Any machinists in the house?

Helping a friend with a little project. Trying to get a small adapter machined but can't seem to find anyone to do it.

Anyone here up to the task (not looking for a freebie, willing to pay) or can point us in the right direction? We tried e-machineshop and the cost for a one off was very prohibitive.

Specs below, machined out of bronze or perhaps steel.

Looks like the whole image doesnt fit in the screen, it can be found here if you need further detail.

http://www.misfittoysracing.com/images/pilotadapter.jpg

Bronze or steel? It's quiet at work, I can take a whack at it next week if you don't mind a mild steel like 1018.

Dan

914Driver wrote: Bronze or steel? It's quiet at work, I can take a whack at it next week if you don't mind a mild steel like 1018. Dan

Thanks Dan, that would be great if you could. Its a pilot bearing adapter so I think mild steel should be fine. Just shoot me a PM with cost and such or if there's anything we can do for you!

My overhead at work is over $400/hr. I won't tell them if you don't.

Pilot bearing adaptor, any stresses or loads involved? If so which direction?

Dan

Those are some damn tight tolerances. That's probably why nobody will touch it.

DILYSI Dave wrote: Those are some damn tight tolerances. That's probably why nobody will touch it.

Oh, oh, oh, I think I just got more expensive!

Kidding, but out of curiosity what were the quotes? You can PM me if you don't want to broadcast it.

Dan

+.0000 -.0005? at what temperature? lol that is a reeeealy tight tolerance.

Yeah, the tolerances are super tight. I turned a one piece PB for the J-H out of Oilite bronze, the recommended tolerance from shaft to bushing was something like .004.

Jensenman wrote: Yeah, the tolerances are super tight. I turned a one piece PB for the J-H out of Oilite bronze, the recommended tolerance from shaft to bushing was something like .004.

BWAHAhahahaha! I had a guy make bushings out of oilite bronze and he zinged the things at a zillion rpm; he spun all the oil out of the material.

RXBeetle wrote: +.0000 -.0005? at what temperature? lol that is a reeeealy tight tolerance.

no it's not... HA!..

thats 13 microns.. Thats a mile in my business. I do it all day every day on the shop floor.

The hydro dynamic journal bearings used on turbos( btw.. very rudely called bushings in a recent GRM arctile) have a 10 micron id/od concentricitiy call out..

bushings? yeah great article.. Well the part about showing a turbo can produce torque was good. But the author showed some major turbocharger ignorance..

You know what they say, If you don't like the tech article write a better one ;)

914Driver wrote:

Jensenman wrote: Yeah, the tolerances are super tight. I turned a one piece PB for the J-H out of Oilite bronze, the recommended tolerance from shaft to bushing was something like .004.

BWAHAhahahaha! I had a guy make bushings out of oilite bronze and he zinged the things at a zillion rpm; he spun all the oil out of the material.

Hey, I discovered that even at low speeds if you get the stuff too hot it'll ooze all the oil out as well. This means I actually had to make 2. :oops:

John Brown wrote: You know what they say, If you don't like the tech article write a better one ;)

sorry but calling a turbocharger journal bearing a bushing is like calling a main bearing on a connecting rod a bushing. It is incorrect and us turbocharger types get upity.. rawr...

now I will say I was happy that he showed that a small turbo 4 can produce wonderful torque characteristics on a miata engine. The old "supercharger" is for torque adage is alittle bit worn and not exactly correct.

pm me, I know a machinist right over the bridge in Pa that can do it, and probably at lower cost than most others.

Im having my buddy sign up to answer some of the questions since Im not terribly familiar with the finer points. he just came to me to see if I knew anyone who could do it.

E-machine shop wanted like $100 or so I think for it or $30 each if he ordered 10 or more but he didnt need 10 and couldnt find anyone else to buy in on them.

I think there is a guy that's supposed to be making them but his lathe died or some such thing and he hasn't had the time/money/inclination to get it fixed yet.

Yeah, tight tolerances, but no concentricity call out; that's a bit odd. I suspect there is a better way to dimension this part.

Jack

diesel injector needles..

5 micron on dia.. +/- .0025mm HA!

which is +/- .000098 inches

There are certainly tighter tolerance in the world than a half-thousandth, but they generally aren't acheived with conventional machining on a lathe, which is what the part in question appears to call for. Combining that tolerance on the ID, with a +/-.001 on the shoulder depth makes for a pretty damn tricky part on conventional equipment.

Alright I couldnt sit on the sidelines any longer, I usually post under another name (see link below) but hit some kind of snag trying to register under that name for GRM.

The project is an LS1 swapped '84 944, Im trying to keep it as budget as possible. The pilot bearing was a particularly hard thing to obtain, one place sells it for 110 bucks and its this fancy thing with a snap ring holding the roller bearing in place... emachineshop can make the one for 280 bucks. Drexel machine shop won't do any kind of vehicle projects (liability stuff). I think Jim covered the rest.

As for the tolerances Im not totally sure how accurate it needs to be, Im just pulling some drawings off of the hybrids website. I assume its so accurate so that it holds the bearing properly?

Additionally you guys are friggen awesome Here is the link to the project: http://www.porschehybrids.com/php/viewtopic.php?f=2&t=2845

would be hard to turn out on a regular lathe with a three jaw..

could probably do it with some careful work in a nice 4 jaw.. but I'd say the tolerances aren't super hard due to the lenth of the part only 1 inch.. Greater than that and you'd be hard to hold that without a good cnc or grinding.

Here is an image of nearly the setup I am talking about, the actual drawing is of an LT bellhousing whereas i am using a one piece LS bellhousing i think the dimensions are there for both. The yellow part is the adapter: http://www.porschehybrids.com/php/download/file.php?id=570

the guys on the board have spec'd these to no end, this is the result of a 30 page thread filled with measurements and technical arguing lol

914Driver wrote:

Jensenman wrote: Yeah, the tolerances are super tight. I turned a one piece PB for the J-H out of Oilite bronze, the recommended tolerance from shaft to bushing was something like .004.

BWAHAhahahaha! I had a guy make bushings out of oilite bronze and he zinged the things at a zillion rpm; he spun all the oil out of the material.

Yeah, I learned that lesson early on. Ended up throwing the shirt away.

Holding a .0005 tolerance shouldn't be overly hard for an experienced machinist on a conventional lathe. It just takes a careful touch. It's a single setup for the OD and ID. The only PITA I see would be facing the back end to length after parting it off.

nickel_dime wrote:

914Driver wrote:

Jensenman wrote: Yeah, the tolerances are super tight. I turned a one piece PB for the J-H out of Oilite bronze, the recommended tolerance from shaft to bushing was something like .004.

BWAHAhahahaha! I had a guy make bushings out of oilite bronze and he zinged the things at a zillion rpm; he spun all the oil out of the material.

Yeah, I learned that lesson early on. Ended up throwing the shirt away. Holding a .0005 tolerance shouldn't be overly hard for an experienced machinist on a conventional lathe. It just takes a careful touch. It's a single setup for the OD and ID. The only PITA I see would be facing the back end to length after parting it off.

2 decimel place length with no surf finish, perpendicularity or flatness. The lenght and face treatment is probably the easiest thing on that bad boy.

I wish i had a clue what you guys were talking about ... ... My hope was to get some time with a lathe at the college shop and actually learn some of this stuff.