Z axis Aluminum blocks on V1 PB+?

[Tdeagan]

Just received the aluminum z axis upgrade blocks I ordered from Printrbot.com. After reading "If you want to upgrade your v1 LC or Plus, they will make your Z axis extremely rigid for even better prints." I foolishly thought the blocks would fit my V1. There aren't any instructions for the part and, after disassembling the PB+, there doesn't look like there's any way to make it fit. Even if I drill mounting holes, the nuts at the base of the cross-support won't let it fit.

Was there an (unstated) requirement to also order the new wood set ($75 that went off sale 3 days ago, after I ordered but before I received the blocks?)

[REPRAP SQUAD]

I dont remember seeing that the aluminum blocks would work for the v1 but if it said it I would contact Printrbot and explain your situation. They might have a way to modify the v1 to get them to fit. When you try and get them to fit what kind of issues are you running into? Is it just not wide enouph or? Some pictures with the block and the v1 under carriage would help me try to come up with a solution. I bought the block, wood and hardware kit to upgrade mine from a printrbot original to the v2. Also if you are trying to get ahold of Printrbot the quickest way ive found is on Twitter.

[Tdeagan]

Excellent points. I was very frustrated when I wrote the above note. I will contact Printrbot, but wanted a sanity check. I've had zero luck understanding what the various dependencies between versions and parts are.

In this case the problem is that the aluminum block has top and short side mounting holes (its purpose is stability, so this makes sense.) Ideally it would fit into the location directly above the current base plate for the Z-axis shaft:

D.JPG

However, the nut at the bottom of the wooden cross-piece doesn't allow this. I suspect that in the V2 layout, the block itself serves as the crosspiece.

C.JPG

The mounting holes on the block do not correspond to any holes in the wood (though some are tantalizingly close, but keep in mind that the ones in this picture are for the locations of the cross pieces and therefor just outiside the positions on the block.) Drilling new ones isn't impossible, but misplacing those holes would result in some degree of mis-position on the shaft (diminishing the value considerably.)

B.JPG

A.JPG

[REPRAP SQUAD]

Would you like me to take pics with any needed measurements of hole locations on my v2. I cant completely disassemble my pb but I can take pics and measurements of any needed parts for you on the v2

[Tdeagan]

Thanks! That's a super-helpful offer! But I should be able to find the DXFs of the V2 laser cut pieces and pull the measures from there.
I think the answer to my problem will be to:
a) give up on the blocks
b) get on the mill and fabricate a component to replace or extend the Printrbot blocks
c) throw myself on the mercy of the Printrbot folks and see if a V2 wood set is available (which would be a bummer after ordering the Y axis bed supports unneeded with V2.)
d) pull out the calipers, measure twice and drill once.

Thanks for the help!!
--tim

[holmes4]

I also ordered the blocks, but haven't received them yet. It would not astonish me if they don't fit the V1 Plus.

[Tdeagan]

Yep. They don't fit the V1 (aargh). Sure would have been nice if the website text made this clear. And I'm not eager to start compromising the rigidity (which I love,) of the unit by removing parts of the existing cross-piece structure. Unfortunately drilling the existing wood isn't really a good option. See the picture below, the top hole required on the side would be too close to the cutout for the top plate nut holder (_maybe_ a big washer would cover here, but ugh.):

E.JPG

[REPRAP SQUAD]

An idea I thought about is you could buy some wood, the same kind and thickness. Then use the old pieces on the base to make a template and adapt the template to fit your needs. A kind of V 1.5 that way you wouldn't make any permanent modifications to your stock base. I did something similar for a build to help out a middle school class when they had some upgrade issues. The wood if I remember right wasnt too expensive. It took a couple of drafts to figure it all out but I had plenty of left over wood for other projects. This has been a few months ago and they are still up and running with no issues.

Just an idea. Im trying to think what I would do to help solve this issues. The aluminum z blocks make a huge difference in my setup.

[Tdeagan]

Thank you so much! It's really helpful to have someone else looking at this.

The blocks have 4 set screw holes but the set only came with 2 set screws per block (which should be fine.) The image I'm playing with in my mind right now is replacing the two wood perpendicular cross pieces with pieces of aluminum bar stock. These would attach to the blocks via the set screw holes on one side and two new tapped holes on the block's bottom. They don't even _have_ to attach to each other at that point. If my machining mojo is good, I could mill out the tabs that attach to the frame and tap them (heck, as long as I'm fantasizing, I might as well mill out the cross cuts to hold the nuts

In any event, the block could serve to hold the cross pieces at a right angle, the bar stock could serve to anchor the assembly to the frame.

I like the approach you're taking, I just have a terror of working with wood. I can generally machine to a few tenths ( 0.0001") on my little Sherline, but I can't manage to cut wood to an eight of an inch to save my life I had a hard time deciding to buy the blocks from Printrbot or make my own (that'll teach me!) Too bad the deck is too wide for the PB+ print bed or I could try printing one!

Maybe I'm not thinking far enough out of the box, maybe I should be trying to think of a way to mount these on top of the deck instead of below. If I have to start modding the frame, might as well leave it rigid and add to it instead of subtracting. My other plans are to drop the printrboard and put in a RAMPS 1.4 for the dual extrusion capabilities. I've just about finished my bowden conversion.

Thanks again for the help!!

--tim

[REPRAP SQUAD]

If you didn't receive the full amount of set screws for the aluminum blocks I would highly recommend putting in a support ticket for them. When I got mine I was also missing some set screws. I had 3 for each block I think but anywho they are very important to the structure of the smooth z rods. Alignment is key and all set screws are required. I like where you are going with this and im glad to have inspired it. Let me know if you have any other questions, I am always willing to help in any way I can. So if you run into an issue shoot me a message.

[holmes4]

The product page description says: "If you want to upgrade your v1 LC or Plus, they will make your Z axis extremely rigid for even better prints." They had better fit the v1! I opened a support ticket to ask about this - my order has not yet shipped.

[Tdeagan]

I started a support ticket, but found all tech questions directed here. This is one of those situations where I just couldn't believe my lying eyes. But now my Plus V1 is torn down on the bench and the truth is staring me in the eyes. Keep us in the loop on how your ticket is resolved (unless you get some sweetheart payoff to keep silent

I love my Printrbot Plus V1. It's well designed, I get _great_prints that look better than the stuff I see from printers costing more than twice as much. Printrbot has created the best value in the market. But things are moving fast and the documentation isn't keeping up. I'm a software developer and totally understand the grief of assuring backwards compatibility. Understanding which parts fit with which versions and revs is a mess. But now I'm really anxious about the bed stabilizers I ordered. This wouldn't be as frustrating if the (apparently critical) upgrade path components weren't discontinued on 5/31/13.

[REPRAP SQUAD]

I completely understand them sending tech questions here, the only problem with that for this situation. Is the fact that we never said it would fit on the v1 as apparently pb did on the site. Which it sounds as if it doesn't fit. I hope the ideas and solutions we've been brainstorming will work as im sure that with modifications it is possible. It definitely needs to be changed on the website. Like I said if I can help in anyway let me know buddy.

[holmes4]

Shortly after I entered my ticket, my order shipped. Still waiting for a reply.

[eckerput]

Could you have gotten the non plus version instead of the plus version of the aluminum block? I know the base is different on the non plus versus plus and it wouldn't be the first time Printrbot had a shipping mistake.

[Tdeagan]

The blocks fit the 12mm Z rod, so I'm pretty confident it's the Plus blocks. However, maaaaybe it's possible that there are V1 and V2 _versions_ of the blocks (I'm actively fantasizing here...) and I got sent the wrong version.

[Tdeagan]

Looking at the PDF on the Printrbot site, the new V2 laser cut wood has the perfect mounting holes for the blocks. Here's a comparison of the old and new frame components:

compare.jpg

[Tdeagan]

the image of the blocks on the Printrbot site is pretty clearly the ones I got:
http://printrbot.com/wp-content/uploads/2013/05/Z-block-12mm-Plus.jpg

So the blocks are clearly only for the new wood set. Looks like I was letting my imagination run away with me thinking there might be two versions (V1 and V2) of the blocks.

I did print some of these:http://www.thingiverse.com/thing:55053 Z stabilzers, but the mounting holes didn't align properly with the frame. I'll try some of these: http://www.thingiverse.com/thing:38143 next.

[holmes4]

Printrbot explicitly says that these blocks are for use with V1 printers. If they're not, then ask for a refund (and if they want them back, have them pay shipping.)

[REPRAP SQUAD]

I think that you would only have to redo the side panels of the base or at least modify the two side tabs so that you can mount the blocks. If you have the time I would recommend adapting part of the v2 design into the v1 in the vversion 1.5. Keep me updated on your build ive been looking into this issue pretty extensively.

[eckerput]

Thinking about it, won't aluminum block hold the top to the walls for you? You probably don't need the screws that are in the way,

[Tdeagan]

The core problems are:
1) PROBLEM: The block won't sit flush in the bracket of the cross pieces without removing the bottom set of nuts holding the horz. cross piece to the vert. cross piece (see picture above.) The screws that hold the top to the vertical cross piece aren't in the way at all. ISSUE: This reduces rigidity (maybe not _too_ much,) but is a frustrating compromise to make when seeking enhanced rigidity.
2) PROBLEM: the side screws on the long ends of the blocks would require drilling holes that would leave a pretty unsubstantial piece of wood between the top mounting hole and the cross cutout for the nut that holds the top in (see picture above.) ISSUE: Might work, but might fracture the wood. No fun to get wrong and have the wood frame losing integrity. Again, maybe not _too_ much, but I'm trying to enhance rigidity.

Ultimately, the issue is that this simply isn't made to fit the V1. I'm sure it could be crow-barred in, but I'm not convinced the results are significantly better than using printed Z-bar enhancers (though so far, both of the sets I've printed (see above) haven't had their screw holes lined up with the PB+'s frame. I need to roll my own.)

I have a support ticket open with Printrbot, we'll see what they say. Thanks for all the help and ideas!

[eckerput]

Let us know how it turns out. I was thinking of getting these for my LC v1. If they don't work, I obviously won't.

[Tdeagan]

No response yet from Printrbot. I decided to go ahead and roll my own stabilizers.
Printrbot Plus V1 Z bar stabilizers: http://www.thingiverse.com/thing:100883
They are rock solid. Very big improvement, I don't think I'll miss the aluminum blocks.

The 12mm shaft is not evenly spaced between the screw holes, it's slightly forward of center, so I had to carefully place the holes, but they're right on in this print. The shaft hole is an extremely tight fit, but that's all for the better. I have no idea if these will work with the new bed stabilizers I ordered (probably not.) I'll likely have to roll my own of those as well. That'll teach me to buy accessories for a tool designed to make it's own accessories

I also ordered some 12mm flange support blocks from eBay

I'm going to mount them upside down to the top of the shafts and mount a cross bar (to eventually hold the dual extruders when I finish my bowden conversion.) Between the cross bar and these stabilizers, Z wobble should not be an issue.

Here's the new stabilizer mounted:

[REPRAP SQUAD]

Thats what I did when I switched to my bowden setup which will eventually be dual. I mounted them to the z axis cross brace. Its a perfect location but, depending on how you mount it it can limit z axis height. My v2+ has a 16inch rod height and about 13 inches is usable with the bowden setup I used. The bowden extruder im using is the best ive seen and it runs very smooth.

[Tdeagan]

Here's the dimensions of the Printrbot Plus V1 (1.5?) Z-Axis hole layout that I used with the Z-Axis stabilizers I mentioned above (http://www.thingiverse.com/thing:100883) Note that the horizontal dimensions are the same for the front and back screw holes, it's the vertical dimensions that vary.

[holmes4]

I have not received any sort of reply from Printrbot, but I received the aluminum blocks yesterday. I concluded that they WILL fit the V1, but you will have to pretty much completely disassemble the base and remove the wood pieces, including the cross brace, in order to install them. The metal block replaces the brace and holds the front, back and top plates together. This is not a simple swap-in mod.

It does require drilling new holes, carefully. It may be a while before I get to this. Mine did appear to come with the requisite screws. If I can figure out how to create drilling template, I will.

[REPRAP SQUAD]

You should definatly document your journey here. it would help a lot of people.

[Tdeagan]

Good news, bad news.

Bad news: Still no word back from Printrbot on my support ticket regarding this issue (6 days.)

Good News: I received my Y-axis bed stabilizers from Printrbot. They should work with my new V1 Z-Axis stabilizers (see above & http://www.thingiverse.com/thing:100883 ) The bed stabilizers consist of horizontal brackets that fit across the top of the Y bushings. These use the V1 screw holes (new longer screws included,) and add standoffs to position it at the correct height above the bed. If I ignore the standoffs for the side where my Z stabilzers are, I can add a couple of washers to make up the height. I'll probably respin the STL for the Z stabilizers to make the baseplate the exact height of the standoffs so that it will work without the washers.

Bonus so-so news. I tried my first attempt at Bowden conversion last night. The pneufit adapters I used were from ebay: "SPC-06-01 Pneumatic Push to Connect Fittings". This fitting uses a British Standard Pipe Taper Thread R1/8". This didn't fit sponnet's bowden conversion STLs. I reworked my vertical extruder base to fit it for the right thread size. Tap size is 8.4mm for this thread, but I'm 'self' tapping with the thread itself into the plastic. I'm using 9.45mm for the base and 9.15 for the tip (it tapers.) Here's the reworked extruder stand: http://www.thingiverse.com/thing:96940, the adapter threaded in perfectly. However, I tried to use sponnet's Bowden cable mod bowden to extruder mount (http://www.thingiverse.com/thing:26963) and the adapter ended up cracking the PLA.

I really need to print the mount in ABS in any case, PLA isn't a great choice for holding a hot end. I'm in the process of working up a purpose built Ubis Bowden mount. So far I have the Ubis model created to test against in OpenSCAD (http://www.thingiverse.com/thing:103189).

I also need to get my Z-axis cross bar built. I didn't really like having the extruder body sitting stand-alone (too much push-pull with the spool.) I'll need to create a cross bar extruder mount to hold that.

[lwalkera]

The block is supposed to replace the lower plate (and the vertical one next to it too if I recall correctly) on the v1. You have to drill two new holes (one on each side) for the other screw hole. At least that's how Brook described it while I was there awhile back.

[Tdeagan]

Ouch! I'm skeptical for the following reasons:
1. You'd actually have to drill 6 holes per side (2 for the top plate, 2 front and 2 back.) These would need to be drilled with very good precision not to put the Z-axis out of true. The top ones on the front and back would leave a very fragile piece of wood between them and the cutout for the top plate nut.
2. My measurements of the offset of the Z-axis hole shows it to be 5.25mm difference between center-to-front and center-to-back on the V1 PB+ and 2mm difference on the Aluminum blocks. This means that the Z-axis shaft hole on the top plate would have to be drilled out (and no longer fit the shaft snugly.)

That's a LOT of fabrication without instructions or notes. At least a drill template or somesuch.

Printrbot has neither responded to my posts nor my support ticket requesting return/refund or explanation on the parts.

I love my PB+ and the Printrbot philosophy/design, but the upgrade path broke down with the V1-V2 move. Parts that need detailed instructions (apparently) went without and many of the parts were time limited and disappeared. Understanding the upgrade path is a crowd sourced mystery. Frankly, if they'd just said the path was to "buy the full wood kit" I would have spent the $75 and moved on. But the clear implication was that the upgrade components could be acquired a la carte (like the bed stabilizers which work great.)

[holmes4]

I pulled my PB+ apart and hand-fitted the block in place. Yes, you need four screw holes, side and top, but the hole for the Z rod itself is fine.


Steve

[Tdeagan]

Excellent news! Thanks for that confirmation, I was loathe to tear it that far down again if the result was going to be disappointment. Did you leave either or both of the cross pieces in place (lwalkera notes that Printrbot suggested that at least the horizontal bottom piece would go and I found the nut that connects the two pieces to be in the way?)

I'm really hoping the vertical cross piece doesn't have to go since that's required to screw down the Y-axis bed stabilizer (and my homemade Z-stabilizer which I'd probably keep if I could.)

[Tdeagan]

Follow up to the thread, Printrbot has reached out to me on my support ticket and is being their normal, extremely helpful, selves.