Engine Tale. Part 1: An Initiative and some philosophyPosted: February 5, 2016
In mid-2014, the board at Ushtara Engineering Pvt. Ltd., decided that over the next ten years we are slowly going to transition from being mainly sub-contract manufacturing company to a company which;
a) Offers services across the product life cycle (design, prototyping, testing, manufacturing, assembly, sales, service through to recycling)
b) Is rich in Intellectual property including creating and owning proprietary designs and processes
We resolved that the best way to initiate this, would be to enter areas where our current strengths including our manpower, specialized knowledge and resources could best be utilized.
After intensive study of markets and introspection, we decided that we should focus on the following areas;
1. Improved Prostheses and Orthoses for the Indian, South Asian and African markets
2. Improved Small Engines for agricultural applications for the Indian, South Asian and African markets
Given the fact that we were already designing and manufacturing components and sub assemblies for the Orthotics and Prosthetics industry, including;
Drop lock Knee Joints for Knee Ankle Foot Orthoses
and Trans-tibial Prostheses
which we have been supplying to Mobility India
and various types of engine components including, Valve spring retainer seats,
rocker arm shafts, Cam follower shafts, and governor shafts;
which we have been supplying to large engine manufacturers such as Beml Ltd. and Mitsubishi Heavy Industries – VST Diesel Engines Pvt. Ltd.,
As part of this initiative, we developed India’s first world class Polycentric Prosthetic Knee, in 2015 which I have written about in another post.
This article series describes our on-going efforts to develop a small two-stroke gasoline engine and the failures and learnings therefrom.
the Japanese word for “to learn” (manabu) is derived from the word for “to imitate” (maneru). I think that’s for a good reason. After all, we were all born knowing nothing, and then we copied the people around us before we evolved our own styles of doing things. Right?
In this spirit, we decided that our first engine should be a 2 stroke gasoline engine (one of the simplest types of engines, with the fewest parts) and that it should be inspired by, if not copied from a Japanese 100cc two stroke.
So we acquired a Japanese 100cc two stroke engine and took it completely apart.
Then we measured everything down to the micron (1000th of a millimeter) and made solid models on CAD Software.
here for example, is the cylinder head.
KNOW HOW AND KNOW WHY
My Dad, likes to say, that the problem with buying technology, as many successful Indian companies including, Maruti, HAL and Kinetic-Honda have done, is that the drawings will show you how to manufacture and assemble the parts but not why they were designed that way.
When we took apart and studied the Japanese engine, we were as concerned if not more, about why every part had to have the dimensions they did
We made detailed dimensioned drawings of every single part, like this partial drawing for a Crankcase Half.
And analyzed them with a handy reasoning tool, called DFMEA. We tried to predict, what would be the effect of a small change in the dimension.
As you might have guessed, we found that many of the parts had been designed with ease of manufacture and therefore cost-effectiveness, rather than power, efficiency or durability as the primary criterion.
Also we found that some parts were the way the were simply because of legacy reasons. In other words, a previous version of the engine had a design feature and it was carried over to this iteration even though it wasn’t the best solution. We hypothesized that this might be because of consequent changes in mating parts, large tooling costs or merely intellectual laziness.
By and large though, the engine that we had chosen correlated well with the theoretical knowledge we had, by then, acquired. Oh yeah, we managed to acquire quite a bit of theoretical knowledge! Anything we could lay our hands on;
- Design and simulation of two stroke engines by Gordon Blair
- The internal combustion engine in theory and practice, Charles F Taylor
- Lots and lots of workshop manuals
- Obscure literature by petrol heads
Like this manual
and this website
We read them, then re-read them, then read them again and crunched the numbers then went back and read them again.
Once we finished measuring and documenting the physical dimensions of all the parts, we went deeper.
Here for example is report which shows the chemistry of the Piston.
Up until now, we could, if we wanted, have put the engine back together, but the effects of the next step were irreversible.
We used a UTM to load the part until it failed, and in the process, provide us even knowledge about how it was made and why it was made so. We generated reports like this one for each part;
We uncoiled the solenoids in the magneto and counted how many coils there were and of what thickness wire
We took the permanent magnets out of the flywheel and measured their physical size and their magnetic fields using a magnetometer.
Then we put all this data into an open source software called FEMM and analyzed how they interact;
Well, what we did up until this point was the easy part, we do this stuff day in and day out for our customers. But now we were unknown territory. We hadn’t as yet designed or manufactured anything as complex as a whole engine. And don’t forget, we were out to make BETTER engine than the one we were studying.
By late July of 2015, we felt that we had enough knowledge to begin making our engine.
We resolved that although we would adopt many of the features from the study engine, we were not bound by logic such as mass-production requirements and legacy factors.
We decided to develop our engine in 3 phases,
Phase 1: Parts machined from Castings and Parts machined from Billet
Phase 2: Parts machined from Forgings
Phase 3: Stamped parts and Plastic parts
We also decided for now, at least, that we would purchase the Electrical and fuel systems.
We began the work of Designing our engine in earnest.
More on that in Part 2.