Fig. 1095.
It is obvious that a reamer must, to produce parallel holes, be held axially true with the holes, or else be given liberty to adjust itself true. [Fig. 1095] shows a method of accomplishing this object. The reamer is made to have a slight freedom or play in the sleeve, being 1⁄32 inch smaller, and the hole for the pin is also made large so that the reamer may adjust itself for alignment.
Fig. 1096.
Fig. 1097.
For short holes the shell reamer shown in [Fig. 1096] may be employed. Its bore is coned so that it will have sufficient friction upon its driving arbor to prevent its coming off; when it is to be withdrawn from the work it is provided with two slots into which fit corresponding lugs on the driving arbor. [Fig. 1097] shows the Morse Twist Drill and Machine Company’s arbor.