Time estimates for this workpiece (2024)

Gas tubes eh?

Dave

Dave, do you need an associate? Sooner or later it seems like we will be working toegther.

I'm not intersted in having some one make these for me, but rather how long people with like 20 years experience think these thinsg would take em to make. I wanna know if I rank up there, if I stand a chance competing against a CNC machine etc etc etc.

Could you start by sending the tubes - doing in house? centre less ground down to size on od? Am uncertain if you take that in one pass, but at that diameter to length in my opinion you would be in need of a steady rest, that slows manual turning down a lot!

Equaly its all beyond standard quill travels on a smaller manual lathe hence your either drilling from the tool post or sliding that tail stock a lot! Would again eat manual time.

Farming out to some one with a swiss style sliding headstock could be the far cheaper option, would be very quick and with a live spindle could easily mill the slot. Long drills + thru tool coolant - gun drill like options would realy motor on the deep holes too. Would simply spit out the completed part. On a run of 200, for what's a relitivly simple programme set-up times not much either. Get down into wanting to only order 5 - 10 a time and manual stuff might win though.

Equally cnc might make it more economical to machine from solid stock rather than tube?

Not at the moment, haven't made any of those parts in a while. I'm going to guess they were originally made in a turret lathe, it's not a rocket science type of part and the length tolerance can be +- 1/8 and it would still work, well, maybe not + side that much. I may open the book and see if I cna find any pics of the tube being made, there was some pretty good detail on the common wealth stuff shown in the book.
Dave

madmachinst said:

Dave, do you need an associate? Sooner or later it seems like we will be working toegther.

I'm not intersted in having some one make these for me, but rather how long people with like 20 years experience think these thinsg would take em to make. I wanna know if I rank up there, if I stand a chance competing against a CNC machine etc etc etc.

Click to expand...

centerless grinding ran through my head, but I don't know if some one can end up doing it cheaper than me just putting up with the follower. Shipping and all. In terms of drilling and reaming, I know I have to utilize teh tool post instead of teh tailstock. Bottom line is, there is no one here who thinks thsi can be made manually for less than 40-60 minutes a pc? Thats what I am thinking these will take me. Just being curious.

Now, turret lathe, Dave you do understand that this thread does not have a die available for it, so how does a turret lathe make that thread?

These could definitely be made on a manual turret lathe, and yes........you could die head them in a Landis die head without difficulty. I think you can make these in less than 40 minutes. The length of the part is your enemy here.

I would either plan on centerless grinding the parts, or rough turn them leaving just enough stock to clean up and pinch them between centers for finish turn on an engine lathe. Centerless grind is by far the best choice. You can run into problems running between centers, so I would only use that option as a last resort.

Rough turning and rough drilling can be accomplished simultaneously on a manual turret lathe like a Warner & Swasey, and total roughing and drilling time shouldn't exceed 12 minutes. This is a very conservative estimate, planning on stopping several times to clear the chips........I would bet you could drill them in less time.
Once ground, reaming the finished hole would take approx. 4 minutes, and die heading the thread just a few seconds. Milling the slot would take less than a couple minutes.

If you put some thought into setting this up, I can't see this part taking more than 20 to 25 minutes or so......assuming your centerless grinding the part. It's been my experience that centerless grinding is fairly inexpensive.

Frank

Home

That's about the right size reduction for relatively painless $$ centreless grinding.

I'd look up Titex for drills & reamers.

Set of dies and you're good to go.

So there's time estimates from 40 mins down to 12 or whatever...

Now fellows.... admiting we've not actually seen the print or the part, but how much would YOU PAY for this part in a store?? $12?... $20?? somewhere in the middle???

It's been a long time since I ran my CNC lathe, but I'll go out on a limb and agree to make them for $10 labor, and toss in 2 bucks for the centerless.... YOU furnish the material.. so you total cost should be somewhere near $12..$14....THhs assumes there's no tight ID/OD concentric requirements that would require OD Grinding the part on a mandrel.

What IS the price of these???

madmachinst said:

say I needed 200 of these made and the workpiece is 4130 aircraft seamless tubing 9/16 OD by .393" ID 9.5" long. I need 5" of the ID at 11mm diameter very smooth. The rest of the ID is .450" rough drill finish will suffice. OD is machined to .531" and there is about 5/8" length of NF thread on there with a small slot going through the thread. Tolerance on the 11mm bore is +/-.001" the slot is like +/-.015" and the rest is +/-.005". Anyone got any idea how long this would take you to make, what kind of equipment you would plan on using. I would like to hear from the manual folks and the CNC folks.

Click to expand...

Maybe I missed something here?

You need to core drill 5" long, and then the other 4", then ream the 4".

Turn a thread on the end of the OD, and mill a slot in it.

Send to grinders...

Something else?

Die head 4130?
I don't know that I have ever ran the stuff, but it sure doesn't sound like a material that I would want to die head. ???

Trying to make a run like that on an engine lathe and compete in a free trade environment would not even keep you in dog-food while you made them!

Those sound like $5/labor parts to me. (not actually seen the print of course...)

---------------------

Think Snow Eh!
Ox

Dude, your forgetting the exhaust ports in the tube.
Just make a Steyer short tube and silver solder it in like they used to.

Dave

Ox said:

Maybe I missed something here?

You need to core drill 5" long, and then the other 4", then ream the 4".

Turn a thread on the end of the OD, and mill a slot in it.

Send to grinders...

Something else?

Die head 4130?
I don't know that I have ever ran the stuff, but it sure doesn't sound like a material that I would want to die head. ???

Trying to make a run like that on an engine lathe and compete in a free trade environment would not even keep you in dog-food while you made them!

Those sound like $5/labor parts to me. (not actually seen the print of course...)

---------------------

Think Snow Eh!
Ox

Click to expand...

$5 labor? no wonder I can't compete. drill to 4" depth .450 and then to depth of 9.5" for the drill and ream to .433" Then make 17/32-36 thread for 5/8" length and a small slot across the threads. All that for $5 labor, how you keep the kids fed?

BTW, these are being sold at the store for $20 a pc and buddy of mine at a competing outfit wanted some made. Looking at the $20 price and hearing from my buddy that some one used to make these for him on manual machinery my curiosity really went wild.
Dave, I'd take care of the gas relief holes with a jig I have made.

He said that he was starting with tubing, so you only have to core it out. Not the same as "drilling" IMO.

I have no idea what these are. It seems everyone else does. Some-one wunna post a link as it seem these aint proprietory...

I can drop all of that off my machine complete. And when she reads "M2" she will [hopefully] say:
"Thank you Sir, May I have a nother?"

----------------

Think Snow Eh!
Ox

Gas tube, Fn-Fal

Dave

Ox said:

He said that he was starting with tubing, so you only have to core it out. Not the same as "drilling" IMO.

I have no idea what these are. It seems everyone else does. Some-one wunna post a link as it seem these aint proprietory...

I can drop all of that off my machine complete. And when she reads "M2" she will [hopefully] say:
"Thank you Sir, May I have a nother?"

----------------

Think Snow Eh!
Ox

Click to expand...

I had no idea what they are untill this post....

SchneiderMachine said:

Gas tube, Fn-Fal

Dave

Click to expand...

So now I WITHDRAW my bid... I want no part of this...

and OX.. I thought you had some multispindle automatics?..
Wouldnt they drop one off in a min or 2 ?