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UV Resin strength & stability


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I've recently purchased an 'O' gauge etched brass/whitemetal kit of this magnificent beast which when built will measure just over 2 foot (610 mm) in length.

 

2395_LNER_U1_Garratt_official_photo.jpg

 

 

It will be built to run, which means two motorgearbox units. The problem is that whilst the chassis are identical the tanks above them are different and contain a LOT of open space making selection difficult. I have two identical units set aside which whilst I can fit them will require part of that open space to be invaded something I'm keen on avoiding.

 

I'm wondering if by 3d printing bespoke designs, one for each end, if I can hide them.

 

Motor & gear selection is no problem - I acquired a commercial quantity of surplus NOS. The basic design criterea is that the gears (helical) would run on steel shafts in brass bearings - so no rotating metal parts against resin to minimise both wear & friction, gears would run between two sides each 3 to 3.5 mm thick, 12 mm deep & around 20 mm long - similar to this:

 

post-8920-0-42515000-1370262708.jpg

 

 

 

What I'm wondering is would a 3D printed (UV resin) gearbox be 'solid' enough not to flex when under load, stable dimensionally over time and resistant to (plastic friendly) lubricants.

 

 

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That would depend entirely on factors like geometry, wall thickness, internal supports, ribs etc.

Without knowing your overall design it's impossible to say

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thanks @Schwarz-Brot Without doubt machining from solid brass is the best option however I don't have access to a multi axis cnc macchine which would be required for the precision gear mesh & if i could find someone to do a one off I suspect the price would be prohibitive.

 

Brass bearings/bushings are a given & mentioned in my op above.

 

I'm also sure filament printing would not be able to give the precision required to correctly mesh the gears. 

 

I do have a 3D uv printer though so thought I'd ask in case anyone had any similar experience or knew where to find data.

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Very familiar with gear & gearbox design, the figures you quote are well outside the mark, mesh on the above gears is +/-0.05mm & this is required to maintain efficiency, reduce noise & minimise wear. Wiggle room is 1950's toy territory. The gearbox above runs like a Rolex watch because of this & I'll not tolerate anything less than well oiled machine.

 

Rough & ready as befits your design is not an option.

 

Back to the subject of the original question, can anyone advise about the strength & stability of parts made from UV resin, or know where such information can be obtained?

 

 

 

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Great way to get people to help you.  🙄

 

To answer your question: manufacturers have material spec sheets.  Use them.  Or, since you have a printer, print it the part and see for yourself.

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