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Greg Parent
06-11-2004, 01:48 PM
Hello all,
Any idea what something like this should cost?

Aluminum tubing - 6061 alloy
T6 temper
38mm OD
0.083" wall thickness
3 snap ring grooves - one outside at .5" from end, two inside at 0.125" from each end

Thanks
Greg

coles-webb
06-11-2004, 02:25 PM
How long is the tubing and how many are you looking for? The length will matter as some lathes will not accommodate that size through the spindle or have room to chuck and use a steady rest. The qty of parts made will also determine the price as set up time is a big cost factor. If a shop has to grind tool bits for one part, you will get charged for that time on that one part. Where if you are getting 1000 parts done the cost is distributed over all the parts and therefore less along with the setup time distributed over all the parts. It may take an hour to setup and only 5 minute to machine. Once set up the cost goes down as the machine is set up. The set up time will be determined by if it can be chucked (if there is a large enough hole through the spindle) or if you have to use a steady rest to support the part. If you are using a steady rest you have to have the room between centers (although the tailstock can be removed to accomplish this sometimes. If the piece is really long you will have to find some one with a long lathe (although 38mm is just slightly over 1.5 inch, which is the size of my spindle hole, so it wouldn't fit through mine. Most lathes have a correspondingly bigger hole through the spindle as the bed gets longer. If you do go to shops to get quotes, find out how much you can buy the material for first. Most shops can get it cheaper than you or I as they purchase more but they will usually hike the price of the material. Also go to more than one shop, as rates can vary widely. Don't expect it to be dirt cheap either. There are allot of costs involved in operating a shop starting with the machinery costs. Also check out local Home shop machinists as their overhead is usually lower and some will welcome the income so that they may purchase more tools. This sounds like alot but it takes alot to estimate a price so the shop doesn’t lose alot of money. Post that info and myself or someone else may tell you what they would charge but this is not a place to solicit or offer services for money, only for information.

Mike

ChrisAttebery
06-11-2004, 02:54 PM
Greg,

Just buy the Kosdon cases if they're still available. :^)

Chris
Ex TRA Level 2 flyer.

Greg Parent
06-11-2004, 03:00 PM
Coles-Webb,

Thanks for the fast reply.

Ooops...I only need two and the length is 36 inches.

Material to be supplied by machinist.

I am just looking for a ballpark figure. I am going to have the work done locally and would like to have an outside opinion as to what can be considered a fair price.

I figure a machinist forum is the place to get multiple machinists opinions. There is alot of geography on this board and I should be able to get a good sample of opinions.

Thanks again.

Greg.

Greg Parent
06-11-2004, 03:07 PM
Chris,
Is the Ex for experimental or for no longer active?
Greg

ChrisAttebery
06-11-2004, 03:19 PM
Greg,

Ex, as in no longer active. Too many hobbies. Too far a drive to Blackrock. 500+miles from my house. Last flight was an L850 at LDRS 20.

There was somebody a couple years ago selling EX cases for around 50-70% of what the Kosdon ones sold for. Check the forums at RocketryOnline.

Good luck,

Chris