PDA

View Full Version : Herless power hacksaw



morrisman
31st Jan 2016, 07:32 PM
I bought this some time ago , a swap meet find. Its been sitting around so I decided to get it running .

The motor required new bearings . The main problem with the saw itself has been worn out shafts and oval shaped holes where the shafts have been rotating .

I reamed out the badly worn bores in the casting where the lower shaft runs , I installed bronze bushes and am using a length of 4140 for the new shaft . I made the pilots for the adjustable reamer , rather like doing a king pin job on an old car. The two bushes have to line up perfectly . The original shaft was 22mm but I had some 7/8" bushes so used them .

The upper shaft uses two long steel bushes , rather odd but one must expect oddities as it is a Chinese made machine , these upper bushes are worn badly , steel on steel isn't a good idea. I plan on using cast iron bushes , hopefully these wont wear as much

The saw has a crude but effective hydraulic device for lowering the blade as it cuts , and a little suds pump . Lots of fiddling about on a job like this . The drive to the blade frame is done with 2 helical gears

I believe there are lots of these saws around, with many different brand names .

morrisman
1st Feb 2016, 08:22 PM
Hmmm well, the two long steel bushes are actually step bored , the diam. at each end is 22mm but the centre is a larger diam. , the centre section holds oil .

I think i will bore out the ends of the steel bushes and press fit cast iron plugs into each end, then bore the plugs to just under 22mm. After fitting , I will ream the bores to 22mm . The original shaft isn't worn , it measures up as 22mm

YBAF
2nd Feb 2016, 01:45 PM
Hmmm well, the two long steel bushes are actually step bored , the diam. at each end is 22mm but the centre is a larger diam. , the centre section holds oil .

I think i will bore out the ends of the steel bushes and press fit cast iron plugs into each end, then bore the plugs to just under 22mm. After fitting , I will ream the bores to 22mm . The original shaft isn't worn , it measures up as 22mm
Sorry, me doddery old brain caint visualise. You'll hafta put up some picys. :)

morrisman
2nd Feb 2016, 07:55 PM
The original bushes, I discovered today are cast iron , not steel

Anyway I have bored out the 22mm section and I will make some new short cast iron 22 id bushes and press these into the original worn bush .