have two sealed bearing that are supposed to be a press fit into the housing. the actual fit is a sliding fit. Is there any way to tighten up the fit between the bearing and the bore for the bearing to fit into.
thanks
OM
YOu could deform the metal by knurling it but the better way is to get the proper grade of locktite made for holding loose bearings.
John
The correct grade of loctite is definitely the way to go. In a pinch, or for unimportant applications you might try a runny type of 'crazy glue' applied after assembly, allowing capillary action to draw in the glue.
Wolfgang
John sez: "YOu could deform the metal by knurling it but the better way is to get the proper grade of locktite made for holding loose bearings."
John,
I'm not familiar with a grade of locktite made for holding loose bearings. Could you be more specific?
As for "knurling to deform the metal", this must be in re. to the bore itself. If so, can you tell us more about inside knurling tools?
Bob Swinney
John
If not subject to really heavy loads and they are almost a press fit, you could try the hacker's trick of popping a bunch of centerpunch marks around the inside of the housing bore. The craters raised by doing that may be enough to give you the "fit" you need.
Works for me...But please don't tell my high school shop teacher if he's still "on the right side of the grass".
Jeff
Could you be more
If so, can you tell
Loc Tite is sort of like milk - you can get everything from skim and
1% right up through heavy cream. I've got an old bottle labelled:RC 609 Retaining Compound Cylindrical Part Bonding red bottle
There may be a newer replacement for this. Or, it may be that any of a few grades will suffice.
I'm familiar with the internal knurling tools that consist of a bar with two sliding heads on it - sort of like a trammel set or an old hand washer cutter - with the knurls mounted on pins on the ends of the heads. Feed screw on the bar to force the heads apart, with two handles on the top side of the bar. Insert the knurls into the hole, expand using the screw, give it a few turns, expand some more, and so on. Just checked the MSC catalog and they carry one, plus a single knurl internal tool. The single knurl tool is interesting in that it is available with counterbored knurls to allow knurling to the bottom of a blind bore.
John Martin
Could you be more
If so, can you tell
messagenews: snipped-for-privacy@>
"LOCTITE RC620 is a...for bonding...cylindrical parts...with clearance not exceeding .015"".
Description straight off the container.
Of course you want to make absolutely sure that you don't get any of this stuff INTO the bearing!
Wolfgang
?Is there any way to
OM
Depending on the cleaance between things - Get some brass shimstock to make up the difference. Push the shimstock in place and press in the bearing. If this is in the way of the shaft just put a hole in the shimstock. I do this more frequently than I like but this will save you the cost of replacement.
Bob AZ
Thanks, John. Good explanation of finside knurl.
Could you be more
If so, can you
Loc Tite is sort of like milk - you can get everything from skim and
1% right up through heavy cream. I've got an old bottle labelled:RC 609 Retaining Compound Cylindrical Part Bonding red bottle
There may be a newer replacement for this. Or, it may be that any of a few grades will suffice.
I'm familiar with the internal knurling tools that consist of a bar with two sliding heads on it - sort of like a trammel set or an old hand washer cutter - with the knurls mounted on pins on the ends of the heads. Feed screw on the bar to force the heads apart, with two handles on the top side of the bar. Insert the knurls into the hole, expand using the screw, give it a few turns, expand some more, and so on. Just checked the MSC catalog and they carry one, plus a single knurl internal tool. The single knurl tool is interesting in that it is available with counterbored knurls to allow knurling to the bottom of a blind bore.
John Martin
Sadly mine and his family is on the wrong side of the ground. Nice guy, young guy, raced midgets. One drunk driver ended the Robert Blume's families world back in the early 70's. I really liked that guy.
I wonder if a combination of red permanent loctite and some close spaced dimpling with a punch would work.
Wes
Could you be more
If so, can you tell
Google is for everyone..... search Loctite and bearings.
you said knurl... I said deform..... with a prick punch around the inside of the housing. It works in emergencies but is not the best way. Possibly a combination of the two. I personally would resleeve the bore if it were that important and the piece was that hard to replace but then I have a lot more equipment to do that type of job since we do that type of repair quite often. Even a piece of shim stock would work. I did that once on an emergency repair on a large sheeve on a big boring mill for a customer. I told them they needed to at least spray weld the shaft and rebore the sheeve but they wanted it to run. I shimmed up the back side of it and told them to plan on making a permanent repair within a month. Eleven months later I get a call that the sheeve was making noise. I told them that they got ten months more than they should have but I wouldn't charge them for it. We made a new shaft and rebored the sheeve in a day and a half.
John
In one shop where I worked we did that for a quick fix. The guys called it a "railroad fit". Our boss said "I used to be a railroad machinist and we always did precision work, nothing like that." We all had a good laugh. Engineman
I have some "Caterpillar" green liquid sleeve and bearing retainer which is made by Loctite. Don't know the specs but seems to be pretty tough stuff.
Don Young
Bearing retaining compound works very well. http://68.72.74.113/PRODUCTS/641.htm If you need to remove it later, a little heat will do it.
Probably was called that because "you could drive a train through the gap".
Stan
For a steam engine you want and need a little slop in the fit - when the item needs to operate anywhere between sub-freezing winter to superheated steam heat there has to be a little room left for slop and uneven expansion. If not, things that are supposed to turn or slide will bind up and seize. You end up with hot journal boxes, cracked axles, broken piston rods...
Allegedly true story: They built the two new narrow-gauge Steam Engines for the Disneyland Railroad from scratch in 1955 - at the Disney Studios Machine Shop where they were used to precision work. Without any directions to the contrary they followed usual procedures and built them to camera tolerances in the thousandths.
First time they steamed an engine up for Walt (probably the E.P. Ripley since it was completed first) they cracked the throttle and it just silently glided away - the Steam Buffs noticed that there were none of the usual clanks or bumps, no errant steam leaks... They had to take everything apart and open up the clearances.
-->--
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.