Been reading the posts but not doing any machining. Married life, work, married life, helping others, married life, breaking four vertebrae in my back, etc., has kept me from doing anything. My machining skills were OK, but not professional. I did fabricate a belt drive for my mini mill and that was the last thing I did. What I want to do now is get back into machining. Can anyone direct me someplace that I can learn proper techniques from? Such as what needs to be done first when building from plans. I fuddle my way through when fabricating something I think of, but want to tackle the little air powered V8 from plans. As I am still recovering from this broken back, it's time to take my wife into the garage to help me fix my stool to sit on...
I'm Back
- Thread starter Rickus
- Start date
Help Support Home Model Engine Machinist Forum:
What I did to learn was to make mistakes making engines. Pick either something from barstock or cheap castings and start making pieces and mistakes. Think through the operations in advance - what you can cut first as a reference surface, how to relate other features to it, how to check the casting and adapt to mismatched cope & drag, etc. Walk it through your head first, then do it in the shop. Let yourself make a mistake once in a while. Eventually you will learn what not to do, how much pressure to put in the vise, how much pressure not to put in the vise, etc. Maybe you make everything for the engine 2 or 3 times, it's a learning process. There are some books with techniques (_The Amateur's Lathe_ by Sparey, _Workshop Techniques_ and _Model Engineer's Workshop Manual_ by Thomas) that also walk you through making some useful tools that you might consider. Some of the Village Press books are pretty good - look for a set of the _Projects_ and _Metalworking_ series. Reading helps, but nothing helps like cutting some metal.
(I was laid up with back problems twice - my wife hauled in some handtools and engine kits for me to assemble laying on the floor. I could only work a few minutes at a time but it sure beat being zonked on painkillers and watcvhing TV).
(I was laid up with back problems twice - my wife hauled in some handtools and engine kits for me to assemble laying on the floor. I could only work a few minutes at a time but it sure beat being zonked on painkillers and watcvhing TV).
Rickus---You have asked a very pertinent question, and one not easily answered. First thought should be give to the constraints imposed on you by the size of your machinery.---Are your lathe and mill large enough to make the parts shown in the plans. Secondly, are your skills up to the challenge. Thirdly, if you have the equipment and the skills required, start with the most difficult parts of the machine you are building. If you can succesfully complete them, then it gets progressively easier as you go along. ---Nothing worse than building all of the easy stuff first, then having to abandon the project because the difficult parts are beyond your machine capacity or your skill level!!!---Brian
That's what I'll do. If you don't makes mistakes, you're not learning. My lathe and mini mill are both from Harbor freight and have served me well. Got my stool to sit on and now to trouble shoot the mini mill since it keeps shutting off when I put a load on it, even drilling large holes.
Tin Falcon
Well-Known Member
- Joined
- Jul 9, 2007
- Messages
- 7,207
- Reaction score
- 788
Here is a resource , actually a collection of resources that may help You.
http://www.homemodelenginemachinist.com/index.php?topic=9413.0
The Basics are all over, in many books and some videos. There are video machining courses you can buy or rent you may be able to take classes at a local tech school or college. If you are luck there may be a fellow Home Shop machinist in your area willing to teach you.
As far as step by step directions for building a model I can think of a couple good options
1) Buy and read all the Shop wisdom of Rudy Kouhoupt books. His plans come with instructions. The plans are all in book format now.
2) )download the Elmer Versberg plans from John-Tom.com again insructions with the plans.
I have said before The home Engineering shop is like a college engineering lab. No mistakes but lots of learning experiences. Sometime you just need to make a practice part before you make one for an engine. heck sometimes you need to make three practice parts.
Keep a notebook and calculator on your bench. do not be afraid to calculate the next cut. And take notes and Photos as you go. If a setup works great use it next time if you blundered document that as well as a pitfall to avoid.
It is likely the mill safety cutting in. Mine does the same thing . the mm is not a Bridgeport and brass and plastics will grab a drill bit and try to suck it in.
There are two ways to avoid this 1) step drill start small then make the hole progressively bigger using larger bits in small steps. the other method commonly used for plastics and brass is grind a zero rake angle at the cutting edge.
You may be able to adjust a pot on the control board so the safety does not cut in as soon but it is like just needs the operator to not take greedy cuts.
And do not be afraid to ask for help here if you need it . We all have times when we cant seem to find an answer we need in the "book"
I help run this board have worked as a pro machinist I still ask questions no one knows it all.
Tin
Tin Falcon
Well-Known Member
- Joined
- Jul 9, 2007
- Messages
- 7,207
- Reaction score
- 788
A v-8 is a worthy goal. and a nice engine.
I would suggest thought ,start with something simple like a McCabe runner or a LMS oscillator. or an Elmer's engine with instructions.
1 ) learn to build a running engine.
2) learn to build a very good running engine like virtual no friction
3) Then learn add the finish and bling to above.
then move into multiple cylinder engines stirlings etc.
A simple engine will teach you faster. It will give feedback sooner and tell you if things are right or wrong. I will be honest with you I am trained By the USAF as a Machinist /welder i started thee engines before I completed a running one.
the second problem with something like a v-8 is more often than not the author will assume you know the basics of set up and order of operations. That is usually learned on simple projects then combined.
As far as operations build an engine like a house start at the bottom and work up. Make a part then make the next one fit the others you have made .As far a cylinder piston fit make a nice smooth true bore on the cylinder and then make a piston to fit it. An exaple of good piston fit if you put te piston in the cylinder the piston shoud move with the force of gravity plug the end it shoud sit in one place.
Also dimensions need to be interpreted . a dimension may say 1/4 or .250 but if you are reaming a bushing for a shaft use a .2505 reamer. If you are pressing a crank disk on the same shaft use an undersize reamer.
Good luck
tin
I would suggest thought ,start with something simple like a McCabe runner or a LMS oscillator. or an Elmer's engine with instructions.
1 ) learn to build a running engine.
2) learn to build a very good running engine like virtual no friction
3) Then learn add the finish and bling to above.
then move into multiple cylinder engines stirlings etc.
A simple engine will teach you faster. It will give feedback sooner and tell you if things are right or wrong. I will be honest with you I am trained By the USAF as a Machinist /welder i started thee engines before I completed a running one.
the second problem with something like a v-8 is more often than not the author will assume you know the basics of set up and order of operations. That is usually learned on simple projects then combined.
As far as operations build an engine like a house start at the bottom and work up. Make a part then make the next one fit the others you have made .As far a cylinder piston fit make a nice smooth true bore on the cylinder and then make a piston to fit it. An exaple of good piston fit if you put te piston in the cylinder the piston shoud move with the force of gravity plug the end it shoud sit in one place.
Also dimensions need to be interpreted . a dimension may say 1/4 or .250 but if you are reaming a bushing for a shaft use a .2505 reamer. If you are pressing a crank disk on the same shaft use an undersize reamer.
Good luck
tin
As said here, I recommend starting on the Elmer's engines. If a bar stock wobbler is an insult to your intelligence, I recommend Elmer's Fancy. I just finished it myself (see the pics/videos section). I believe I used almost every machining operation there is in its construction (3 and 4 jaw chucks, form tools, left handed tools on the lathe, boring on mill and lathe, indexing head, rotary table, compound vise, knurling, jig building, single point threading, etc).
Most of the plans call only for steel, but branch out and try all kinds of material. You can incorporate aluminum (I prefer 7075), brasses, and 304 or 316 stainless almost anywhere in these models. You'll find that with proper technique you can get a good finish on any material. Also these plans can be improved in many ways by adding bronze bearings at proper places, adding cosmetic features, whatever suits you. I think the V-8 is a great goal, but if you start small, you'll learn more quicker. You'll make mistakes, learn what not to do, and you'll end up with some nice shelf pieces along the way, and by the time you get to the V-8, you'll be building first-quality parts.
One more suggestion: When you make a mistake on a part, don't just throw it straight in the scrap heap. Try to figure out a way to salvage it or fix it first, you'll learn a lot this way as well.
Most of the plans call only for steel, but branch out and try all kinds of material. You can incorporate aluminum (I prefer 7075), brasses, and 304 or 316 stainless almost anywhere in these models. You'll find that with proper technique you can get a good finish on any material. Also these plans can be improved in many ways by adding bronze bearings at proper places, adding cosmetic features, whatever suits you. I think the V-8 is a great goal, but if you start small, you'll learn more quicker. You'll make mistakes, learn what not to do, and you'll end up with some nice shelf pieces along the way, and by the time you get to the V-8, you'll be building first-quality parts.
One more suggestion: When you make a mistake on a part, don't just throw it straight in the scrap heap. Try to figure out a way to salvage it or fix it first, you'll learn a lot this way as well.
