A

avi8tor50

Well Known Member
I'm at the point of mounting the main gear legs and then the nosegear leg.
Have been studying the discussions of the problem with the bolt that attaches the nosegear leg to the engine mount and the proposed solution, i.e. the use of the taper pin instead of the Vans bolt.
Fisrt of all, I would like to know how many of you RV nosedraggers have actually had a problem with that hole.
In addition, it does NOT seem like this is a problem-free solution. Several builders have reported difficulty reaming the hole with the tapered reamer.
Soooooo...
What is the consensus? Do we install the taper pin PROPHYLACTICALLY or do we wait for the problem to show itself and what is the true incidence of this problem?
Please feel free to comment. I think this is an important issue for all builders constucting the "A" models.
Thanks.

Peter K
9A QB
 
I went the taper pin route after finding that I had drilled a "less than perfect" second hole in the mount tube. I had trouble getting the taper pin from ACS (I think it was on BO for 3 months) and gave up trying to drill the taper hole and took it to a machine shop. I supplied the taper pin reamer (Mcmaster-Carr). There's no way the nose gear leg can be done by hand.
But Its done and its SOLID!

If you decide to do it let me know 'cause I've got several extra taper pins and a reamer....

Frank in CT
RV-9A (Subaru H4)
 
alternative to taper pin

i'm going to be trying an alternative to the taper pin solution. i already have the .311 reamer, and i am going to try that with a close-tolerance bolt. vans actually sells a close-tolerance bolt that will most likely suffice -- NAS1305-26 5/16 1.625 $5.40 (it's 1-5/8 grip length instead of 1-9/16, but another 960 washer or two should fix that)

i'm hoping this milder solution will prove effective. i'll keep a close watch on the gear at condition inspections, and if i see a problem, i can always graduate to the taper-pin solution at a later date.
 
I also had trouble hand reaming for the taper pin. I believe the nose gear strut itself is a little hard for hand reaming. While I was applying pressure to get the reamer to cut, I also allowed the reamer to drift off to the side. I now have an oval hole in the tube the nose strut slides into. I'm looking at welding up the hole so I can redrill or ream the hole. The nosegear strut itself is almost reamed to the correct depth, so I'm going to have to make a decision about replacing the strut. If I abandon the taper pin idea then I need a new strut. (about $200.00). Bottom line, be carefull when you are reaming the parts! I already have the .311 reamer, so I probably should have just used it instead of trying to "improve" the design.
 
taper pin

Frank & Mike
I 'm at the point of trying to ream my nose strut for the taper pin, already have the tools, just waiting on the back ordered taper pin from ACS. Frank, you said it can't be done by hand. Did you resize the hole to an S or 11/32 drill bit size first and use plenty of cutting oil? What were you using to hold the tapered reamer? Did you try to do it while mounted on the firewall or locked into some kind of vise to hold everything rigid.
I have Jim Ellis's procedures, does anyone else who has done this have any recommendations or techniques before proceeding.

Oldgeezer
RV9A
 
I did step drill up to S diameter. Reaming was proceeding fairly easily until near the end when I started using a lot of pressure, and wasn't paying enough attention. By the way I have two extra taper pins and washers if somene would like them. I had to buy 5 from ACS when I purchased mine. Cost plus shipping, I'll mail them tomorrow if someone wants them. Probably between $15 and $20 total.
 
Taper Reaming Nose Strut Assembly on Firewall

I am considering taper reaming the nose gear assembly with the engine and mount still on the firewall. I would S-drill and taper-ream the strut off the aircraft and in a vice, then ream the corresponding holes in the engine mount. Has anybody been successful with that approach?
Leland
 
tapered vs straight

I built a 9A and used Vans method. After 350 hrs, no problems and all seems well. I'm building a 7A and decided to use tapered reamer and pin. It can be done by hand, but it is a bit of work and probably 4 or 5 hrs. I would probably use Vans method if I do it again. :rolleyes:
 
Taper pin

I tried the taper pin method, was unsuccessful, and would not do it again. The reason for my lack of success is my own fault.

I spent many hours, not just 4 or 5, trying to hand ream the nosegear strut. I think that I may have work hardened it when drilling the hole to prepare it for the taper pin reamer. In any case, I screwed up the hole with the tapered reamer trying to do it by hand. The fix was to take it to a machine shop where I asked them to drill a hole for a close tolerance 7/16 bolt. The bolt was about $25 and the minimum shop charge was $60 to drill the hole. Perhaps I was not clear in my instructions to the machine shop about "close tolerance". I should have told them to ream the hole so that the bolt would be a tight fit. I even gave them the bolt. The hole is a regular 7/16 in hole and the bolt slides in and out :(

I could go one size up, but I am about at the upper limit of how large a hole and bolt can be used. The current situation is acceptable, but no better than Vans standard arrangement. If I try to improve it, with another expensive bolt and the machine shop messes it up, I would really be up the creek.

If I were to do it again, I would ream the hole and use a slightly oversize bolt. I am not being critical of the concept, just saying that it has its pitfalls if you screw up...as I did.
 
You must log in or register to reply here.