I bought the rikon and then I realized that my Delta was vibrating terribly...just like you. I then starting learning how to properly true and balance the wheels I had. There are some techniques to balance the wheels you have and it makes a world of difference. Google it. I did, however, find that the one way truing system, while klunky and difficult to use got me the best results. After messing with it, my delta is now smoother than the rikon, and the rikon was very good to begin with. While I agree with Rick G on the wheels. but I did not have good luck with that one way balancing system. The extrusions that they want you to put the wheels in were not true them selves. In our turning club we had three people say the same thing.
Besides the wheels being out of round, the biggest problem that grinding wheels have are the bushings. They mostly come with plastic bushings, and you usually need three of them stacked together......see the problem? If you look the Rikon wheels are sized to the arbor...no bushings....that is one reason why they are smoother. Besides that, they are not great grinding wheels. I replaced them. Next time you order from woodcraft, order a couple of their bushing sets....it will improve the performance of your old Delta tremendously. They are not cheap, like 19.00 per set, (One wheel) but they are well worth it.
About 3 months ago I bought a CBN wheel....it is awesome. If you get a chance, watch one work sometime. After getting both grinders running smoothly, I set up a two grinder workstation. I bought Sabre (nova) skew grinding jig and now have skew with only one facet, as opposed to the 3 to 5 I used to have. Two grinders is handy and it sounds like that could be within your reach. If you can not find balancing procedures, PM me with your email and I will send you a PDF.
