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View Full Version : Anyone need gear hobs, dirt cheap?



mixdenny
05-15-2015, 05:55 PM
I was doing an in depth search in the tooling/hardware aisle at HGR (at risk of life and limb, or at least an ankle), and spotted a good looking metal case. It contains 22 gear hobs, either new or very clean. However, the original owner misspelled them as "hobbs", then HGR tagged them as a "hoobs tooling kit". I don't think anyone is going to locate them in a search. Marked down to $64 for all of them, 3 bucks each. They have lots of numbers engraved on the end, so at a quick glance I didn't make out what they are. There are lots of different types, all look like sizes that would be useful to hobbyists. They probably fit a 1" arbor.

I was tempted, but I made it this far without having to make a gear, why start now! Never did find the bearing I went in search of.

Dennis

http://www.hgrinc.com/productDetail/Tooling/USED-HOOBS-TOOLING-KIT/04150640025

Toolguy
05-15-2015, 06:02 PM
It is just common sense that hobs would be useful to a hobbyist!:p

Zahnrad Kopf
05-15-2015, 06:02 PM
Careful... the box has markings that indicate they're mostly Spline Hobs. I'm tempted, but have many already and don't get much call for their use these days. In all honesty, even if spelled correctly the price is about correct...

mixdenny
05-15-2015, 06:21 PM
Careful... the box has markings that indicate they're mostly Spline Hobs. I'm tempted, but have many already and don't get much call for their use these days. In all honesty, even if spelled correctly the price is about correct...

Interesting. Why are there so many rows of cutting teeth for a spline? Don't you just mill one tooth profile down the shaft, index to the next one and cut it? You can see I don't have any experience at hobbing! By the way, tomorrow (Saturday, May 16th), that aisle is on a 50% off sale.

Dennis

Zahnrad Kopf
05-15-2015, 07:40 PM
Interesting. Why are there so many rows of cutting teeth for a spline? Don't you just mill one tooth profile down the shaft, index to the next one and cut it? You can see I don't have any experience at hobbing! By the way, tomorrow (Saturday, May 16th), that aisle is on a 50% off sale.
Dennis

Hi Dennis,

Well... one _can_... That's fairly common for your typical Straight Side/Flat Root type Spline. There are many, many other types of Splines, though. They start with Involute Splines ( like Gear Teeth and 20 ) and also 30 , 37.5 , and 45 Splines. There's Flat Root, Fillet Root, and more options yet for specials. And if one were making any quantity of import, one would want to Hob them instead of milling them... :)

Too, it's a bad picture ( fairly sure that's their intention ) but it appears that many of those Hobs have been sharpened numerous times. The gash widths appear much larger than the Tooth widths are, so there's likely not much life left in them yet. For the price tomorrow, it's almost worth the gamble and to come away with a good storage box! LOL.

Hope that helps.

flylo
05-15-2015, 07:45 PM
Those aren't Hobbs, can't you read? They're Hoobs!

becksmachine
05-15-2015, 08:00 PM
That didn't take long, 4:55 PM PDT and they are listed as sold.

It is usually a good thing that I never hear about these things until it is too late! :)

That reminds me Dennis, I still owe you for past favors concerning HGR.

Dave

oldtiffie
05-15-2015, 08:42 PM
http://www.hgrinc.com/inventory/0415/0415064/20150420095642077_L.JPG


Originally Posted by mixdenny

Interesting. Why are there so many rows of cutting teeth for a spline? Don't you just mill one tooth profile down the shaft, index to the next one and cut it? You can see I don't have any experience at hobbing! By the way, tomorrow (Saturday, May 16th), that aisle is on a 50% off sale.
Dennis


Hi Dennis,

Well... one _can_... That's fairly common for your typical Straight Side/Flat Root type Spline. There are many, many other types of Splines, though. They start with Involute Splines ( like Gear Teeth and 20 ) and also 30 , 37.5 , and 45 Splines. There's Flat Root, Fillet Root, and more options yet for specials. And if one were making any quantity of import, one would want to Hob them instead of milling them... :)

Too, it's a bad picture ( fairly sure that's their intention ) but it appears that many of those Hobs have been sharpened numerous times. The gash widths appear much larger than the Tooth widths are, so there's likely not much life left in them yet. For the price tomorrow, it's almost worth the gamble and to come away with a good storage box! LOL.

Hope that helps.

Agreed that they all seem to be for splines - but the writing on the box cover gives it away - but some of it is hard to read.

mixdenny
05-15-2015, 10:48 PM
Agreed that they all seem to be for splines - but the writing on the box cover gives it away - but some of it is hard to read.

So there are numbers like 12/24, etc. What does that tell us?

Dennis

oldtiffie
05-15-2015, 11:02 PM
So there are numbers like 12/24, etc. What does that tell us?

Dennis

Machinery's Hand Book under "Splines" will or should give you all you need to know about "stub" involute splines.

https://www.google.com.au/?gws_rd=ssl#q=stub+splines

oldtiffie
05-15-2015, 11:09 PM
Originally Posted by Zahnrad Kopf

Careful... the box has markings that indicate they're mostly Spline Hobs. I'm tempted, but have many already and don't get much call for their use these days. In all honesty, even if spelled correctly the price is about correct...

Interesting. Why are there so many rows of cutting teeth for a spline? Don't you just mill one tooth profile down the shaft, index to the next one and cut it? You can see I don't have any experience at hobbing! By the way, tomorrow (Saturday, May 16th), that aisle is on a 50% off sale.

Dennis


Nope - the spline hobs cut with both the dividing head and the mill arbor rotating together at the required ratio as the mill table is fed forward to feed the gear blank into the hobbing cutter.

You will need a true universal horizontal mill as well as a universal dividing head connected to and driven by the mill table lead-screw via a gear train (like a lathe).

To come to grips with it you will need a bit of reading time and Machinery's Hand Book

Zahnrad Kopf
05-15-2015, 11:19 PM
Nope - the spline hobs cut with both the dividing head and the mill arbor rotating together at the required ratio as the mill table is fed forward to feed the gear blank into the hobbing cutter. You will need a true universal horizontal mill as well as a universal dividing head connected to and driven by the mill table lead-screw via a gear train (like a lathe).
To come to grips with it you will need a bit of reading time and Machinery's Hand Book

Or one could simply go with the more elegant ( and proper ) solution of using them in the manner they were intended. In a Hob. ( the machine, not the cutting tool ) http://bbs.homeshopmachinist.net/images/icons/icon14.png

oldtiffie
05-15-2015, 11:23 PM
True enough Zahnrad.

But I was trying to keep it in a "use in the HSM shop" level - even though in most if not many cases it would be a "big ask" in many HSM shops - mine included.

Zahnrad Kopf
05-16-2015, 12:06 AM
True enough Zahnrad.
But I was trying to keep it in a "use in the HSM shop" level - even though in most if not many cases it would be a "big ask" in many HSM shops - mine included.

Fair enough! Point well taken. :)

becksmachine
05-16-2015, 12:30 AM
Nope - the spline hobs cut with both the dividing head and the mill arbor rotating together at the required ratio as the mill table is fed forward to feed the gear blank into the hobbing cutter.

You will need a true universal horizontal mill as well as a universal dividing head connected to and driven by the mill table lead-screw via a gear train (like a lathe).

To come to grips with it you will need a bit of reading time and Machinery's Hand Book

Have you ever seen a "true universal mill" that coupled the spindle to the table feed and thus to the dividing head?

Or a picture of one??

Dave

jhe.1973
05-16-2015, 12:42 AM
Have you ever seen a "true universal mill" that coupled the spindle to the table feed and thus to the dividing head?

Or a picture of one??

Dave

I have. I had been a tool & die maker for West Bend Company (cookware) and most of the equipment was between WW1 and WW2 vintage.

So were the toolmakers come to think of it! :D

Anyway we had a couple of Milwaukee double overarm universals w/all the tooling. As I recall, the power feeds for the table, knee & saddle were geared to the spindle so it was a small matter of having a driveshaft to the dividing head (or rotary table) come off of the table feed.

I never used these setups, but being curious, I had checked out what was in each of the tool cabinets during my year and a half there.

Black Forest
05-16-2015, 06:12 AM
My Klopp Universal mill can be rigged up that way. I even have the gears that came with it to connect to a Universal dividing head which I don't have.

becksmachine
05-16-2015, 06:14 AM
Have you ever seen a "true universal mill" that coupled the spindle to the table feed and thus to the dividing head?

Or a picture of one??

Dave

Ok, now I have also!!

Well, at least a picture.

:o

Dave

https://www.youtube.com/watch?v=pVZbOv063Tc

oldtiffie
05-16-2015, 07:31 AM
Originally Posted by oldtiffie

Nope - the spline hobs cut with both the dividing head and the mill arbor rotating together at the required ratio as the mill table is fed forward to feed the gear blank into the hobbing cutter.

You will need a true universal horizontal mill as well as a universal dividing head connected to and driven by the mill table lead-screw via a gear train (like a lathe).

To come to grips with it you will need a bit of reading time and Machinery's Hand Book



Have you ever seen a "true universal mill" that coupled the spindle to the table feed and thus to the dividing head?

Or a picture of one??

Dave



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