The Poet Creek Express - Foamie Hybrid

[KCStudly]

Thanks for having a look BC Dave. Karl works hard to achieve his goals and the shop and tools are part of the fruits of his labor. He is the best type of friend to have. I never mind giving him a hand, being there for him to bounce ideas off of, getting that rare call in the middle of the night when you just need someone to get you out of a hard spot, or just being a friend, because he is always there to do the same for me. Kind of the definition of a best friend, isn't it?

Shadow, the short answer to, "Why make one when you can buy one?" is because I CAN. All of the ones that I have seen in the market are clunky looking and in the $300 price range. Not that I can't afford it, but why should I spend a significant chunk of money on something that does not appeal to me aesthetically? TPCE is a vision of mine. I want to see that vision come to life.

GPW gets it. I am a mechanical person. I do mechanical things for work and hobby. This is a hobby for me. I looked at pop-ups, I looked at a Wazat, and I drew a sketch of a profile that appealed to me on a scrap of cardboard. Guess which one I keep coming back to in my mind. Guess which one I can picture at Poet Creek. Guess which one I know I would always regret if I did not see it through. This is a journey and, in a way, a tribute. My Dad would be pleased and proud of me for building this hitch; he'd think that I had accomplished something pretty cool!

I have spent zero $$$ on machining. All of the machining has been done at Karl's shop or at my work place off the clock (though I will likely offer Dave Z. a case of beer for his time just to show how grateful I am for his help and personal time). I get your frustration with engineers that have no real world experience, too, but we, none of us, are perfect either. We learn from our mistakes. The OZHitch self aligning feature is good and I am sure that at that weight rating under certain circumstances it would be quite beneficial.

Remember, I am sharing the design process with you all, so you are actually seeing me come through these issues as things progress (and I am further along now than what you have seen). I had already seen some flaws in my first iteration and have already done some rethinking here and there. By having the forward U-joint pin be removable (as opposed to the rear U-joint pin) I should be able to position the U-joint by hand, and jack the tongue up or down (just like the OZHitch guy did in the video). If I need to give a little tug on the tongue or bump it to the side with my knee a bit, I don't see how that is much different than getting a std ball to align. Since the TPCE will be much lighter than their 7k lb rating, I am betting that I will be okay w/o those alignment dogs. If I'm wrong, I'll be the first one to admit it! I also have the ability to do something about it if need be.

Thanks for sharing your opinion. All opinions and suggestions are welcome here. That's one of the great benefits of this site!!! We lay everything out there and everyone is free to choose for themselves which method works best for their own needs and abilities.

Stay tuned, update on pintle and sleeve machining (with pics) soon.

Camp on!

[KCStudly]

Pete42, Thanks. Glad you are enjoying my build. My car hauling trailer (shown previously) was put together with my first welder, a little Miller buzz box and a bunch of 6013 rod. In fact, later in the build I actually switched away from the MIG and went back to the stick because I was having problems with wind blowing the shield gas away. Not a problem with stick.

[KCStudly]

Okay, I hope all these lathe pics are not boring you! (A little machinist's pun there.)

Here are the pics that should have gone with all of those words I wrote on getting the pintle shaft thread right (post dtd Wed. 2/29/12).

Here's the mild steel pintle shaft blank already roughed down for the thread, with the under cut and radius at the washer shoulder and big shoulder (can't really see the radii in the pic, but they are there). Note that the shaft where the bushings will run has been left short here for more stability while cutting the threads.


Indexing the ends of shaft x axis.


Indexing the end of the thread cutting path.

Note that the boring bar that was in the adjacent tool holder had to be removed so that it would not crash into the jaws of the chuck.

Cutting threads.


That thread was unacceptably loose when checked with a test nut, so Dave parted it off and started again. Here is thread #3 almost done.


And here it is done.


I spun the test nut on and off a couple times and that was enough to burnish in the fit; fits perfect now!

Now the stock has been rechucked further out and the portion where the bushings will ride is being turned down close to the final finish.


Couple more passes, notice the amount of material being removed.



And in this one the cutter has already started to retract, but I thought the droplets of coolant captured in mid air was pretty cool so I am feeding the pic hungry crowd.


Here you can see that the work piece has been turned around and the chuck is clamping on the bushing area of the shaft (not to worry about damage because it is only rough size at this point). You can see the thread at the far end inside the thru hole in the chuck. Both the pintle shaft and bushing sleeve are coming from this same piece of stock, and the OD for both of these needs to be 2 inch, so the 2-3/8 OD stock was turned down. Here it is all turned down and being fit checked with the little tongue front xmbr.


And here are a couple of pics showing the hole in the sleeve with the boring bar. This bore was left about 1/32 under size and will be reamed to final fit with the bushings after the sleeve is welded into the little front xmbr. That way any effects or shrinkage from welding wil be accounted for.



Dave had been working on this during breaks and lunches, plus about an hour each evening three nights this week. (I tried to stay out of his way for the most part so did not get photos of each and every step. ) This evening I had to cut out at the bell in order to get to an appointment, but I did see that he had parted off the sleeve piece, had turned the alignment spigot into the hub end of the pintle shaft, and was getting ready to put the final finish on the bushing area of the shaft. It is likely that the parts will be sitting on my desk when I get into the office in the morning and I will get pics of them next.

Can't thank Dave enough for his part in all of this, except to give a shameless plug for his powder coating business,
http://www.zzpowdercoating.com/Pictures-of-Our-Work.html

Last night I worked on the issues I did not like about the removeable U-joint pin and came up with this.


I made it so that the pin drops in from the top. There is only one keeper button at the top of the pin, and the pin does not stick out the bottom of the yoke at all; it is flush on the bottom so it can not snag on anything, but it is still in double shear. I added a post for a padlock and a small profiled block that drops onto the post to act as an anti-rotation device and lockable hold down for the pin. I will use a padlock intended for coupler latches that has the lock shaft proctected by the body of the lock, making it difficult to cut the lock off with bolt cutters, like this one.
Master Lock

All for tonight, thanks for stopping by.

[KCStudly]

Just a short update to fill in a few images.

Here's that first concept sketch that I mentioned. I keep this at my desk front and center on the little wooden platform that I have my monitor up on. I use it for inspiration, and, occasionally, as a de-stresser.


Sure enough, the pintle shaft and bushing sleeve were on my desk this morning. Dave knew that I was hoping to have it for this weekend and (since much of the plant works four tens) made sure he finished it up before the end of his week. Thanks Dave!!!


And here are the same parts mocked into position (w/o the brass bushings).


Karl has some stuff going on tomorrow, and while he has said that I am welcome to work even if he's not there: (1) It tends to be less efficient because I never seem to know where everything is, tools and such, and (2) it's just not as much fun without the social aspect. I've been burning up the midnight oil and will take a break and go to the monthly cowboy shoot out at the range tomorrow morning (Sat.). Sunday will be a build day.

[pete42]

I liked the bigger pictures...........

[KCStudly]

Yeah, me too, on the pic size. Not sure what happened there, but if you click on them they get bigger. Then you have to hit the back button (takes too much time). I'll try not to let that happen again, Pete.

Thanks for watching!

[KCStudly]

Edit: Looks like the smaller images are automaticly sized down from my uploaded size. Guess we're all going to have to get used to clicking on images and then using the back button.

Well when I woke up yesterday it was raining pretty hard, so I chose not to go to the CAS (Cowboy Action Shoot). Went back to sleep and caught up on some much needed rest in preparation for today's build progress!!

Still working on the swivel coupler parts, I started right in with clamping the second clevis (U-Joint Yoke). Based on the experience with the first clevis sucking in when welded I used two of the .010 thk aluminum flashing shims per side this time.

　
Anybody see anything wrong with this picture? Me neither...at the time.

First root pass on each side.


(Sorry, some of these pics came out blurry.)
　
Almost there, both sides.



　
Fully welded.


Note the contour of the weld will support rounding over on the sander.

Welded the inside of the first clevis. Note the alignment/plug weld hole in the center of the hub.


　
After Clevis 2 had cooled down I started measuring to see how much it had pulled with the weld...something wasn't adding up.
Uh oh.

Doh, forgot to put the two 1/8 cap plates in to represent the bushing flanges. Here you see that the first clevis has shrunk to where only one of the 1/8 plates can be inserted with the flashing shims, and the second clevis won't accept any.


Oops.

Interesting to note that there were two of these 1/8 inch plates in there, plus two of the shims when I welded the first clevis, and now only one fits easily.

Well I surely was not going backwards, and was not going to start clevis 2 over. We briefly considered milling out the yoke ears, but I did not want to thin them this much, so the remedy will be to mill the sides of the U-Joint down to suit the clearance required for the bushing flanges and a small running allowance. Each end of the U-Joint will be slightly different to accommodate the different yoke sizes.

Moving on. Welded the inside of the second clevis.



Sanded the first clevis.


　
Made the little lock tab for the newly designed U-Joint removable pin retainer.


Here's another mock-up of the pintle shaft and related parts.


Checking the stack up of the bushing sleeve and bushings.

　
Put the big fixture washer and nut on the pintle shaft and checked the inside measurement of the pintle shaft shoulder-to-washer against the previous measurement (no pic). Things were too tight. Dave Z. had done a good job on the pintle shaft, but the thrust bearing surface of the thrust shoulder was a little rough and I would have liked a bigger radius where the shaft meets the thrust shoulder. So, even though the shoulder had ended up a little thinner than the plan (slight mental math error by Dave) I decided to take a skim cut off of the thrust shoulder instead of the sleeve. This would allow me to improve the finish of the thrust face, and at the same time increase the radius. I found a carbide cutter that had a chip out of it and sanded it to the radius I eyeballed would match the new cut to the old radius. Took a while to do this on the Bader...Carbide is really hard!

Can't really see the details, but this is a pic of me plunging the radius cutter along the face of the thrust shoulder in Karl's lathe, just until it kissed the OD of the shaft.


Took about .030 off leaving about a scant 3/32 radius. Hit the outside edge of the thrust shoulder with a flat file to deburr/chamfer, and checked the stack up fit directly.


Running thrust clearance is now about .025. This new pintle shaft is spot on the max dimension of 1.500 inch so the bushings won't go on until they are installed in the sleeve and reamed to size. Also, the forward bushing will need to be chamfered slightly on the ID to clear the larger radius on the shaft.

With that set it was now okay to weld the bushing sleeve into the little front xmbr. Pulled a couple of 1/4 inch scraps out of the bin and set the xmbr up to establish the required stick out, square axis and parallel faces.


Four good opposing tacks, then 1 inch arcs alternating in a star pattern. And the resulting welds.


　
Blocked the xmbr up off of the sleeve and shimmed the xmbr end caps up.


Tacked the cap plate on.


Shim left a reveal that will be left unwelded for now.


Then welded the three sides of both cap plates, leaving the reveals unwelded.

　
Mock-up the xmbr to one of the tongue rails. Now you can see that the reveal provides a weld prep where all three pieces will be welded at once when the xmbr is attached to the tongue.

　
I can weld this.


　
Did the rock slider cap plates in a similar fashion. Here they are welded on three sides.

　
I was going to leave these parts at that, nice welds standing proud, but Karl says, "Aren't you gonna sand them?". Me, "No, it's a trailer, not jewelry." Karl, "Oh, I always sand everything. You could catch a rock on that edge." (Chiding me, I know.) "You're pulling my leg, com' on," I said while looking at the nicely sanded radii I had so proudly done on the main frame rails, "I'm not gonna hold the frame up to the Bader when we weld it up." Karl, "Flap wheel." Damn, got me there, off to the Bader, and here they are all sanded up nice.

　
Wife worked on Saturday, so finished early to have a nice meal together at a small local pasta shop (http://www.paulspastashop.com/index.htm, in the summer you can sit out on the deck overlooking the Thames River), sauteed shrimp, asparagus, mushrooms and herbs in a white wine/olive oil sauce over fresh linguini. Lots of garlic. Yum.

[GPW]

Pretty AMAZING KC !!! Beauty work !!!!!

[KCStudly]

Why thank you, GPW. I appreciate your generous comments.

[GPW]

KC, You can bet if I had your knowledge and access to tools , I’d be making my own stuff too... There’s something extremely gratifying just starting from scratch and seeing it through to a logical conclusion ...

[Captain Monkeyshines]

Definitely! If I had half the skills that are shown here I'd build everything I could. As it is I have to muddle through with all my thumbs and make sure that, in the end, I still have all my thumbs intact. Excellent work!

This build is going to be awesome, and that tear will look great sitting on Poet Creek (not that I know how to get there, but the pic you posted of it is beautiful)

[KCStudly]

I started out ...no, check that.

I was always fascinated by the projects my father would accomplish. His were usually more of a civil engineering nature; digging out the hillside in the front yard, building forms and pouring a sweeping concrete staircase with planter box tying in the steps from the driveway to the upper yard, then more poured steps on up to the front door of what is now my sister's place (old family house). He did all kinds of large and small projects. Dryer's broken? Don't call a repairman; take it apart and figure out what's wrong with it. He seemed to have a thing for terracing. Raised bed gardens up on the side slope of the front yard (that's when I learned what a water level was..."Uh, dad...what are you doing with the garden hose?"), and later, at his home in Washington State, he had terraced the whole back yard with flowing arcs of railroad ties and fruit trees. Knowing dad, he probably did it all by hand with a shovel and block and tackle. Probably made the block and tackle himself, too, knowing my dad.

The sill plate on the rear corner of the house was rotten out because the rear porch was a sand filled concrete shell placed right up against the house. He broke out the porch, jacked up the house, replaced the sill, and repoured the porch with a little concrete gulley separating it from the foundation of house. Got a problem? There's a solution. Hard work? Yup, but can do, it's a challenge. I actually wish I had gotten more of that from him. I'm actually kind of lazy unless I have my teeth into something.

My first real mechanical work was when I was a freshman or sophomore in high school. My good friend John's family was into stock car racing at the local speed bowl. Worked on those race cars every night (it seems) for a couple of years. Then another friend and I were into drag racing muscle cars (...the big block Chevelle I mentioned). He had an early '67 Camaro that ended up being either the fastest street car, or muscle car (I forget which) at Bonneville for a time (...unofficial because they threw the blower belt on the return pass and were unable to repeat). His younger brother worked with him on that project and later made it on to “Monster Garage”, the wheel standing ambulance episode. They showed a video clip of the Camaro at B-ville on that show. We started out just making neat little custom parts out of aluminum to make our cars a little lighter and cooler. Things like throttle and return spring brackets for the carburetor. All the while I was doing drafting and excelling at math.

Mom says I was mechanical from day one. Every once in a while somebody will tell the story of me as a wee toddler rubbing my wrist raw trying to figure out how the jack-in-the-tin-lithograph-box-windup-puppet-toy worked. Hold jack down close the lid on hand while peering in to see what was happening in there; drag hand out from under the latch; crank, pop, repeat. I was fascinated by the parts I could not see under the cloth skirt of that pop up puppet! I wanted to see what made that thing work! It’s no wonder I didn’t figure out how to take it apart.

[GPW]

KC , I took all my toys apart .... once I figured how they worked , I no longer wanted them ... Got a used Erector set once... played with that for 20 years ... I guess I was the only kid on the block that mitered Lincoln Logs ... All starts EARLY eh , the “understanding” !!!!

[KCStudly]

At the last chunkers meeting we were trying to noodle out a concept for how to get the new design to fold down to a reasonable height for transport over the road. Busted out Eric's kids Lego set and did a rough scale mock-up.

Toys, tools, creation; it's all just play time unless you are getting paid. Then it's called work!

[KCStudly]

Got some work done on the swivel coupling parts tonight. Lots of chips cut on the mill.

To get from work to Fab Mecca there are several routes that I can take and they all end up being about the same amount of time, so I usually mix it up just to keep things from getting boring and to keep my eyes open for anything interesting. Spotted this Tioga motor home on a Ford Econoline cab/chassis being torn down. Looked like a bomb went off.



Started by sanding the second clevis.


Note that we didn't bother putting a hole in the hub on this one as it will be landing on the open end of the draw bar tubing and will not have anything to pilot off of, or to plug weld to.

Laid out and prick punched both yokes (clevises, clevis', clevii?) for the U-Joint pin holes. Karl jumped on the mill and set #1 up with a 13/16 slugger bit (under size for 7/8 reamer). He ran with it and this allowed me to stay on the camera a bit more, as well as to lay out the prick punches for the corresponding holes in the U-Joint. He knows his way around his own tooling better than I do (duh) so for the time we had this evening it worked out better to just let him run with it.





The slugger cuts a very accurate hole much quicker than a std twist drill would. However it was not long enough to reach through to the far side; which was key to maintaining a straight axis through the bushings to prevent binding. If we were to unclamp the yoke and flip it to drill the other side the holes would never run true to each other. So Karl dug out a std 13/16 twist bit and ran it through the other side from this side (this pic is actually clevis 2 being cut).


This is Karl sharpening up the bit by hand on the Bader.

(This frustrates me a little because I had gifted him a Drill Doctor and, as far as I know, he doesn't use it. I think if he did, he would never sharpen another bit by hand again. Oh well, horse to water.)

The bronze bushings must be pressed into a very accurately sized hole (7/8 in this case) so that they have the correct interference fit and don't slip and spin in their bores. This requires the final bore to be reamed to size. Here is the reamer being started.


And here it is going through the far side. Notice that the cutting flutes are aligned in both holes at the same time.


Here they both are reamed and lightly deburred. The short T-shape round piece is one of the slugs cut from one of the clevis ears, and the longer one is from the U-Joint that I'll show next.

(Don't mind the metal dust, I hadn't wiped them off yet.)

Here is the U-Joint being slugged out.



Chips.


Lots of chips.


Second hole.


Not too exciting, but you like pics, so...



So we were chit chatting and popped the U-Joint out of the vise before either of us realized that Karl had not run the reamer through yet, but it didn't really matter much because he had forgot to ream the first hole, too. We will have to reindex the holes and ream them at another time, no biggie. Of course I cleaned up the mess we made on the mill and wiped the water based coolant off of the parallels to prevent rust.

Karl sent me on my way with a little slug of bar stock that fits the center hole in his rotary indexing table (I'll get pics next time). My next task for after work is to turn the other end of this slug to fit these new holes in the yokes and U-Joint. By using the slug to align these holes to the center of the rotary table we can then dog these pieces onto the rotary table and rotate them past a cutter in the mill, putting a 1 inch radius on the ends of each clevis ear and both ends of the U-joint.

Once the bushings are pressed into these parts, the bushing bores will be finish reamed to the 5/8th pin size in a similar fashion.

All for now.