If you are using batteries, could be that they're getting weak. Another thing to try is possibly reducing the spring tension somehow. The springs are designed for horizontal operation, you have it vertical. Nice job though, hope you get working.I'm not saying you should modify in any way your spider . Just don't want anyone getting upset if something goes wrong. I was messing around with it tonight adding clothing. Just lightweight stuff and it ran good for awhile but then the locking mechanism started giving out. It goes through the pop up and the pull down motion but when it it gets the part where it stops and locks into place it pops back up again. Kinda ticking me off a little. Maybe i'll be able to fix it. Just a warning.