May I first thank you Jeff for your comments regarding my articles in MEW, also those regarding filing machines with which I have little disagreement, other than the degree of their relevance in the majority of home workshops. Because of that, I would like to make some points which I consider, for the one attempting to make one, to more home workshop biased.
Incidentally, the filer was as a result of a request to the magazine for one to be constructed in the home workshop. It had therefore to be a design that the vast majority could make.
You mention that the mechanism should ideally be in an oil bath, but such a design would make it a non starter for very many home workshop owners. Leaving out the VSM (variable stroke mechanism), easy, it can even be made without a milling machine.
I agree that the open nature of the design permits the entry of filings and will reduce is working life, especially if not cleaned after heavy use. I have though looked at mine which was used extensively for a clock being made and the amount of filings in the important areas is very small. The VSM can be easily removed by the removal of four very accessible screws when access for cleaning becomes easy.
We have to consider when items are made in the home workshop the degree of use that they are likely to get. Typically, when I purchased my Mill Drill, with no spare cash then available I had to make a cutter chuck to suit screwed shank cutters, This was made using normal mild steel and had just turned surfaces, 22 years later it is still working as well as the day it was made. However, if it had been in use in an industrial environment it would have been consigned to the scrap bin very soon.
Whether my design is better than others at long edges, curved or straight, I was not commenting generally, but specifically about the MLA-18, surely it will be less difficult with a 1/2” wide file than the 1/4” file that that machine uses. The suggestion of using belt sanders where straight lines are being worked to will be valid in some cases but many will not have a belt sander, I don't, and of course will not work on enclosed edges.
With regard to using the machine for sawing, I have contact with one contributor to MEW who owns a commercially made machine and who tells me that he probably uses the machine more for sawing than filing. If one goes to my website and clicks on the link in the bottom right hand paragraph this takes you to an American workshop owners site who on the page has a link to a manual for a commercial filer. The front page states, It Files, It Saws, It Hones.
My web page also shows the skeleton clock I have made and for which the filing machine was used extensively.
If visitors to this thread have read this to the end, and I hope so. May I say that I am not saying that Jeff is wrong and I am right, far from it. If then you are considering making a filing machine than do study both viewpoints, making a choice on the type of work it is likely to undertake and the degree of use it will get. Also of course, balancing this with the workshop facilities you have available for the task.
Harold