SD70M - Powered

[ConnorL]

Hello,

I had been working on a project for about a year now. The original thread on the forum is long gone, so I will be reposting my progress here.

Since March 2013, I had been working and adjusting my model in Solidworks 2013 that I created from a single image, scaled it to original size...then scaled it down to 1:450.

First, it was originally a dummy unit...but I took it even further.

I am working on creating a powered SD70M locomotive, this is extremely challenging since the chassis width are so narrow that the official T-Gauge motor won't even fit.

Instead, I used a 3.2mm Shicoh motor instead of the standard 4.0mm Shicoh motor to power the locomotive.

I had to do a lot of calculations to figure out the correct gear that are suitable for T-Gauge's motorized wheels, when I did...I headed down to: http://www.shop.kkpmo.com/ and ordered my gears from there according to the diameter that I had specified.

I went all over the places (websites) and ordered parts, I ordered some 0.6mm, 0.8mm, and 1mm brass rod which will be used as fitting for the worm-type gearbox.

At last, I ordered a Shapeways model of this locomotive that recreates an actual model of your 3D model according to the scale you put it in.

Stay tuned for more and deeper into parts.

[GarrattHamster]

Hi ConnorL

This is some truly great work. I really can not wait to see future up dates of this locomotive. keep up the great work.

[ConnorL]

Finally got settled back home.

After creating the 3d models, they were separated and prepared for Shapeways to be printed.

After that, an order was placed at Shapeways and the waiting game begins.

In about 2 weeks, I received my package in the mail which contains the 3d model.

The hardest part was creating the drive shaft since the parts are so small and fragile...but I managed to.

I removed the images, because they are too big and might causes problems to some users but the links are present.

EDIT: Also I can't upload pictures anymore since they exceed 2MB.

[spoiler]http://i39.tinypic.com/1euq0l.jpg[/spoiler]

(Sorry for poor camera quality, I will get a macro lens soon)

[spoiler]http://i43.tinypic.com/ip9isn.jpg[/spoiler]

[spoiler]http://i40.tinypic.com/2ryh8va.jpg[/spoiler]

[spoiler][/spoiler]

[ConnorL]

Sorry about this MASSIVE picture, the spoiler function doesn't work.

[GarrattHamster]

Hi ConnorL

The loco is looking great. I have to say i am quite invested in knowing how much you think she could pull. And ask if there any chances of any future clip's of seen in action.

[dkightley]

Sorry about this MASSIVE picture, the spoiler function doesn't work.

Its not that this feature doesn't work.....its a customised add-on patch to the bulletin board code that I haven't got installed.

EDIT: Also I can't upload pictures anymore since they exceed 2MB.

You've never been able to upload pictures to this forum above 450kB in size....and I'm afraid I'm not going to be in a position to allow large file sizes. I don't have any sponsorship or external funding to pay for the hosting of the forum - it comes out of my own pocket! If I allow large files, then the day I have to start paying more will be sooner rather than later!!

[ConnorL]

Ah thanks for the clarification, I thought it was built-in. I didn't know what we had limit haha.

[jesse6669]

Looking really REALLY good! Does your mechanism run? Understanding it's a prototype I don't necessarily expect so, but I'm sure it will. You have most of the parts down!!

Not to hijack the topic, but photo posting here is a bit tricky. If the image is big you need to scroll around (I found you can right-click and open in a new tab though, this works pretty well.)

I think it looks best if the image is re-sized to 640x480, although I didn't do that with my own most recent pics.. Might try using hosted images from Skydrive and see how that looks.

[ConnorL]

Thanks jesse for idea, I'll see if I can show pictures from google drive. Hopefully that will prevent it from "shutting down for extended bandwidth" and resize pictures before posting.

While holding the train in the air, the mechanism works, but I'm having hard time getting it working on the track because I had to hold the wire to the motor and it won't stay connected.

I'm designing the electrical contact for the wheels right now and when I do, I'll let you know how it goes.

[dkightley]

On the subject of images....see here: viewtopic.php?f=3&t=89

[ConnorL]

It had been really quiet these days, anyway I had updated the model to include electrical pickups (they won't be 3d printed).

I am seeing if I could find some companies that can do etching services really cheap for a simple part, I was planning to use copper since they are very conductive.

If I couldn't find anyone, I will try to do the etching myself at home using corrosive liquids used for PCB board etchings.



If you or anyone know who can perform etching services, please let me know!

[Alex]

Looking really good.

Not sure if copper would be the best though, it doesn't have much spring.
Saw this company mentioned on rmweb for etching, http://www.ppdltd.com/web_site_3/page_1_intro.html

[jerrybigcat]

Phospher bronze would work better for you pick-ups.

[ConnorL]

Thanks for the suggestions! I noticed that you are right, copper isn't flexible. I'll go with phospher bronze or I can order several different materials and experiment them.

For 3D models...I won't be able to work on them anymore. My solidworks 2012 license had expired and I'm not in college (home for job) so I will have to wait another year (Fall 2014) to renew my license.

In that case, I will be practicing using Autodesk Inventor (Similar to Solidworks) and modeling from there.

[jesse6669]

You might try Blender. Pretty powerful but takes some getting used to.

See: http://www.blender.org/

[ConnorL]

Ordered my Shapeways models, it will be here on Monday the 6th. One of my part was rejected since they don't approve the supports ( they required 0.8mm x 0.8mm support, I used two 0.5mm x 0.5mm supports).

I tried to beg then that it worked last time, lucky these were only the spare parts, the main parts are still coming. I will figure a way to change the support of these parts.

[ConnorL]

Couldn't do much while Shapeways are still shipping the models to me, while waiting, I remade intermodal train cars that will go with the SD70M.



I was wondering if the brake steering wheel is too big/tall?

[ConnorL]

Got my shapeways, a huge improvement to the gearbox. The wheels no longer touches the bogie, I am now facing a problem since the first 3D print of this train.

I don't know what is the correct gear ratio of the T-Gauge train that were used. I think I'm "skipping" or getting the gears jammed on each complete rotations.

Do anyone know what the exact specification of the gears that are used in all T-Gauge trains?

I might have to order different number of teeth in a gear and experiment which is the best gear to be used.

Holding the train, powered, the wheels spin freely at full speed, when I try to make it move at a slower speed...it gets jammed every 1/5th to 1/3th of a rotation.

Thanks

[dkightley]

If you're getting occasional jamming, his must be due to the small manufacturing offset errors in the holes in the gears.

You'll need to run the gearboxes in with some abrasive paste in the gear mesh.....something like toothpaste! Run at a medium pace for as long as is needed to "grind" off the high spots.

Once run in, you'll need to clean all traces of abrasive out....

[ConnorL]

Thanks, I'll try it out. I still think the gear is the problem, I think that I designed the gap too large where the gears will "skip" or jam. I'm not sure but I will take the train apart and play with the gears by hand to see if it is defective or contains "too many teeth/not enough teeth".

You can see the two new print batch that came in, they looked A LOT better compared to the original since Shapeways printed them in a good orientation. (The first print is the one that's more white w/ rough surfaces)





I took everything out of the original body into the new body, it fits a lot better and the wheels doesn't hit the bogie anymore.

I am wondering...is anyone interested in purchasing SD70M as dummy unit? I might have to put them together and ship them to you. (It is very fragile when installing the wheels.)

NOTE: These are not the final product, the final product will include brass etched handrails.