Thread: What did you learn today?

Needed to keep an 5" long x 7.5" dia cast iron hub from (a) drooping in the 4 jaw while centring it and (b) coming out of the 4 jaw when turning it. A self aligning bearing and housing kept in place by the tailstock did the job nicely.

The part is a front hub from a Howard V twin cultivator. The job was to backfill a badly worn oilseal surface with braze and turn it back smooth - nothing critical, the idea is to reduce oil loss from a torrent to an occasional drip. The rough whiteish looking surface (its actually a standard braze colour) just outside the circle of bolt holes is the built up area. Half of the braze I could turn with standard carbide tooling, the rest I needed to grind a piece of HSS to get to it.

The thing I learned here is that at 137 SFM (4.5"dia @ 115 RPM) when turning braze my cutting edges were disappearing before my eyes. Any thoughts as to what is going on here?

I think you are too fast Bob. Steel is roughly 100ft/min and my tables suggest half to 3/4 of that for bronze. I find it odd that brass is around twice that of steel.

Michael

Hi Bob,
unless all the flux, which is now a hard glaze has been removed it will dull HSS pretty quickly.

Phil

Today I learned that Toyota use these clever 2 diameter bolts to hold the seats in their utes and presumably lots of other things in lots of other vehicles as well.

Its basically a 10 x 1.25 bolt with the first 6mm reduced to 8.6dia, the thread is continuous across the dimension change. I'm assuming the skinny threaded portion somehow enables Toyota to screw these bolts in at a million miles per hour without worrying about thread damage.

Yep. They are referred to as "pilot point" bolts/ screws in the trade.

Michael

Well i learnt today that Bridgeport mills are made by Adcock and Shipley....you probably already knew that but i just thought Bridgeport was the brand name!

Ew

Originally Posted by Ueee

Well i learnt today that Bridgeport mills are made by Adcock and Shipley....you probably already knew that but i just thought Bridgeport was the brand name!

Ew

More correctly, *some* Bridgeports were made by Adcock & Shippley. B/port licensed them IIRC. My J head is an A&S manufactured unit.

PDW

Originally Posted by PDW

More correctly, *some* Bridgeports were made by Adcock & Shippley. B/port licensed them IIRC. My J head is an A&S manufactured unit.

PDW

So Bridgeport were a company in their own right? The wiki page is pretty devoid of any decent info. At some stage i guess Bridgeport could not keep up with the demand so they licensed them, and then of course all the copies came along too. They are now owned by Hardinge.

Ew

Originally Posted by Ueee

Well i learnt today that Bridgeport mills are made by Adcock and Shipley....you probably already knew that but i just thought Bridgeport was the brand name!

Ew

Ueee,
If memory serves me correctly, Bridgeport machinery was acquired by Textron conglomerate I think maybe early 80's partly as a result of rising environmental concerns in the USA, they then had the castings poured in Indonesia and then sent to Singapore for finishing. Not sure when this finished though. Alan.

Originally Posted by Ueee

Well i learnt today that Bridgeport mills are made by Adcock and Shipley....you probably already knew that but i just thought Bridgeport was the brand name!

Ew

A textbook I have claims that at least 12 different companies in Spain were making Bridgeport spinoffs at one time or other

Mike

Originally Posted by morrisman

A textbook I have claims that at least 12 different companies in Spain were making Bridgeport spinoffs at one time or other

Mike

The basic principle has been widely copied and done much better (IMO) than B/port did it; I particularly like the Kondia and Lagun turret type mills with 40 taper heads. However A&S were licensed by B/port to make the mills and they are a pretty exact copy of the original. My J head has the classical B/port name and script cast into the alloy housing along with information identifying A&S as the actual manufacturer. My M head has the same script but states it was made in the USA rather than the UK. I'd like to get my hands on another M head as I have a project lined up for it.

A&S made quite a lot of machine tools. I was drooling over one of their little horizontal mills some years ago but had no practical use for it.

PDW

Things I learned this weekend:

1) RF45/MD45/HM64 Screw binding - If you find that your machine binds when traveling in one direction or both directions one thing to check is that your screw mounts are actually tight. I had an issue where the machine was smooth as butter in one direction and binding in another. I found that the reason it was binding was that the X axis mount was not tight and it was moving. This was causing the binding in one direction of travel. Unfortunately one has to remove the table to tighten it back up again.

Side note: I am pretty sure the screws were reasonably tight - the vibration caused by milling down some 1045 shook lose my milling light bolts and by the looks of it my X screw mount bolts!

2) Don't idly trust your 3d Taster. I got caught and I should have known better. It is good to check the accuracy of instruments from time to time. It would have taken me less than 10 minutes to test my tasters accuracy, yet I did not. And I got caught and had to throw out a part that I had been working on for the better part of two days.

3) Coolant systems require thread tape on every connection. No matter how tight you think your connections are, the chances are they will leak. Thread tape fixed all 5 leaks for me.

4) Coolant systems are messy - best have some small free standing machine guards on hand to deflect the splash where you want it. I managed to contain most of the splash and keep it on my table thanks to some small stand alone perspex guards I made a while back.

5) If your 3D Taster starts producing erroneous readings, check that the probe tip is tight. I spent an hour and a half setting the concentricity in vain, only to notice the shaft was not tight. Tightening up the probe shaft, and setting the concentricity and it now measures perfectly. I am almost 100% certain that the lose shaft was causing the errors and that the concentricity was most likely OK.

6) If you have to (or have a penchant for breaking expensive devices) set the concentricity on your Haimer 3D Taster back off all the hex screws positioned around the taster (4 of them recessed). They will be tight as all buggery, but trust in the Haimer provided hex key. Once they are all loose, then tighten one, and it will again be break the hex key tight. Keep turning and it will break free and move the probe. Rinse and repeat until your heart is content, or your taster runs concentric.

Originally Posted by bob ward

Needed to keep an 5" long x 7.5" dia cast iron hub from (a) drooping in the 4 jaw while centring it and (b) coming out of the 4 jaw when turning it. A self aligning bearing and housing kept in place by the tailstock did the job nicely.

The part is a front hub from a Howard V twin cultivator. The job was to backfill a badly worn oilseal surface with braze and turn it back smooth - nothing critical, the idea is to reduce oil loss from a torrent to an occasional drip. The rough whiteish looking surface (its actually a standard braze colour) just outside the circle of bolt holes is the built up area. Half of the braze I could turn with standard carbide tooling, the rest I needed to grind a piece of HSS to get to it.

The thing I learned here is that at 137 SFM (4.5"dia @ 115 RPM) when turning braze my cutting edges were disappearing before my eyes. Any thoughts as to what is going on here?

Carbide tooling does not like intermittent cutting.Perhaps if it was roughed out with a HSS tool first to take out the hills and valleys better finish may be obtained.

Grahame