How do I cut...

[MattM]

twenty rounds of 3/4" 1018 to 4.5" +/- .003? Ends must be faced and nicely finished (no saw marks). This is a "production" job so time is of the essence. I have a power bandsaw, lathes, mill, etc. No CNC.

 

[Tony Wells]

Sawed long, but close. Random skim one face to min cleanup and break edge. Bore soft jaws with shoulder to stop against and fin oal, break edge.

 

[rock_breaker]

If possible a stop for the correct length and a slitting saw on your mill may do it. My experience with rebar is that it heats quickly and is not the most fun to machine. Are you making 20 pieces 4.5" long or cutting 20 bars (20 ft?} into 4.5" long pieces?
Have a good day
Ray

 

[machinejack]

Mr. Rock mentioned rebar? There are hard spots in there that eat tooling. I mainly cut to + length on saw and mill the ends. Pretty fast this way. Most lathes don't have a thru hole stop.

 

[MattM]

Not rebar 1018 steel.

 

[MattM]

Mr. Rock mentioned rebar? There are hard spots in there that eat tooling. I mainly cut to + length on saw and mill the ends. Pretty fast this way. Most lathes don't have a thru hole stop.

Thru hole stop? That's sounds like an idea, how to do it?

 

[Bobby Bailey]

I would do like Tony, except I would use a collet with collet stop, as I have the collets.

 

[epanzella]

I would band saw them slightly over and face in collet with stop.

 

[chips&more]

I would do differently. 1018 is gummy. The tit in the center of the face is hard to control. Surface finish is critical. Length is critical. And time is critical. For these reasons I would not use a lathe. I would ruff cut on a power band saw. Then surface grind the ends using a “V” block to hold the part. Both finish and length would be VERY easy to control. I do it all the time. And if you set-up like I said, it’s also fast. Good Luck…Dave

 

[MattM]

Thanks, I have a surface grinder. How would I control length?

 

[BGHansen]

How about band sawing slightly long, then face one side on the lathe. Then go to the mill and mount them vertically in a V-block and dust the opposite side to length. Only problem I could see with collets and a stop is you have to make sure you draw the collet in the same depth each time. Turn a little tighter or have a slight variation in diameter your length will be slightly off. Might be within your tolerance as I'm really splitting hairs here.

Bruce

 

[MattM]

Th

How about band sawing slightly long, then face one side on the lathe. Then go to the mill and mount them vertically in a V-block and dust the opposite side to length. Only problem I could see with collets and a stop is you have to make sure you draw the collet in the same depth each time. Turn a little tighter or have a slight variation in diameter your length will be slightly off. Might be within your tolerance as I'm really splitting hairs here.

Bruce

That sounds like a winner.

Here is what I thought of last night. Face one side, DyChem the other sides, scribe with my height gauge, turn to mark. Should be within tolerance?

 

[MattM]

Th

How about band sawing slightly long, then face one side on the lathe. Then go to the mill and mount them vertically in a V-block and dust the opposite side to length. Only problem I could see with collets and a stop is you have to make sure you draw the collet in the same depth each time. Turn a little tighter or have a slight variation in diameter your length will be slightly off. Might be within your tolerance as I'm really splitting hairs here.

Bruce

That sounds like a winner.

Here is what I thought of last night. Face one side, DyChem the other sides, scribe with my height gauge, turn to mark. Should be within tolerance?

 

[RJSakowski]

As others have said, I would saw oversize. Then face one end. I use a spindle work stop so I would set up the stop. Fix the work on the 3 jaw, lock the carriage, do a trial face, measure, correct for the error with the compound, and face the parts.

Here is the spindle stop that I made. There are other versions shown in this forum as well.
https://www.hobby-machinist.com/threads/lathe-headstock-work-stop-g0602.32809/

 

[P. Waller]

Made 30 of these annoying little beasties this past Friday, .403" Dia. X .561" long with a groove .25" Dia. X .375" wide in the center from 316 stainless.

Started with a 48" lenght of 1/2" round, turn, face and chamfer with a 35 Deg. insert, groove with a .083 wide OD groove tool then part .010" long. Bored soft jaws .410" X .530" deep and faced/chamfered to length, 750 RPM's with flood coolant. 4 hours including set up, would have run it at 2000 RPM's in a collet but our 1 collet chuck was in another lathe. That speed with an 8" 3 jaw will turn the coolant into mist

 

[P. Waller]

How about band sawing slightly long, then face one side on the lathe. Then go to the mill and mount them vertically in a V-block and dust the opposite side to length. Only problem I could see with collets and a stop is you have to make sure you draw the collet in the same depth each time. Turn a little tighter or have a slight variation in diameter your length will be slightly off. Might be within your tolerance as I'm really splitting hairs here.

Bruce

A dead length collet chuck does not move the collet, a spindle stop through the collet will also maintain length as the part can not move.
Kalamzoo makes a nice little 5C chuck that I hold in a 3 Jaw for quick set ups that is dead length. Less then $400.00
https://www.ajaxtoolsupply.com/ka5c...MI56jGnd3f2gIVjwOGCh2LPQfbEAQYBiABEgLUavD_BwE

 

[rock_breaker]

Got the wrong material, MattM is right rebar is a real mess.
Ray

 

[bhigdog]

Saw slightly oversize. Mill to length in a vertical mill using a collet block or V block with a stop in the vise or even clamped to the table. Use a high helix 4 flute and side cut it. Likely a better finish than facing 1018 and should easily hold +- .003. De-burr by hand on a belt grinder. Quick set up and easy peasy.........Bob

 

[Tinkertoy1941]

bhigdog has the best idea!
Cut to length leaving minimal stock for clean up
Good old KURT vise with a solid stop!
V blocks and collet blocks have to be very clean for consistency
mill one end
you already know what your dimensions are when you turn the part around
mill second end belt sand
I had a race one night with the lathe hand cutting lift pins for big draw dies
I completed my batch in half the time the lathe hand took!!
The mill cut did not leave ANY center ****

 

[MattM]

Second that. Tried it today on a few pieces. Learned something very valuable. I'll use it for the rest of the pieces.

Next question: "What should I as a home hobby (amateur) machinist charge for this job"? This is "egg money" but I do like getting paid as affirmation for my efforts.

 

[bhigdog]

You really should compute your over head, costs, depreciation, etc etc etc. But to keep the fun in the hobby just make it $50 an hour plus material. Cash if possible. Enjoy your eggs......bob

 

[MattM]

If I added in all those costs it would be more like $100.00 an hour. I'm only charging $30.00 an hour. I know this is low but I'm an amateur amateur machinist. If I had to do this for beans and bacon The Wife and I would be living under a freeway venturing out with cardboard signs.

Cash is King.

I put this small ad on CL:

"I have a small machine shop consisting of: a Monarch 10EE lathe, a Clausing 13x36 lathe, a full size mill, a shaper, a surface grinder and the usual other tools and machines.

Please call or email if I may be of assistance with your small machining projects. No TexT. Trades considered for work performed. Prices are low because this is mostly a hobby for me. You will be told up front whether or not I can handle your project. No charge for consulting or estimates."

Fun. So far I have had several very interesting and (to me) challenging jobs and more coming. I've met some interesting people and made some friends. Like I said, "Fun".

 

[bhigdog]

Don't sell yourself short and don't under charge. This is a race to the top not the bottom. Get yourself over to the Practical Machinest Forum too. Lots of good advice from guys in the business there. Caution, they can be a snarly bunch but they know stuff I don't know even exists. Good luck and I'm guessing you won't end up under a bridge..............Bob

 

[MattM]

I'm not interested in starting another business. Been there done that many times. Now it is about increasing my skills and meeting interesting people.

Any money that trickles in will be used to buy more guns and other tools.

This forum has been a great help. I very much appreciate it.

 

[Giles]

twenty rounds of 3/4" 1018 to 4.5" +/- .003? Ends must be faced and nicely finished (no saw marks). This is a "production" job so time is of the essence. I have a power bandsaw, lathes, mill, etc. No CNC.

As mentioned--I would saw slightly longer and then finish in lathe.
If these are 4.5" long, I would place in chuck with a parallel between face of chuck and stock. LIGHTLY tap stock against parallel and machine.
Use a tool with small radius that is honed.
If surface is not satisfactory, leave a few thousands and grind as suggested.

 

[MattM]

As mentioned--I would saw slightly longer and then finish in lathe.
If these are 4.5" long, I would place in chuck with a parallel between face of chuck and stock. LIGHTLY tap stock against parallel and machine.
Use a tool with small radius that is honed.
If surface is not satisfactory, leave a few thousands and grind as suggested.

That's pretty much what I did. No problem and it wasn't necessary to grind. Customer is happy, charged him two bucks apiece. He provided the stock.

 

[solo]

I've used a cold saw before, and held parts to very close tolerances and not a bad finish. I wish I had one.

 

[MarkM]

Why not just part them in your lathe to size. Slight leading edge on your cutoff blade with some rake. You should be able to get a good finish on the pc. Cut. Face the new pc. Set up for length and part. Chamfer with file before parting is complete. Sometime i ll hand feed and then move over a few thou before complete then run cross feed for finish. Take up your backlash in your compound before you start the cut. Lock carriage , hand feed , retract parting tool and move over a few though, now part with crossfeed power feed. I Usually stop power feed before cut is complete then hand feed the part off.

 

[MarkM]

Should have stated you may need to make a support bushing. Delrin if avaliable. Bore hole to size and turn down the other end and place in drill chuck. Could make a stop in the bushing if more parts down the rd. Flying today, forgot to mention this before plane took off.