Monarch 60/61 change gears - possible group buy

[beckerkumm]

It appears that most Metric threads I would need to cut can be done with 35,40,50 tooth 16DP, 14.5PA gears. I can deal with those but the tough gear is the 127T that needs to compound with the existing 75T on the machine. Those gears in steel are no longer made by Browning but can be ordered from Linn Gear. I have to have them made and the cost is reasonable at approx $125 each. They would need to be bored out and bolted to the gear. The Boston 127 is much more expensive and cast iron and looks to be more difficult to attach.

Before ordering I was wondering if anyone else would have a need as it is easy for me to order extras. the lead time is 6-8 weeks.

Dave

 

[nt1953]

Before you invest too much money, time, and labor, take a look at this:

Metric Threading on a 1954 Series 61 Imperial Monarch

Once again I have needed the ability to cut metric threads on an Imperial lathe, so I made 4 gears to be able to cut most metric threads. Using the 25T gear that was already on the lathe (top left gear in the picture below) along with the 4 aluminum gears shown in the second picture I can cut...

www.practicalmachinist.com

 

[beckerkumm]

Thanks for the thread. I'm still looking into the 127T gear as an alternative. I have a 25T drive gear with missing teeth. My intent was to turn it down and bolt various 1/2" thick change gears to it. I found them cheap so the only real outlay is the 125 for the 127T gear and I avoid machining spur gears. The 127 could remain on the 75T gear. The idea is worth looking into more as 10dp spur gears can sometimes be found cheap and the machining isn't hard. Dave

EDIT Some of the spur gears needed are not stock so the same method of using change gears mounted to a bored bushing could be used or made up new. It still seems like the 127T gear compounded on the 75T may be the least work in my case.

 

[texasgeartrain]

I'm a little bit interested just to have options on hand. Though I really don't do much in metric. I'd be curious the cost of the more expensive gear.

 

[ballen]

I don't know about the Monarch setup, but for cutting metric threads on my Logan 10" lathe there are two options that work well. One is a 47/37 compound gear. This ratio is 1.2702, which when multiplied by two gives 2.5405, whereas the correct ratio would be 2.54, since 25.4mm = 1 inch. The error is small enough (2 parts in 10,000) that for anything except cutting lead screw threads it's sufficient. Another very good combination is 80/63 (error is 1 part in 10,000).

 

[beckerkumm]

I went ahead and ordered two 127T gears from Linn. Will see how they look when they are done in 4-6 weeks. I will sell the extra for the $120 it cost if anyone has an interest. The Change gears are 16dp vs the 10dp original so the 127T is only about 1/2" larger than the 75T it attaches to. Then really only two additional gears are needed for common sizes. I'll report back in a couple of months with success or failure. Dave

 

[texasgeartrain]

I'll take it. Pm me paypal address or what you need. We can guesstimate shipping if you like as well.

 

[greggv]

in the future try americn chain and gear in la. better prices and lead time

 

[beckerkumm]

Thanks for the reference. I got a quote from Rush gears and one was $3600, two were 1800 each and down to about 1000 ea for quantity. It may not be an apples to apples comparison but the NOS Browning I found ( now discontinued ) was $355 so the $110 from Linn seemed about the same price as the involute cutter needed.

Dave

 

[Zahnrad Kopf]

I can't recall their forum name, but we made some 61 127T gears for a forum member last year. Maybe they'll see this thread?

 

[Evan Lewis]

I think you would find it helpful to use my online computer program for gear train calculations to find out what threads you can cut with your own gear set, and how it might improve by adding another gear. It does not cost you anything to use the program.
RideTheGearTrain.com
Evan