DSM59 - The Wrong Choice?

bradjacob · Apr 17, 2017

Guys - I'm creating this thread because I'm still experiencing some frustration with this machine.

1. I only get batches of 10, 20, 30, 50, pieces. It will never be (more) that that, only those small batches.
-- Was it the right choice to get this machine?

2. Am I unrealistic to think that I can achieve (and hold) a .0004 tolerance on this .236 (stainless-316L) stock, with this machine?

3. What would be the "best" shouldering tool that's easy to work with - are there any modern options?

4. Tool-lengths. Is there some "proper" method of which tool to begin with? Do you start with the part off tool, the center drill, or some method of where to begin?

5. Can someone tell me if (at the very least) my "Approach" is correct in terms of the drawing below:

A. Center drill, drill, ream
B. Turn shoulder (with the Hardinge tool that has 2-tenths increments)
C. Use the ground-tool that will create the nose-angle (this is the part-off operation).
D. Use a face tool to size the final length
E. Repeat (a whopping 9 more times)

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TDegenhart · Apr 17, 2017

I assume you are referring to the od, as the DSM59 is not setup for turning. Are you able to get 6mm TGP stock? Or are you trying to use a roller box tool?

Tom

alan speyrer · Apr 17, 2017

Brad, you should be able to hold .0005" with your Dsm 59. Your tool setup order looks good, remember to have each tool sticking out the same length, or close to the same length. Turret lathes just take time and imagination to learn how to setup and how to combine tools to speed up operations. Stick with it!, or buy a small gang tool CNC.

bradjacob · Apr 17, 2017

TDegenhart said:
I assume you are referring to the od, as the DSM59 is not setup for turning. Are you able to get 6mm TGP stock? Or are you trying to use a roller box tool?

Tom

Yes, the OD. The tools I have for turning are a few (T3, T4, DSM1 and Boyar Schultz 00RT box tool). The one's I'm (using) for this setup is the T4.

For the stock, I got a quote for precision ground stock at $240 for a 3' length. So that's why I wanted to turn the shoulder from 1/4".

bradjacob · Apr 17, 2017

alan speyrer said:
Brad, you should be able to hold .0005" with your Dsm 59. Your tool setup order looks good, remember to have each tool sticking out the same length, or close to the same length. Turret lathes just take time and imagination to learn how to setup and how to combine tools to speed up operations. Stick with it!, or buy a small gang tool CNC.

Oh Alan, that would be surrounding to defeat!! LOL. I (do) want a CNC in the future, but this lathe is really throwing me on the ground and kicking me int he ribs a few dozen times. Humbling me... I want to figure it out and be able to smile knowing that I learned a lot. Because, it's been a LOT of learning, just no producing yet :-(

bradjacob · Apr 17, 2017

alan speyrer said:
Brad, you should be able to hold .0005" with your Dsm 59.

I ran some test pieces and below are my numbers. I'm assuming that due to stick-out and the stock being flimsy, I get a bigger dia. on the right side.

Collet Side, ------ Right Side, ---------Difference
-------------------------------------------------------------------------------------------------
.2363 --------------- .2369 ------------------ .0006
.2369 --------------- .2377 ------------------.0008
.2372 ----------------.2393 ------------------.0021 (not sure what happened with this one)
.2363 ----------------.2370 ------------------.0007
.2360 --------------- .2366 ------------------ .0006

So it looks like it's fluctuating within .001, but the flex in the stock is making it hard to control. Maybe a box tool is better, but the one I have is the DT Tool that uses carbide inserts. I guess the way to dial in would be to make a test cut, then part off, dial in a little more, then take another cut. I won't be able to move in tenths with an insert.

TDegenhart · Apr 17, 2017

The flex is the reason you need a roller box tool. The roller supports the work like a follower rest.

Tom

pmtool · Apr 17, 2017

If this job repeats maybe get a shop to centerless grind the stock for you? I think you need to look around more for stock. There are places that specialize in supplying ground stock to screw machine places. That 240 may buy you 3' or 20' of stock as the material cost are almost nothing in that size. All setup time for the grinding place.

Greg Menke · Apr 17, 2017

Suggest getting a copy of the Warner Swaszey "Tools" book- it goes into a lot of detail- kind of pricey but I've found it really helpful even if just to list the various options ie roller boxes can have rollers before the cutter or after, with various tradeoffs and advantages. Cutting pressure on the turret has its effect too. Workpiece might be a little stiffer for the turning ops if you put the drill & ream later.

Ray Behner · Apr 17, 2017

Parker Steel (800-333-4140) in Toledo has 6mm 316L TGP in stock @ $85.00 for two 12ft lengths. The reason for the 85 bucks is, that is their min. Betcha they'd chop them in half to ship UPS. That would be a lifetime supply for you, but seems like you wouldn't have to open your wallet too wide.

alan speyrer · Apr 17, 2017

Most of those numbers are good, except that crazy number. Roller box tool would be best for such small diameter, and yes they can be a pain to setup! Or you could get ground stock, if you think this job will repeat. Honestly, I spent a year using my turret lathe before I was happy with my abilities!, I made lots of junk parts. Often times if I see a job on pm, I will go try and make it on my turret lathe, time myself, check my tolerances, if all is good, I bid on the job, 9 times out of 10, someone bids lower than I.

bradjacob said:
I ran some test pieces and below are my numbers. I'm assuming that due to stick-out and the stock being flimsy, I get a bigger dia. on the right side.

Collet Side, ------ Right Side, ---------Difference
-------------------------------------------------------------------------------------------------
.2363 --------------- .2369 ------------------ .0006
.2369 --------------- .2377 ------------------.0008
.2372 ----------------.2393 ------------------.0021 (not sure what happened with this one)
.2363 ----------------.2370 ------------------.0007
.2360 --------------- .2366 ------------------ .0006

So it looks like it's fluctuating within .001, but the flex in the stock is making it hard to control. Maybe a box tool is better, but the one I have is the DT Tool that uses carbide inserts. I guess the way to dial in would be to make a test cut, then part off, dial in a little more, then take another cut. I won't be able to move in tenths with an insert.

hitandmiss · Apr 17, 2017

bradjacob said:
Guys - I'm creating this thread because I'm still experiencing some frustration with this machine.

1. I only get batches of 10, 20, 30, 50, pieces. It will never be (more) that that, only those small batches.
-- Was it the right choice to get this machine?

2. Am I unrealistic to think that I can achieve (and hold) a .0004 tolerance on this .236 (stainless-316L) stock, with this machine?

3. What would be the "best" shouldering tool that's easy to work with - are there any modern options?

4. Tool-lengths. Is there some "proper" method of which tool to begin with? Do you start with the part off tool, the center drill, or some method of where to begin?

5. Can someone tell me if (at the very least) my "Approach" is correct in terms of the drawing below:

A. Center drill, drill, ream
B. Turn shoulder (with the Hardinge tool that has 2-tenths increments)
C. Use the ground-tool that will create the nose-angle (this is the part-off operation).
D. Use a face tool to size the final length
E. Repeat (a whopping 9 more times)

Question answers.

1. Yes it the right choice for a manual machine.
2. No it is not unrealistic. The process needs refining.
Start with the DSM-1 not the T4. Feed in slowly and back slowly, use a sharp ground tool with a fairly small radius on tip (.010" or so).
The back feed is critical to shave off from the deflection of the turn operation. If you still have trouble with deflection, drill after the O.D. Turn.

3&4. I start with the cutoff tool, then set the stock stop with a short scale. I have a 2" one and a set of short ones with a handle.
Then I would work on the O.D. Turn with the DSM-1.

Next spot,drill with a stub parabolic drill (not a jobber length in a drill chuck) in an adjustable drill holder.

Reaming may be a little problematic for only a few parts.
I would do that in your SB 10L, oil up the TS ways and hand feed the reamer by sliding the TS.

Face and chfr the left end of part and cutoff.

Second op the detail A area after reaming and face to length. There appears to be a flat at the end of maybe .004". That when faced with a very sharp tool there should be minimal burr.

For very short runs, I have found it easier to break the process down into several operations as I got the experience setting up more complex setups.

Bill

FredC · Apr 18, 2017

If the machine is tight you may be able to hold those tolerances but it will be taxing on you and time consuming. We ran tens of thousands of a part that needed .001 tolerance over the whole length. The part was 1 1/2 inches long so turning the OD was time consuming even though the machine was capable of holding 1 tenth. We got the material straightened and centerless ground for nearly the same price as the raw 9/16 bars! We used a Hardinge SST 14 mm collet and polished the internal edge of the bore so it would not scratch the material. The long bearing surface and thin slots on this collet prevented any damage to the OD surface.
Those that suggested buying larger quantities of centerless ground material are steering you in the right direction. You will save time and frustration.

Fulcircleny · Apr 18, 2017

Brad,

I know you want to figure this out BUT the time you waste, is just a waste. Call Alexandria precision, in New Jersey, 877-300-2919, they list 6mm 316 project 70, in 6' lengths for 39.47 per six foot. the STANDARD tolerance is minus .0076mm (-.0002) I buy ground 6061 from them for a 'pin' I make a lot of. quality is great, as is delivery, and price.
Best of Luck,
Chris

bradjacob · Apr 18, 2017

Fulcircleny said:
Brad,

I know you want to figure this out BUT the time you waste, is just a waste. Call Alexandria precision, in New Jersey, 877-300-2919, they list 6mm 316 project 70, in 6' lengths for 39.47 per six foot. the STANDARD tolerance is minus .0076mm (-.0002) I buy ground 6061 from them for a 'pin' I make a lot of. quality is great, as is delivery, and price.
Best of Luck,
Chris

Hmm... that's who quoted me the $240. I'll look into the info you gave me, THX!!

bradjacob · Apr 18, 2017

FredC said:
If the machine is tight you may be able to hold those tolerances but it will be taxing on you and time consuming. We ran tens of thousands of a part that needed .001 tolerance over the whole length. The part was 1 1/2 inches long so turning the OD was time consuming even though the machine was capable of holding 1 tenth. We got the material straightened and centerless ground for nearly the same price as the raw 9/16 bars! We used a Hardinge SST 14 mm collet and polished the internal edge of the bore so it would not scratch the material. The long bearing surface and thin slots on this collet prevented any damage to the OD surface.
Those that suggested buying larger quantities of centerless ground material are steering you in the right direction. You will save time and frustration.

Thank Fred. See this is EXACTLY what I wanted to hear. I did inquire about ground stock, but thought that I could be a hero and turn in. And I know you *can* - but at my beginning level of experience with this particular machine, it's (literally) "pays" to go with ground stock, already finished.

bradjacob · Apr 18, 2017

hitandmiss said:
Question answers.

1. Yes it the right choice for a manual machine.
2. No it is not unrealistic. The process needs refining.
Start with the DSM-1 not the T4. Feed in slowly and back slowly, use a sharp ground tool with a fairly small radius on tip (.010" or so).
The back feed is critical to shave off from the deflection of the turn operation. If you still have trouble with deflection, drill after the O.D. Turn.

3&4. I start with the cutoff tool, then set the stock stop with a short scale. I have a 2" one and a set of short ones with a handle.
Then I would work on the O.D. Turn with the DSM-1.

Next spot,drill with a stub parabolic drill (not a jobber length in a drill chuck) in an adjustable drill holder.

Reaming may be a little problematic for only a few parts.
I would do that in your SB 10L, oil up the TS ways and hand feed the reamer by sliding the TS.

Face and chfr the left end of part and cutoff.

Second op the detail A area after reaming and face to length. There appears to be a flat at the end of maybe .004". That when faced with a very sharp tool there should be minimal burr.

For very short runs, I have found it easier to break the process down into several operations as I got the experience setting up more complex setups.

Bill

Bill - thank you. This is EXCELLENT, real-world examples and the tips sound like they're perfect - really appreciate it!

bradjacob · Apr 18, 2017

alan speyrer said:
Most of those numbers are good, except that crazy number. Roller box tool would be best for such small diameter, and yes they can be a pain to setup! Or you could get ground stock, if you think this job will repeat. Honestly, I spent a year using my turret lathe before I was happy with my abilities!, I made lots of junk parts. Often times if I see a job on pm, I will go try and make it on my turret lathe, time myself, check my tolerances, if all is good, I bid on the job, 9 times out of 10, someone bids lower than I.

This is good to know Alan. I feel like I'm not crazy and that these (are) tricky to learn at first. And jobs on PM?? They offer jobs to bid? Had NO idea...

alan speyrer · Apr 18, 2017

Brad, I was referring to the manufacturing resource section of this forum.

bradjacob said:
This is good to know Alan. I feel like I'm not crazy and that these (are) tricky to learn at first. And jobs on PM?? They offer jobs to bid? Had NO idea...

Peter Colman · Apr 21, 2017

You are getting good advice here, I would add that with this size of bar, you may get 'whirling' i.e. the bar flying around in the draw tube, a plastic pipe with od of the bore of the tube and bore same as the rod may help keep things running true.

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