NH 630 634 638 Round balers

Couple days ago someone started the thread “Round Balers” , he was looking for advice on small round balers and someone suggested NH 630, 634, 638. Whats the difference between these models? They are all roughly 20 year-old 4x4’s with twine tie, right?

All twine tie, many of the parts interchange, but not all.

I run a 630, there is a serial number break in the model, I did note when I looked up some parts, the numbers were the same for all three balers. I know the belts are all the same, hyd cylinders the same (but different seal kits!!!)

You can get a "high moisture kit" in some of them.

Later ones have a tipping bale ramp, not a fixed one. Most later models have lights.

Differences in twine door latching, tension springs (single on later ones, I have double ones), hyd piping to tailgate cylinders etc.

I've been able to get any part from NH for my "before" 630 (oldest one) I've been slowly working making it "new" again.

Simple machine in my opinion. Someone who works on them a lot may have better ideas on anything critically different.

The BR730 and BR7050 were newer versions, CaseIH also has the RBX441/442/443/444 etc. in CaseIH colors. So I think they made the basic machine from 1989 to recently.

I run on 42 PTO HP fine, bale at 4.4 MPH, only need to gear down with a full chamber and pulling up grade. Previous owner had it on 64 PTO HP, said he baled a lot faster than I can.

What I like running on "less" power is you are less likely to tear something up. I had a bearing go and I could tell immediately as the tractor lugged slightly and I stopped to check. More power might have resulted in a burned up baler.....