Recent content by Christo_AU

Hi Dave Thank you, I calculated the cycles and its about 10% of an auto's v-belt cycles before replacement, also at no load. The assembly has since been readjusted and its much easier to turn now, I measure it at about 0.6 Nm. It should all be okay. Hi mfgenggear Thank you for the great...

Thanks Dave, thats a relief. I have since also spoken to my boss. Although he isn't too concerned, he did mention that if the two shafts aren't parallell (red lines), the pulleys could wear out the belt. This could also happen if the pulleys aren't on the same level (purple lines). I think this...

Good day I am not very experienced with the design of powertrain parts and would appreciate any help. I have designed a v-belt and pulley assembly, please see the picture below. The load (platform lifted with screws) is normally driven by a servo motor. In case of a power failure, the...

Hi All Thank you for all the feedback, much appreciated. I found the following standards relating to commercial truck/semi-trailer transport. This is only for on-road transport. Might help someone in future. ISO 13355 (in the latest edition theres 3 PSD's from different countries) ASTM...

Hi btrueblood Thank you for the feedback. I obviously can't disclose any details, but we do have some freedom with the design loads as this will only be transported by commercial semi-trailers on asphalt and reasonably well maintained dirt roads. We also aren't bound to 810 in the requirements...

Hi All I am designing a modified shipping container to be transported by truck on both asphalt and dirt roads. This is a defence job, so the design loads are typically obtained from MIL-STD-810. However, the off-road truck transport vibration PSD from 810 seems extremely conservative (Table...

Hi All Some help please. Does anyone know how to calculate the torque required to lower a load with a screw jack? Plenty of formulas available for raising it. Or even a formula to calculate the ratio of torque required for raising versus lowering? I think these values will not differ by much...

Thanks all, this is very helpful. Yes Ed, those shoulder bolts definitely would do the job. I was just curious.

Thanks for the ideas Tmoose. Unfortunately I don't have a sketch to share. This is a general question. The example in the original post is just an example, not a specific problem I'm trying to solve.

Thanks for the feedback all. I have used this approcach before where it isn't possible to use "off the shelf screws" to achieve the connection required. Sometimes the design constraints can't be solved with standard fixings and a bespoke solution is required. I feel that it's a lot cheaper to...

Some help please with a newbie question. If I machine a big screw, will it retain it's strength and hardness? Does it have the rated strength and hardness throughout it's thickness or is it softer in the centre? For example: Using a lathe, I turn down an M20 bolt to have a shoulder with an M10...

Thanks all for the feedback, much appreciated.

Hi All. I am investigating damage done to some steel brackets which connect a shipping container to four screw jacks used to level it. I have never been involved with the investigation of damaged steelwork before. I want to confirm that there are no cracks at the welds using dye penetrant...

Thanks all for the feedback. This has been most helpful.

Thank you EdStainless. Is this only applicable in countries where NaCl salt is used to melt ice on roads? Or would this happen in dirt roads in Australia with other salts encountered in the soil?