ok flash, how about a crash course in jaw crushers. What I think I'm looking for is something with a 18-24" x 8" hole. I need to be able to get from 1" to 4" minus material with a single pass. I'd also like the machine to be able to transported on a lowboy without oversize / overload permits. If it was a towed unit that would be fine too. Production wise 20 ton per hour would be fine, no more than 40. As for feeding the unit I plan on using my jd 450c trackloader. For power, either it needs to have its own diesel or it can be pto powered as long as it doesn't take more than 125hp.
The material I'll be crushing is pa bluestone or flagstone. Its best described as limestone that comes in layers. The layers varry from 1/4 and under to 8" thick the deeper you get in the quarry. Most quarries quit at about 6" rock and move on to better areas, so a thick jaw isn't a necessity. Most beneficial might be a interlocking rippled jaw so that a 1/2 x 12 x 12" pice doesn't slide thru when the jaw is set for 1.5" minus.
Idealy I'd like to be able to load both the crusher and the deere on to a lowboy then pull the trailer with my tractor. But I don't know if that is feisable.
How am I doing, is what I need out there, or do I have to make it?
I really don't think you're going to be effective with your sights set on an 8" opening. From what you describe you're dealing with a sometimes longer slabby type product and that is going to need plenty of room to come along the feeder and make the right angle turn down ito the jaw. Otherwise you'll get 'bridging' where the entrance becomes blocked.
For material like that sometimes an horizontal shaft impactor (HSI) is better where the feed mostly doesn't need to change direction as it goes into the crushing chamber. I find one of the biggest reasons an HSI might not be used is because of rapid and expensive wear. You're in limestone so that is not a factor - or shouldn't be. They can also tend to generate a lot of fines but will definitely give you a greater size reuction in one pass with none of the 'slivers' passing through.
I don't know if you can get this model in the US but if a jaw is what you really want, then what you're describing is ideal for the 9.7 tonne (21,230lb) Komatsu BR100J 24" x 13" track mounted jaw. It has a plate feeder usually but is also available as a BR100JG with a vibrating grizzly feeder. We buy them used from Japan where they are often found in their domestic market - but it may be a Japan domestic only offering. Certainly the two we've imported are not EPA compliant but one is a 1995 model (about 2600 hours)so pre EPA regulations and could come to the US. They're relatively cheap, we sell them under 3000 hours for US$73,000 and they're as reliable and easy to use as you could ever imagine. See if your Komatsu dealer can get you one?
Komatsu also make a BR60R which is another sub 10 tonne machine but this time an HSI on tracks. You can get older ones with very few hours on them and they'll also be pre EPA rules.
Another mobile jaw model is the Nordberg LT63 which may be available in the US but that's a 17 tonne machine. They're also getting up in price, I know of one here but its likely to cost US$120,000 just to by, it has a Deutz engine and is a very low hour 1995 model (pre EPA) so it could come to the US.
On softer rock as you describe the Hitachi HR240 - a very similar direct competitor to the Komatsu BR100 (but with less power) could be good. They're similar money to a Komatsu too.
If you're wondering about these older machines being still low in hours, so do I. But when I get them here they are genuine. I don't know what the Japanese do (or don't do) with them but I don't argue. They still sell them as a year 1995 and priced the same as others with the normally expected hours. They are only very few in comparison, but we find them occasionally and when we do, we buy them.
When in Europe recently I discovered the Rockster range of jaws and HSI's and they look very good and quality machines. They have some under 20 tonnes but with the strength of the EURO vs any other currency yu'd want to be holding your breath and sitting down when you learn the price of them. It does seem though that the Japanese and Europeans have the lighter crusher market to themselves. The Japanese have the advantage for now with the more favorable exchange rates, but I personally think their equipment is better too.
I hope I've been able to give you a few ideas there. Gordon