Hardinge change gears

oldgreydog · Feb 3, 2008

I have a perplexing question.
Does anyone know what the type of gear tooth and pitch is for Hardinge change gears? It seems as though it is 22 pitch but the tooth style and pressure angle are vague. I also need to know if the change gear brackets (banjo) for the BK model lathes are interchangeable with the H models. I have tried Hardinge but they no longer support the BK model. Also, what are these gears worth both as an assembly and by each?
I got a recent quote from a gear company for $1400 for a 30 tooth steel 22 pitch gear OUCH!

Peter Colman · Feb 3, 2008

There are conflicting views on this and there have been discussions here before, however I have also been horrified by the Hardinge prices and simply cut my own using 15.5 degree 22 DP cutters and have no problems at all. One of the considerations is that you control the meshing when you assemble the clusters on the banjo, so any mis match is controlled
While you are at it, make a double thickness 30tooth and fit ballraces inside it to use as an idler.
I can not help with the BK banjos.
Peter

L Vanice · Feb 3, 2008

Probably Peter meant he used 14.5 degree cutters, which are easy to find. MSC sells them for $37.25 each.

Larry

Jim S. · Feb 3, 2008

The gears are 22 DP, 20 degree PA, but....

As Peter said, there have been several discussions of the gear specs. I have a copy of an original Hardinge blueprint which lists the change gear specs as 22/29 DP stub, 20 degree PA. The 29 merely means it is a 22 pitch gear with teeth cut to the depth of a 29 pitch gear. The Hardinge print lists the individual gear dimensions for every change gear from 22 to 128 teeth.

The gears are straightforward to cut but 20 degree PA cutters are very hard to find. If you do find a cutter, simply cut the teeth shallower than a full depth 22 pitch gear but you must start with the proper overall diameter so that when cut shallower you arrive at the correct pitch diameter. I have cut several and they work just as well as OEM gears.

Peter's suggestion of cutting new gears with the commonly available 14 1/2 degree cutters is a good one. I have never tried it but gear literature says you should not try to mesh gears of different PA. Given the considerable expense of OEM gears, it would not be hard to make a complete set of required gears at 14 1/2 degree.

The standard HLV-B banjos are the same as on the H models.

Jim

L Vanice · Feb 3, 2008

Actually, 20 degree PA cutters are more "modern" than 14.5 degree PA cutters. They are easy enough to find in standard pitches. But the catch is that 22 is an unusual pitch. But Wholesale Tool does have 22DP 20PA cutters in No. 1, 2 or 8 only for a ridiculous low price of $10.80 each.
http://www.wttool.com/category-exec/category_id/13807/nm/High_Speed_Involute_Gear_Cutters/page_num/9

MSC has no 22DP 20PA cutters in their catalog.

Mixing PA's in a gear train would cause life and noise issues, but might still work if you are stuck for the correct gears and not too fussy about results.

HLV-H banjos and a few gears show up on eBay fairly often. The gears are usually just the ones you need to cut 10 TPI threads. I suppose they came with the lathe as standard equipment and then got separated over time. I think I have several of them that I need to sell. I have seen the metric banjos on eBay, but don't have one myself.

Larry

Mark Rand · Feb 4, 2008

Certainly on the HLV, all of the gears including the internal ones are 22/29DP stub form. This weekend I cut the last gear needed to completely rebuild the apron gearbox on mine. I managed to get a full set of 22DP/14.5PA cutters apart from the #5 cutter at a model engineering show last year. I've made all of the gears in this form apart from the pinion that runs against the rack. On that one, I ground a 22/29 rack form cutter and cut the pinion on my shaper.

If there are no existing changewheels to be wasted, it may make sense to just go out and either buy new 24DP gears or spare 20DP gears for another lathe. In this part of the world, 20DP/14.5PA changewheels for a Myford are about 2/3 the price of new 24DP/20PA gears. In either case, it is probably not worth manufacturing new changewheels unless your time is free.

oldgreydog · Feb 5, 2008

Prices?

thanks for the great wealth of information. I will try cutting my own change gears with 22dp/20pa cutters. How about the banjo and Std. gear change prices, anyone find out what the prices are new from Hardinge? Or even what the general market price is for used gears and banjos?

OGD

L Vanice · Feb 5, 2008

"Or even what the general market price is for used gears and banjos?"

I sold a good HLV-H banjo with the 10tpi gears for $139.55 + s&h on eBay in 2003.

Larry

Jim S. · Feb 6, 2008

Here's a current auction

http://cgi.ebay.com/Hardinge-HLV-H-...yZ104241QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

glennview · Feb 8, 2008

Hardinge gear pitch

I was directed to this site and this particular thread by an Ebay seller of some Hardinge hlvh gears when I asked him what the gear pitch was. I have some Hardinge Cataract gears that look very much like the hlvh gears. I sized the image of the Ebay seller's hlvh gears to match my Cataract gears. The gear tooth configuration certainly looks identical. I was told by the person I bought the Cataract gears from that they were 30 pitch. Can anyone verify? BTW, I do not have any gears to sell. My reason for asking is that I need some gears and I want to know if the hlvh gears are compatible with the Cataract gears. it would be faster to buy gears than make them, but if I need to make them, I need to know the specifications of the Cataract gears. I will try to attach an image of some Cataract 25 and 50 tooth gears.

stephen thomas · Feb 8, 2008

Quote:"How about the banjo and Std. gear change prices, anyone find out what the prices are new from Hardinge? Or even what the general market price is for used gears and banjos?"

I bought a couple banjoes with various gears on them for under $50 ea. on ebay, and got my metric gears (127T + some others) there for about $80 IIRC. Someone has one (metric with metric banjo) on now asking $400, though. A couple years ago it was cheaper by far to buy hardinge gears on ebay than to buy SB gears. But it seems to be changing.

Cataract gears: I have 4 or 5 dozen cataract gears. They are 30P. I don't know the PA or any modifications to tooth form.

BTW, to determine the P of your gears, count the teeth on one, and measure the OD. Then add 2 to the tooth count, and divide that number by the OD. P = (N + 2)/Do
For instance, my 100T gear measures 3.38+" on the OD. 102/3.38 = 30.1xxx Since pitch is a whole #, this is a 30P gear.

The reason for the slight variation is that pitch is actually a function of the pitch diameter. If you have a set of wires and a chart to compare, you can measure over the PD directly, and use actual number of teeth to divide buy the PD to get P

smt

L Vanice · Feb 8, 2008

I have made quite a few replacement gears for Hardinge Cataract lathes and mills and for the 1940's split bed lathe chasing attachment. They are 30 DP 14.5 PA, and cutters are not hard to find. I cut the gears to the standard dimensions explained in Machinery's Handbook and they work fine with the original gears. I have not made any of those gears for years, but I recall that I had to grind a keyway broach to .050" thick and make some special keyway broaching bushings and gear cutting arbors.

Larry

rob daniel · Feb 8, 2008

metric change gears

I haven't had the need to cut metric on my HLVH but it seems everyone wants the option.
Anyone on the site set up with a hob or fellows shaper? If we committed to a small run maybe everyone would be happy.

bikepete · Feb 9, 2008

Re metric threading: read (all of) this first:

http://www.practicalmachinist.com/vb/showthread.php?t=116971

Works perfectly with Myford gears on my HLV-BK, assume also OK for HLV-H.

Rich Y · Feb 13, 2008

Any other sources for 22DP 20 PA cutters? I ordered from Wholesale Tool and they only have two sizes left in stock. I need a source for the other 5 or 6. Thanks.

ij metal · Nov 16, 2012

hi new hear i am looking for a metric banjo for my hardinge if any one has one for sale e mail me at [email protected] thanks john

Shuttle Guy · May 2, 2014

Hello all, I'm new to the forum because my HLV-H is new to me. I find this thread particularly interesting probably because I don't know many of the intricacies of gear design and fabrication. I see where some guys are making their own gears for threading on their HLVs because as I've learned recently factory parts are well north of reasonable for the most part. in any case, I haven't seen anyone mention cutting new gears on a water jet machine and I'm wondering why that is. aside from the cost and availability of a WJ it seems like it mat work, especially given the fact that the machine software has a gear design utility. I was curious today and created a 127 tooth gear with a 22 pitch and a 20 deg PA with the water jet CAD program. I printed it true size and compared it to a factory 127 tooth gear. From what I can tell the only modification to make it exact would be to cut the gear OD to match the factory OD. Does this make sense to the experts here? Perhaps the only thing left to do is cut one and try it. Any suggestions or comments?

Peter Colman · May 6, 2014

Sorry guys, been doing other things and not keeping up to date with this thread, I can hob 22 p gears up to 5" diameter and mill larger ones, I have had no problem with change wheel set ups as you control the meshing on the banjo and can find the 'sweet' point, in this way the pressure angle is not that critical. The apron gears must be right as the centres are fixed.
If you are happy with 22 dp gears for normal change wheel use, including 127t, then I am happy to make them at a fraction of the Hardinge price.
Peter

rmsfla · May 6, 2014

There is a fellow on the Yahoo groups .. the Hardinge mill group who had made several gears for the members

He ,I believe worked at a gear manufacture made me a few 22 tooth gears for my HLVH

They were dead on.
Price was IIRC about $30

Robbie

Mark Rand · May 6, 2014

Shuttle Guy said:
From what I can tell the only modification to make it exact would be to cut the gear OD to match the factory OD. Does this make sense to the experts here? Perhaps the only thing left to do is cut one and try it. Any suggestions or comments?

If you can cut them out accurately that way, then reducing the OD to match the factory OD will give gears that will work with the factory ones.

Strictly, to make 22/29DP Felllows stub form gears the addendum and dedendum of the teeth should be that of a 29DP gear and the clearance should be .25/22"

Good luck.

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