Frame Building Tools
I’m very proud to present the LAN 71 range of tube mitre cutters, made by Andy Newlands in Portland, Oregon.
These extremely high quality cutters are now available in the UK via Wilkinson Cycles. For enquiries please contact: mwilkinsoncycles@gmail.com
Andy is a highly skilled frame builder and frame tool maker with 40 years’ experience. See http://www.strawberrybicycle.com/ for more information.
Pictured here are sizes 36.4mm, 35.0mm, 31.7mm and 28.6mm.
Other sizes are also available; please feel free to contact me for details.
The cutters are made from T-15 PM (particle metal), also known as powder metal and sintered.
The cutters are blanked out on the lathe in the Strawberry workshop then heat treated locally and precision ground by McKenzie Tool Grinding also in Portland, Oregon. The particle metal is harder and tougher than 8% cobalt M42 high speed steel with a similar red hardness property.
T-15 PM has the same components as conventional T-15, but it is manufactured in such a way that uniform carbide distribution and even particle size is obtained.
T-15 PM grinds far more easily than conventional T-15 for form grinding and resharpening tools, and is much tougher than conventional T-15. It can withstand shock and is not nearly as brittle as conventional T-15, retaining excellent high wear resistance and red hardness.
A choice of good quality Chinese-made 3/4″ straight shank arbors or R8 taper arbors are also available.
Please email me for prices and postage: mwilkinsoncycles@gmail.com
Cutting speed info:
The question of what rpm range is suitable for tube mitring has come up several times. The answer has several parts – machine rigidity, flood coolant or not, proper feed rate, cutter diameter, tube material hardness, tube gauge, etc., are some of the factors. One place to start to determine a good rpm is to use a surface feet per minute table for drilling – this seems to be conservative even though the chip flow created by a drill bit is not the same as that from a tube mitre cutter. To simplify, let’s assume a small mill is used without flood coolant, hand feeding, 1-1/8″ (28.6mm.) cutter, 4130 material with a Brinell hardness of 179 and a 0.9mm. wall thickness. Published tables of surface feet per minute (SFM equals the cutter circumference times RPM) for drill bits show a range from 60 to 90 feet/min for material with a Brinell hardness under 200 which 4130 satisfies. RPM equals 3.814 times the SFM divided by the cutter diameter in inches, which for a 1-1/8″ cutter gives a range from 200 to 300 rpm. If the material is heat treated and has a Rockwell (RC) hardness number between 35 and 40, the resulting rpm drops to between 100 to 135 rpm. With a little trial a good speed with the parameters unique to the condition will be found.
W A R R A N T Y
Terra Nova Cycles, LLC (TNC) warrants to the original purchaser of LAN71 tube mitre cutters that they shall be free from defects in material and workmanship. Please note that like all high speed steel cutting tools the LAN71 tube mitre cutters are brittle by nature. Because of this fact and because the conditions of use cannot be studied by TNC, no refund will be made for broken cutters. TNC’s obligation under this warranty is limited to furnishing without additional charge a replacement or, at its option, repairing or issuing credit for any cutter which shall within one year from the date of sale be returned freight prepaid together with a copy of the original invoice to TNC’s workshop and which upon inspection is determined by TNC to be defective in materials and workmanship. Complete information as to operating conditions, machine setup, and application of cutting fluid should accompany any product returned for inspection. The provisions of this warranty shall not apply to any LAN71 mitre cutter which has been subject to misuse, improper operating conditions, machine setup or application of cutting fluid or which has been repaired or altered. The cutters are not guaranteed against tooth breakage.
