it just seems to make sense to use a spacer at the corners so the heat bed is always in a fixed position, which means the glass clipped to it will always be the same height, so you don't have to recalibrate the bed level every time you mess with anything. If we use say, a 1/2" spacer at the corners, there will be a gap between the heat bed and cork, which is good, but the heat bed will lose heat to the air, hence the question about using some soft insulation underneath that doesn't put any force on the bed, but still insulates the bottom

2) How critical are the dimensions of the rod guides that are attached to the gantry? We're supposed to print these and I'm not sure how great these will be considering we've never printed anything before

3) regarding 2, it would be nice if there weren't any pieces the user had to print, since some buyers will be first timers, we don't have anything to print with yet! So now we are forced to build with stock M5 rods, print the pieces for the ACME rods, and tear it apart to install the ACME rods. Same thing with the bed extenders. Looking at having a commercial outfit print these so we can build the Deluxe mods right away.

[uncle_bob]

Hi

The assumption is that you first build the "normal" version of the printer. Then after it's all running, debugged, and printing like crazy ... you do the upgrade to the Deluxe package. As you have noticed, you need a working and debugged printer to do the Deluxe parts.

The tolerances on all the parts are fairly tight. I would not build a printer with parts that are not done well. There will be all sorts of issues down the road if you have print issues on the parts.

The springs are there on the bed to allow you to do fully manual bed leveling. You adjust the screws in each corner of the bed to get it level. With spacer blocks, that process is not going to work. You either do the aided software based manual leveling or you go with a probe.

As you do the build, keep in mind that mechanical accuracy matters a lot in a printer. The accuracy of a kit like this is pretty much entirely up to how well you align everything as you put it together. Take the time to get it all square and flat ....

Lots of fun.

Bob

[augerpro]

So we've built the machine, did a crude manual bed level and the first print was quite good! It was a 1" cube, but somehow printed only 1/2" in height. I'm searching Slic3r, and the software (can't remember the name, starts with a "p") that is in the manual that had to be used to feed the gcode via USB as Marlin wouldn't see the SD card in the one screen. That all looked good and the only thing I see in Marlin is maybe Zsteps is not right, it's set at 4000 currently - is this right for the M5 guide screws? I'm tempted to change it to 8000 and see if prints the cube the correct height.

Looking around Marlin and the slicer program I'm realizing there are ALOT of settings that I have no idea what they do...

Also the bottom of the cube was not flat, it must have pulled away from the bed. We are using Aquanet on teh bed, set at 70C, and Hatchbox PLA filament. Extruder at 200C. Any advice?

[uncle_bob]

4000 is the correct number for the M5 rods. It hasn't changed in forever and ever on the M5 screws. The Acme rods do use a lower number so you might have loaded the "deluxe kit" firmware. Rather than trying to change individual settings, I'd figure out the basic load error. Colin's firmware is a good starting point and there are lots of custom settings. Much better to get the right firmware version in there. If the firmware is correct, try swapping stepper modules on the Ramps.

First layer is very much related to how accurately the printer is set up. 80% of the stuff you do in carefully setting up the printer is targeted at getting a good first layer. The "right" hairspray is Garnier Fructis Super Hold 5 from Walmart. If that's not available where you live, there are custom made "3d print" sprays that will do the same thing. PLA normally isn't very hard to get to stick.

So what to do:

1) Get the right firmware from the Makerfarm site and load it.
2) Reformat your SD card (it can't be a real big one) so it will read properly
3) Get the right hairspray
4) Check all of the dimensions for flat / square by measuring diagonals. They should be within a mm or so of each other.
5) Spend some quality time doing a good bed level

Once that is all done, you do test prints to work out just how thick the shim you used really was. You offset the head from the bed level zero by playing with the Z offset in your slicer. For a 0.2 mm layer, you will be doing it in 0.05 mm steps or less to get a proper first layer. Re-check the bed level every couple prints to make sure things are staying tight and nothing is drifting. It is pretty normal to find loose screws for the first week or so of printing.

Lots of fun !!

Bob