depends on how complex the part is. i can get a part done in 2 hours or a few days. 2D or 3D parts?
Hi Guys,
I guess this is a bit of a "how long is a piece of string" question but im trying to get an idea of what can be achieved in an 8 hour day on a 3 axis machine centre, Okuma 15,000rpm spindle.
This would include drawing the part up on solidworks, running it through cam and then through the machine, the machine would already have all of the tools set that are required for the job.
I guess im wanting some pictures of what you guys have done in 8 hours. I am trying to gauge the efficiency of my staff.
Even more than 8 hours would be fine, what can be achieved in a week, 40 hours?
Thank
You
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depends on how complex the part is. i can get a part done in 2 hours or a few days. 2D or 3D parts?
Cannot be answered ... define the question better.
1.
A mold part can easily be 1200 hours work before running the machine, and just the finish cuts at 12.000 rpm/1 mm endmill may take 3-5 days, or 100 hours runtime or more.
2. Simple bushings, adjustment nobs, spacers ...
You might make 200-400 per table, and might make 2000 per day, easily, depending on size, tolerance, material, features.
Vertical CNC tends to hang out at max 8000-12.000 pieces per week ...
and if higher numbers of parts are needed, other techniques are employed.
Stamping, metal injection molding, rotary transfer, depends.
Lathes tend to be both slower and faster..
They use typically max power for acceleration/deceleration, 1-2 secs, and running full-on over time is not too desirable.
Otoh, bar-fed work can have 100 piece/hour cycle-times, sometimes more, and if the spindle does not need to stop they can be very productive.
Yet again, specialist lathes ($$$) with dual spindles or more, can easily multiply the productivity per hour in pieces.
The vast majority of all workshops are not very productive.
Most spindles actually cut ie work 10-20% of time time or less.
Based on looking at actual spindle-use time on a variety of machines from a variety of shops.
Avg. spindle on times per year are 1000-2000 hours per year.
Of that time, around/less than half is cutting.
There are 7000+ hours in a year.
Also, you cannot *accurately* measure productivity by
- material removed (vs Hp and machine size)
- parts produced
- swarf produced
Without fully defining the problem that is multi-dimensional.
Productivity is usually seen as maximum $$$ made vs theoretical capacity to earn.
However, any nr of constraints are mostly determinant or the critical paths in that scenario.
Like major aerospace manufacturers (I know some) MUST absolutely do low-profit slow parts, in single-few unit quantities, a large amount of the time.
Because they cannot fail to deliver these parts to their customers, if they ever expect to get the next major orders for $$$ again.
Companies making regulated parts (critical auto parts like brakes, suspension, driveline, or medical parts, nuclear, defense, scuba, pneumatics, etc) often need to do the ancillary parts as well, to certify records keeping requirements, technical audits, etc.
No-one is ever the fastest, cheapest, biggest, smallest, most accurate, or best.
It is ALL a compromise vs what You make, what are your goals in time and money $$$ and resources.
A very high end large lathe, say from Mori Seiki, might not make a 1" part as well in accuracy as a tiny lathe like the Moore Nanotech.
? Which is more productive ?
Best practice is to minimise ongoing heavy costs vs net income streams aka formula:
gross profits = billing - machine-costs(payments) - (work + materials + tools + overhead) - risks.
Opportunity costs - gross profits = profits before taxes.
Mostly, a decent "shop rate" + low burdened rate + low ongoing fixed costs AND a high utilization % = efficiency.
Some do this with very low nr of personnel and manual machines. I know some, with 500.000 $ / yr net profits, per person, 2 of. Net.
Some with 2 people, HUGE CNC lathe (1.5x3.5 m size). == 500.000 $ net profit pp, 1 of. Net.
Some with 10 machines, 50 people, huge VMC ( 2.5 m x 1.4 bed), very low spindle use (2%), zero repairs essentially in 5 years, zero downtime. High profit, much bigger company.
(Ship 50 pallets per day of steel products.)
All 3 are very efficient and very profitable and have very good businesses.
Hope this explains a bit ...
Thanks for your replies.
I will post a picture of one of the products we make, there is 5 main parts, the biggest part being the most time consuming to produce as there is 7 positions in the 3 axis machine.
The biggest part also taking the longest time to get right and draw up. We designed this from scratch.
To get those 5 parts draw up, everything correct, through cam and machining correctly in the machine to the point we can produce parts to sell we are looking at about 1000 hours. What are your guys thoughts?
Also parts are all aluminium.
Designing and prototyping is a lot different than "how many parts can you make in a day".
Gerry
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50 hours is a lot for that little part, and 1000 hours is insane for the set of parts. When you mention these hours are you adding the time of your employees together or did it take 1000 hours?
Are your machinists well paid?
Do they have reason to be motivated?
Do they have the experience in CNC Machining or is this a learning experience for them?
Are the parts being engineered with machining in mind?
Do they have the tools they need?
What kind of machine are they using to make these?
Thanks for the reply.
Yes pay is up there for this country.
I only have one guy running the Okuma MB56-VA, when I took him on, his first main job was to draw up and machine those 5 parts, yes there was a lot of fiddling around to get it all to work correctlu, we made probably 5 of the middle parts before we got to something that worked correctly. He has 20 years experience in this trade running machine centres. The same guy that draws them also runs the machine so he has a pretty good idea of what can and cant be machined so he draws the parts to suit the machines capabilities.
I hope you didn't misunderstand me but the 1000 hours was designing prototyping to the point we can machine the parts to sell, when doing a run of 15 of each of those parts (75 parts in total) it takes about 180 hours to machine them all, that of course is not all machine running time but all up from start to finish incl setting up and so on.
Tools, he also had to decide what tools were required and set them in the machine and also the cam software, but if you want to include all of that in the hours it has taken then from start to finish including every part on the chassis including all the pins and plastic parts (seen on the photo with the rifles sitting in them) then we are looking at about 1300 hours to get to the stage where we have something that we can produce and sell.
Hi,
Yes sorry I was more focusing on the smaller 50 hour part as that didn't really have any prototyping and probably easier for you guys to give me an idea how long to machine.
"how many parts can you make in a day" is not really what I was wanting to know, more along the lines of from start to finish what can be draw up and machined in an 8 hour day. I was interested to know if that smaller part I posted could be achieved in that time.
Your experiences seem pretty typical, to me.
The vast majority of people, including most machinists and most business owners, have no idea of how many hours are actually spent learning how to "produce" a given part.
Once you have a process, and some products made, the cycle becomes vastly faster.
Thus, to make the first larger product for retail, might well take as You said 1300 hours.
The next iteration of same, might only take 100 hours.
Next, 30 hours.
And, after production improvements, perhaps only 10 hours.
The small part would be done by many jobshop professionals in less than 8 hours, imo, ime.
If and only if a sketch aka dimensioned drawing exists.
"Developing" a part is very different from only making/manufacturing it.
The design & development can take any amount of time ...
and multiples of the 8 hours are quite possible, depending..
I can spend 1 hour on design and programming, or one month. It all depends...
Cheers
Roger
Your experiences don't sound far out to me. You appear to be prototyping from idea/concept to part completion which takes alot of thinking back and forth. The hours add up. This is alot different then getting a print,programming, then running. Question is after you eat those initial costs, can you make it back up with sales? If so, you'll likely catch up on those tough hours down the road. Nice job on the parts,btw.
Some of my parts... I can drill a single hole.
First thing that I think of when looking at those parts is the need for a rotary platform with appropriate fixturing . A rotary is an added expense but it'll quickly pay for itself over and over again thru efficiency
A poet knows no boundary yet he is bound to the boundaries of ones own mind !! ........
a lot / trust me i work on Okuma and i know the machine
i develop lot of particular fixtures for custom stuff, and i craft parts with same destination as yours, but from steel
i have procedures and tools for 2d parts that eliminates unnecesary movements, speeds up cutting, allows fast clearance edit, etc etc etc
solid for your parts ? out of the question ... is not related to Okuma ; design is not production and those parts are simple ...
about efficiency, depends on production type : i invest time in preparations, so to deliver stable setups; once all is stable, i speed them up
we are merely at the start of " Internet of Things / Industrial Revolution 4.0 " era : a mix of AI, plastics, human estrangement, powerful non-state actors ...