30mm bore

I have 6 circular 3/8" mild steel thick plates that were waterjet cut with a slightly undersized central hole. The center hole needs to fit a 30mm shaft. What would be the fastest/easiest technique for sizing the hole, it is about 5thos undersized. thanks, rick

Reply to
semidemiurge
Loading thread data ...

Adjustable reamer

Reply to
Tom Gardner

It depends on what machines you have to work with and what tol. you have to hold the hole size to.

Reaming the hole to size would be the fastest way if you have the proper equipment.

A lathe and a reamer would work, A lathe and a boring bar would also work. The reamer would be faster.

John

Reply to
John

Depends on what tools you have available. With a rigid machine you could indicate them in and bore out the hole with a single point tool, ie, either spin the plate in a lathe or use a boring head in a milling machine.

With less rigid tools or to avoid indicating you need a reamer or even a big drillbit. You can get 1-3/16" adjustable reamer for $35 from MSC, don't know how well that would work.

You could also go at them with a half round file...

What kind of fit on the shaft do you need?

Reply to
cs_posting

Most of my tools are in storage awaiting completion of the new shop. That includes a manual vert. mill and manual lathe. I might have access to them but it would be a PITA. The plates are endcaps for a custom Delrin bending disc set that I am making for my newly acquired 3 roll bender (mini tool gloat;). The fit doesn't have to be perfect. I will need to eventually drill and/or bore similar holes in the 5"dia. Delrin. I could wait 2 months un til the shop is done, but I am just itching to try the angle roll out. rick

cs snipped-for-privacy@hotmail.com wrote:

Reply to
semidemiurge

=========== A lot depends on the accuracy you need. Accuracy costs time and money. Don't use anymore than you need, but use all you need.

Given that you only need to take out 5 thou. try a brake cylinder hone, or even a slotted dowel with emery paper. You will wind up with some bell mouth, but this may not be a problem, for example if you are going to weld the plates to the pipe. Be sure to keep moving the hone or dowel.

Unka George (George McDuffee)

...and at the end of the fight is a tombstone white with the name of the late deceased, and the epitaph drear: ?A Fool lies here, who tried to hustle the East.?

Rudyard Kipling The Naulahka, ch. 5, heading (1892).

Reply to
F. George McDuffee

Buying a reamer for this application (adjustable/chucking/hand) would be a huge waste of money given that you have a lathe available.

Does the hole act as a bearing surface? Too much slop could cause the shaft to deform the surface of the hole over time (and visa-versa). Mind you, mild steel is certainly not a great bearing material anyway.

Bore it on a lathe. You can do it on a mill, but a lathe will take far less time and hassle.

You can size the hole using a drill, but you'll have to be very careful. Such a small cut on a such a large diameter will cause the drill to grab unless everything is securely clamped *and* you have a powerfeed available (Bridgeport quill for instance).

Regards,

Robin

Reply to
Robin S.

An hour's work with an 8" half-round file. Use a second cut or smooth cut file depending on the speed and finish you want. lightly chamfer a scrap end of the

30mm bar to give you an indication of how close you are to the right size on the holes.

Mark Rand RTFM

Reply to
Mark Rand

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.