Can a boring head do this job?

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This is a drawing of a European trailer hitch by Westfalia Automotive
in Germany. It's used on some Audi models. Unfortunately, it's not
sold in the US, so it only comes with a 50mm ball, part of the
cast/forged removable portaion. =20
The 50mm ball will be a close fit in a US 2" coupler, but there will
be some slop, and probably increased wear.
One option I considered is to have the 50mm ball plated to increase
it's diameter to 50mm, or even do it with a tough paint..=20
The machining alternative is to cut the ball down to a post to fit the
balls from Convert-A-Ball hitches:
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I doubt it's possible to do this in a lathe, since it would be
severely unbalanced even if you could fixture it. =20
The way I see it being done is to mount it on a mill and use a boring
head to cut it down. Is this possible? (I don't have a mill yet)
BTW: The way this hitch works is that you pull the knob on the side
and twist. It retracts the pins into the cone-shaped section and
latches in this position.
When you insert it into the receiver and push up, a lever trips the
spring-loaded mechanism, which forces the pins out into holes in the
receiver.=20
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Reply to
Doug Warner
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This is a drawing of a European trailer hitch by Westfalia Automotive in Germany. It's used on some Audi models. Unfortunately, it's not sold in the US, so it only comes with a 50mm ball, part of the cast/forged removable portaion.
The 50mm ball will be a close fit in a US 2" coupler, but there will be some slop, and probably increased wear. One option I considered is to have the 50mm ball plated to increase it's diameter to 50mm, or even do it with a tough paint..
The machining alternative is to cut the ball down to a post to fit the balls from Convert-A-Ball hitches:
formatting link
I doubt it's possible to do this in a lathe, since it would be severely unbalanced even if you could fixture it. The way I see it being done is to mount it on a mill and use a boring head to cut it down. Is this possible? (I don't have a mill yet)
BTW: The way this hitch works is that you pull the knob on the side and twist. It retracts the pins into the cone-shaped section and latches in this position. When you insert it into the receiver and push up, a lever trips the spring-loaded mechanism, which forces the pins out into holes in the receiver.
lol. i'm sorry to say, after clicking on the link the other day in the "what is it" thread.... the thing in this link kinda reminds me of that other thing in the other link. yuk. (this would be the industrial "steeley dan" version of that other thing.) i guess that's why it's sometimes good to NOT see certain things, they remain stuck in your head long after (that's why i chose to not click on the ball bearing thread link, figured it might be images i didn't need burned into my brain.) :-)
b.w.
Reply to
William Wixon
Doug Warner wrote in news: snipped-for-privacy@4ax.com:
You are looking at 0.4 mm differential on the radius, which is the effective coupling in a ball hitch. This is most likely insignificant. The manufacturing tolerance on the stamped steel hitch is most likely more than that.
Reply to
Anthony
You could indeed use a boring head in the mill to do this. But I wonder if you need to. 1 inch is 25.4mm So two inches would be 50.8mm. And .8mm = .0315". I think that you could probably get away with this. If you do use a boring head when you get your mill consider that the boring head will probably need to be run in reverse. This is because most boring is done with right hand bars. Which of course have the cutting edge on the left. Anyway, when the bar is turned around in the boring head to machine the outside of the part the boring head must revolve in the opposite direction as it did when boring. If the shank for the boring head screws into the boring head it may unscrew while cutting. This may cause some exitement. It may also break the boring bar. I put "forever" Loctite on the threads for one boring head after having the thrill of watching the carbide tip disintegrate. ERS
Reply to
Eric R Snow
Anthony wrote in news:Xns9744BC1C5D962acziparle3sp835@216.77.188.18:
Actually, .8mm or 1/32", but yeah I don't think that would be a huge deal. You could always smack it with a BFH to get a tighter fit.
Reply to
D Murphy
IMNSHO it sounds like you're over-thinking this.
50mm is 1.97 inches, the US hitches are made to fit over a 2.00 inch (50.8mm) ball with a little bit of built-in clearance so it'll turn. The added slop is negligible, both for the ball-to-arm locking pin and the ball-to-trailer connection - hitch it up and go.
The corollary being that's WHY they chose 50mm for the ball, not because it's a nice round number. And I'll bet you that if you track down the other ball sizes available, one will be within a gnat's ass of 1-7/8" or 1.875" - perhaps 47mm or 47.5mm. (1.875" would be 47.625mm)
Perhaps one of the European folks can confirm this? Paging Nick Müller, Please pick up the White Courtesy Phone... ;-)
They may not offer the 2-5/16" equivalent (2.3125" or 58.7375mm) ball for that particular hitch, that size is meant for far heavier trailers than an Audi passenger car should be hitched to.
All I'd do is measure that the hook-over 'latch' part and the front lip of the trailer hitch cavity have plenty of extra overlap, to ensure a positive lock. If the gap between the two is 1-3/4" or less (which would ensure there's no way the trailer is coming off the car short of a major collision) it should be fine - if it's larger /then/ I'd worry about it.
You should be able to pick up the back wheels of the car part way off the ground with the trailer tongue jack as a test.
As for wear, that's why you're supposed to wipe the dirty grease off the ball and out of the hitch once in a while, and add a healthy dab of grease at all the contact points each time before you hitch up. I keep a little tube of Sta-Lube White Grease in the toolbox for that, and if you run out you can always use whatever grease is handy.
Which would render the entire assembly as 'Untested', and if you ever had an accident where the hitch fails you are in big trouble. If you need the 1-7/8" equivalent ball adapter, go find an Audi parts counter man who really knows his way around the books. If they can locate the part number, the part can be ordered.
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Reply to
Bruce L. Bergman
Thas what Anthony sayd. Radius vs Diameter :-)
Nick
Reply to
Nick Müller
"May I help you?" :-) So you want me to go out with the caliper and check some ball joints?
BTW: Nice you found that Umlaut-u on your keyboard. A "u" is acceptable.
Nick
Reply to
Nick Müller
Agreed.. I was thinkiing a more precise fit may be needed. My existing 2" ball fits the stamped coupler perfectly, with absolutely no sideways slop. I suppose this could just be from wearing-in. =20
I'll give it a try, if I can find a dealer who will ship to the USA.=20 -- Email reply: please remove one letter from each side of "@" Spammers are Scammers. Exterminate them.
Reply to
Doug Warner
D Murphy wrote in news:Xns9744D3253FF47BW12BU20MU38SY@130.133.1.4:
0.8 Diameter, yes...I was referring to the radius, which is all that really contacts on a ball hitch.
Reply to
Anthony
snipped-for-privacy@gmx.de (Nick Müller) wrote in news:1h8ua3z.1qdw61h1f85noxN% snipped-for-privacy@gmx.de:
Yup. I missed that.
Reply to
D Murphy
I just measured a 2" ball I bought from Harbor Freight. It is stamped 2". It measures 50.58mm dia.
Trailer hitch couplers are not very fussy or precise. A significantly oversized ball could be a problem, but a 50mm ball should work just fine.
Reply to
Don Foreman
No, but you could assist in confirming my suspicions that the other 'European standard' ball style trailer hitch sizes (if any) were chosen to coordinate with the US standard trailer hitch ball sizes. It seems obvious to me that 50mm was selected to be cross compatible with 2".
I believe 'your end of the world' ;-) uses pintle ring hitches for big stuff rather than the 2-5/8" ball. If we're going to mount a pintle hook, there is a 'combination' hitch where the end of the pintle hook is also a ball. Just leave the latch open.
I cheated and cut-and-pasted - but there's always 'Character Map'. If you use them enough you remember Alt+0169 is for ©.
Welcome to the melting pot that is L.A. - Around here, if you can nail down the proper pronunciation of everyone's first and last names (from all around the globe) you are off to a very good start. They may insist you call them by an 'Americanized' name in casual conversation, but out of respect I'm going to get their proper name right anyway - even if I sprain my tongue each time I use it.
There was a big collective "Thank you! over here from the ethnic communities recently, when the LA City Transportation Department found a big dusty box of tilde's and other accented characters on their shelf ;-) and 'fixed' a lot of street signs - one example being Doña Pegita Drive.
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Reply to
Bruce L. Bergman

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