Adding an Openbuilds Openrail Y axis to a Taz 3/4/5

I haven’t lubed the rails on mine. I don’t think it would hurt, but I don’t see that it would help all that much either. The bearings in the wheels would be what you would want to lube, but they use sealed ones. I’ll do some research and see what they recommend.

If your wheels aren’t in constant contact throughout the entire travel path, you might have a rail toe-ed in. It’s also possible that one of the rail support pieces is too tall due to a momentary overextrusion and has caused a slight bump. I had that happen to one of my first set. I removed the bump and everything lined up nicely.

As soon as the new roll of filliment gets here, I’m going to finish that Y end plate overlay piece to use the exposed end hole of the openrail extrusion for better positioning. I’ve been putting it off because other projects have been soaking up my development time.

Would it be possible for you to post the corners and supports in STP format? Or is there a way to convert from STL back to something editable?

Sure, I’ll upload those tonight. I usually don’t bother uploading STP files unless someone asks for them because no one was ever downloading them.

Here you go!
Openrail_corner_2_0_a Left.stp (573 KB)
Openrail_corner_2_0_a Rightt.stp (571 KB)
Openrail_y_support_2_0_a left.stp (37.5 KB)
Openrail_y_support_2_0_a Right.stp (35.7 KB)
Bedmodification.stp (114 KB)

I have been studying your pictures and posted micrometer head measurements trying to suss out which one it might be.

From the pictures, it looks like it might be an Insize 6372 series, but that’s a pure guess.

From the dimensions you listed in post 15709, it looks like a Starrett 463MP might work, but their schematics don’t mention a retaining ring or mounting base.

I was told it is a mitutoyo, but it doesn’t have a label so it may be a knock off of some sort. I got it off ebay for $30. If you end up with one that needs different mounting dimensions I will be happy to make a variant for it. Ill see if I missed any model numbers on the second one on my ao 10x which is easier to get to

Edit: the guy has more of them for sale http://www.ebay.com/itm/Precision-Micrometer-Head-/160677507469?hash=item256920318d

Thanks for the link. I’ll snag one of the knock-offs off eBay for now. I’ll also check out ye olde harbor freight to see if they have something cheap.

I’m some ways from tackling the z-axis anyhow. I’ve only just this afternoon begun firing off openbuild and mcmaster orders for the x and y axis upgrades.

Thanks again.

Two new, optional parts today. These are reinforcement plates for the front and back Y endplate designed to make rail allignment and parallel keeping easier. I haven’t printed these yet, so as usual, things may change. There is also a 50/50 chance that I have the motor mount plate holes mirrored. Either way, here they are:


This is the back side. the protruding bit is designed to go between the openbuilds extrusions
Taz_Openbuild_Y_Endplate_Reinforcement_motor_1_0_b.stl (87.7 KB)
Taz_Openbuild_Y_Endplate_Reinforcement_Idler_1_0_b.stl (90.8 KB)

Will I need to specifically drill holes 4.975 and 7.2mm?

Or can I use standard sizes?

The hole sizes are pretty critical. You can get those specific drill bits from mcmaster Carr for around $10 for both. The 7.2mm drill bit is the most critical because the cam hole has to be straight, and able to apply enough friction to the cam lobe to prevent the wheel from backing off the rail. The other hole could probably be done with a standard bit, but if you are ordering the 7.2 anyways, why not get the right one at the same time for that hole as well?

I redid the two optional X allignment plates since the motor one was just flat out wrong. I never noticed that the front and back plate are actually a completely different shape. OOps. Anyways, they are fixed now. Printing the back one now, once it’s done I’ll post pictures.

I also redid the drill guide plate with an optional connected piece. it uses a bunch more plastic, is thicker, but should help better allign the drill holes. You will want to print two, and line them up in the X axis with extreme precision (side to side) front to back allignment doesn’t matter as much as long as they are square.
Taz_Openbuild_Y_Endplate_Reinforcement_Motor_3_0_c.stl (119 KB)
Combined Drill Guide Plate.stl (316 KB)
Taz_Openbuild_Y_Endplate_Reinforcement_Idler_2_0_c.stl (103 KB)

Here is a picture of the completed front and back reinforcement plate on the machine. The final parts are also below.



Taz_Openbuild_Y_Endplate_Reinforcement_Motor_3_0_c.stl (119 KB)
Taz_Openbuild_Y_Endplate_Reinforcement_Idler_2_0_c.stl (103 KB)

Is there something unusual with the holes in the Combined Drill Guide Plate?

When I import it into Simplify3D, preview mode shows the holes being filled in. Printing does fill the holes in as well.

I was able to change the layer height in Simplify3D from .25mm to .2499mm. Now it slices fine. Guess it’s a Simplify3D thing.

huh, wierd. The part looks manifold, and it was one of the simpler extrusions so it shouldn’t have any internal wierdness. Glad you got it working though!

I’m getting ready to drill the bed plate, and am attaching the drill guides.

One thing though, how do I attach them? The 16 screws that were previously used are quite small compared to the 16 holes drilled in the bed plate and allow for lots of play…kinda defeating the purpose of the drill guides.

Either bigger screws, or just clamp them down really tight with the existing ones, using a T square to the bed edge to get them lined up and in place. I used the clamp method. If you lightly tighten them and then force them to the outer edges of the hole that should also stabilize the allignment.

Sounds good. Thanks for the quick response!

[edit] I wound up using drywall screws to hold the drill guides in place. They matched the diameter of the already drilled 16 holes near-perfect and allowed me to secure the bed at the same time.

Nice, good trick to know!

Hi piercet,
Very good job with all these mods!

I finally got all the pieces and now I’m in the process of upgrading my TAZ5. I started with the Y-axis since it seemed to me the most easy to do. But then I hit a couple of problems. If I’m not mistaken, you work on a TAZ4. And it seems that Aleph has made some minor changes to TAZ5. I got mine on May, 2015.

The first problem is with the motor mount, where the top screws are lowered by about 4mm. As a result, I had to “destroy” your endplate as you can see at the picture below:


And then, right after I had the holes for the wheels drilled, I found out that there is a 2.5-3mm offset between the fixed and the offset wheels. Center to center distance in your design is about 19.1mm. In my case is about 19.4mm. So I had to drill new holes only to find out then that I had issues with the endstop switch and then with the belt and finally after a few more drills I ended up with a “swiss cheese” bed plate!!

Could you please post the .step files for the endplates? So that I can do the fine tuning for my version of TAZ? …after I have finished putting everything back together successfully!

Thanks