I'm interested to know, what machine is used to resurface flanges to make them flat, if they were warped during fabrication.

 

A surface grinder would do an awsome job or you could lick it with a fly cutter in a well set-up mill.

 

all depends on the part. resurface a cylinder head intake or exhaust flange on a brigdeport and it will be bowed on both sides with high spot in the middle. the head is so large that the table must traverse too far and the weight of the part and machine itself bend the gibs/ways downward so the thing will be off by a good deal. if its an exhaust part, setting up flat and level with tubes and crap all in the way will be a tedious adventure.

i large flatbed belt sander is probably the most reasonable means. surface grinder is out.. you cant really fixture something with tubes and its gonna warp after welding if you were to surface prior. for things not requiring high precision, sliding the item back and forth on sandpaper over a perfectly falt surface like a marble inspection slab or something works well. ive surface harley and dirtbike heads like this many times.

true surfacing machines are those where the table and part sit still while a head moves over the bed with a flycutter or composite wheel. not fixed spindle, sliding table.

what are you trying to do exactly?

 

Mike no offense but you need to get a new machine or have yours checked. There is no problem doing an intake or exhaust or even a head (although it's not the best for a cylinder head but in a pinch it will do a good job) with the right cutter and enough table travel. I have surfaced allot of intakes some of which have been on one of the fastest alky dragsters in the country and have no problem. I bought my bridgeport new quite some time ago and it is still in very good condition and it also has the longest travel available with chrome ways.

I do agree with you that the best thing for flanges is a belt sander. Use a good belt like a norton zirconia (blue) for the best and fastest results especially if the flanges is stainless. 80-100 grit a 6x48 is a good size and about the minimum for doing flanges These can be bought for as little as 170 dollars from many places sometimes less. The only thing that i strongly suggest is replacing the motor and motor pulley with a 1 1/2 to 2 hp (Northern Tool works) and a pulley that is larger 2 1/2" to get more belt speed. Make these changes and you will have a kick *** belt sander that is as good as a 1600 dollar delta or kalamazoo

 

Mike- this is the machine you are talking about. It's called (per the tag at the bottom) a Rotary Broach.

Our mills have no problem holding a few tenths (.0003) flatness across the entire travel of the machine, the largest of which in our shop is 48."

FlashMN, just what are you trying to do anyway?

 

belt sander or a mill

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KFMRC &raquo;</TD></TR><TR><TD CLASS="quote">Mike no offense but you need to get a new machine or have yours checked. There is no problem doing an intake or exhaust or even a head (although it's not the best for a cylinder head but in a pinch it will do a good job) with the right cutter and enough table travel. </TD></TR></TABLE>

thats the thing, enough table travel.

im not refuting your statement, but ill go a little farther to explain my answer. my bridgeport ..

is the same ancient little 9" x 42" bed that hobbyists and small shops are most likely to own. i considered that the person asking was not likely to have access to a large or more modern bridgeport when i answered, since otherwise he probably would be asking a machinist instead of posting here.
i worked in machine shops as a kid and most are gonna have a few small Bports and maybe one or two of the big guys. i agree, the monsters with big tables and bases (dont know size or model off hand) should have no issue handling a cylinder head. mine at 30 odd years old is worn like all the rest. doesnt matter how much you tighten the way adjusters.
i tried a cylinder head flange a few weeks ago and no matter how i center it, to get the flycutter all the way off the head the table is hanging way out and bows the ways down a few thousandths. i figure the table is a good 180 lbs and the head plus my fixturing is another 80. just too much for a tired machine. it isnt the reason we have it in the first place and it suits our non-precision needs around here just fine.



this is the machine that my crap gets bored and surfaced on, and no i certainly do not own it.


thats what i mean by fixed bed, sliding spindle.

 

Well I'm not exactly trying to do anything right now, was planning to make few exhaust manifolds, so just asking if I warp them during welding, that what should I use to get them machined flat.

 

some people bolt them to cylinder heads or clamp them to heavy plates during welding to reduce warpage. the belt sander is probably youre best bet for the time/money