V-Slot is totally solid, reliable, and modular

There was an early batch of bad bearings, but those were fixed a while back (last year). Make sure it's the bearings first and not incorrect assembly, over tightening. If that doesn't fix it, talk to Openbuilds, they were quite helpful with the bad bearings (my first set was from the bad batch).

For some reason, that size bearing is prone defects more than other sizes. They aren't very strong either, I've destroyed dozens of them in 3d printers. I only use them in the V-wheels now.

Tight and loose spots are often out of round belt pulleys.

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brucehvn
Are you using their plates, or did you print your own? I found that when printing my plates/gantrys, if the holes are just slightly too close together, the eccentric spacer can rub on the v-slot at certain points of it's rotation.

I have both the mini-V plates and printed plates. They were crunchy from assembly time (and re-assembly time once I discovered that the spacers needed to go between the bearings), regardless if they were on the eccentric spacers or straight ones.

FWIW, my experience with the mini-V plates and eccentrics was that the eccentrics were out of adjustment travel after a few weeks, and it was not possible to get the plate to roll without slop. I'm thinking about going for the full-size V wheels on printed carriages for my next round.....

After hearing about the problems with those bearings I haven't even touched the thought in my mind about getting those.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

We have 27 sets of mini V-wheels sitting on our printers (plus a few spares), they all work fine.

Of the first 9 wheels I bought last year, several were crunchy, and several were drilled off center, but again, these were from the bad batch and Openbuilds replaced those. The 27 we got since then have worked great and we plan to use A LOT more.

It's just a bearing, you can buy these by the truckload for cheap, and considering how cheap and easy they make building linear assemblies, even if I got a few bad bearings, Openbuilds would deal with it, or I would just buy a box of bearings and still come out ahead compared to other linear systems.

About how much would one of these v guide systems set you back? Can't find any prices on Misumi unless I ask for a quote. This seems like a good alternative to guide rails if the price is reasonable.

Everything is right on the site:
[openbuildspartstore.com]

V-slot starts at $10 a meter, and wheels will actually cost you almost as much as the rails. Before you discount it, you have to consider the entire package. The rails may cost more, and you still need wheelsets and either buy a carriage or make one, ,but you don't need linear sliders, you don't need to fabricate a linear system. It's all there and made to work together. Yes, people make delrin rollers for Misumi, but you are riding on a very sharp corner, which is not ideal. So you have to look at the whole package.

V-slot (and the diagonals) were how I manage to get the complete Griffin OS down to the $500 range, even for a 1000mm tall version. What I spent on rails and wheels, is less than most Kossel Miniowners spend on sliders alone.

You can get the pre-cut Kossel Mini length V-slot from Ultibots for about $60.

Edited 1 time(s). Last edit at 09/16/2014 05:12AM by sheepdog43.

Not only is it cheaper, but lighter and stiffer than linear rails. I did a few unscientific tests and actually found V-Slot to be less than half the weight of Linear rails [the longer you get the smaller the proportion as you need more weight to compensate rails than aluminum extrusion] for 1000mm and still stiffer even along the thinner axis of the V-Slot. Yes, the wheels are relatively costly, but you're getting what you pay for. I expect these wheels to last quite a while. As already stated, with V-Slot being framing and linear motion in one, you are needing a lot less to get where you want and end up saving in that regard. Like Newegg, I trust everything to work, and any issues I've had so far have been handled in the best ways I can think of. Beyond the product, they're a good company that you just can't go wrong with.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

So you'd recommend openbuilds as a source? I'm guessing Misumi will be expensive, though they have some interesting lead screws. As far as a platform goes, I'd think you can actually use the wheel itself as one (maybe 2 in parallel in the parallel grooves) if you manage to mount your parts directly in the hole in the bearing:

I I__I I____
I I__I I____ {{{ other parts }}}
I I....I I
wheels

Has anyone tried using a v groove wheel (with or without platform) as a support for a (x or y) lead screw? That is, connecting the nut to the either the wheel directly or to a platform running on a v groove. I'd imagine that could be a good way to keep the load on the screw down and improve performance.

Edited 2 time(s). Last edit at 09/16/2014 04:50PM by anvoice.

Openbuilds is the manufacturer.
Openbuilds has a few open source printer designs that use it for various axis.

I'm thinking of ordering some V-slots right now, but I'd like to make sure I've got all the hardware needed for mounting. Does anyone know what length M5 screws (low-profile) work best for connecting the corner brackets? Also, do I need two tee nuts for each bracket? Hard to tell from openbuilds website.

Edited 1 time(s). Last edit at 09/27/2014 08:48PM by anvoice.

With 10mm long screws, I had enough reach to attach printed brackets. When attaching their 3mm thick stepper motor mounting plate, the 10mm screw bottomed out in the extrusion before grabbing the bracket. Two washers under each screw worked as a temporary fix until the proper 8mm screws arrived. Every bracket/plate they have listed includes the thickness specs, so please be sure to adjust accordingly for whatever thickness brackets you are using.....

Thanks, appreciate it. Having to order more is exactly what I want to avoid, I'd rather get everything from the start.

You say the 10mm scrws have "enough reach" with corner brackets, I'm guessing the 8mm will be too short? It seems then that I can try to get a bunch of 10mm screws, and since I'll be printing most of my own plates/motor mounts I should be able to adjust accordingly.

Do the corner brackets secure to tee nuts inserted in the slot, or some other type of hardware?

I didn't use any of their brackets other than the 3mm thick stepper mounting plate, where the 10mm screws bottomed out in the slot just a touch too soon to hold the plate. With 4mm thick printed Cherry Pi delta corners, the 8mm screws were a little bit too short.

If you want to only buy one screw, going 10mm long with a bag of washers to use for spacers where they are too long and bottom out in the slot is a safe bet. I do not have the patience to read specs and do the math, so I subsequently ordered a bag of 8mm screws and replaced every one that had washers under it in a moment of OCD. All of the specs (including a mechanical drawing of the V-slot extrusion with measurements) are on their web site (some of their corner brackets are 4mm thick), so you can work out the proper screw length to use for every part on your project before you order anything. For me, it was easier to just order both sizes of screws, and fall back to an 8mm screw when the 10mm screw was too long.

I used their T-nuts for everything, although I did later buy a couple dozen "post-assembly" (rotate-in) T-nuts from Misumi to add things that I forgot about. AndyCart likes to use regular old hex-shaped nuts with printed T-slot inserts that he found on Thingiverse on the Cherry Pi printers, which is a way to shave some costs especially in the UK where T-slot nuts are apparently more expensive than the USA.....

Edited 1 time(s). Last edit at 09/28/2014 07:44PM by vreihen.

Nice, thanks for the info. I'll probably get some 8mm to be safe, better to keep things neat. The t-slot insert idea is clever, might try that out.

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anvoice
Nice, thanks for the info. I'll probably get some 8mm to be safe, better to keep things neat. The t-slot insert idea is clever, might try that out.

Motedis is a good source for extrusion and tee nuts etc

Extrusion stuff

They also do a cut to size service at no extra cost and have smooth rods etc as well.

Another company that are good for other bits is Dold and they are good for smooth rods in all sizes along with Leadscrews and all sorts of mounting hardware.

HTH Doug