Split bushings

[Gordon]

When making split bronze bushings is there a way to make them other than making two and machining half of the bushing away? If I make one and split it there is a gap since the thinnest saw I have is .010 so there is a .020 gap. Am I missing something?

Gordon

 

[Mike1]

Make the two halves soft solder the two halves together which will be your centre joint, machine and bore to size, melt the soldered joint and you have your split bush. ( With no saw gap )

Mike 1

 

[Gordon]

I may give that a try. Actually it may be possible to do it with the two halves just held together in the lathe chuck. The OD is not s critical and the ID can be reamed to final size in position. I actually have some half round stock which is close enough to try it. Some times we need a jog to think of a way we have not tried before. Thanks

 

[awake]

Has anybody tried doing this using superglue or Loctite? I wonder if either would hold adequately once the wall of the bushing gets thin ... ?

 

[chrsbrbnk]

the method one where you take a over sized shaft, split it , machine the two inside faces, then hold them together some how say soft solder then the resultant shape is this oval kinda thing really needing a four jaw to hold well and to machine the outside you need stock to hold on to using up alot of stock .
the method two where you machine each half separately usually by holding on to some extra stock and milling off the waste side. the only stock conservation approach is to use a long enough piece of stock to part the end one off then machine the next half right after stepping along thru the required number of bearing half's this method does have the virtue of making the id and any flanges concentric with very low effort and usually faster than the first method. Also it allows machining in wear allowance in the first milling set up off the bearing split face with out any weird set up effort but it use more stock than the first method and bronze can get spendy or not available right then
method three would be to machine both bearing halfs on the end of a bar at the same time on a cnc mill this would also use up significant material depending on the dia of the tool needed to machine the inner faces but might be fun to watch

 

[Cogsy]

Whether you soft solder or not, it's a good idea to mark the orientation before you separate them so you end up with a truly 'matched set'.

 

[TonyM]

In the past I have soft soldered the split. It's the way we used to do it in my youth to make crusher bearings. A sharp tap to split to avoid heat distortion.
Small bearings can only be separated by heating. On my latest set I split a longer piece of stock, machined flat the mating faces, and and bolted them together leaving enough to machine a set of bearings. Machined everything for the first bearing marking the first finished end to ensure correct orientation, parting off with a more angled parting tool. I put a soft cloth down to collect the two halves as the fell. Then carried on and machined the second. It worked a treat. The downside was the waste of around 1/2 inch per two sets of bearings.

 

[leerkracht]

Two piece bearings

turn with oversize outside / undersize inside
split / mark the parts , polisch the faces , glue white good quality thin ca glue

polisch the faces flat, make a mandrel, clamp with bolt inside turn the outside to size possibly the groove to size, make a pot chuk where the workpiece fits correctly, clamp the bearing with 2 small clamps outside so you can make the inside centric and to size, break the 2 parts carefully remove the remaining glue (very little), now you have a bearing where the inside very little needs to be lapping less than 0.005 mm.
success

 

[Iampappabear]

Two piece bearings

turn with oversize outside / undersize inside
split / mark the parts , polisch the faces , glue white good quality thin ca glue

polisch the faces flat, make a mandrel, clamp with bolt inside turn the outside to size possibly the groove to size, make a pot chuk where the workpiece fits correctly, clamp the bearing with 2 small clamps outside so you can make the inside centric and to size, break the 2 parts carefully remove the remaining glue (very little), now you have a bearing where the inside very little needs to be lapping less than 0.005 mm.
success

View attachment 114898

 

[Iampappabear]

When manufacturing large split bushings ie 6-8" diameter, we found one of the bigger issues was holding the bushing tight enough in the four jaw without crushing it which results in a bearing that is mishapen. We found that by matching inverted V's that matched the V grooves in the inner surfaces of the 4 jaw chuck prevented the bearing from twisting out of position and right out of the chuck completely.

This method takes a little extra work but once you know the spacing of the grooves in the chuck and you have a tool ground to the correct angle it is worth the it. Typically on a 6" long by 6" diameter bearing we only needed about 3/4" in the chuck saving a lot of expensive bronze.

 

[Apprentice707]

For small bearings, I have taken suitable flat stock and fastened them together with super glue. Mounted them on my 4 jaw independent chuck being careful to centralise the join and machine them to the required dimensions. For those that require checking against existing holes/shafts for fit then establish a round area to hold in a collet and then use a collet, not a chuck to machine the other end which will still be square. This worked for me in the past, but then the bushes I usually make are less than 1" in diameter.

A workshop is a great place to hide from any virus. (That's what I told the wife)

x
B

 

[peterl95124]

I've made lots and lots of split bearings for my various engines, I tried the soft solder approach once because I read about it in a book, but its a mess and I never even finished that bearing, instead I just use a 4-jaw chuck to hold the pieces together and machine them.

CDA 932 / SAE 660 leaded bearing bronze is sold "oversize", I saw it in half with a thin slitting saw, thin enough that minus the saw gap the OD is still good.

Typically I slit from both sides of the rod, and the cuts never exactly match up in the middle so I file them if possible or re-machine them if that's what it takes.

I usually buy a foot long piece, half in the vise and half sticking out to slit it, then you've got 6" pieces to hold in the 4-jaw and turn the end of into a bearing, lots of material for the chuck to grab even after making seven or so bearings for a V-12.

It's a mystery to me as to why folks bother with solder or glue, guess its one of those bad idea that just won't die sort of things.

HTH,
Pete.