Thrifty Telescope Severe Binding

[four]

We are having an issue with extreme friction on a TTB Telescoping tube that is preventing it from extending at all. The bottom block is suspected as the culprit.

@Ryan_Dognaux or anyone else, do you know of any solutions?

[Skyehawk]

Double check the extrusion is actually straight and the inner one is free of dents.

It is also possible the delrin block is too large for the extrusion you sourced. Measure the two with calipers and then by hand (slide block into tube and feel) to see how tight it is both with the springs attached and just on its own (no fasteners or springs)

[Ryan_Dognaux]

Things to try -

1. If you machined the tubes recently, ensure there isn’t any swarf in the tube itself. I highly recommend taking some compressed air & blowing out the tubes. A few metal shavings in there can really bind things up quick.

2. I would inspect your tubing to ensure it is square. If you are seeing significant wear on the delrin block, it’s likely that the tube isn’t square or maybe there’s a spot on the tube that has dented inward some. You can always try sanding that block a bit on the areas that are interfering to see if that frees up it - happy to send additional blocks as well, don’t worry about messing those up.

3. Loosen the locknuts up some across the board. Not enough that they’ll fall off, but enough that the entire mechanism isn’t super tight. If these are overtightened it can bind everything up.

Try these steps and feel free to message me with some pictures of your assembly so I can offer other suggestions too.

[Emerson1706]

For 1706 and 9401 we had to slightly file down the blocks to match the extrusion either team had. A trick we’ve used on 1706 is getting it to where it is able to slide in, and if it’s still tight you can hold the extrusion with the block in it up to a light. Anywhere you can see light past the block is good and you need to sand/file down where there is no light passing through. (Like a light based feeler gauge)

The blocks should eventually be at a point where you can put them in the top and they slide out the bottom. Especially with this year’s climb not putting a lot of bending on most climbers it’s not as critical the blocks are precise, then of course don’t over tighten and strain the tube out of square at the top when mounting the top aluminum blocks.