You'll find the descendants of KNECHTEL's from about 1500.Throughout history most surnames have gone through changes in spelling, even between generations. Often a name was recorded by a scribe simply by its sound, thus changing the name's written form. If the name change had been recorded in contracts or legal proceedings, this spelling often became a part of standard usage. Depending on the region, a name's spelling may vary quite considerably. In some cases the familyname changed from KNECHTEL into KNECHEL or KNEGTEL (Dutch and Belgium family) and into KNECHTLI (Swiss family), etc. As far as we could find all the Knechtel's ( > 3300 persons), Knechel's ( 395 persons USA), Knegtel's (353 persons) and Knechtli's (458 persons),Knechtly's (117 persons Switserland + USA),Knechtle's (162 persons), Knechtl (130 persons Austria), Knehtl (35 persons Slovenia), Knichel's (540 persons most of them in the USA), Knochel's (952 persons from Gumbrechtshoffen, Alsace and Offenbach, Palatinate, but about 90% of them in the USA), Knachel's (235 persons most of them in the USA). In most cases you can follow your line back till the 1500's.
My ancestor was also a Knechtel, but when he came from Bohemia to the Netherlands in 1746 he changed his name in Knegtel.