I never heard from T-rex when I contacted them about my crack. one day a new slider just showed up.
The instruction sheet I got with mine show to torque to 41 lb/ft. The "Bin O Facts" shows 35 lb/ft for those 12mm lower front engine mounts.
Thank you, Warchild!Gentlemen -
We have heard from Tom of T-Rex-Racing.com on this issue.
He stated that the broken frame sliders apparently came from a bad batch. He claims the sliders that are currently for sale are totally free from this defect.
He also stated they would be refund you 2x the amount that you paid for the item, whether you got them from eBay or from their website: T-Rex-Racing.com.
So... youse guys with the broken sliders probably should contact Tom.
I had noticed the same thing on mine when installing them. To compensate, I added a shoulder washer with the approximate Delrin to metal bushing offset. I was satisfied with my result even though it wasn't a perfect match and about .020" of the Delrin was compressed.today i installed my sliders from t-rex. for the price i thought they were very nice. mine didn't look like the ones in your pictures. i did some machining on mine because as shipped they place a large compressive load on the delrin which will cause it to split even without bubbles. i only took pics of the right side although both sides required a little work.
the hole
the slider as delivered. the insert didn't even make it to the end of the plastic.
after machining.
you wouldn't need a lathe to do this. the same thing could be done with a dremmel or put a bolt thru it with a nut to clamp it and spin it with a drill while you filed it.
I'm not buying it.
It could be a bad batch. I work in a manufacturing facility and yes bad batches happen, most of the time it caused by a machine *** up. yes the machinery could have been poorly maintained by a lazy operator, but the injection molding machine may not have shown any type of malfunction. unless they X-ray all of the work done, there is no way one can really tell if it is done right, until it gets used sadly.
I think your suspicion is correct. Looking at the cost of any other frame sliders out there, these are about 60% cheaper than anything else. That was the main reason I purchased them. My thoughts at the time were; " What are the chances of something being wrong with a solid piece of Delrin". I guess I got my answer.
I think they make good products.
I don't think there is a direct correlation...the chances for a manufacturing mistake are increased with a very low production cost.
I could be wrong, but I doubt they are molding these sliders. The sharp corners on the parts seem to suggest that they are bar-fed in a lathe and chopped off, which would be much faster and use a hell of a lot less energy. Since the biggest cost in slider manufacturing(manufacturers who use the good stuff anyway) is the plastic itself, some manufacturers will buy tons of cheap, recycled plastic to lower overhead. If the plastic is cracking, it most likely hasn't been through an annealing process like the more expensive plastic. Our plastic costs are pretty high, but we get good tech support from our suppliers, and we can feel confident that we are selling a quality product. Like any other company, we have looked for ways to reduce our overhead, but ultimately we get what we pay for. For those seeking further info, try looking up "Acetal" in Wikipedia, or "centerline porosity".I think they make good products.
I'd love to have one of their front stands!
I'm just questioning their molding process. “Buy factory direct and save. No middlemen." sounds like they might be molding their own sliders.
They might be well intentioned and simply out of their depth.
This next observation belongs with my earlier post:
Look at Fencer's photo. That's a different part than yours and shows voids developing in a different area along the core.
This definitely looks like a process issue and not a bad batch.
I don't think there is a direct correlation...the chances for a manufacturing mistake are increased with a very low production cost.
My right side T-rex slider also did the split, I emailed T-rex and they asked for a picture of the problem. I emailed the picture and received a brand new one from them within a couple of days, I can not complain. And yes mine were torqued to 35 foot pounds. The left side has not had the problem as of yet.
