Werowance attempts Upshur Vertical Single

[Art K]

I can't add much as far as silver soldering as all I have done is a brass muffler. But you do have to get it hotter than you would expect before it actually flows. Personally I didn't like the idea of a built up crank and avoided it. I also wanted counter weights and felt Hamilton's suggestion of bolting on counter weights was just asking for it to fly apart at the most inappropriate time(such as any time it's running). I tuned mine so that in it's prime it would run 7500 RPM. That being said, if your intention was to run it at a sedate pace you should have no problems with it. Mine did run as low an RPM as 450. You could make your flat stock longer and that would act as a counterweight.
Art

 

[werowance]

hi John, i dont have a pic of the real piece but here is one of a test run i did to see if it would work. what i did was cut a groove right where the cross drill would be from the top and then in that groove i bent silver solder around most of it and cut in 2 halves so that i could still get a piece of wire straight down the cross drill hole. so basicly there was a oring of solder on the inside as well as instead of a steel pin i used a piece of silver solder in the pin hole. below is a picture of the test piece without the solder and before pushing it together. the result was a nice clean part that when hit with a hammer on the end to see if it would hold up. it didnt budge.

 

[werowance]

this weekend i got the crank web radius cut and all brazed together. i put in the shops easy bake oven (yard sale toaster oven) for 400 deg F for 4 hours. dont know if that was necesary but wanted to hopefully relieve any stress built up from the brazing before i cut the center dowel out. no picture after the braze because i left it all clamped up and put it in the oven. 4 hours later it was bed time so i just turned it off and left it for the night. im sure there will be alot of cleanup tonight on it.

 

[werowance]

hmm after my ios update on my phone my pictures arent working. let me try it from the hmem iphone app instead of pc

 

[werowance]

the last photo is all solder put in the grooves as well as some sticking out of the cross drill holes. right before being clamped together with steel spacers.

 

[Brian Rupnow]

Werowance--I wish you all the luck in the world with what you are doing. I have built one or two crankshafts that were made from pieces silver soldered together. The ended up with far more run-out than is acceptable. One piece crankshafts from 1144 stress proof steel are scary to machine, but have a far better chance of "running true"---and if they don't run true. you can put one end in the 3 jaw chuck and tap the other end around with a mallet until it does run true. Or---Make the crankshafts from pieces Loctited and pinned together. I found that the heat from silver soldering put stresses into the crankshafts that never come out even, and the cranks don't run true. Let us know how you do with that one.---Brian

 

[werowance]

well so far not to good. there was some seepage of silver braze on the piston rod dowel of the crankshaft which also stuck the spacers to it. i managed to get them loose by spot heating the spacers but there is silver braze that will need to be cleaned up. on top of that im out of emory cloth so i just put it to the side and quit last night. its probably all wobbly to i dont know yet. ill try to test it tonight and just see how wobbly it is before trying to clean it up which i dont know if i can or not without ruining the "true" of the dowel the piston rod runs on.

lock tight and pinning does sound easier to me if that will hold up which sounds like it has for you Brian.

 

[Brian Rupnow]

Werowance--I'm up to 30 engines now, and the only crankshaft to break was one of my very early silver soldered ones. Pinning and loctiting works. One piece works. I have had a few crankshafts that had enough run-out to make visibly wobbling flywheels--(I hate that).

 

[JohnBDownunder]

I do recall seeing the test piece photo thanks.
Loctite does seem to be the model machinist's magic glue and as has been said it certainly avoids distortion and stresses from heating required for hard solder.
Seems there are many forms of Loctite and I have a loctite PDF of some 48 pages of what to use where and naturally I cannot find the download link for it or I would post it for those interested.
Oh Well,
John B

 

[Cogsy]

Back when I sold Loctite products we were told 680 was to be considered 'permanent' assembly and was recommended for fitting bearings to shafts, etc. From the Loctite site:

"High strength, methacrylate ester acrylic liquid designed for the bonding of cylindrical fitting parts, particularly where low viscosity is required.
LOCTITE® 680 is a green, high strength, methacrylate ester acrylic liquid designed for the bonding of cylindrical fitting parts, particularly where low viscosity is required. The product prevents loosening and leakage from shock and vibration. It provides robust curing performance. It works on active metals (e.g. mild steel) and on passive substrates (e.g. stainless steel and plated surfaces)."

This sounds perfect for assembling a model crankshaft.

 

[werowance]

well I was going to use 638 green. ill look up 680 and see if I can get some of that.

thanks all.

Bryan

 

[werowance]

received the loctite 680 Monday as well as my 1/16 drill rod that i will use to cross pin with. i glued the 2 pieces together with the 680 and clamped them Monday night so that i could drill and ream them as a single piece last night. ill have to say that i couldnt tell any difference between the 680 and the 638 other than maybe the color was a little lighter. but where it counts id have to say it was as strong or as weak as the 638 is. they popped apart with hardly any effort after i removed the clamp. now im not sure that 680 is designed for mating 2 flat surfaces together as i read the 638 was more for say a rod through a hole that was a tad oversize. to be honest for 2 flat surface joining the red permetex locktite i get at the auto parts store works better for me.

i do plan on using the 680 though for assembly once ready to cross pin and peen the pins though as i feel that it will work well in a situation like that.

oh and once more note the 680 does have an advertised expiration date on the bottle - which mine expires next year. whereas i dont see an exp date on my other bottles of locktite.

this is not bashing the 680 or anything cause i know each formula has its own special purpose, just wanted to share my experience with it. ill post back once i have the crank done.

 

[Brian Rupnow]

Werowance--I pay close to $100 for a 1.69 ounce of #638 Loctite, so I use it for everything, and have had no problems with it.---Brian

 

[werowance]

wow, 100.00? I paid about 30.00 for it. maybe the difference in US vs CA currency?

 

[werowance]

actually I just looked, it was 15.00 US for 50 ml which I'm thinking is equivalent to 1.69 ounces right? and that was for the 638

 

[awake]

weworance, where did you find it for $15? At that price, I'd be tempted. Thus far, I've gone the auto parts store option of Permatex thread locker in blue (medium strength) and red (high strength) - which have been working fine for me for a variety of projects, but I have not (yet) tried them in a model IC engine!

 

[werowance]

ebay, this is the seller I bought from last time

 

[Brian Rupnow]

1.69 ounces is 50 millilitres. $100 Canadian is $76.62 American. I buy mine through Brafasco, a Canadian nut and bolt company.

 

[awake]

ebay, this is the seller I bought from last time

View attachment 113426

Thanks!

 

[Brian Rupnow]

I just ordered the same from Ebay. Cost me $27.45 Canadian. $10.50 of that is for shipping. That still ends up being far less than what I pay locally.--They seem to be taking Canadian dollar at par.---Brian