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Complete manufacturing of complex components: NILES-SIMMONS machine concept „CLOSED-DOOR-MACHINING“

NILES-SIMMONS deve­lo­ped the machi­ning con­cept “CLOSED-DOOR-MACHINING to meet the ever-incre­asing requi­re­ments con­cer­ning the manu­fac­tu­ring of com­plex, high-pre­cis­ion parts and com­pon­ents initi­ally for the avia­tion industry.

This con­cept allows the com­plete machi­ning of parts in one con­ti­nuous pro­cess within one machine and wit­hout any ope­ra­tor inter­ven­ti­ons. It is appli­ca­ble for various part types which, his­to­ri­cally, had to be manu­fac­tu­red in seve­ral pro­cess steps on various dif­fe­rent machines.

Tur­ning-Mil­ling-Cen­ter N30 MC with CLOSED-DOOR-MACHINING manu­fac­tu­ring concept


When using the “CLOSED-DOOR-MACHINIG”-concept, a raw part is clam­ped into the machine and after seve­ral fully-auto­ma­tic re-clam­ping and re-chuck­ing pro­ce­du­res, it can be remo­ved as a com­ple­tely finis­hed part. The machi­ning runs enti­rely unin­ter­rupted and depen­ding on the part com­ple­xity shifts can be over­lap­ped a num­ber of times throug­hout the cycle.

Since the pro­cess runs fully auto­ma­ted, the time asso­cia­ted with labor-inten­sive part-hand­ling pro­ce­du­res moving parts bet­ween seve­ral machi­nes is remo­ved and lay down spaces can be redu­ced. Simi­larly, the tasks for ope­ra­tors are also redu­ced since less machi­nes are requi­red and less ope­ra­tor inter­ven­ti­ons are necessary.

By inte­gra­ting all neces­sary tech­no­lo­gies into one machine, such as tur­ning, mil­ling, dril­ling, deep-hole dril­ling, bot­tle bor­ing thread cut­ting, gear hob­bing, power ski­ving and grin­ding, there is no need to use spe­ci­fic sin­gle machi­nes, which con­sider­a­bly leads to a much more cost-effi­ci­ent pro­duc­tion over the long term.

For the imple­men­ta­tion of the con­cept we intro­du­ced seve­ral new machi­ning and mea­su­ring tech­no­lo­gies. In doing so it is now pos­si­ble to achieve extra­or­di­na­rily high accu­ra­cies of <5µm in a pro­cess-relia­ble way by the use of scan­ned part mea­su­ring through RENISHAW Sprint mea­su­ring sen­sor and auto­ma­tic tool com­pen­sa­tion after the mea­su­re­ment cut. As well as Sprint there are also other various touch mea­su­ring sen­sors such as RMP60 or RMP600 fit­ted to carry out other mea­su­re­ment tasks.


Renis­haw Sprint mea­su­ring sensor


At the same time, the mea­su­re­ment of all neces­sary tools also takes place, again fully auto­ma­ted within the machine using a touch mea­su­ring sys­tem for fixed tools and an optic mea­su­ring sys­tem (laser) for rota­tio­nally sym­me­tric tools.


Inte­gra­ted tool mea­su­re­ment with laser


In order to accom­mo­date the large num­ber of tools requi­red to-be-used, it is pos­si­ble to con­fi­gure two tool maga­zi­nes head­stock and tail­stock side with a capa­city of up to 144 tools each to ser­vice the multi-axes tur­ning-mil­ling unit. The tools can be exch­an­ged auto­ma­ti­cally into the working area from eit­her side.

Alter­na­tively, for spe­ci­fic machi­ning tasks an addi­tio­nal maga­zine can be applied for the coun­ter spindle or tail­stock sided bor­ing bar slide. This long tool Maga­zine has a maxi­mum of 16 posi­ti­ons for long tool car­tridges. These long tools are also exch­an­ged auto­ma­ti­cally into the second slide.

The long tools with up to two meters in length can be ope­ra­ted with high coo­lant-pres­sure of up to 300 bar and respec­tively with a high flow rate of up to 150 l/ min. Con­se­quently, any deep-hole dril­ling requi­re­ment can be achie­ved as part of an extre­mely sta­ble and relia­ble pro­cess. The tem­pe­ra­ture-con­trol­led coo­lant can be pro­grammed with both pres­sure- or volume-con­trol­led and moni­to­red via sensors.


Addi­tio­nal bor­ing bar maga­zine for com­plex inter­nal machining


For sur­face opti­miza­tion of the parts, it is also pos­si­ble to inte­grate grin­ding ope­ra­ti­ons in the machine. The grin­ding wheel can be exch­an­ged, mea­su­red and dres­sed fully auto­ma­ted. For spar­king, there are also sen­sors available. The coo­lant, which needs to be posi­tio­ned close to the pro­cess, is con­trol­led and posi­tio­ned by a sepa­rate, pro­gramma­ble NC-axis.


Pro­cess inte­gra­tion: Grin­ding inclu­ding dres­sing unit and spe­ci­fic process-software


A hig­hest equip­ped machine with tur­ning-mil­ling unit, bor­ing bar slide, tur­ret (bot­tom), main- and coun­ter spindle as well as ste­ady rests and tool change units can be con­fi­gu­red with up to 32 NC-axes. Due to this com­ple­xity, a CAD/ CAM sys­tem with inte­gra­ted post pro­ces­sor is essential.


Tur­ning –Mil­ling – Cen­ter N30 MC inclu­ding bor­ing bar maga­zine and up to 32 NC-axes


Fur­ther­more, a liquid-coo­led spe­cial con­crete machine bed is used to achieve hig­her tem­pe­ra­ture sta­bi­lity and to ensure the reques­ted accu­ra­cies despite varia­tion of tem­pe­ra­ture. The machi­ning cen­ters are also equip­ped with dam­ping and vibra­tion redu­cing com­pon­ents such as FEM opti­mi­zed slide-geo­me­try, hydrau­lic clam­ped com­pon­ents of the part-axes, dam­ping sur­faces in machi­ning direc­tion and rol­ler gui­des of the machi­ning axes in size 45/55.

To ensure a clear and easy ope­ra­tion it is used a Sie­mens OP 19 panel with addi­tio­nal touch­screen for pro­cess monitoring.

The pro­cess secu­rity within the “CLOSED-DOOR-MACHINING “-con­cept is signi­fi­cantly enhan­ced through NILES-SIMMONS com­pre­hen­sive soft­ware modu­les dri­ven by indus­try 4.0, such as Volu­metric Com­pen­sa­tion Soft­ware, spindle modu­la­tion, axis com­pen­sa­tion, tool breakage- and drive monitoring.


Soft­ware modu­les PCS and VCS for hig­hest pro­cess security


The smooth inter­ac­tion of these soft­ware com­pon­ents with the sophisti­ca­ted machi­ning- and mea­su­ring tech­no­lo­gies and the resi­li­ent and well-con­cei­ved machine design builds the foun­da­tion for suc­cessful “CLOSED-DOOR-MACHINING “wit­hout ope­ra­tor intervention.

This effi­ci­ent machi­ning con­cept is suc­cessfully run­ning at num­e­rous cus­to­mer faci­li­ties world­wide and has estab­lished in the mar­ket with great success.



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If you have any ques­ti­ons about the machi­ning con­cept or about our machi­nes and tech­no­lo­gies, please do not hesi­tate to cont­act us:


NILES-SIMMONS Indus­trie­an­la­gen GmbH
+49 371 – 802 204