Oh dear, I asked the wrong question XD. I am a little confused how to attach the y-belt to the anchor screw. I took photographs of how I attached it. Did I do it correctly?

 

Ok, so I tried again. Just lashing it against the belt seems to twist it somewhat. Is this correct?

 

OK, I think I got it this time. I thought I would upload a final pictures , in case it helps anyone.

 

So to get perfect holes for the Z Uprights and Y Rails for the first step (TrueUp Glide Frame Assembly) I created some jigs. All you do is attach the jig to the rail using the tapped center hole and a M5 screw and M5 slide t-nuts. Then you drill the holes with a 5mm drill bit.

Here is a picture of one set up. Note that you also screw an M5 screw into the threaded rail. I don't currently have a rail that has been threaded, so I wasn't able to attach one in these pictures .

 

I also created a two jigs for the MK3 build plate. First you attach jig one to the MK3 build plate using M3 screws. Then you drill out the 4mm, 5mm, and 7mm holes. Then you remove jig 1 and attach jig 2 to the plate with a M5 screw in the 5mm whole and a M7 screw or M7 drill bit. Then you drill the 5mm hole, add another M5 screw to secure the jig, then drill the last 7mm screw.

Note you will need a fairly large printer to make these jigs. If anyone wants I can try breaking them down into smaller prints. Enjoy!

 

Keith, In the kit assembly guide, there is very little information about the Z End Stop screw other than to thread it in. There is no information as to how long the screw is suppose to be, if a nut is embedded into the guide, or any information on the knobs. Is there a link somewhere with that information? I checked out the TrueUp instructions and it didn't say much there either.

 

Are there STL files for the parts other than the glide?

 

I would appear that my printer made the hole for the nut just a little bit too big. Can only get it to spin around in the hole. Will have to try reprinting the part.

 

Must have over looked them. Will go back and check again. Thanks.

 

I wonder if an eye bolt and j-bolt attached to it aren't a better option to fix the timing belt?

 

For my build, I designed a belt clamp to use so I didn't have to use a closed loop belt.

 

So my x-axis and y-axis are working great. However, I am having a very hard time getting the z-axis to work properly. When I home the z-axis, the nozzle comes down towards the bed for the fast home, than does a weird bobbing motion (backlash?) as it proceeds with the slow home. Has anyone else seen this behavior? Unfortunately, this messes up the first couple layers as the nozzle doesn't actually rise for the first few layers. After the first few layers, it seems to work OK. I have recorded a video of the behavior below, its a little hard to see but the nozzle makes a strange circular motion.

 

Some notes regarding these: I printed my tapered glide bushings slightly wide, then sanded them down for a perfect fit with no play. Also, I used an M5 drill bit in a tap holder to create small indentations in the back-center of each bushing. These little notches for the set screw prevent the bushing from slipping up or down relative to the glide body.

 

Good printer... I like it!

A question for Keith Davis: if I want to change the heated bed with an MK2 314x214mm alluminium type (and place it in landscape mode) what I have to change in your project?

I think:
- enlarge the X profile frame parts to contain the 314mm length bed
- change the closed belt size (what's the new length??)
- change the support plate to something else (advice??)
- I don't know if I need to change some firmware parameters (bed size)

 

Thanks for your advice, I'm consider to modify my printer as yours.

I've another question:

I see the gear ratio for Z screw (16:20) 20 teeth pulley and 16 for motor, and I read your explain about the microstepping for Z and the resolution of 0.05mm. Can you explain me the connection between gears ratio and microstepping remove (full step)?? I don't understand very much.

In my project I've 20teeth GT2 pulleys for both screws (trapezoidal T8x2) and motor

 

That's all clear now, so on MKS Gen I need to set a "1 Full Step" for the Z motor using the jumpers under driver!
Now in Italy it late night.. go to sleep tomorrow I'll get much more reading...

Thanks so much!!

 

So in regards to the Z steps and using a lead screw. A lot of the screws, like the ones from OpenBuilds, are 2mm screw pitch, but that is the distance from one groove to the next. Because the screw has 4 starts, there are 4 separate grooves. So one rotation of the screw would move the nut 8mm. So, with 1:1 on the gears, one rotation of the motor would be 8mm on the Z axis. So 8mm / 200 steps = 0.04mm per step. Is that math correct?



I am using a 20T pulley on the motor and 40T ones on the screw giving me a 2:1 ratio meaning my steps would be 0.02mm. From what you said, that is too large of a step?

And does it matter if the driver uses microsteps to get to the full step location?

 

EDIT: Hah. Keith, you literally answered my question while I was asking it! Thanks. (Summary: I didn't realize that using microsteps to get from one full step to the next was just as accurate as using full steps, only smoother, and therefore preferable).

This explanation makes sense, but why does your assembly guide indicate 3 jumpers (for 1/16 microstepping) under the Z driver, as opposed to no jumpers (full step)? Also, why does your firmware configuration have 1600 for the Z axis steps/mm (shouldn't this be 3200 for 1/16 microstepping)?

On my current build (using M8 rod for the Z axis & 4:5 gearing) 3 jumpers (1/16) & 3200 steps/mm in firmware is producing the expected motion distances.

Are you suggesting that it would be preferable to switch to no jumpers (full stepping) & 200 steps/mm in firmware? If so, would you expect this to require a change to that driver's current trimpot setting?

 

That's true, my lead screw is T8x2 start 4 also, so each entire revolution moves the nut of 8mm.
With my actual configuration is 1:1 (20T - 20T) what I need to config for driver step? Better to change pulley (and closed belt too) or setting different driver divider?