Author Topic: Steam Tractor 3/4" (Rudy K)  (Read 170220 times)

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #60 on: October 05, 2015, 04:18:38 PM »
Achim, Nicolas, and Jason,
Thanks much for the comments and support!
Kim

Offline Don1966

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #61 on: October 05, 2015, 10:55:04 PM »
Hi Kim, I hope I wasn't to harsh with you, if I was you have my apologies my friend. I do know your learning and I hope you continue to challenge yourself with every project you build. I need to tone myself down a bit and just follow.

Regards Don

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #62 on: October 06, 2015, 06:14:26 AM »
Hi Kim, I hope I wasn't to harsh with you, if I was you have my apologies my friend. I do know your learning and I hope you continue to challenge yourself with every project you build. I need to tone myself down a bit and just follow.

NO!  Not at all Don!  All I every feel from you is helpfulness and encouragement!  All I was trying to express is that I'm a rather slow student.  :-\

Its my turn to apologize if I made my post sound any other way.

I truly appreciate, and need, all the advise you and others provide.

Thank you for taking the time to respond so often to my questions, confusions, and difficulties.  Heaven knows I have a lot of them! :)

Thank you Don!
Kim

Offline kvom

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #63 on: October 06, 2015, 03:37:51 PM »
Just an observation:  once the spokes are fastened to the hubs there is no way that they can move at the rim.  You could just cut them off flush without any other fastening.  Alternatively, make the length extend just past the rim's edge, use a center drill to make a slight depression in the end, and peen them to the rim with a punch.

Even easier, use green loctite at the hub and/or rim.

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #64 on: October 17, 2015, 09:35:00 PM »
Thanks for the comments kvom!  Sorry for my belated reply.  It's been a busy few weeks and I haven't had much play time.  I was able to steal a bit of time today, but not much. Anyway, here's my questionable progress.

Attempting to follow all the excellent advice I've received, and the little experience I've gained on my soldering technique, I cleaned all the parts for the first wheel VERY well.  All bright and shiny!

Then I made rings of Stay Bright solder (silver bearing, low tem solder), and used the Stay Clean past flux,  and got each joint ready.


I decided to start on the hub, thinking that it would hold all the spokes in as I worked on the outer rim.  I was planning on doing the hub joints in several sections - maybe 3-4 joints per heat session, that way the joints could be facing up and I'd have gravity to help the solder flow down.

So, I carefully applied the heat.  It mostly worked. But of course, many thing went wrong.  It started out great, but as I moved to other sections, the flux would boil, popping the spokes out of their holes. And the joints that were facing down would get too hot and the solder wicked together to make a big blob.  Anyway, I think I got it. I'll just have a good clean up job to do here.


I'm thinking that a full circle of solder on each spoke might have been too much?  Maybe? Though most of the joints look great.  I've got that one ugly blob there.

After I did the hubs, the outer rims were much easier. I could do them one at a time (ish).  I would do 4, then turn the wheel.


Clearly, the person who did this soldering job was a rank armature. :embarassed:  But I think after clean up, it should look passable.

Hopefully the next one will go better.  I think I may do the outer rim first next time, so that the spokes are more likely to stay in place when I solder the hub.  Does that sound reasonable?

Thanks,
Kim
« Last Edit: July 07, 2017, 08:55:09 PM by Kim »

Offline b.lindsey

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #65 on: October 17, 2015, 09:48:13 PM »
Looks good to me Kim, the clean up will make a surprising difference. Just a thought, what if you had laid the wheel on its side to solder the spokes into the hub. Heat applied to the end of the hub would likely have gotten things hot enough to melt them all at once or very close together at least. With the flux and solder rings, I suspect enough would have remained at the joint to secure things quite well.

Bill

Offline Don1966

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #66 on: October 17, 2015, 11:06:26 PM »
Looks good to me also Kim, not bad for a first at all. You could put a band around the spokes sticking out to keep them in place till soldered and could trim them closer. Or do as Bill suggest, but I am not sure how much pressure it would apply to the hub. Maybe placing it on another ring would help keep pressure off the hub.
One bit of advice I want to give you. I would of left the hub bore under size in the event that the wheel doesn't run true, but you could always bore it and put a sleeve if it doesn't.

Don

Offline ICEpeter

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #67 on: October 18, 2015, 12:02:49 AM »
Hello Kim,
Have a dumb question: Why couldn't you do your soldering by laying the wheel flat onto one side and solder the first side that way. Then turn it over onto the other side and solder the other side. In my opinion, that would have avoided the blob(s) of solder running down and puddling because of gravity pulling the solder that way, and, if the solder would still be running to one side (the underside) it would not puddle in one spot but under each spoke, maybe. Just my thought.

Peter J.

Offline Dave Otto

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #68 on: October 18, 2015, 12:16:55 AM »
Hi Kim

Doesn't look too bad to me either; only a couple things. As you have have figured out the ring of solder is way to much for that small joint. I would just feed it in from the roll when the parts are the proper temperature. Also as you probably know now the flux turns a nice caramel color when it is the proper temp; if it turns black you got it too hot.

You should be able to melt the solder by touching it to the metal with the flame removed; if not your parts are not hot enough yet.

As for the blob just heat it up and flick the excess away with an acid brush; you can add some flux and re-flow it to smooth it out.

The next one will go better.
Dave

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #69 on: October 18, 2015, 02:37:34 AM »
Bill, Don, Peter, and Dave,  thank you for your excellent comments!  You have some excellent suggestions for tuning-up my process here.  Laying the wheel on its side would probably help decrease the blobbing issue, as would using less solder.

I also think it might help the issue I just discovered tonight - as I mounted the wheel in the lathe for a little power assisted cleanup, I found that the wheel is WAY out of whack!
Needless to say, I was very disappointed.  :(

The hub is more than 1/16" off center and there is an awesome in/out left/right wobble going on. 


I played around trying to heat up the rim enough to move the wheel, but that's just too hard.  I could go to a bigger tip to get more heat, but I don't know how I'd move it in any controlled way to get it centered.

After crying in my milk for a while, I came up with this plan:

Do the 2nd wheel lying flat.
Do only one end of the spokes on one side first, and check for concentricity.
Do the other end of the same side and check for concentricity again.
Do the same for the other side.

Assuming I can get the 2nd wheel better, then I will probably just cut all the spokes on the 2nd wheel, which will make it possible to get them all out one at a time.  Then I'll clean up the rim and the hub, and try it again.

If you have better suggestions, please feel free to share! :)

Thank you for following along, and for all your help!
Kim
« Last Edit: July 07, 2017, 08:57:35 PM by Kim »

Offline ogaryd

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #70 on: October 18, 2015, 03:33:23 AM »
Hi Kim, I think I would build a simple fixture to hold things true while soldering.     Gary
"Effort equals Results"

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #71 on: October 18, 2015, 06:49:10 AM »
Hi Gary,
Thanks for the suggestion - I like it a lot!  Now I'll have to cogitate on that a while to come up with a simple, but elegant fixture to use for this.

Should have been obvious, but Rudy doesn't suggest that in his instructions, nor have I seen anyone else use a fixture for this job.  Maybe I just need more help than the average model engineer... :)

Thanks,
Kim

Offline Jasonb

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #72 on: October 18, 2015, 07:55:59 AM »
Kim, the usual way to assemble model traction engine wheels is to do them on their side. Make a central post to hold the hub in place and two or three clamps to locate the rim so it stays concentric to the hub. If there is any dishing on the wheel then pack the hub up as needed.

File a small flat onto the hub end of teh spoke so any excess flux can escape rather than have it act like a piston.

Flux the lot and work round feeding in the wire. For jobs like this I like "solder paste" that is flux mixed with finely ground soft solder, just brush it onto the joint like you would the flux and apply heat.

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #73 on: October 18, 2015, 03:57:06 PM »
Thanks Jason,
That certainly sounds like the way to go!
KIm

Offline ogaryd

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #74 on: October 18, 2015, 06:17:33 PM »
Kim, I forgot to mention, I wouldn't recommend aluminum for your fixture. It acts like a heat sink And wicks the heat away. Hardwood would probably work fine for this project. Gary
"Effort equals Results"