Date: Wed, 17 May 1995 18:01:43 -0700 (PDT) From: Eric Westland Subject: Plating, etc. Thanks to all of you that responded to my concerns about using wax paper - I will sleep well tonight although the roll is going back to the kitchen. As I mentioned in my last posting, I have been going about the business of making all of the section II metal parts. Brock wanted almost $600 but the materials, including bell crank bearings was $160. It's taking some time to build them (so what else is new), but I have managed to put them together with some basic machines and a little ingenuity. A wood cutting band saw with a metal cutting blade, a belt/disc sander and a drill press really have helped. I already had the equipment, so I did not need to buy it all, but if you do not have it, with the kind of money you could save making your own parts, you could buy the equipment and have it for your entire project (at least that is what you could tell your wife :-) ). I got all of the equipment years ago from Grizzly, a machine importer. The band saw is somewhat lame and was about $250. The drill press is very good and costs less than $200. Their belt/disc is fantastic and I could not work without it. They ship mail order from both the east and west coast and have been around for many years. But even if you were to buy from someone else, these "extra" tools do come in handy. Anyways, my question regards the cadmium plating of the 4130 steel parts. There is a couple of places close to me that do cad plating for Boeing and will do the work for me, but one asked for the "KSI number" for the steel - this evidently determines the baking time, if any, to undo any embrittlement that takes place during the plating. Would any of you engineering-types have this info handy? Thanks, Eric Date: Thu, 18 May 95 9:43:50 EDT Subject: Plating, etc. (fwd) Eric writes: >As I mentioned in my last posting, I have been going about the business >of making all of the section II metal parts. Brock wanted almost $600 >but the materials, including bell crank bearings was $160. Good advice about tools, etc. deleted. (I assume Eric's not interested in competing with Brock :-) hint, hint?). >Anyways, my question regards the cadmium plating of the 4130 steel >parts. There is a couple of places close to me that do cad plating for >Boeing and will do the work for me, but one asked for the "KSI number" >for the steel - this evidently determines the baking time, if any, to >undo any embrittlement that takes place during the plating. Would any of >you engineering-types have this info handy? It sounds like they're asking for the strength in 1000's of PSI (normally abbreviated KSI) for the 4130. My 22nd edition of the "Machinery Handbook" lists 4130 as having: Ultimate Tensile Strength (UTS) Yield Strength ------------------------------- -------------- 81 KSI to 179 KSI 46 KSI to 161 KSI You can see there's a large range, depending upon the heat treating. I assume you've bought the raw material from Wicks, Alexanders, etc. I don't have the catalogs in front of me, but you might be able to get the numbers from there. If not, a phone call should get it for you - the supplier should know what they're selling. If they don't have these #'s, they should at least be able to tell you the temper of the steel, which the plater could then use to figure out the strength. Let us know what you find out. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Thu, 18 May 95 12:25:06 est From: "Phillip Johnson" Subject: Eric Westland Writes: > Anyways, my question regards the cadmium plating of the 4130 steel > parts. There is a couple of places close to me that do cad plating > for Boeing and will do the work for me, but one asked for the "KSI > number" for the steel - this evidently determines the baking time, > if any, to undo any embrittlement that takes place during the > plating. Would any of you engineering-types have this info handy? Wicks Catalog gives the Tensile strength of 4130 as 95,000 psi (95 KSI), and the yield strength as 75,000 psi (75 KSI). Phillip Johnson Date: Mon, 22 May 1995 12:05:25 -0700 (PDT) From: Eric Westland Subject: Metal Parts, cont... I called Wicks today and spoke with Don about the "KSI number" of 4130 steel. He was helpful, but did not know anything about it. I suspect that after talking with the plating guy and reading your thoughtful responses, that this number has to do with the strength as you said. The plating guy told me that after doing the cadmium plating, if the KSI number was above 160, it would need to be baked at 375 degrees for 8 hours and that it could be done at home as long as they were baked within 4 hours of the plating. A range of 145-160 would take 3 hours and anything below 145 would not need to be baked. Therefore, since the highest KSI number in the catalogs is about 100, these should not need any post-plating heat treatment, right? But then again, I am going to take the roll/pitch control handles and aileron bellcranks that I made to a certified welder to weld prior to plating since it's been 10 years since I did any welding. So, how might this heat from welding effect any of this? I response to the question about which Brock parts are worth getting, the answer depends on what tools you have and to some degree, your skills. It is my opinion that Brock charges fairly for some of the more complicated parts, but then again, he can charge you $9.60 for a 22" piece of tubing for the nose gear torque tube. When I first got started, I sent in a big order for all the section one parts. It was big bucks, $1,800 if I remember correctly, and I remember getting the order and thinking that there was nothing special to some of them and regretting that I had not been more careful in what I ordered. What became more frustrating later was that some of the parts had to be reworked to fit correctly, especially the canard parts. What follows is a partial list of parts and what I think, for what it's worth: All of the nose gear parts are either a "fair" value or would be just too hard/time consuming to make yourself in which case you just have to suck it up and pay. The nose gear torque tube crank (MKNG-611) which I mentioned earlier is nothing special and you will need to cut it anyways. I plan on replacing this part with a piece of steel tubing as another pilot had his shear off. The canard/elevator parts are much in the same category as the nose gear parts. Jim White and I made our own lift tabs out of thicker 2024 T-3 and also used a larger diameter bolt for the canard attachment, so I made up some larger CNL bushings. The NC-6 plugs had the allen head screw hole mis-drilled so that it hardly touches the hinge pin and even if it did, you can't get to it if you shorten your canard as the weights will be in the way. If you could find some stainless rod the right diameter, you could make your own hinge pins. The rudder/brake pedals are expensive and I know that there are a couple of other sources for them. Ron Kidd installed some from Weldtech that look more like conventional pedals (did they cost the same, Ron?) and I know there is another source as well. Even Aerocad might make some (is this right, Sid?). I would look into it if I was doing this again. I am making the section II parts myself - controls and landing brake stuff. None of it is too hard to make. I will have the 4130 welded professionally as I mentioned before and it may be easier to use stainless to begin with so you can get around the cadmium plating issue. I would buy the CS1 and CS1A rod end inserts from Brock. Time-wise, they are cheaper to buy. Anyways, if you have a specific question about a specific part, don't hesitate to ask. As I mentioned before, many of the more expensive parts are just too specialized to do yourself and it's frustrating when after spending all of that money, to have to spend an afternoon grinding away on your nose wheel casting to make the wheel fit right. Later, Eric Date: Mon, 22 May 95 16:10:37 EDT Subject: Metal Parts, cont... (fwd) Eric W. writes: >The plating guy told me that after doing the cadmium plating, if the KSI >number was above 160, it would need to be baked at 375 degrees for 8 >hours and that it could be done at home as long as they were baked within >4 hours of the plating. A range of 145-160 would take 3 hours and >anything below 145 would not need to be baked. Therefore, since the >highest KSI number in the catalogs is about 100, these should not need >any post-plating heat treatment, right? The reason for the post-plating baking is to protect the high-strength steel from hydrogen embrittlement (the same thing that kills nuclear power-plant piping) brought on by the pickling bath during plating. I would be very surprised if the 4130 that Wicks was selling was the very high strength version, and since you're seeing numbers around 100 KSI, I'd agree that no baking is needed. >............................. But then again, I am going to >take the roll/pitch control handles and aileron bellcranks that I made to >a certified welder to weld prior to plating since it's been 10 years >since I did any welding. So, how might this heat from welding effect any >of this? Given that you're not using the ultra-high strength 4130, it shouldn't (if you have a good welder). The heating and cooling cycle may weaken the steel somewhat, but I doubt these parts are highly stressed anyway. Certainly Brock welds them with no problems. -- Marc J. Zeitlin E-Mail: marcz@an.hp.com Date: Mon, 22 May 1995 19:09:35 -0400 From: RonKidd@aol.com Subject: Re: Weldtech Rudder pedal assy The Weldtech rudder pedal assy is nothing like the Brock. It is mounted overhead and has toe brakes similar to conv AC. It is (was) abt $ 700.00, but it provides for a lot more leg room. I am 6'4" and could not get my feet back far enough with the Brock setup. The pedal assy is designed for front mount master ctl and is very slick. It is heavier though, probably 8-10 lbs. Weldtech also makes an engine mount that is, in my opinion, far superior to Brocks. Comperable in cost. Nat does not endorse any Weldtech parts. I am told there was some kind of disagreement early on between them. His roller bearing torque tube & stick bearing setup is also nice. Very smooth. Ron Date: Mon, 22 May 1995 20:13:45 -0400 From: JIMWHI@aol.com Subject: Brake Pedals I have modified the Brock brake pedals that gives better braking and saves weight over the design shown in the plans. I will be sending it to Nat for publishing in the Cozy Newsletter. Hopefully you should all see it by this fall. The design uses the Matco cylinders and is adjustable, unlike the design shown in the plans or detailed in the recent newsletter. It is similar to the design recently printed the newsletter. I modified the Brock parts, but you could save about $500 if you fabricated them yourself. Except for the curved metal pieces on the passenger side, the brake pedals as shown in original plans and supplied by Brock should be relatively easy to fabricate. I wouldn't get to hung up on cadmium plating these parts. When I cut the tabs off the Brock parts, I noticed that the cadmium plating did not extend into the corners of the tab, which is where corrosion would take place. I don't care for the Weldtech parts because they're heavy (ugh). Email or call me at 503-690-8173 if you want to know more specifics before the newsletter. Jim White Date: Tue, 23 May 1995 23:49:41 +1000 From: allana@interconnect.com.au (allana@interconnect.com.au) Subject: Re: Metal Parts, cont... >The rudder/brake pedals are expensive and I know that there are a couple >of other sources for them. Ron Kidd installed some from Weldtech that >look more like conventional pedals (did they cost the same, Ron?) and I >know there is another source as well. Even Aerocad might make some (is >this right, Sid?). I would look into it if I was doing this again. > Aerocad make rudder pedals that are more adjustable than the Brock pedals and of slightly different design than shown in the plans. They have also have larger diameter tube joining each pedal. Cost is slightly lower than Brock. Allan Date: Wed, 24 May 1995 07:46:16 -0700 (PDT) From: Eric Westland Subject: 4130 Once upon a time, the tubing for the aileron controls behind the fire wall was aluminum. Due to fire concerns, it was changed to 4130. I believe this is correct, but in any case, my question is : why are the rod end inserts cad plated, but the tubing they go into not? Since they are both 4130, should they both be plated or could they just be protected with something like paint? I'll be checking it out with Nat when I talk with him next, but I was wondering what my " "engineer pool" thought :-). Later, Eric