Since 1973, Micro-Matics of Fridley, MN, has been manufacturing CNC Swiss precision screw machine products including many kinds of contacts & pins, ground shafts, hardened bushings, rivets, screws, spacers and other custom parts for the medical, dental, aerospace, commercial, defense, computer, telecommunications and automotive industries.

According to Jason Wobig, Operations Manager, "Micro-Matics is primarily an aerospace and medical components, Swiss machining job shop. We make components that are thousandths of an inch up to an 1-1/4" in diameter. We started out with the old manual style, Cam driven Swiss machines and we're one of the largest Escomatic shops in the Midwest.  And as the company's grown and evolved, we've turned into Swiss job shop, mostly Citizen machines like the M16,  a L12, and a M32, as well as a few Star and Tsugami machines that give us a wide variety of capabilities."

In 1996, Matt Saccomanno, CEO of Masa Tool, was frustrated with the limitations of conventional collets and workholding systems when performing secondary machining operations so his solution was to develop a high-precision, collet-type workholding device for small parts machining.

The Microconic system consists of a cartridge and collet, with the cartridge fitting in the machine just like a standard legacy collet. The cartridge is a self-contained precision mechanism using the machine’s standard collet closing function, which means that the Microconic system can be used on any machine utilizing 5C, TF20, TF25 or TF37 collets. 

According to Saccomanno "Since a collet system for any given machine must be made large enough to fit the maximum workpiece diameter capacity of the machine, the result is the standard collet mechanism is designed to handle the largest workpieces, which means it is excessively forceful and bulky when used for the smaller workpieces. Smaller parts get sacrificed, because they typically require a higher degree of accuracy and the workholding is more critical."

The Microconic system consists of the cartridge, which fits into your machine like a standard collet, and the Microconic collets which fit into Masa's unique cartridge.  Every Microconic cartridge comes standard with extended nose for unsurpassed rigidity because of it's single piece construction.

"In fact, the cartridge is so accurate that it can be used as a gauge to verify machine spindle accuracy," said Pakiz.

Thayer explained how the Microconic system has worked for Micro-Matics "With the Masa system we're able to dial in a nice specific tension to hold that catheter part without crushing it or deforming it at all and having it on center.  In a nutshell, we get better quality parts consistently with tighter tolerances. It's lead to a really significant improvement, it's increased throughput, so we have more parts at the end of the day."

"As a result of the implementation, the scrap rate on this part dropped dramatically once we added the new Masa system by at least 30%." added Wobig. 

According to Masa Tool, the Microconic cartridge  concentricity is guaranteed to be within 5µm (.0002") runnout and the collets are hardened and precision ground to the highest quality standards. The regular, UM10,  10mm collets, that  Micro-Matics is using in their F20M10 Cartidge are available from Ø0.2mm (.008") to 10mm (.394").  In additon to the TF 20 spindles, the same collets can be used in TF25, TF37 and 5C sub spindles.

"With the Microconic system, we didn't need to buy any special collets for any specific profile, we just got the actual diameter for the OD of the part and we're running it with that. The spaces in between on that collet is small enough that it's not distorting the round to flat portion if it even gets into there at all. So there's no timing issues at set-up. We just put it in there, set our tension, and start picking them off." added Wobig

Thayer continued "The extended nose pieces on the Microconic cartridge helps on the catheter tips because  you can get closer up to where I actually have a supporting back end.   Because if I'm too far away from that supporting back and you have more of a tendency to crush the front of that part. The Microconic gives me a better tension on the part.  On the distal coupler, we have to use a boring bar, or a facing tool to create the back face, which is round. We'd have a lot of trouble trying to hold without nibs or anything on there. And this holds it so that the part stays a little more square, and we're able to turn it better."

When dealing with very small parts and setting with small gage pins, accidents do sometimes happen.  "The only problem I've had with it was when somebody was trying to set the collet tension with a pin. They put the pin into the slot and not the hole and wrecked the collet. Because the pin was able to fit inside the slot so when they started tightening it up, and the pins started deforming the collet was wrecked because it wasn't in the hole in the center." said Thayer.

Masa has indicated that they will release a new TF 15 and TF16 Cartridge with an entire series of smaller 5mm capacity collets at IMTS 2022.

The push-type F201M10 micro-workholding cartridge system replaces F20-201 cartridges allowing the user of Microconic collets to achieve concentricity within 5µm (0.0002") in production use.

For use in high precision, small diameter CNC turning applications, it enables users to move more work to the sub-spindle for reduced cycle time.

The F201M10 cartridge is compatible with spindles that accept F20-201 collets including DIN 136E, Meister Swiss 136E, Schaublin F20 (76-201), Southwick & Meister F20-201, KEB (MasWerks) MC20-201, and Hardinge F20-201/4709 collets.

This article originally appeared in
Today's Medical Developments
July 5, 2018

Microconic’s cartridge is made of exotic high-chromium tool steel, triple tempered and cryogenically treated to provide stable construction. All functional seating surfaces are ground with extreme precision on a one-piece, ultra-rigid body structure.

“The cartridge can be used as a calibration gage to verify the machine spindle accuracy,” Co-owner Chip Prescott notes.

Microconic collets are finished to exacting standards with a five-step grinding process that removes the effect of heat-treat warpage. Also, the proprietary Microconic form of the closure surfaces is inherently more accurate than traditional collets, providing for a greater full-accuracy working range.

Cartridges are available to fit in push-type dead-length collet closers and also draw-type closers: F20M10 (for TF20 collet replacement), F25M10 (for TF25 collet replacement), and 5CM10 (for 5C collet replacement). All of these cartridges use the same Microconic UM10 collets, with more cartridge sizes in development to be released soon.