Author Topic: Chris' Build of a Lombard Hauler Engine  (Read 295435 times)

Offline Steamer5

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #900 on: March 06, 2017, 08:34:30 AM »
 :popcorn: must get more  :popcorn:

Great "how to" Chris, be good reference for the future. Jo's link looks like it would be very helpful too

Cheers Kerrin
Get excited and make something!

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #901 on: March 06, 2017, 02:13:13 PM »
Thanks! I got one more made before the pool run last night, should have the last one this morning, and get a start on the large bevel gears.

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #902 on: March 06, 2017, 05:33:09 PM »
Some pics from the pool run last night.
Some of the group in the shallow end:

and some video of my new lobsterboat and of one of the guys minisubs leaping around


Today, back to the gears...
« Last Edit: June 05, 2018, 05:29:03 PM by crueby »

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #903 on: March 06, 2017, 09:10:35 PM »
And back in the shop this afternoon to continue work on the differential gears. I finished the last of the small gears,

and got a start on the two large ones for the output shafts. Started by turning a length of bar stock to the outside diameter, 1.67", and drilling the starter hole for the shaft,

which was then bored out to size

Then set up the compound rest to the complent of the angle for the first gears, 68.2 degrees, and turned in the bevel on the face

and then came back with the boring bar and recessed the center of the face by 0.060" to get it below the depth of the teeth.

Then moved the chuck back over to the rotary table on the mill, which is still in the same position as it was for the smaller bevel gears. The one difference for the larger gears is that rather than cutting on the back face with the long axis of the mill, these will be cut on the front face with the short axis, which lets me keep the table at the same angle but get the complementary face of the gears.

With the mill table zeroed with the cutter just touching the face of the bevel, then moved in the tooth depth, started cutting the teeth. These larger gears are 60 tooth, so the advance angle on the rotary table is 6 degrees per cut.

Here is the gear after the first pass,

and then the cutter was lowered 0.021 and the rotary table moved 1.5 degrees (counterclockwise this time, since it is on the opposite face from the small gears), and a second pass was made to shave the outer ends of the teeth:

and then the cutter raised the same distance above center, and the rotary table offset 1.5 degrees clockwise, for the third pass:

With the teeth complete, back over to the lathe to part off the gear. This was done in two steps to leave a thicker area around the hub.

And the completed gear test fit on the differential unit - all seems to mesh nicely, so I must have gotten the math right the other day! 
 :cartwheel:



So, one large gear down, one to go, then I can make the output half-shafts to hold the large gears.

But first, a celebratory chocolate mint chip cookie!
« Last Edit: June 05, 2018, 05:29:13 PM by crueby »

Offline Kim

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #904 on: March 06, 2017, 09:17:13 PM »
That is just too neat, Chris!  You must fell like doing a happy dance right now   :whoohoo:
Kim

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #905 on: March 06, 2017, 09:18:06 PM »
That is just too neat, Chris!  You must fell like doing a happy dance right now   :whoohoo:
Kim
Oh yes! Its always great when days of work come out successfully!

 :cheers:

Offline scc

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #906 on: March 06, 2017, 10:35:47 PM »
Very impressive Chris,  So far I've chickened out from attempting gears. That diff. looks fine.         Regards...........Terry

Offline 10KPete

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #907 on: March 06, 2017, 10:42:09 PM »
Well, there's no doubt in my mind where to go when I need some gears cut.. :naughty:

Pete
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Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #908 on: March 06, 2017, 11:12:20 PM »
Very impressive Chris,  So far I've chickened out from attempting gears. That diff. looks fine.         Regards...........Terry

Straight spur gears are not difficult at all, practice on a gouple scraps and you'll get it pretty quick. Bevel gears are a bit fussier, but its the same basic steps with just a couple added wrinkles.

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #909 on: March 06, 2017, 11:13:01 PM »
Well, there's no doubt in my mind where to go when I need some gears cut.. :naughty:

Pete

Yup - to SDPI's website?!   :ROFL:

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #910 on: March 06, 2017, 11:20:58 PM »
After a good relax time and some dinner, I went back and cut the last bevel gear. Knowing the setup was good made this last one go a lot faster, plus I finally got up the nerve to try something that the Ivan Law book remarks upon: on small gears, you can actually skip the first pass and just do the final two, since they are taking off such a small amount on small gears. The blank I was starting with had enough length that if it went wrong, I could still get one more out of it, but it all worked out fine.
Here are all the parts so far for the differential unit:

and how they look put together:





Next up will be the half shafts that the large gears ride on. They will have a hole in the inboard end that goes over the axle stub in the center plate, and a narrower section at the outboard ends that the drive chain sprockets sit in. The axle shafts will project in from the large gears and ride against the center plate hub to give the proper spacing for the gears. The speed difference from the center plate to the half shafts is very small, and only present in turns, so I dont think I will bother with bronze bearings there, just some grease.
« Last Edit: June 05, 2018, 05:29:30 PM by crueby »

Offline Brian Rupnow

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #911 on: March 06, 2017, 11:48:02 PM »
Very nice work Chris. I have no issues with plain spur gears---if you have the correct gear cutters it's just straight math and paying attention. I have one set of 45 degree bevel gears that I made following an Australian fellows tutorial on making them, and there is a lot involved with making them. I have the one set up on my "Brag shelf" but wouldn't want to make them very often.---Brian

Offline crueby

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #912 on: March 06, 2017, 11:53:49 PM »
On these I had some problems at first getting the depth right, I think I made the face width too large so the teeth at the inside ends got too skinny. There are numerous write-ups and calculators out there, but none seem to give complete details on how to calculate everything. The Ivan Law book gets close, but since his example was for the simplist case (two 20 tooth gears) there are things left vague for other cases.

Offline Don1966

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #913 on: March 07, 2017, 12:23:23 AM »
But first, a celebratory chocolate mint chip cookie!

Yeah, yeah! We all know what's in those cookies......got to be some good stuff, but the gears look great ther Dog.  :praise2:

Don

Offline steam guy willy

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Re: Chris' Build of a Lombard Hauler Engine
« Reply #914 on: March 07, 2017, 12:58:46 AM »
Those are geeeerrraat and you make it all look so easy some lovely work going on here......really inspirational..