Combines CDF question

[tbran]

The adjustable grate is just an added benefit. I would still go with the CDF. This has less loss in our area if nothing else simply due to the fact of being able to run at higher rpm, thus more centrif force. Better grain quality, less hp and less cob problem.

 

[tj]

Don't want to start an argument, but I guess I need to point out the differences between rotors. The advantage of either rotor is that slower rotor speeds are possible without increased HP requirement, since the mount_rotor bar arrangement prevent material from escaping to the cylinder center -- holding the crop against the concave, helicals and cage surface. Also, it's pretty much understood that the faster the rotor speed, the more chance for grain damage, whitecapping problems and that trash will be torn up worse and that more cobs will be broken up. Main differences are in bar mounting -- we mount bars flatly so the leading edges of thte teeth and the top arch of the bar are effectively used. The CDF has the bars sloped forward. Difference in feeding is that the leading edges of the teeth on the flatly mounted bars engage the crop much more effectively than the rear of the teeth on the sloped bars. The sloped bars pinch the material while the flat mounted bars impart more of a tumbling action and trash doesn't need to be torn up as much for separation. Other main difference is that we use a 20" diameter tube while CDF uses a 18" tube. Our rotor maintains material at a 1" closer spacing to other components than CDF -- in addition to the sweep agitators which we use, I think that's why grate adjustment isn't as critical with our rotors. Also, with a 2" larger tube diameter, centrifugal force will always be greater at any given rotor speed. There's more to this, but these are probably the main points. Hope it's clear. Terry Welch

 

[tbran]

Oh no argument, either is better than the stock unit I would say. We can with the CDF run 50 - 100 rpm faster without grain damage. I like the bars angled like your cylinder. What I would like is your system on the smaller diameter cylinder in the separator side. After threshing the material expands and we need the extra room. Interesting ideas, all.

 

[tj]

That could be done -- ramification might be that we'd need to offset the last 2 rows of bars a little for the transition, might even want to take existing 4 hole bars from the discharge side and cut them in 1_2 in order to customize mount lengths to concave width (that would be about 2 1_2 rows over the concave and grate areas respectively). A big advantage could be that the rotor size could be made adjustable by spacing_shimming out the bars (can't do this on a rotor with forward sloped bars). I've thought of doing that in the past, and will likely try it one of these days, but leaving things at the full diameter as at present, appears to work very well without all of the work involved. Problem with these machines is that they have so much potential that even though we've all made large improvements, I don't think that we've quite reached the ultimate.

 

[sidekick]

I believe St.Johns can use your cyl shaft to build their rotor saving some dollars.

 

[turbo]

So what is the overall diameter of your rotorIJ Do you have pictures of your SweepsIJ

 

[tj]

Overall diameter is 25" -- same as original rotor. Yes I have pics of the sweeps -- not great photos (not an ace photographer here) but they beat trying to describe them. Can't post photos here, but I can email them.

 

[R72]

I will take some emails of your set up. Do you have a web site. frasers@inetlin.ca

 

[Brian]

Yep your right. We have already decided to go with a St. Johns in one machine. Have talked with one guy who has St. Johns and he loves it.

 

[tj]

I'll email pics in the A.M. Website is www.stjohnwelding.com -- needs a serious upgrading, and photos aren't current, but you should be able to get an indication of how the sweeps are mounted.