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Essay Contest - Machining Metal as a Hobby

By Rob, on December 8th, 2009

Read the winning essay: Honest – all I ever wanted to do was make some stuff …

We got discovered by StumbleUpon, which suddenly brought thousands of new visitors to MachinistBlog.com. It was probably the first time that most of them had visited a web web site about machining metal and I feel that I wasted a great opportunity to try and convince them that it can be a wonderful hobby. I would like to add an article that explains how it can be fun, rewarding , useful and affordable. But I’m not the world’s best writer and I think it would help if they heard it from more than one person. So, I’m having an essay contest and awarding four cash prizes.

The Contest

Write an essay that explains why machining metal is a great hobby. Your goal is get someone who might know nothing about machining interested in doing it as a hobby.

You should probably assume that your readers may know little or nothing about machining. They may also not know what you can make or do with machine tools, or how much it costs to get started. I’m not sure, but it might be helpful to tell them what got you interested in machining or about a project that you’re really proud of.

The Prizes

1st Place – $75

2nd Place – $50

3rd place – $25

Early Entry Prize – $25 (awarded randomly to an essay received before December 25, 2009)

Picture Bonus – Prize winners will receive a bonus if their essay includes at least one picture.
1st place will receive an extra $15, 2nd place $10 and 3rd place $5.

Prizes will paid by check. (I understand this could be a problem for winners outside the US, which is where I live. If so, I will try to accommodate you by paying via PayPal, or by some other reasonable arrangement).

The Rules

Deadline for entries is January 31st, 2010.

Entries must be posted to our forum. (Please let me know if you have any problems using it).

Your essay should be 1500 to 3000 words. I’m not going to be strict about it, especially if you include multiple photographs with your entry.

Any writing or photographs that you submit must be your own.

You retain the copyrights to your writing and any pictures you submit, but you must agree to give me (Rob) the right to continue to use them on MachinistBlog.com for any purpose.

We can correct grammatical, spelling, and punctuation errors, unless you really don’t want us to.

You can enter more than one essay if you want, but you can only win one prize.

You have to promise not to sue me or beat me up because I’ve overlooked something that should be included in the rules, or because of circumstances that I have little or no little or no control over.

Join the forum discussion on this post

Bogstandard’s “Paddleduck” Engine Plans

By Rob, on November 30th, 2009

This is not just a set of free plans for a working model steam engine. It’s a well-written, well-organized, profusely illustrated 113-page tutorial about machining metal.

If you’re an inexperienced machinist who at least knows the basics I would strongly encourage you to download these plans and build this engine. Don’t let the picture fool you – this is not a difficult engine to build. It will definitely take some time and patience, but if you follow Bogstandard’s step-by-step instructions I think you will probably find it’s not as hard as you might think. By building this engine you’ll learn a lot more than you would by making the typical “wobbler” engine many beginning machinists often build. You’ll also acquire the confidence you need to tackle much more complex machining projects.

There are two more reasons for building this engine. First, it was intended to be made inexpensively out of junk or scrap materials. So it ‘t probably won’t cost you a lot, even if you’ll have to buy all the metal for it. You’ll also find that Bogs tries to help minimize the cost of tooling by suggesting cheaper alternatives when he can. The second reason is that you’ll be able to find help if you have questions or need some advice. The designer is well known for sharing his knowledge and experience and I’m sure that if you have a question, he or one of his friends will try to help you.

I am not a beginner anymore, but I’m not that experienced either, so I’ve decided to start building it when I finish the Stirling engine I’ve been working on. I think I’ll learn a lot because Bog’s tutorial is full of techniques and methods that I’ve either never tried or haven’t practiced much.

The plans use metric units, which could be an issue if you’re in the US or another country still using the Imperial system. I’m in the US (upstate NY) but I don’t think it’s a big problem. I’m building an engine now from metric plans and most of the time I just convert the dimensions to inches and machine the metal to whatever size that is. But I have had to substitute SAE sizes for fasteners and threads because I don’t have much metric-size tooling. I’ve also had to make some substitutions when I’ve wanted to use standard-size material, like drill rod for shafts. Those substitutions require a little bit of extra thought and planning, but it’s not a big deal.

“Bogstandard” is a pseudonym for John, the engine’s designer. He can regularly be found on the MadModder forum. He was also on the Home Model Engine Machinist forum for a long time and you can find a lot of his writing there. I don’t know why John picked the name he did, but I do know that he goes out of his way to share his knowledge and help others, and he does it with a wonderful sense of humor. I’ve learned a lot from his posts, which almost always include lots of good photographs illustrating what he’s talking about. When I asked him for permission to make his plans available here for download he said:

“I have made it my life’s ambition to at least give the new people in model engineering an insight into the easy or alternative ways to do things, rather than the usual methods employed by the ‘elite’ and ‘know it alls’, who seem to think that newbies are there purely for ridicule and tongue lashing in public.”

John’s design is for a marine style twin-cylinder slide valve steam engine that could be used to power a model boat. It’s about 4.5-inches high, about the same in length and about 2-inches wide. It’s known as the “Paddleduck” engine because it first appeared as a series of posts on the Paddleducks steam engine forum from May to July 2007. The construction of each part is described in a simple and easy-to-understand manner. Bogs also includes the answers to questions that others had, along with some of the suggestions and comments he received. Here’s an excerpt where he describes how to finish the cylinder bores:

Reaming the Block Holes

I said last time that we had finished with the blocks for the moment.

I forgot that not all of you will have the means to get a good enough finish on the bore: they will most probably vary from a slightly dull surface, thru what looks like screw cutting to digging out the hole with a hammer and chisel.

If you can borrow a reamer, and your hole is still slightly undersize, use one, otherwise this is how I would get an acceptable finish. You can go out and buy adjustable laps, but that costs a lot, just to get a couple of holes cleaned out, this isn’t the totally correct way but it will be better than what you’ve got at the moment.

Start with the largest hole, stick the last drill you used through them and wiggle about side to side, the one with the biggest wiggle is the biggest hole.

Mark the largest hole with a felt tip. Now chuck up a piece of material to make the lap out of, have it sticking out of the chuck by 1.5 times the length of the hole plus 25mm (1″), I use hard nylon but aluminum or brass will also suffice, I get better results with the softer materials.

Carefully (no heavy cuts here, material sticking a long way out of chuck) and turn down the rod until it just pushes through the hole for a length of 1.5 times the length of hole (like Pic 13).

Now we need to spend a bit of money unless you are from the old school and have some in your garage. We need to buy some fine and coarse grinding paste, Halfords is about the cheapest at about £3 and you get a grinding stick with that as well. This quantity will last you for the rest of your life.

Dab a bit if the coarse stuff along the length of the lap, you don’t need a lot. Get a piece of hardwood and with a rolling action in combination with turning the chuck by hand (you have stopped the lathe I hope) embed the surface of the lap with grinding paste, what you are doing is making a very accurate round file.

Select the lowest speed on your lathe and switch on. Keeping well away from the chuck feed the hole to be lapped onto the lap, get ready to let go on this initial feed in just in case it bind up and sticks. If all is well the lap will be turning (without you going round with it) in the hole. Now just gently move the block up and down the lap in a sort of rotary twisting motion. You need to keep the lap fully into the hole at all times.

Change the block position 90 deg around the lap every so often, eventually you will get the feel and a rhythm going.

Do this for a couple of minutes, stop machine and check the bore, it should have started to smooth out. Repeat as necessary, wipe off, recharge, turn the block around and come from the other end of the hole, until the rough stuff has gone, then wipe off coarse grinding paste with white spirits and recharge with fine. Repeat the operation.

You should after a while end up with a nice round, parallel bore showing slight scratch marks on the surface, these scratches will help the bedding in process as they retain oil while the pistons and bores are wearing against each other.

Clean off the grinding paste and turn down the lap to fit the smaller hole, and repeat the process again. When finished give the bores a very good clean out to get rid of any remaining grinding paste.

If you remember from before, the pistons are going to be made to fit the bores, so they don’t need to be the same size.

Put the lap you have just made in a safe place, you might make something else where you can readjust the size and use it again. I will do the pistons in the next article; it will give time for the batteries to recharge on my camera.

In addition to a large assortment of tips and tricks, Bogs covers topics such as safety, engine turning, climb/conventional milling, turning eccentrics, drilling deep holes, silver soldering and more. Again, I’d like to suggest that you download the plans and at least take a quick peek at them.

Download The Plans

Individual Chapters (PDF, 1.6 – 3.7 Megs)

Chapter 1 – to page 14. Includes the Table of Contents

Chapter 2 – pages 15 – 29

Chapter 3 – pages 30 -45

Chapter 4 – pages 46 – 60

Chapter 5 – pages 61 – 73

Chapter 6 – pages 74 – 84

Chapter 7 – Appendix 1/Part A – Design Sketches, pages 85 – 100

Chapter 8 – Appendix 2/Part B – Design Sketches, pages 101 – 113

All Chapters

Zip File (22 Meg)

Self-extracting File (22 Meg)

DXF/DWG Component Files (18 Meg, self-extracting) – Richard Harris and Nigel P. Henry took Bog’s hand-drawn part sketches and created DXF and DWG files that can be opened by almost any CAD program. If you don’t have one then you can use the free viewer they included. Bog’s hand-drawn plans are pretty good bu if you would like a more formal set of drawings then get these. They can also be used to construct the engine using CNC machines.

Rebuilding an Albrecht Drill Chuck

By Mikey, on November 24th, 2009

Here’s another excellent article by Mikey. It will show you how to take a worn or abused Albrecht keyless chuck and rebuild it to be like new. - Rob

I was really stuck. No, this wasn’t the ordinary kind of stuck. This was one of those seriously awful expletive deleted kinds! Having just bought my first “genuine Albrecht chuck” on eBay, I was stoked. I recall thinking, “I’ll just overhaul that puppy and have me a precision keyless chuck for cheap!” Talk about naïve – that first chuck brought me to my knees!

It resisted all my efforts to get it apart, had an arbor stuck in there that didn’t fit any of my machines, and I was beginning to have that sick “paperweight” feeling. Yes, I did the penetrating oil and the hammer taps every time I passed it for three days, repaired my strap wrench twice, spoke a lot of “nice” words to it, lost sleep over it and almost picked up my torch! Pathetic but all true. Sound familiar?

I looked for help on the net and, to my dismay, found very little! I won’t recap the misery that ensued but I did eventually get that chuck rebuilt and promised myself that if I ever learned to work on these things effectively that I would share it with my fellow hobbyists because nobody should have to go through that! This is my attempt to fulfill that promise.

I have since rebuilt seven of these eBay specials and have learned a thing or two that work for me and I hope they work for you. If you’re stuck like I was then read on and we’ll learn how to get the thing apart, get the arbor out, and get it back together again as painlessly as possible.

As always, work safely and proceed at your own risk.

We will use the C80-J2, a 5/16″ capacity chuck that I bought on eBay,
for our rebuild. Its jaws were galled from a spinning drill bit in an
over-tightened chuck and were replaced during this rebuild. The rest of
the chuck showed little discernible wear.

Albrecht Anatomy 101

The 5/16″, 3/8″ and ½” chucks in Albrecht’s Classic Series have the same anatomy, differing only in size. Once you know how to work on one of them you will know how to work on all of these. I have not worked on the other chucks in the series but suspect they are the same.

This is a cut-away of the typical Albrecht chuck and their nomenclature.

Typically, there are three obstacles you will face when disassembling an Albrecht chuck: getting the collar locking screw out, getting the hood off and getting the arbor out. The rest is easy. I would encourage you to read this to the end before beginning work on your chuck as there are some CAUTIONS to be aware of. When working on precision assemblies with parts that are expensive to replace please work carefully and take your time.

Disassembly

Before breaking down your chuck consider putting it in your drill press or lathe and use a steel brush to clean the knurled parts and gently polish up the smooth areas. I suggest wiping it down with alcohol or lacquer thinner first to avoid burnishing in the surface contamination. This is best done before you break it down so grit doesn’t get into your nice clean chuck.

Remove the slotted collar locking screw. Caution: Be sure to use a screwdriver that fully engages the slot to avoid damaging the head. Quite often these screws are in there really tight. A 5/16″ chuck takes a metric size 4.5 screwdriver blade, while 3/8″ and ½” chucks both take a size 5.5. I suggest you clamp the chuck in a padded vise so you can apply controlled pressure directly in line with the screw. Once the screw is out wedge the tip of an old screwdriver into the slot in the collar to open it and the collar will simply slip off the tail of the body.

Now we need to get the hood off. Albrecht recommends clamping the shell in a fixture and removing the hood with a strap wrench. Okay, maybe with their strap wrench! My Klein strap wrench has only been able to budge the hood on one chuck but by all means try it. If it fails …
Here is an option that does not damage the hood and gets the tightest hood off in a few seconds. Trust me – you want to make these.

These two 3/8″ thick aluminum plates have holes bored to the diameter of the body and hood. Once the slots are cut the hole opens just enough to fit nicely. The small secondary hole is to prevent the plate from cracking under compression. By the way, the factory uses this type of plate (1/4″ thick) to hold the shell when removing hoods. Once made, label them so another chuck of the same size can be worked on. You will need separate plates for different sizes of chucks, of course, but they are simple to make with a hole saw followed by a boring head.

The smaller plate slips onto the body just below the angled step, while the larger one clamps onto the upper part of the knurled area of the hood. The threaded part of the hood is at the lower part of this knurled area and no pressure is applied to it if you position the plate as shown.
A large C-clamp is applied to the slotted side of the larger plate and the lower plate is clamped in a vise. Tighten the C-clamp so it does not slip. If the shell spins, tighten the vise (degreasing the plate and shell really helps here). Use the screw of the C-clamp for leverage and even the tightest hood will come right off (RH thread).

Once you have loosened the hood but before you take it off, move to your workbench and work over a shop towel or tray.

Remove the hood and move the spindle up (turn the part of the body where the collar used to sit) about half way and slip the jaws out. Now screw the spindle up further and it will push the jaw guide up so you can lift it off the shell.

Remove the spindle and body by pulling them straight out. Remove the 25 ball bearings. Caution: don’t drop them on the shop floor as you will need ALL of them.

You should now be able to see the end of the arbor through the rear of the body, which can sometimes be driven out with a punch. Caution: There is great potential for damaging the internal threads of the body here. I would suggest slipping a small piece of thin-walled tubing in there before using a punch. Also be very sure to fully support the end of the body where the arbor exits before you let the BFH fall.

It isn’t unusual to find that the arbor is in there so tight that a punch fails to budge it. Here is an option that has worked every time I needed it.

Cut the arbor, leaving about ¼” of arbor sticking out. Put the spindle body in your lathe and drill and tap for a bolt of your choice (I use a 5/16-24) at least ½” deep. You want this bolt in the center of the arbor stub so tension is applied along the axis of the arbor.

Transfer the body to a padded vise and find a socket/pipe/hollow thing that fits. Using a heavy washer under the bolt head, tighten the bolt into the tail of the arbor stub through the socket. The outer edge of the socket bears on the spindle body. Most of the time this will pop the arbor out but if it doesn’t, use your punch from the inside and give it a few taps and the arbor should come out.

If your arbor is through-hardened (most “hardened” arbors I have seen are case hardened) and you cannot drill and tap it then your best option is to use a hydraulic press. Support the end of the body, not the ring halfway up, when doing this.

Your chuck is now completely disassembled and you can clean your parts with degreaser, then hot soapy water and blow them out. After cleaning the spindle and body threads wipe them with lacquer thinner before setting them aside. Now you can begin inspecting the parts to see if any are damaged enough to warrant replacement.

Continue reading → Rebuilding an Albrecht Drill Chuck

CAD & CAM Software

By Rob, on November 18th, 2009

I unexpectedly bought a CNC mini-mill a couple of weeks ago and since then I’ve been trying to learn about CAD and CAM software. It came with the very popular Mach 3 controller program and that will be enough to get me started cutting metal. But my understanding is that sooner or later I’m going to need CAD/CAM software if I want to design a part on my computer and then make it on the mill.

So I’ve been trying to find the best software in my price range. So far all I know is that there are a lot of similarities between choosing software and finding a compatible girlfriend. There are lots of choices available, so you have to visit a lot of web sites to find software that catches your attention in a special way. Then you have to download the demo version and see if you enjoy spending time with it. You also have to try to find out if the software has the features and capabilities you’ll need to develop a successful long-term relationship. Unfortunately, serious issues may not become apparent until after you have invested a considerable amount of time, effort and money into your relationship.

I sought suggestions on CNCZone.com for software that would meet the following requirements:

I’m just a hobbyist, so it has to be affordable. $200 is probably the most that I might be willing to spend and I would prefer to pay $100 or less. Free is good, and I know that there is free software available. However, I don’t want to spend a lot of time learning how to use a free or cheap program just to save a few bucks and then find out it won’t do what I need it to do.

It has to run on Windows. I think Linux is great but I’m not willing to switch yet.

Free and easy-to-understand tutorials have to be readily available for it. This is really important. I’ve played around with CAD software in the past and they all seem to have a long learning curve. That doesn’t bother me, but it does bother me when there aren’t any good tutorials for beginners or you have to pay for them.

I was given a lot of good suggestions. Unfortunately there was no consensus, so it looks like I’ll be trying software demos for a while.

By the way, I don’t need to get CAD/CAM software right away. But there’s a fairly inexpensive AutoCAD course I can sign up for in a couple of weeks that might be helpful. However, I know I won’t be able to afford my own copy of AutoCAD when the class ends, and I don’t know if I will be able to transfer the knowledge I’ll learn to another CAD program. What do you think?

Before I go I’d like to suggest Tormach’s Whitepaper if you’d like to read a good introduction to CAD/CAM software.

Pages

Random Quote

Essay Contest - Machining Metal as a Hobby

The Contest

The Prizes

The Rules

Bogstandard’s “Paddleduck” Engine Plans

Download The Plans

Related Links:

Rebuilding an Albrecht Drill Chuck

Albrecht Anatomy 101

Disassembly

Continue reading → Rebuilding an Albrecht Drill Chuck

CAD & CAM Software

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Random Quote

Essay Contest - Machining Metal as a Hobby

The Contest

The Prizes

The Rules

Bogstandard’s “Paddleduck” Engine Plans

Download The Plans

Related Links:

Rebuilding an Albrecht Drill Chuck

Albrecht Anatomy 101

Disassembly

Continue reading → Rebuilding an Albrecht Drill Chuck

CAD & CAM Software

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