Machine shop projects

precisionworks

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CPF already has the Materials/Mechanical/Machining forum & this thread is not meant to duplicate a forum that works very well. Rather it is intended to offer a look at some of the projects that go through a typical small job-shop. The term job-shop means that virtually any type of work is accepted whether big or small, complex or simple, from any customer who walks through the door (or sends an email, text, fax, etc.) The goal of a job-shop is simple - understand what the customer wants, do the work, move on to the next project.

Some job-shops run contract work that involves the production of multiple pieces of the same or similar parts on a repeating basis. The work provides a somewhat dependable source of business & helps eliminate the peaks & valleys of working on a day by day basis. Sometimes the work is interesting & technically challenging but other days it is sheer drudgery ... imagine drilling one hole in each of 500 steel blocks & then going back to tap those same 500 holes. Not as bad as it may sound once a system is developed to efficiently process the work.

Look for lots of images of work in progress. Quite a bit will be light related while some will cover other areas that I hope are interesting to the reader. We'll have to see where this goes but there's quite a bit of interest on CPF about how things are done. This thread should help answer some of those questions.
 
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precisionworks

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Please Note - Shipping Charges

Anyone who's done business with me knows that they pay actual shipping charges. No "handling fee", no add on cost, I just pass on what ever I'm charged for the shipping service. Most items go out by United States Postal Service flat rate - if it fits into a flat rate carton that's the way I prefer to ship. But ...

USPS seems to raise their rates with every new moon. If you see a shipping charge quoted in an old thread or old post it's probably too low. If I provide a shipping quote in March (for instance) and USPS raises their rate in April when your light is ready to ship you'll be charged the new (higher rate). I don't make a penny on shipping so I have to pass any shipping price increase on to you.

Domestic rates for the USA are up somewhat but International rates have increased at a faster pace.

If you prefer shipment by UPS or Fedex that's fine - just let me know before I provide a total.
 
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precisionworks

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No work because it is already half past beer thirty in Illinois. :party:
At the Precision Works shop the Bud Light is always on :nana:

Well?? ICno work!!?? Someone is slacking...


Allow me to whine a bit but don't panic ...
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The past week saw nothing done in the shop as I was working on an electrical installation in a customer's factory. It started simply enough with a site evaluation, something that should have taken an hour under normal circumstances. Finished that ten hours later & found out that the company would not pay my bill for the ten hours as they considered it "bid preparation time". That was Strike 1 but the project still looked profitable so onward we went.

Contacted my regular assistant who rescheduled his work around this project. Advised the plant manager that I'd be bringing my assistant at no charge to them & the manager said no, they would provide any help that was needed. That was Strike 2 and the little voice in my head said "this is not going well". Since it seemed it could get no worse I stayed in the game.

Went out & purchased all the parts, roughly $10k USD. Then the email arrived from the on site engineer advising me that he would not allow the utility company to disconnect the 480 volt supply at the transformers. Said more clearly, we'd be working at the bottom of the panelboard & the top of the panelboard (about 24" or 0.6m) would still have 480 volts at the main breaker lugs. Strike 3 & I bailed. Wrote a quick email of withdrawal from the project & offered to deliver their parts, got that done at 1500 on Friday, got the check immediately to the bank & called it done.

Rant over. Got back into the shop today & started to catch up. May soon post a photo or two of an interesting project fabricating a stainless steel fuel manifold. It certainly has to come out better than the electrical installation:hairpull:
 
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MrSypher

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YEah it sounds like it Barry.. I awaken here early with a major splitting headache (way too much Techquila for the Saint) & can't see straight.. Hope you both got to let loose alittle and made it to a bed safely.. I'm going back to sleep.. G'nite..

Oh Barry, I have a few more pieces that I need to ship over to you.. Could you PM me your addy again.. ThanXx
 

precisionworks

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Hope you both got to let loose a little and made it to a bed safely.. I'm going back to sleep.. G'nite..
Turned out the lights at midnight & saw your post at 0310 when I got up for a glass of water. The Android touch screen is way too small for a reply at that early hour :)

Oh Barry, I have a few more pieces that I need to ship over to you.. Could you PM me your addy again.. ThanXx
PM's are disabled but an email was just sent.
 

precisionworks

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This is a skid plate for a large finishing mower. The owner wanted it built heavily so I sectioned a piece of 8" diameter (203mm) Schedule 80 pipe. The thinner plate clamped in the vise jaw is only 1/4" thick ( 6.4mm) so the heavy pipe needed lots of preheat before welding. Flame is from a 100,000 btuh oxygen-acetylene rosebud tip. Even with this much heat input the pipe required almost five minutes to reach a uniform 400° F (204° C).

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A clamp was positioned on each side to tightly draw the parts together & welding began ... but I forgot to take photos of that :(
 

precisionworks

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If the gear were any larger (or my lathe were any smaller) this would not work:

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This item is made by Boston Gear & replaces an identical gear that cracked in half after 60 years of service. The old gear had been repaired a number of times and could no longer be fixed. Boston Gear supplies this one with a 1.250" (31.75mm) starter bore & that is enlarged to the needed size. Finished bore will be 1.775" (45mm) and that is done with the boring bar shown in the images.

The fixture that holds the gear for machining is called a face plate. It has a number of drilled & tapped holes and threaded studs are screwed into the holes. Aluminum flat bars are used to spread out the clamping load.

FWIW Boston Gear sells that item for $550 USD & it still had to be bored to fit.
 

fyrstormer

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Wow. 60 years? That's a good run. I hope some of my tools last that long.

That gear looks like it's cut to mesh with a worm gear. It must rotate fairly slowly. I thought lathes spun very fast?
 

precisionworks

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That gear looks like it's cut to mesh with a worm gear.
Good call, that's exactly the purpose of the gear. It is used to tilt the table (images below) that goes on a large radial drill.

Right hand inside the base casting & left hand moving the shaft outward so a good mic reading can be obtained.

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Measured the shaft is six places & got good repeat readings so the gear is ready for final boring:

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I knew a gantry crane was needed & this job will pay for the steel & casters that were used for this build. Foot print is small, only 5'x5' (1.5mx1.5m) and height to the top of the I-beam is 95" (2.4m). There's just a touch of clearance above the I-beam so the gantry can be rolled around. The trolley & air hoist were purchased some time ago & the whole project took just 8 hours.

The current air hoist is pretty small, rated at just 500 pounds (227 kg). I'll pick up a 2000 pound (907 kg) hoist whenever a good deal comes along. Although the structure could easily lift more weight the casters are the limiting factor.
 
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precisionworks

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Dean, Smith & Grace 25" (635 mm) swing with 10" (254 mm) hollow spindle. About average size for this shop which manufactures down-hole drill equipment. A 4-jaw chuck mounts at each end of the spindle so that long work is well supported for threading near the chuck without using a steady rest.

This one gets a well deserved facelift - clean, fill, prime & paint. I bid the job at 30 hours which seems about right for a machine with a 120" (3 m) bed.

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Images above were taken after 4 hours of initial cleanup :nana:
 
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precisionworks

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I don't even want to know what it takes to move this stuff around.
LOL. They are surprisingly easy with the right equipment. Bigger factories often have a pair of overhead bridge cranes - imagine the gantry crane shown in post #12 but with the vertical supports 100' (30 m) apart, located right next to the inside walls of the building. Use a chain sling to attach each end of the lathe to one hoist, lift only enough to see a little daylight under the machine & move it anywhere the bridge crane will take it. A mid sized machine like the DS&G isn't too bad to move this way.

Factories that don't have overhead cranes can use "machinery skates". These are low profile wheel rollers & a forklift (or two) is used to pick up each end of the lathe so the skates can be positioned under the machine. If the concrete floor is smooth & level it takes only three or four people to push it around.

This machine weighs 18,000# (8160 kg) & the big challenge is to lift it off the flatbed transport truck, swing it over to the factory door & get it inside the building. The owner rented a mobile crane for this job :)

Image of the lathe at the previous factory:

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Slowest spindle speed is 4.2 rpm & the top speed is 290 rpm.
 

precisionworks

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What on earth would you use a 4.2rpm lathe for?
Excellent question :)

Let's do the math first. This machine swings 25" over the bed but will also swing 45" in the gap, exactly where faceplate work is done. Running a 45" (1.1 m) part gives a surface speed of 50 sfpm (15 m/min). Just the speed for turning harder materials, those around 400 Brinnel.

Most of today's shops won't use that low a speed too often. But low speeds were common in the 1950's when this machine was made as high speed steel was the tooling of choice. As carbide tooling became more & more prominent the speed range of most lathes moved upwards. Most large swing machines from the 60's & 70's will go no slower than about 10 rpm.
 

precisionworks

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it's a heat-dissipation issue, right?
Exactly :)

A large diameter part (say 45") at 4.2 rpm has a surface speed of 50 sfpm (15 m/min)

A small 1" diameter part has to turn at 191 rpm to have the identical surface speed. Surface speed of the part has a great effect on machining. Run a hard material too fast & the cutting tool can cause the part to harden even more. Cutting tools break down much more quickly if the surface speed is too high.

This machine will often turn material that's of larger diameter so the slower spindle speeds are necessary to keep the surface speed in the optimum range.
 
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