I feel that Dremel went a bit cheap in making their 90 degree attachment and their flex tool. They both get really hot during use, but then look at how high the RPM is on the 4000. There is no need to run these attachments at 35,000 RPM. Since its variable between 5 and 35k, keep it about 15k and they will work as advertised. I trim and shape steel with mine and there is no need for higher rpm for that application. The few extra seconds of cutting time just isn't worth it.
