I have been slowly plodding my way through building this model of Oliver Evans Beam Engine and have come across something that I'm not sure how to do.
The drawing shows a relief. I'm not sure what is the best or even correct way to do this.
!. Doing this is by working out the steps and using a mill to cut out deeper and deeper steps.
2.Sitting the base upright and cutting it with a fly cutter. This means making a right and left cutter.
3. Buying a 25mm x ? slitting saw and again mounting the base upright and making repeated overlapping cuts down the face.
I'm not even sure that this will clear the eccentric. If anyone has got a good idea and perhaps has even built this model your advice would be appreciated.
As the base is only 5mm thick I would be inclined to just make a rectangular opening in the base. Then if the eccentric does not clear it is easy to open out the hole and if necessary make suitable relief in the wooden plinth which I assume the 5mm base sits on.
In the days before mills were common in home workshops, the recess may have been done by clamping the work to the lathe cross slide and using a between-centres boring bar to produce the recess. A flycutter mounted securely in the lathe chuck may also work. The work is well supported with either approach. depth of cut could be controlled by adjusting cutting tool position outward in the boring bar or the flycutter. Just food for thought.
A single point tool in the end of a bar set to swing the 25mm radius would do just worked up and down, no need for left and right hand.
The other option is to cut out a hole and then let in a piece with a concave top which would be easier to cut than having to stop at the edges of an integral recess. or you could bend some sheet to a curve and let that into the hole.
Perhaps too late maybe? Another alternative to the curved slot underneath the eccentric would have been to add some 'pads' underneath all the other parts. A simple mod if it is planned out at the start though.
I am surprised that nobody else has built this although ME4159 was a long time ago.
Phew, only 2001. I was thinking from that statement it was a pre-WW2 design. This is like a few weeks ago to most of us so haven't got round to it yet.
Perhaps too late maybe? Another alternative to the curved slot underneath the eccentric would have been to add some 'pads' underneath all the other parts. A simple mod if it is planned out at the start though.
Phil H
Sorry Phil there is no eccentric on the flywheel. So I'm not sure what you mean.
I was trying to address your original snag regarding the machining of a tricky radial slot underneath the eccentric i.e., if you used rectangular pads underneath each of the parts that bolt down to the baseplate, the eccentric would be higher up and hence no need for a clever curved slot. Easier to describe with a sketch.
I was going to say that having no compressor I wondered if my garage vacuum cleaner would do the trick on blow. As you can see (and hear) it did. I have no idea what the pressure is though.
I found it amazing that it was April when I'd finished the flywheel which was the last component to make. Time definitely speeds up the older one gets.
It was the first time I'd used you tube and it had me running round in circles and the only things it offered to share with were all the well known apps and a lot more which didn't give me any option than to post the URL. Thanks again Michael.