Floating reamer holders

[RSG]

Thanks for the info in Reamer Holders 10K Pete! If I go that route I will definitely make my own. There's one on YouTube exactly as you describe called the Hemmingway Kit.

Pete, I have a cheap offshore set of gauges but disassembled them as you mention and cleaned them up nice. They telescope at both ends smoothly and I try to allow the post to center itself in the hole then tighten them.

Harold, I know the "feel" you talk about having and think I have that part down however I lack the confidence in my ability to transfer the same feel to the micrometer. I have found that even if you hold the gauge on a slight angle of perhaps one degree the micrometer will give you a different measurement, leaving me to wonder which one is correct.

[Inspector]

While good telescoping gauges are an inexpensive means of measuring bores I would suggest you look at a dial bore gauge set in the size range you want to measure. Once set for a size you can measure the diameter easily and repeatedly. They also show if there is any taper in the hole and ovality. Best way to set it up is with a ring gauge the same size or close to the hole you are making. If you make a lot of sizes then a set of gauge blocks and an accessory kit to set up the exact size you want is great to have and has the versatility for use on the mill. You can also set the dial bore gauge with a good micrometer held in a stand.

A bore micrometer is fast to use but to cover a range of sizes you need a several or a set and still need ring gauges to verify they are set properly. Lots of people don't read the instructions and don't turn the friction barrel enough to properly seat them in the hole getting errors. Most bore mics require three full turns to take a reading. Fine in thicker/stronger materials but the hole can distort if the materials are thin.

Pete

[johnfreese]

Look for a used Glenzer or Scully Jones floating holder. I got mine on the Bay.

[RSG]

Thanks John, will do!

[10KPete]

John is correct about those old ones if you can find one. The Hemmingway unit seems to be correctly designed, and I may purchase their plans as I find I'm needing one again and the design is a bit simpler than the one I did over 30 years ago!

Thank you, RSG, for pointing out Hemmingway's!

Pete

[johnfreese]

Floating reamer holders sometimes show up on eBay. Look for Glenzer or Scully Jones brand. They are built to allow only radial float. If your tailstock does not feed perfectly parallel with the spindle you will get a bell mouth hole with or without a floating holder. As lathes wear the front of the tailstock tends to become lower than the rear. Shimming can correct that. If your tailstock spindle is dead nuts parallel with the spindle and concentric with it a floating holder is not needed.

[pete]

Unfortunately few to possibly no lathes including brand new ones are ever going to be absolutely perfect in both the horizontal and vertical axis. Horizontally is fairly easy to check and adjust using a DTI attached to a chuck face or face plate and swung side to side. But it's still tough not to have gravity affect the vertical measurement even with a light weight DTI. https://www.youtube.com/watch?v=u08SfxVgxNg The best tool room lathes are built (or there supposed to be) so the tail stock base is made a couple of thou high to help compensate for future wear and the quill is purposely biased uphill and towards the operator a 1/2 thou or so over roughly 6" for work piece weight and cutting tool pressures. On the best lathes the head stock is also scraped or ground so it points up and towards the operator another 1/2 thou or so in that 6", again for that weight / cutting tool pressure. https://www.youtube.com/watch?v=wtKIyUa_P_k About the easiest method of checking the head stock to tail stock alignment I know of is facing & turning a piece of scrap to as close as possible to the quills diameter, move the quill up until it almost touches the work piece face, light pressure on the quill lock and then mike or indicate across both diameters both horizontally and vertically. https://www.youtube.com/watch?v=qWnusZiJdqY&t=35s for an example of how it's done. Any mis-alignment will show in the measurement. That test assumes the quills Morse Taper is of course concentric to the quills O.D. It may or may not be on an off shore machine or one that's had a lot of use. A good hardened and ground MT test bar and checking the horizontal / vertical with the dti on the cross slide would be better of course, but not many will have those. On a worn lathe the quill could be pointing just about any where. As Harold mentioned reamers should cut more accurately in a vertical spindle mill and to state the obvious, sadly no lathe with all there minor built in inaccuracy's and gravity working against you plus any wear is going to get close to a good condition and well aligned mill or even better jig borer.

After some thought RSG those slightly loose fitting bearings with your current reamer may not be an actual issue. With an accurate straight spindle through the bearings inner races you could then set them in position and aligned true to each other using a Loctite bearing retaining product?

One big help I've found for getting a better and more consistent "feel" when measuring with those telescoping gauges for anyone who hasn't tried it yet is to lightly hold the mike in a small smooth jawed vise. Mitutoyo makes a proper micrometer vise with plastic faced jaws, but one of those grinding / tool maker vises would work just about as well if you've got one. It's (or at least for me it is) way easier to get that light drag when sweeping the radiused gauge face across the micrometer anvil and also keep the gauge square when your not trying to juggle the micrometer with 3 fingers while rotating the mikes thimble with another finger and sweep the gauge with the other hand. A pro with decades of constant micrometer experience probably wouldn't need that crutch like I do.

[RSG]

Thanks guys!

Pete, thanks for the in depth response along with links. I am going to try that one test turning a bar the same dia as the quill just fore curiosity sake. My lathe is of Chinese origin but it's only 9 years old as I bought it new so any wear should be minimal. Not saying it's accurate, just not from ages of use LOL.

As for sleeve retainers from Loctite, I have it and have used it in the past for repairs to reels brought to me where required, but I don't want to go that route for my product. Owners of these types of fishing reels tend to get techy and want to change the bearings thinking it will improve performance (which it won't, at least for my reels anyway) and if they ever try to take them out on their own without the proper equipment they'd surly to be in trouble. That said the guys that buy my reels usually send them in if service is required due to the cost of the reel and risk they take damaging it.

I should be receiving my new reamer that I sent to my friend in Ohio who owns a grinding/machine shop. He reviewed it and ground it to 3 tenths under so we'll see how that works. I'll keep you informed.

[Mr Ron]

I'm hardly an expert on anything, but what comes to mind is to ream 1 or 2 tens under and finish to size by lapping. I think that way, a consistent diameter can be achieved.

[John Hasler]

pete writes:

One big help I've found for getting a better and more consistent "feel" when measuring
with those telescoping gauges for anyone who hasn't tried it yet is to lightly hold the mike
in a small smooth jawed vise. Mitutoyo makes a proper micrometer vise with plastic faced
jaws, but one of those grinding / tool maker vises would work just about as well if you've got one.
It's (or at least for me it is) way easier to get that light drag when sweeping the radiused
gauge face across the micrometer anvil and also keep the gauge square when your not trying
to juggle the micrometer with 3 fingers while rotating the mikes thimble with another finger
and sweep the gauge with the other hand.

I do the opposite: I clamp the gauge and sweep the micrometer. I like your way better.