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Post by doubletop on Feb 29, 2016 5:08:26 GMT
Jim
Something similar to your weighbridges was in Model Engineer in the past few years, including the bathroom scales. It has been in the back of my mind to do something similar because the 0-4-2 arrangement lends itself to too much weight on the un-driven rear wheels.
I also know I need to do something about the springing. The original leaf springs are in use on the rear, provenance unknown. As I was adding more and more to the loco I noticed the driver axle boxes topping out. It was just before a weekend test run was planned so shot down to Mitre 10, Blackwoods Pykels and Twiggs to collect together a set of, off the shelf, Century springs . They were too long so cut in half and hurriedly installed. Nothing much has been done in that department since.
Somewhere I've got a copy of the works drawing giving the correct loading. Unsurprisingly, if I recall correctly, it should be roughly equal on each axle.
Pete
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Post by ejparrott on Feb 29, 2016 10:05:22 GMT
One of the next projects for me and the Chairman at Rugby is to sort out an axle weighing station. He's acquired a set of scales as used in weighing pallet trucks. Years ago we built one for the raised track at Swansea, transformed a number of engines using that to properly set the springing
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Post by doubletop on Mar 20, 2016 10:33:16 GMT
I had a bit of a inspiration and wondered if the rear axle was located at the correct height in the axle boxes. So I whipped out the axle and checked it. It was wrong Sat about 1/8" to high meaning the back end was too low. The axle boxes went into the mill and 3/16" shaved off the bottom. It sits level now.
If you recall the article in an me issue for a dyno car using the strain guages from cheap digital scales? I found some the other day equivalent to 6quid each. 0-45kg 10gm resolution. With a bit of re-engineering I'm considering clip on scales that mount on any existing track to measure axle weight. 90kg per axle should be OK for most of us?
The things don't deflect that much so sitting them just proud of the rail with pads for the other axles could work without having to modify the club steaming bay. And it would be portable.
Pete
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Post by doubletop on Jul 11, 2017 9:47:19 GMT
I've been doing a bit of a tidy up since this photobucket fiasco and revisited this thread. Since my last post I've built the weighbridge. It uses two strain guages from cheap baggage scales. The rails section fits on the end of the steaming bay, with a further rail extension attached to that. Change the length of the 4 spreader bars and the guage can be convered from 7.25" to 5" or 3.5" guage. The output is displayed on a mobile phone. You'll notice that the calibration values are 9Kg and 18Kg. Thats because I've got some 9Kg CI blocks I use as calibration weights. Using the method described in the article by 'Artisan' 'Locomotive Springing Adhesion and pulling Power in ME4470 I've managed to get 10kg of the weight of the loco forward onto the two driven axles without adding any more weight to the loco itself. Traction has been noticibly improved. Pete
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Post by steamer5 on Jul 11, 2017 17:54:27 GMT
Hi Pete, That weight shift will make a huge difference! Slipping uphill will be a thing of the past!
Cheers Kerrin
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Post by doubletop on Jul 24, 2017 10:48:46 GMT
Hi Pete, That weight shift will make a huge difference! Slipping uphill will be a thing of the past! Cheers Kerrin Kerrin At PN that uphill turn around the tree and the sap coming from the tree itself will alway be a challenge regardless of how well the springing is set. However, we'll see if it has made a diffrence next March Pete
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