Extending the PBJR Z axis

[SilverFingers]

Would it be as simple as buying longer rods and replacing them?

I think I'm going to head to Lowe's later this week and pick up some longer rods.

Should they be made out of a certain type of metal?

[Bob-StPaul]

Does Lowe's sell smooth rod? I don't recall seeing smooth rod at any hardware store...

[JonS]

Would it be as simple as buying longer rods and replacing them?

I think I'm going to head to Lowe's later this week and pick up some longer rods.

Should they be made out of a certain type of metal?

I just yesterday took delivery of some parts from McMaster-Carr for this purpose. I'm upgrading my z-axis threaded rod to M8 and going over to a dual-nut with compression spring set up. When ordering I decided I high as well try to add a few inches to the z-axis.

I bought the following:

1 90024A080 Metric 18-8 Stainless Steel Threaded Rod, M8 Size, 1-Meter Length, 1.25 mm Pitch
2 90690A055 Metric Brass Hex Nut, M8 Size, 1.25 mm Pitch, 13 mm Width, 6.5 mm Height, packs of 25
3 94125K839 Metric Compression Spring, Music Wire, 39MM Overall, 11.0MM OD, 1.00MM Wire, packs of 5
4 6112K15 Hardened Precision Metric Steel Shaft, 8 mm Diameter, 800 mm Length

I intend to cut the rods and install them this weekend.

(I also bought a 6" x 6" borosilicate (Pyrex) glass plate for my heated bed, but that's a different subject.)

[SilverFingers]

Interesting. Let me know how it goes

[SilverFingers]

Does Lowe's sell smooth rod? I don't recall seeing smooth rod at any hardware store...

Well they definitely have threaded rods but perhaps you're right. I should probably order 'em from McMaster like JonS

[mrsamnc]

Would it be as simple as buying longer rods and replacing them?

I think I'm going to head to Lowe's later this week and pick up some longer rods.

Should they be made out of a certain type of metal?

I just yesterday took delivery of some parts from McMaster-Carr for this purpose. I'm upgrading my z-axis threaded rod to M8 and going over to a dual-nut with compression spring set up. When ordering I decided I high as well try to add a few inches to the z-axis.

I bought the following:

1 90024A080 Metric 18-8 Stainless Steel Threaded Rod, M8 Size, 1-Meter Length, 1.25 mm Pitch
2 90690A055 Metric Brass Hex Nut, M8 Size, 1.25 mm Pitch, 13 mm Width, 6.5 mm Height, packs of 25
3 94125K839 Metric Compression Spring, Music Wire, 39MM Overall, 11.0MM OD, 1.00MM Wire, packs of 5
4 6112K15 Hardened Precision Metric Steel Shaft, 8 mm Diameter, 800 mm Length

I intend to cut the rods and install them this weekend.

(I also bought a 6" x 6" borosilicate (Pyrex) glass plate for my heated bed, but that's a different subject.)

I'm very eager to read, or better yet see, how this goes for you and the steps taken. I'm will be changing my z rod either to M8 or acme as one of the first real upgrades on my PBJR.

[gyronictonic]

You can use 8mm drill rods too. It's not chrome plated but it's definitely cheaper. Since you are only replacing the Z, you don't have to worry about wear n' tear.

http://www.mcmaster.com/#88625K67

[JonS]

Here's the status. I increased the z height by 3.5-inches. I installed a double nut system with compression spring (using Alaster's bracket: http://www.thingiverse.com/thing:64738) but found that there was too much tension throughout much of the travel for the stepper. It got a bit better after some lubricant, but still wouldn't move over the full range.

I've reverted to the original, single bolt configuration for now. I think I'll try a weaker spring.

It's mostly working now, after resolving an issue with a loose GT2 pully on the y-axis that strangely decided to show up after the first test print (I installed it a week or so ago and it was fine). I now have one remaining issue which is that I can't go above 130mm even though I set the print area height in the printer settings to be higher than that. I'm stratching my head over this one. It's not mechanical interference. Repetier just won't allow me to go higher (the z shows up as red if I try to manually go above 130mm).

[JonS]

Okay, now I find that (after measuring the height) I'm only actually going to 100mm!

A quick search shows that Marlin has a parameter for travel limits. I wonder if it's set to 100mm on the printrbot version of the firmware.

[RetireeJay]

I think that all the Printrbots share the same firmware. There is a hard-coded limit, but it is at least 200mm because the PB Plus can go that high. There's a whole long thread in this forum about extending the Z axis even further for modified Printrbots
viewtopic.php?f=21&t=2239&p=28820&hilit=z+axis+height#p28820
- but I think you should be able to reach 200mm without modifying your firmware.

[JonS]

I think that all the Printrbots share the same firmware. There is a hard-coded limit, but it is at least 200mm because the PB Plus can go that high. There's a whole long thread in this forum about extending the Z axis even further for modified Printrbots
viewtopic.php?f=21&t=2239&p=28820&hilit=z+axis+height#p28820
- but I think you should be able to reach 200mm without modifying your firmware.

I thought that the Jr has a different version of firmware. I believe some of the axes are inverted (must be something to do with the Australian market ).

There's a thread here (http://www.printrbottalk.com/forum/viewtopic.php?f=21&t=2239#p18154) on extending the axes and someone created a new firmware version that allows soft control using M codes, but if I'm correct that there are minor differences for the Jr., that won't work for us.

[SilverFingers]

So I got my rods from McMaster Carr, and it wont let me go further than 100mm either. We need a fix for this!

[getSurreal]

They must have flashed a bunch of printrboards for the Jr. and sent them out for everything. My Printrbot Plus v2 would not travel the full distance on the z axis and one of the motors directions was flipped (y axis I think) until I reloaded the latest firmware. Try reloading the latest printrboard firmware.

[mrsamnc]

JonS, how's it going? Any luck pushing through the 100mm barrier? You're like Chuck Yeager for us PBJR owners.

[JonS]

No update yet. I've been otherwise occupied. I need to try the new firmware that lwalkera posted.

I'll see if I get time this weekend to give it a go.

[JonS]

I can now go beyond 100mm in the Z-axis!

My Y homing is all messed up, so I've got some work to do to sort that out.

Something that's strange: I've set my maximum height up in the Printer Shape configuration tab in Repetier, but while I can go above 100, Repetier shows the height in red. Where's it getting that 100 soft limit from?

[JonS]

I had to reverse my y-axis plug (and change back to positive calibration). Everything is working now.

I how have up to 7-inch of z-height!

[Lemm]

And what have you done in fact ? Firmware update or just setting the limits in Repetier higher ?

[JonS]

And what have you done in fact ? Firmware update or just setting the limits in Repetier higher ?

Oh, my apologies. I forgot this is all spread over several threads!

1. I updated to lwalkera's unified firmware: https://github.com/Printrbot/Marlin/releases/tag/unified-v2 [EDIT: Updated to permanent home]

See this thread: http://www.printrbottalk.com/forum/viewtopic.php?f=22&t=4452&p=29496&hilit=unified+v2#p29496

Version 2 is the one that works. Don't download the original v1.

This adds soft limits for the travel using the M208 command. I've not set up my limits yet.

2. I reversed the y-axis plug on the Printrbot.

3. I set my new max. z-height in the Printer Shape configuration in Repetier.

[Lemm]

thank you for the summary

[mrsamnc]

Yes! Thank you! I'm adding this to my mod list for sure!

So what X/Y/Z lengths are you going after? What length did your Z rods end up being cut to? The 800mm rods are quite pricey.

[JonS]

So what X/Y/Z lengths are you going after? What length did your Z rods end up being cut to? The 800mm rods are quite pricey.

Both my rods were cut from that one 800mm rod (using a Dremel cutting disc). That's why I bought that height. It worked out the lowest cost means for me to get two rods at something like 350mm ea.

I had a restriction in height due to my Jr being on a shelf with another above it. I think I added ~3.5 inches to whatever the original rod length is.

I've not changed my x and y axes as that would require that I swap to a larger heated bed. I only installed the heated bed a couple of months ago, so I wasn't looking to change it.

[lwalkera]

1. I updated to lwalkera's unified firmware: https://dl.dropboxusercontent.com/s/vr95m92an5p94av/Marlin-unified-v2.hex?token_hash=AAGpXJZRrD62dkNN1sOBX2GFjbo0cqSGJPGPNAmlzUew8A&dl=1

That link will probably go down soon, the best place to get releases in the future is at the Printrbot github page. The link for that release is https://github.com/Printrbot/Marlin/rel ... unified-v2

[JonS]

Here's my first 7-inch tall print!



Previous biggest owl versus Mega-Owl!

[Lemm]

wow and printtime ??

[JonS]

wow and printtime ??

Print time was about 8 hours. That was with 0.2mm layers and 0.1 fill.

[DJNOS1978]

Why is everyone only extending the z-axis? Is the x and y limited to firmware? Why not just "flip" it?

[mrsamnc]

Why is everyone only extending the z-axis? Is the x and y limited to firmware? Why not just "flip" it?

I chose the Z Axis (for my first axis-mod) because of it's simplicity and to be able to immediately be able to print taller objects, more specifically, vases for my wife. I found the Z Axis to be my most limiting axis when picking prints from T-verse.

[DJNOS1978]

So it is very possible, although more difficult, to extend the x and y axis also? Is the firmware the limit to how big a printrbot can be?

[REPRAP SQUAD]

Yes the firmware has a hard limit to my knowledge. I do know that the simple has a limit as well as the plus. The simple extensions that they recently added require a firmware update.

[REPRAP SQUAD]

I would assume that you could load up the new firmware that is designed for longer axis's on the jr v2. That should allow you to at least e tend to the size of the new larger v2. At least tgats what I would do and save myself a huge firmware headache.

[JonS]

Extending any axis requires a firmware change. So once the z axis has been extended the new firmware would allow extension in the other axes too.

The reasons I only have extended my z axis? One, it only requires new off-the-shelf metal rods that can easily be cut to length (it doesn't require construction of a new x,y carriage); and two, I had only recently installed my new heated bed and borosilicate glass plate and I didn't want to throw them away and buy new ones.

[Lemm]

I would assume that you could load up the new firmware that is designed for longer axis's on the jr v2. That should allow you to at least e tend to the size of the new larger v2. At least tgats what I would do and save myself a huge firmware headache.

Do you know the limits for the jr v2 axis ?

[DJNOS1978]

I was under the impression from reading the forums that the firmware is the same on all printrbots, except for the simple. Is this the case?
If not then I assume you would need specific firmware??? I also was under the assumption that 8x8x8 was the max print on all printrbots due to the firmware. But I saw someone had a z-axis at like 24". What sets this?

[REPRAP SQUAD]

They have an even larger z axis then that. Its called the super z. Im not sure of the size of the jr v2 bjt I know its the same as the LC since it took its place. At Printrbot. Com they list under specification the size of the models. Theres all kinds of different firmware. The simple has atleast 2 different firmwares, jr is different as on of its axis is the opposite of other bots, the plus has its own and also Printrbot will soon be releasing even more firmware for the Printrbot plus v2.2 and v2.3, which makes your plus even wider. Also the plus has another one for the lcd/dual extruder setup and soon to have 1 for the triple extruder setup. Thats not even including all the non-official branches of firmware.

[DJNOS1978]

I will go read some more. But from what you are saying....Any modification will need new firmware. How would I know which firmware to get? If I wanted to go for the super z axis what firmware is suggested? Is it in the package?

[mrsamnc]

So it is very possible, although more difficult, to extend the x and y axis also? Is the firmware the limit to how big a printrbot can be?

Theoretically you can go as far as you want, but realistically you'll reach a point that your stock setup will not be able to go further without loosing its accuracy. You must take into consideration the design and inherent capabilities of your printrbot to be able to travel those distances without negatively impacting your print. For example, I have some 500mm rods I bought in a 6-pack and "for kicks" put a pair on my X Axis. At 500mm, there was a great deal of deflection, twisting and movement in the bed, caused by the narrow "base" the x-axis carriage has and because of the lack of support under the rods. If I were to try and use 500mm x-axis rods, a complete re-design of the x-axis structures would have to be done. While it is possible, it's nothing I will be doing with my current Jr. I think if I go beyond the 8" mark, I will be building another bot that is designed to be big.

I will go read some more. But from what you are saying....Any modification will need new firmware. How would I know which firmware to get? If I wanted to go for the super z axis what firmware is suggested? Is it in the package?

Check in this thread above. JonS gives a link to the version he used, along with details. I will likely use the same version to take advantage of my 500mm z-height upgrade.

[lwalkera]

The unified firmware on the printrbot github page will work with all current bots with or without LCD or Extrudrboard. All you have to do is set your limits and calibration, then save them to EEPROM.
https://github.com/Printrbot/Marlin/rel ... unified-v2