Customer Testimonials - Hear what our customers have to say.                                                                    

March 7th 2005   2" Diameter Chatter-Free Boring Bar                         

           Compact is a manufacturer of pneumatic air cylinders. Standard stroke lengths on the cylinder body start at 1/8 inch stroke up to around a 6.0 inch stroke. This is pretty much our common stroke range for all our advertised bore sizes. Cylinders within this stroke range are generated on a CNC lathe with Custom Macro B programming but then there are the customers that have specific need for longer versions sometimes up to 16 inches long. With bores this long, the cylinders were sent to the big turret lathes out in our shop for the boring process but a rough bore leaving the bore undersize was the best we could do. They were then sent to the honing machine where the bore gets honed to a finished size. After the honing process they get sent to manual lathes where two internal grooves are generated.  With cylinders this long trying to bore a 3.0 diameter hole and maintain a 32 max rms finish could not be accomplished and three processes were necessary to get the cylinder to the same stage our CNC lathes were producing the shorter versions.

We contacted Toolcraft Inc. of North Carolina and made an inquiry about a boring bar they called “Chatterfree”. We had them to send us a 2.0 diameter bar 20 inches long. For our first job, we set up on a 3.0 diameter bore x 15.5 inches long and bored the cylinder with a finish that was held within the 32 rms tolerance. With the bore to finished size, we were then able to generate the two internal grooves and face the part to length all in one chuck-up which kept all cuts concentric and parallel with each other. We not only were able to eliminate 2 operations but we increased our level of quality at the same time.

We have since purchased a 1.0 and a 1.500 diameter bars. Thanks Toolcraft for helping us keep our quality high and our pricing low.

 Kind Regards,  Bobby Moore,   Process Improvement Coordinator,  Compact Automation Products

April 20th 2005  18 1/2" Chatter-Free 50 Taper Milling Cutter

We are cutting using a rotating milling cutter with a 50 taper.  Using a conventional tool we were unsuccessful cutting at any depth.  We decided to try milling with 2 ½” index able cutter in vertical machining center using a Chatter-Free milling cutter.
The distance was 18 ½” from gauge line to end of cutter.  We were able to successfully cut .1600 DOC running at 1500 RPM at 21" per minute in a steel casting.

May 3rd 2005   1" Chatter-Free Boring Bar

In our application we were machining military parts.  The material was an Aluminum Alloy.  We took a round blank stock approximately 5" in diameter and roughed the ID to .0620 wall thickness.  The overhang of this part was in excess of 7" and the chuck was clamed on about .250" of material.  The required wall thickness after the finish cut was .0200 with a finish of 32 rms.  We continually failed this process because of chatter.

We used a 1" Chatter-Free boring bar from Toolcraft Inc. and were successful at this process running 3200 RPM with a .0035 feed rate on a Slant 50 turning center.

May 5^{th 2005 1 3/4" Chatter Free Boring Bar (Custom)}

Duff-Norton in Charlotte, NC.  

Components were bronze worm gears used in jacking systems.

The particular part we were testing on was 10.81” in length with on ID of 5.377”.  The process we were attempting was to cut acme threads to a depth of 5.961 with a pitch of .750 using several passes of about .0012 DOC using a 1 ¾” Chatter Free Boring Bar. 

The prior processes involved adding some finishing clean-up passes ranging from .0010 to .0005 DOC to clean out the chatter.  RPM’s were also held to a low rate due to excessive chatter at higher RPM’s using a heavy metal bar.

The CFT Bar we tested with included a replaceable, coolant through head as well as a hole pattern on the head collar that allowed for head replacement reversal as well as different sizes and types of heads, such as V thread.  We set the bar at 14” tool overhang and began running test parts.  We were able to run a total of 10 parts free of any chatter on two different worm gear sizes.  These two gears were parts we had determined were the most challenging for us to machine and not have chatter.

In both cases we were able to increase the RPM’s of the operation.  On the first gear, the smaller of the two, we were able to increase the RPM from 160 to 241, the second gear, the larger of the two, we were able to increase the RPM from 240 to 313.  We were also able to eliminate the clean up passes.  Since chatter was not present, they were not necessary.

This test proved that the CFT Bar would be beneficial to us in that the chatter was eliminated and the cycle time was reduced due to increased RPM and the elimination of the clean up passes. 

Additional benefits of the CFT Bar in our application is since the head was designed to be removable, with the addition of a left handed version of the acme thread inset head, this bar would be able to produce all 6 of the different gears made on the machine.  Insert life was also increase from 5 parts per insert edge to over 30 parts per insert edge.  Set-up time is greatly reduced by changing the head of the bar only, and not the entire bar, when changing over. This , eliminates the need to re-align the bar in the tool holder.