CNCzone.com-The Largest Machinist Community on the net!



Home Page Mark Forums Read Today's Posts My Replies Classifieds Reviews Photo Gallery Web Links Share Files Advertise With Us Ad List
Go Back   CNCzone.com-The Largest Machinist Community on the net! > MetalWorking > General Metalwork Discussion


General Metalwork Discussion Discuss everything relating to metal work.


This forum is sponsored by:

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Ban this user!
Old 10-29-2007, 07:38 AM
 
Join Date: Oct 2007
Location: USA
Posts: 30
kwhizz is on a distinguished road
Tapered Seat Finish

We are turning some parts that have a 60 Degree Internal seat in them....It starts at about 7/16 and tapers down to about 3/32 where it meets the center thru hole.....we are putting the taper in with a small Boring Bar because of the small thru hole........we are having trouble with consistancy of the surface finish.....material is 4340 ....28-32 rc......Is there any tricks or special Tooling for getting rid of the circular boring finish grooves.......need to be a 1Rms or better on Profilimeter readings.....

Thanks
Ken
Tweet this Post!Share on Facebook
Reply With Quote

  #2   Ban this user!
Old 10-29-2007, 09:34 PM
 
Join Date: Oct 2006
Location: USA
Posts: 669
307startup is on a distinguished road

It sounds like a combination of a VERY small radius insert & much smaller feed rate is going to be necessary to accomplish that finish...
Tweet this Post!Share on Facebook
Reply With Quote

  #3   Ban this user!
Old 10-29-2007, 10:10 PM
 
Join Date: Oct 2005
Location: US
Posts: 247
ctate2000 is on a distinguished road

Use a center lap to finish the operation. Buy it from MSC. Put the lap in drill press and turn slow if you can't see the flutes as the tool turns you are going to fast. Hold part against tool with hand pressure and lap to achieve finish. You may want to leave a thou or three for finish as the lap will cut slightly. The lap is not usually agressive enough to move the hole but I would verifly the dimensional correctness on the first few parts. Try to get the best finish possible from the machine tool before lapping. Oil the lap good each time and blow the flutes clean before each part. You can use the machine tool to do this if you are trying avoid hand work I would feed to depth and dwell for 1 sec or so with lots of coolant.
Tweet this Post!Share on Facebook
Reply With Quote

  #4   Ban this user!
Old 10-30-2007, 09:45 PM
 
Join Date: Aug 2006
Location: US
Posts: 244
cdlenterprises is on a distinguished road

Your not going to hold a 1 RMS finish using any conventional machining method that I know of. Lapping as mentioned before is probably your best bet. This is a huge shot in the dark but you may be able to burnish it some how, but the small size may be a problem. I would give the guys at Cogsdill a call and see if they can help....
__________________
I don't know much about anything but I know a little about everything....
Tweet this Post!Share on Facebook
Reply With Quote

Reply




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
I'm looking to buy a used seat of Gibbscam zak GibbsCAM 4 07-03-2011 11:38 AM
Anyone interested in a used seat of OneCNC Lathe? Edster OneCNC 3 03-07-2007 11:19 AM
I might buy a seat if.... bpmufx MadCAM 11 12-07-2006 09:58 AM
About to become the youngest seat holder in OneCNC Cold Fusion OneCNC 13 06-28-2004 03:23 PM
onecnc in the driving seat peter OneCNC 22 12-09-2003 03:52 AM




All times are GMT -5. The time now is 09:20 AM.





Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2012, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO
Template-Modifications by TMS

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353