Great video Keith. It's always a pleasure to watch your progress on the planer. I love old machines as well, and I personally think that it is fantastic that you are not only performing the restoration, but documenting it with these great videos.
Learned a few tricks regarding getting the mandrel squared away (tapered away!), thanks. Your humble approach to your work is a delight for me to experience. I admire your skills. Again, thank you.
A really great video. Keep up the good work I have always liked machining things and now that I am retired I am getting my lathe and other tools in condition to start using them again after about 35 years of sitting in the back of the garage.
Hey Keith.. Just wanted to say how much I admire and appreciate your skills, both in metal work and video production. To have either is rare, but to have both, well, its almost nonexistent! I've yet to meet you, but its only a matter of time, as I'm just "up the road" in Macon and have a few Olivers on the restoration list. Thanks again Keith!
Keith, I was taught as an apprentice that for every .001" off interference allow .0013" compression in the bore. It has always worked pretty well for me. If I am using the press I turn down a slight lip about .001"-.002" and about 1/8th. long, to align it square before pressing. It doesn't make any difference to the bushing but avoids it going in crooked. Clive
0.003 size difference on the diameter would be 0.0015 on each side with respect to the ways. Therefore, your tailstock was originally on center and your first grind removed all taper from the mandrel and made it a cylinder. Subsequently offsetting the tailstock 0.001 toward you gave you a 0.002 undersize on the tailstock end after grinding.
Well, I did the reaming on the four sets of bearing blocks today and did not shoot any video of it. I did shoot some video on cutting keyways on my horizontal mill though. I will have four more bearings to do for the outfeed rollers at some point in the future and I will make a point to show the reaming process on those.
Good stuff Keith! Didn't think of using a mandrel to ensure concentricity between the ID and OD, makes good sense though... Will have to buy some lathe dogs now.
What do you think Keith...rather than a tapered mandrel, another option would have been turning the mandrel 1.48-49ish OD and using CA glue to secure the bushing to it...then turn the outside. Heat it up to release the CA glue and lightly ream it again to remove any glue residue from the inside of the bushing. I think thats how I woulda done it 🤔
couldn't help but notice your "apprentice error" while trammeling the mandrel: the mic showed 0.003 taper, the trammel indicated 0.0015 taper. both gave you the SAME reading. with the mic, you were reading full OD taper. with the trammeling of the dial indicator along a lengthwise face, you only read HALF the full OD taper (variation in a single wall of the 2, lol). so, technically, your tailstock was PERFECT when you began. now, technical question: would you get a "better" bearing (longevity, lube economy, etc) if you babbit the interior of the bronze bush? as in finish turn OD to proper size, internal bore to a rough finish about 1/8 inch oversize, pour full of babbit, hog drill, then ream after pressing? my idea is you basically then get a "clevite tri-metal" bearing (babbit, bronze, iron), as well as a far faster "renewal" in later service ( pour over a mandrel, and ream). granted, another time consuming step, a little more dough in materials, but as you say, no CPAs are watching, lol. thoughts?
First, the taper on the mandrel is very slight - only a couple of thousandths of an inch over the length of the mandrel. Second, you are only pressing them on tight enough so that they do not slip while turning, which really is not a true "press" fit - it does not take much as long as you are taking relatively light passes. I have used this technique many times over the years and have never had a problem - and it is a standard practice that has been used in machine work for over 100 years...
Just like doing cutless bearings on my Wellcraft. Though we put the cutless bearings in Dry Ice and heat the bearing holder...just like butter....getting them out? That's another story and takes a special tool. LOL
With the process shown would it not have been better to turn the outside dia of the bushing material in the lathe to allow a "press fit" in the bearing carrier and then part off before freezing the bush and heating the carrier then pressing the bush into the carrier, This would then have allowed the carrier to be chucked up in the 4 jaw and then turning the inner surface and reaming ? That is the process we used when installing non stock size turbocharger bearings, which gave us a better fit than the process employed. No mandrel is required then, and cooling the bearing material and heating the housing to "press" the bearing in means you have a really tight friction fit. I'm only asking to understand the reasoning and thought process that was employed to machine the parts in the manner you did, not to flame or demean.
I've seen this effect before. It seems to me that human nature is such that given a resource or tool the tendency is for that to stop the natural thinking proccess in its tracks. Keith's problem here, I suggest' is that given this dammed arbour he has become stuck in having to find a way to use it. It also looks as if many of his plaudits have failed to notice this.
Yes, I've seen it in other You Tubers as well- skill as a machinists does not mean the guy is a good job planner. Another popular guy does things that are in the realm of Rube Goldberg, as you say, almost an exercise in using every tool available. The other effect is the "cult leader" syndrome in which followers will not tolerate any criticism of the leader.
These days there are a lot of amateurs filming themselves refurbing stuff. It horrifies me to see them sanding and grinding stuff on the lathe without protecting it from abrasive dust.
You might want to try manual focus, provided the camera offers the option. Other than that, those old machine tools and soon-to-be-rehabilitated machinery are enough to make me drool.
Hello Keith! Is it possible to turn the od and id without cutting to length first, then you don't need the use of a mandrel. By the way, i really like your videos :-)
Very, very interesting and I appreciate all the work that goes into making and uploading the video. However, it would be great if you scrapped the speeded-up sections- they really don't convey much useful information and the videos could be a good deal shorter - you can cut after the first few seconds and dissolve to the last few seconds if you want to shew the complete tool pass. Also your sound is very variable - I assume you are in a busy workshop with other operations going on round you, but if quieter backgrounds, or closer mic positioning, could be achieved that would make for better audio. Lastly, you don't indicate what turning speeds you are using for the various operations, which is useful knowledge to have. But thanks, and I'll watch lots more.
Keith, thanks for the demos and explanations. Some of us are still early in the learning process, but I'm following your explanations just fine and learning lots. I do have a question about an alternate solution to the mandrel...would it have been possible to just hold the bushing between live centers? Or would that have created too much runout, let the bushing flex too much, or was it just a matter of no length to clamp the dog onto? Just looking at alternatives...your method obviously works. Can't wait to see the planer running! -- Mike
Hello KR, one thing i don't understand is why we have to use the lathe dog instead holding the part directly on the chuck? I have 4 lathe dogs (different sizes) and never used them - because i don't know when to use them.. Regards, and another great video. Love the details.
so you buy a mandrel and find it needs to be reground. Then you remember to run the part the correct way.Then you grind it to fit. Then you end up with one end of the bush forced onto the taper thereby spreading it. Then you leave the other end of the bush unsupported inside. Then you have to reset your tailstock because you reground an unsuitable arbour. then you end up with a bush that starts to go into its press fit because it spread on the arbour when you turned it and now its returned to shape and you look slightly unsure as to why it's doing that. A bush 2 thou bigger does not start in a hole like that. Why did you portray yourself as being so confused and out of your depth? Why did you not either make an arbour to fit or indeed friction drive it between centres? This would have taken a fraction of the time.
