HANDLE & BACKSTOP BARS
The handle and the backstop bars are all made from "20 nominal bore" heavy wall pipe.
This has an OD of 26.9mm and an ID of 20.5mm. The wall thickness is 3.2mm.
It is normally supplied in 6.5m lengths and a length will cost around
$50, but a full length would have enough material for 5 Handyman
(It is also possible to make these parts from solid shaft but it would be twice as heavy and would cost twice as much).
You will also need 3 off M12 x 55mm Socket Head Cap screws
. These screws have part of their length as plain shank
and this is most important for this method to work properly. (Shorter
length screws are normally threaded all the way to the head and are not
suitable for this application because Loctite will not cure properly in
the threaded portion of the screw).
- Cut 2 pieces of pipe to 400mm long each. These will make the backstop bars.
- Cut 1 piece of pipe to 500mm long. This will make the handle.
- Next make 3 sleeves from dia 20mm steel bar. The length of the
sleeve should be 15mm less than the length of the bolt and the internal
hole should be the same diameter as the bolt.
- Check that the sleeves will fit in the pipe. If the pipe
has a prominent internal seam then it may be necessary to drill out a
short section of the pipe with a 20mm drill bit.
- Make sure all the parts are clean and then coat the sleeve both inside and out with Loctite #680.
- For a faster cure you could also spray Loctite Primer on the bolt and the inside of the pipe.
- Assemble the parts such that the sleeve is flush with the end of the pipe and there is 15mm of thread showing.
- Leave undisturbed until the Loctite has cured. This will
take about 2 to 3 hours but if you are not in a hurry it is preferable
to leave it overnight.
- Repeat the procedure for the other backstop bar and for the handle.
- Drill a 11mm cross hole near the end of each bar. This will be used for tightening the bar.
- As a finishing operation the bars can be chrome or nickel
plated. (If you are a hobbyist constructor you may be happy with
sanding and then polishing the bars with Autosol Metal Polish).
Finished Backstop Bars and Handle:
The above procedure provides a very simple method of obtaining a
threaded end on the pipe and requires only a simple sleeve to be
manufactured. Loctite #680
works best if the parts are clean and the fits are reasonably close; 0.1 to 0.2mm diametrical clearance is preferable.
to "Handyman" Index page.