Anyone who has assembled a NexDome has noticed tje inherent thumping, as the dome turns over the walls. In some cases the dome sections are NOT level with each other and this presents a more profound problem. This can cause the dome to stall or stick which can effect the dome rotation kit to jump the track or grind the gear.
Several have mentioned filling the space so I did. I used a modeling clay and filled the spaces between the dome sections. In a few areas I added material to level out a few of the uneven transitions.
It worked for exactly 2 days. First the added leveling material fell out as the dome ran over the wheels. Even after the clay fell out the dome was much quieter and ran smoother with the spaces being filled. The dome also didn't thump, stick or stall. The next time I was in the dome, all but a few, of the clay remaining in the spaces fell out. Other than cleaning up the clay the dome is no worse for wear.
I wanted to use a material that could be removed easily, in case of having to remove the dome for any number of reasons. I did not sand or otherwise rough up the area and I'm thinking that might be required.
If anyone has tackled this please post here.
I will keep reporting back as I try other materials or techniques.
Steven
I have indeed though about it, designed it (in Fusion 360), bought the wood to cut on my CNC router... not done yet as my dome is being replaced (long story and Nexdome is not the cause of the needed replacement).
So once that is done, I'll probably finish to cut the wood in segment and finish the flat wood ring to put between the dome and the wheel (I also did something similar to Alex with my 3mx3m short structure under the dome).
Anybody ever considered putting a plywood ring on the bottom of the dome? I used Alexander Tardiffs design for a dome ring on my observatory structure and was thinking maybe something similar on the dome itself. Maybe use some quarter round to keep the wheels in place. This should eliminate the gap problem and help with leveling from one panel to the other. After 3 years with my dome I feel I spent a lot of money for a product that was not up to par. Too many bugs. Too many repairs. Too many redesigns.
I grabbed a photo of the putty in the spaces between the dome sections. Remember you're looking at this upside down from underneath the dome behind the track.
It's installed in the gaps between the dome panels where the wheels thump. I stuffed it in the cracks and smoothed it out. A few were too high, so I sanded them down. Just follow the directions on the package and make sure you have some water to wet your fingers to help form the putty. It's pretty easy. A little goes a long way. I started with a large marble size piece of part A and B.
@Steven Green where did you apply the apex molding in your setup, can you take a photo of what worked well and how much you used for it? I picked up the molding per this threads recommendation and I'll be playing with it soon. @Stacey Mills , it would help if you could post a picture of your work on that too.
Also, did you guys sand or finish it with anything to make it transition well?
Thinking I might go the same route - for those who have been living with teh hack for a while, thoughts? Will it stop me dismantling the dome later if I need to?
one link among others : https://rti-zone.org/macosx_x2dome_plugins.php
I don't see any way to PM users here. Check my website and you should be able to find my email there :)
I'm in the bay area too so yea.. air quality is really bad (I'm slightly north of Berkeley). It's probably better here as we're not in direct line of a fire but the last few days have been fairly bad. Safety first .. so do what you need to do to stay safe !
Let me know how the Apoxie Modeling compound works as I will probably do the same.
Rodolphe
Even with the new wheel system me and Alex are using, sometimes some of the wheel are not touching, because the dome is not round and not "flat". So having more wheel helps as more of them do touch at any given time.. but they never all touch at the same time... at least not in my case.
I'm not using the standard Nexdome walls, I had a square structure build and tried to use the ring that comas as the dome+ring kit. Didn't work well at all so I did the same thing as Alex Tardiff :
I got the wheel from Amazon but they won't fit on the standard wall as they are much bigger :
https://www.amazon.com/gp/product/B07K57YM2X/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
I also put 16 wheels instead of the original 8 vertical ones (and use 8 of the original ones as Alex did).
So this helps a lot but is probably not doable on the original Nexdome walls
I'll be interested to know the result too. Even though in my case the thumping is reduced by the fact that I did my own wheel circle like Alex Tardiff with bigger 125mm wheel, I would like to make it as smooth of a ride as possible.
I can also confirm that the dome is everything but round :) (as my wheel were carefully installed as a circle .. and the dome was not turning properly .. so some adjustment was needed which is easier to do with support wheels on bracket and horizontal wheels on bracket too ).
Like everyone else, I've experienced the "thump-thump" which is an unavoidable byproduct of the way the panels must be molded. If you want to fix this once and for all, the product you need is called "Apoxie." It's an epoxy modelling clay that has the consistency of putty, sticks to anything, including ABS plastic and cures rock hard. It's not cheap at $25 (Amazon), but you'll be pleased with the result.
So it has been awhile since I worked on controlling the thump thump thump of the dome while rotating. I ended up using gorilla tap, found it in white, in ~4" strips between the sections of the dome making sure it was stretched tight. I have to say the thumping has been reduced by at least 70% and the wheels no longer get trapped where there is an offset to each section. It has held up well over the summer, and it has been setting record highs, and appears to be my solution.