Building my LitePlacer - seeking advice

[urosg]

Almost done... The instructions for hardware assembly are really out of this world, they are really great, there is almost nothing you can miss, maybe just a small correction as stated before from another user, where you mark back extrusion with the same color on both sides, that one had me for a minute.

The instructions for cabling could be a little more detailed, maybe in a way to remind the assembler how many cables you need at specific point, as I had to reopen the cable chain three times as I first put in the cables for solenoid valve, limit switches and stepper motors; next I had the camera put in the holder had to put the cable; next I had to put in another power cable for the LED ring; this is maybe just one side note to put in the assembly instructions so that you can prepare all the cables in one step - or maybe it was just my experience as I had my 20 month old son "helping" with the assembly

Little preview - missing the downward camera LED ring and shades.

One pictures will be coming next from the bottom of the assembly where I have put a 4port USB hub to connect TinyG and both cameras to, so I have only one USB cable towards the computer.

One problem I have to solve is also the top cable chain when the gantry is in X MAX position, the far end (the bend) of the cable chain is so heavy that the chain drops down - the second link in the chain that is screwed on the head "jumps out" from the sockets, I have already put extra cable ties around the link, it helps a little but not enough - any insights (seen on the second picture - red cable ties)?

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[urosg]

Some pictures what happens when "Test X" is performed.

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[urosg]

Solved it, since I didn't use the plate to fix the chain to the extrusion for Y axis and had it fixed to the table directly I had the plate extra, I fixed it on the p&p head and tied the chain to it, so now it doesn't drop down.

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[JuKu]

Clever! I had thought about your problem without finding a good solution; looks like something I might want to have as a standard, the z motor attachment plate could well have the support built in.

[urosg]

Thank you!

Now I have come across another problem that seems to just present it self, I was doing the calibration and stuff, preparing the component tapes and when I went to the job tab and remeasured everything all was OK, but then I clicked "calibrate needle" now I see there is a problem with the A motor it sounds just as it would be missing steps, I have tried to increase tension on the belt with now luck, removing the vacuum tube also doesn't help, even rising motor current did not help, I have also taken down the pulley and re-positioned it to make a better fit with no luck.

Any advice would be greatly appreciated.

[JuKu]

To diagnose: With motor power off, does it rotate freely? If so, does it rotate using another motor driver on TinyG? Can you rotate another motor with TinyG A axis?

I have no problem replacing a faulty part, but we need to first find if there really is a fault and in what part. (Sounds like a broken motor, but let's be sure.)

[urosg]

Motor does rotate freely, this I tested quickly today before going out, will test with motor drivers later in the day and let you know.

[urosg]

My findings
1. motor does rotate freely
2. coil pairs match up with approx. 4Ohm resistance on each coil (red/black and blue/green)
3. resistance between different coils is not infinite but about 1.5MOhm (ie. red/blue)
4. switching Z and A axis outputs on tinyG proved that motor4 driver works as the Z axis motor moved when pressing to turn A axis; A axis motor still dead when pressing up/down for Z axis in LitePlacer software
5. replaced wires for A axis motor - no change

First indications were that the motor is OK (rotating freely), but after ruling everything else out I guess it's a bad motor.

[JuKu]

Strange symptoms, but I agree, bad motor. Replacement sent.

[WayOutWest]

One problem I have to solve is also the top cable chain when the gantry is in X MAX position, the far end (the bend) of the cable chain is so heavy that the chain drops down - the second link in the chain that is screwed on the head "jumps out" from the sockets, I have already put extra cable ties around the link, it helps a little but not enough - any insights (seen on the second picture - red cable ties)?

This happened to me too; it is a real problem.

Dragchains are not designed to support themselves flying in the air the way the liteplacer uses them.

For the Y-axis it is easy to "flip" the dragchain so it rests on the table; there are photos (Malte's, I think?) showing this.

For the X-axis it is a real problem; the dragchain is supposed to rest on the gantry, but the liteplacer doesn't have enough space between the v-groove wheels on the top side of the gantry.

I had to resort to supergluing the first few links of the chain, but long term the machine needs to be altered so there is room for the dragchain to run underneath the z-axis motor... that's how every other machine does it and the dragchains are designed with those mechanical assumptions in mind.