Eccentric Control Rod Continued.

Earlier I showed the making of the eccentric strap, the eccentric sheave and the control rod for the valve control eccentric.  However I had to pack up my workshop and store my equipment etc in a container supplied by the builder who had to resurface the unsatisfactory floor following the fire I suffered in 2010.

I have made a little progress on the engine but not as much as I would like, but I have finished the valve control mechanism.  Here is a little article showing the finished piece.

Connecting rod made from 'scrap' material as described in earlier posting

This component was made from 'scrap' 2mm thick sheet steel.  I try to reuse so called scrap wherever possible, not because of cost necessarily but for a variety of reasons including convenience - I may have a suitable bit handy - or for environmental reasons - less waste.

Clevis

This was simply made by cutting and filing from a short piece of solid bar. It has to be finally finished to size and some final polishing.

Eccentric strap showing construction

complete valve control rod assembly with eccentric sheave

Rotary Table Indexer - Overview - 1

Some more pictures and description of functions.

All images are clickable to enlarge

The indexer has various functions:

1. Jog;
2. Division;
3. Degree;
4. continuous;
5. Program; and
6. Setup.

Jog:

The Jog command allows the table to be moved by a fixed angle according in either direction i.e. clockwise (CW) or counterclockwise (CCW) depending on which of 8 function buttons are pressed. 

Division:

The Division command will step the table a step at a time when the command button is set.  Awkward divisions are easy, simply type in the number of required steps and use the command button to step the table as required.  Difficult divisions such as 127 are no problem.

Degree:

This command is self explanatory, simply type in the number of degrees required and the command button will step the angle one at a time.  E.g. 60o degrees for a hexagon.

Continuous:

Again self explanatory - one commenced the rotary table will turn continuously at a predetermined speed.

This function could also be used to operate an X or Y table.

Program

Up to 10 user defined programs can be stored.

Setup:

This allows user parameters to be set up such as worm - wheel ratios, trigger settings to allow for different Stepping motor controllers, plus many others outlined in the documentation available on the forum.

The cost of building is relatively low, mine cost probably less than £20.00 to build but I did search around for inexpensive sources of components.  The most costly items were the PIC chip on which I embedded the supplied firmware, the display, and the case.  The latter was an inexpensive buy from Maplin though.  The keypad was built up from a simple circuit board and PCB buttons for about £2.00.

Cost could be reduced with a home made case.  For the practical ones amongst us, I made another case from some surplus oak planking, a bit of 3mm ply for the back and some coated steel sheet from a defunct desktop computer case for the front.

Stepper Motor and Controller.

Disassembled Device to Show Controller and Motor and home made keypad

The controller was an inexpensive Chinese one from an eBay source and has proved to be quite satisfactory so far.

The stepping motor was again a buy from an eBay source and is a 200 step, 439 oz in motor, which is more than powerful enough to run my small rotary table.

At the moment I am using a 12V power supply salvaged from an old laptop computer, I will probably upgrade this to a more powerful PSU at a later date.

Sourcing components carefully can find some good equipment at decent prices, I use eBay etc where possible and avoid the extra expense of using dedicated suppliers but it needs a knowledge of what you need for the job in hand.  It is well worth carrying out some of research before buying.