X-axis limit switch interference continued, short drag chain?


(Grant Hultman) #1
  1. The beginning of the Gantry drag chain is 2.5" off Y1 Rail Carriage. Does not seem to be long enough, please see attached pictures. After starting the hello world test things got a little shakey lol no problem. Not sure if I need more tension on the Z-axis belt tensioner. The drag chain is pretty tight in the pictures on the right side.

  2. Despite my best efforts I did not offset the Gantry drag chain towards the back enough and got caught up on the X-axis limit switch anyway. I guess I will need more VHB remount the drag chain with a greater offset. Was a note missed on the placement of that or is it just the OCD that makes us want the drag chain to run on top of the gantry?

I am beginning to wonder if the wiring harness got switched up, I would still like to confirm that before I break it down. If anyone has a link or expected dimension of the drag chain that may be helpful.
I found the metal bracket limiting due to the Gantry drag chain not having a lot of play for and aft. The bracket really squares that drag chain up.

I know Carbide will be there to help but I like cutting to the chase with what the community is recommending. I am new to the hobby but I am studying Construction Management and Engineering at Purdue North West so I am up for the challenge!IMG_0912 IMG_0912 IMG_0911 IMG_0910


(Gary) #2

Honestly I believe they are too short myself. I never did like the tight radius it had to span the entire gantry. I ended up replaceing both with longer larger drag chains I bought off Amazon.


(William Adams) #3

If it’s too long you can remove a couple of links — there are some notes on this on the wiki.


(Luc) #4

I had the same problem and I used a bit of insulation foam strip to keep the chain away from the sensor but still resting on the gantry. Easy peasy!


(Grant Hultman) #5

@HDRyder That is likely what I will be looking to do! Your setup is fantastic. I would love to learn more about your setup and thought process. Water cooled is very cool.

@WillAdams The problem is that I am actually falling short. I took 2-3 links from the Y-axis drag chain and added them to the x-axis drag chain. Now it is long enough’ish.

@luc.onthego That seems like a great option. I ended up having to remove the 1 of the 2 bolted connections and sliding the drag chain towards the rear and was only able to use 1 bolt in the slotted connection. If the slotted hole on the “L” bracket was just a little wider (or longer) I would have been able to play with the geometry just enough to avoid the conflict.


(mikep) #6

short drag chain: alternately, you move the “starting point” of the drag chain a bit away from the end of the rail, making the loop a little bigger…

Running the power cable from the router along the drag chain can lead to some problems. If it’s working for you, that’s great, but if you get some disconnects from the software, the first thing anyone will tell you is to move the power cable. Adding a ferrite onto the power cable can help too. That lump that looks like a ferrite on the power cable isn’t - it’s an anti-theft tag that can be removed.


(Gary) #7

Also I did redo my cable harness from scratch to add length where needed and moved wires that went across the back of the gantry to inside the gantry cavity to clean it up.


(Daniel Moran) #8

Just got my XXL in the other day and have it all setup. Noticed the exact same thing with the drag chain interfering with the limit switch.
I took the same approach Monkiestyle did (Drag Chain Blocking Limit Switch). I had plenty of those nylon spacers they give for mounting tv’s to the wall and used a dremel to cut them down to 3mm. Then, also in the tv mounting supplies, i had two longer screws that were perfect for the job with the same threading.
This allowed me to extend out the drag chain arm in order to offset the entire chain back a bit and out of the way of the limit switch.
Next I’m printing this thing now (https://www.thingiverse.com/thing:2675656) which will let me secure the other end of the drag chain to the left-y-axis plate rather than relying on sticky VHB.
Lastly i had to take a few links from my left drag chain and insert it to remove the tension on the other chain when in the far right position.
Movement is perfect now… no tension on the wires.