Velodyne LIDAR repair VLP-16 - Page 1
Forum section: electronics / repair

author: lunacyworks
author_rank: Contributor
timestamp: October 24, 2021, 08:56:17 am
content: I have a Velodyne VLP-16/Puck with a cut cable. It was sent to me to use as a demonstration for a Right to Repair educational session. The issue is that there are no outside screws and I am not sure how to open the case.I have included some pictures that were publicly posted on the web of a teardown. That shows no screw holes on the top cover or bottom cover.Again, any help in the proper technique to open such a unit would be appreciated.

author: lunacyworks
author_rank: Contributor
timestamp: October 24, 2021, 04:56:26 pm
content: As a side note, the screw hole on the top is not I believe a screw hole but centering hole to keep the spinning shaft from going out of alignment.Also the 4 screw post you see on the bottom are to mount the pcb board to, and do not present on the under side (outside) of the case.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: October 25, 2021, 03:37:14 pm
content: Having worked at Velodyne, I would say in general, they want to protect as much as possible their designs from being reverse engineered.From what I can tell by the photos, unscrewing the caps, top/bottom may get you inside. I would think some leather straps around them might help. You may find that it is unscrewed clockwise too, just to confuse you!!!

author: lunacyworks
author_rank: Contributor
timestamp: November 01, 2021, 05:45:27 am
content: I would assume you are correct here, otherwise, it would be some type of glue that was heat-activated. I will gently try your suggestion.

author: Trixie
author_rank: Newbie
timestamp: June 19, 2024, 10:45:36 am
content: Necro-posting to a person that will come here from google: find the hex-screw. It's hidden, but it is your entry point.

author: gbin
author_rank: Newbie
timestamp: June 25, 2024, 05:08:37 pm
content: I'll necrobump again this one so people don't have to guess.1. Check out at the bottom of the device in the photo mount type screw2. Mine had a bunch of hot glue blocking the hex head screw3. Use a sturdy tweezer to remove the glue / scratch it off with a small hex key.4. The hex screw is some stupid american format, I only had 1/8 in but it was not good. 3mm is too big, 2.5mm is too small. I used a TR14 bit (torx) gently and it worked.5. Turn counter clockwise (normal unscrewing) holding the top of the lidar6. The top will pop off, you see on the original pictures the screw hole on the opposite side of the top part (some comments are obviously misleading from other users, why?).

author: J0sh
author_rank: Newbie
timestamp: July 03, 2024, 07:44:02 pm
content: Quote from: gbin on June 25, 2024, 05:08:37 pmThanks, gbin! To add-on to their comment, the screw is inside the 1/4-20 hole on the bottom of the unit. Look down inside, at the bottom. You first need to pluck out the hot glue blob that's down on the bottom, which you can easily extract by bottoming the tip of some tweezers through the hot glue and twisting. It'll pop right out. Then I found that a T15 bit worked well (no play) to loosen the screw. As you loosen the screw, hold the top cover of the unit and lightly unscrew until you feel the screw free of the cap. The screw only has a 5mm or so of engagement on the cap. Once the screw is free, you can twist the cap until it comes free of the body (it can spin freely once the screw is disengaged - there's no wires or anything preventing rotation). It has an O-ring to seal against the lens, so you need to twist a bit to get it free of the stiction. Once the cap is off, you can then remove the lens by twisting and pulling up on it - it's also just held to the bottom half via O-ring.

author: J0sh
author_rank: Newbie
timestamp: July 03, 2024, 07:49:37 pm
content: Also, to add-on further, the color-coding of the wires for a VLP-16/Puck is as follows:

author: Tomppalainen
author_rank: Newbie
timestamp: January 07, 2025, 04:57:51 pm
content: Related to Velodyne Puck 16 pictures in this thread, can the lens unit be lifted up without risking to cut off some wires? From the first picture it seems that there are two thin wires soldered to upmost PCB. If I unsolder those two wires and carefully lift up the lens unit (after removing the clip from axis), is that all that is needed?

author: Tomppalainen
author_rank: Newbie
timestamp: February 10, 2025, 02:46:05 pm
content: As a reply to my own message, after things were figured out. So, in order to access the cable connector from lower PCB, you have to1) remove the cap as instructed above (shortly: unwind the screw from the bottom side and just slide the cap off, it is not attached to anything any more)2) pick the lock socket carefully form the shaft and note three washers under it. Order and orientation of these washers is important thing when re-assembling the sensor.3) It is NOT REQUIRED to detach the upper PCB from lens unit, I did for learning. In my case, lens unit was somehow glued or otherwise tightly fitted to lower ball bearing and it required a little trick to separate it from the shaft (and thus the non-spinning part of the lidar):3 a) Place a suitable sleeve over the shaft so that you can hammer the bearing off the shaft. In my case it was something like 8mm nut, but whatever that fits over the bottom screw is suitable. The nut is visible in pictures below. I used some bigger screw driver's soft handle as a 'hammer'.3 b) keep the lens unit in your hand and hammer the shaft gently so that the lens unit is detached from the shaft. There might be some glue and any way there will be the magnetic force from motor to resist your intentions.4) After removing the lens unit, lower PCB is visible. Unsolder two thin wires from it, remove the four screws and carefully lift the PCB so that you can pull it apart from the connector. Beware thin wires below the lower PCB, they are long enough to lift the PCB from shaft but you have to be careful.5) The connector is MOLEX Pico-Lock, part number for the pins is 5040520298. In my case, it was sufficient to replace the pins, i.e. the connector housing could be reused.6) When assembling the unit again, I had to add 1.3mm thick washer (inner diameter 7.0mm, outer diameter 9.9mm) over the original washer on the shaft before carefully putting the lens unit back again. The three washers on top of the upper bearing must be slightly over the lock socket level. The lock socket should BRIEFLY push the spring washer (the middle washer of the three) downwards. At least in my case, if there were no additional washer under the lens unit, the bearing rotated against the shaft, causing very unhappy noise.6a) Note that it is easy to scratch laqcuer layers on lens unit's magnets.