Part 3, Making the Lathe Bed
..Having been giving some thought to this for a while, what would be the easiest sort of lathe bed to make, which would give a reasonable degree of accuracy for float making..?
In the end, I decided upon a simple 'monorail' design, which would allow the basic 'tailstock' to move up-and down and also support whatever I can come up with for a moveable toolholder.
If any one out there is copying this, the bed is made using standard, stock-sized brass strips; the centre rail being 1/2"x3/8", which is flanked by 3/8"x1/8". I bought everything from my local supplier, but small stock sizes like these can be had from many different Craft & Hobby shops. The idea is that the tailstock travels on these two pieces and is guided by the centre rail. It sounds a bit complicated but you will see how it all goes together very soon.
Of course, it would have been much nicer to have made an 'H' section bed, from one piece of material instead of three, but I don't have a mill and so am limited to what the old Myford is capable of.
The lathe motor is fixed to the base with four M4 cap-head screws from underneath. The through-holes are a little oversize to allow for motor position adjustment and have a steel washer at the bottom of each counter bore to prevent the screws from 'burying', like this..
The next thing was to make and fix the centre rail. This is held in place by a series of M3x0.5p countersunk screws-again, from underneath. Here you see the 2.5mm tapping holes being drilled..
..then the M3 holes tapped right through..
It is now ready to be set into position. I did this by carefully measuring and marking out the centre position on the base board, then clamping it whilst the first hole was drilled through the wood. It is always best to get one screw in place first, then check for alignment before putting the others in.
The centre rail is now fixed in place..
Now it's time to add the side plates, upon which the tailstock will move.
The two pieces were cut to length, then drilled & tapped in similar fashion to the centre rail. I used a clamp to hold these firmly in place whilst the through-holes were drilled in the wood. Thes will be held by M3 cap-head socket screws, again, from underneath, with the counter-bored holes reinforced with steel washers.
This more-or-less completes the lathe bed. It is not permanently fixed yet because there are a few more holes etc. to go into the wood, which will be polished before final assembly. There are quite a few in it already!
..And this is the bed with the motor in place.
The next step will be to make the tailstock from that roughly cut block of steel.
The first thing was to try and true-up the faces, by taking a light skim cut, holding the block in the 4-jaw chuck..
..but we'll continue that next time.
If the pictures look any different this week, it's because I am having a lot of problems with uploading from my Photobucket account. I can open the 'Get Links' menu but they will not 'copy', so Mark has kindly advised me to use the 'tinypic' option..
Regards for now,
wm+