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Old 06-21-2013, 10:27 PM   #76
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Originally Posted by hitcharide1 View Post
What're the chances of getting Rick to drive the GLC with his old pan? Enquiring minds want to know....
...rick entertained the idea of using his old 966 parts to build a modern belt pan...I told him do it...the more the better............but do you REALLY want to run against him???.............
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Old 06-22-2013, 07:11 AM   #77
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...rick entertained the idea of using his old 966 parts to build a modern belt pan...I told him do it...the more the better............but do you REALLY want to run against him???.............
Oh yeah! I haven't had my rear handed to me in awhile and I'm overdue!
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Old 07-15-2013, 05:48 PM   #78
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Conversation moved here from "European 2wd 1/8th pan car on-road Classic class" thread:

howardcano:

I apologize for this delayed response.

The 32 pitch gears now available (Kimbrough, etc.) have a 3/8" bore, so they can be used on any axle up to and including 3/8" diameter by using appropriate bearings or bushings, or none at all. Most contain at least 12 balls, so they should easily handle the torque demands. Ground rods/drill blanks for the axle are easily obtained. But someone would still need to create the necessary hubs/etc., which is quite a bit of machine work. I no longer own a lathe, or I'd be tempted to try it myself.

aarcobra:

I think 32 might work but from my experience drill rod is not tough enough for axles without hardening, maybe in 3/8"... Also you have to thread it for the nut/screw used to adjust the tension on the balls and I can't figure out how to attach the inner diff plate to the axle without a bunch of work. If you look at Associated and MRP, it looks like they are just pressed on and never come loose...

howardcano:

By "straight" axle, I'm assuming you mean "locked". For me, a locked axle and clutch brake would take the fun out of the class, for the following reasons: The locked axle makes the car more difficult to drive, and the clutch brake will likely be inconsistent due to the high temperatures it sees. But I'd be willing to put up with the clutch brake if the cost savings made the class more popular.

aarcobra:

Right, if it proves to be enough cheaper! My thinking is: we did it before, why not at least try it again?

howardcano:

Performance-wise, it makes more sense to put a disk brake on a jackshaft, away from the clutch heat and any oil coming from the front motor bearing. The jackshaft makes using a ball diff much easier, too.

aarcobra:

Here's where I screwed up again. I think this discussion needs to be in the "no Frills" thread not this one for "European 2wd..." Although I am interested in both, I am trying to answer the question whether an 1/8th scale gas car would be of interest if it was available/sturdy/cheap/ and fun to race. You and I have seen this class continue to shrink in participation for a decode or more and I believe although there are many reasons, cost and the ungodly complexity and speed of the cars are at least contributing factors.
I am attempting to determine what such a car would look like, could the cost be low enough to be a factor, and would it be fun enough to race so that it could become a viable racing class. I think of it as like a 1/12th pan car which has changed little over the years and the VTA class which is a spec class the differentiates itself enough to attract racers old and new.

howardcano:

I don't think this stuff is for the average racer, only for tinkerers.

aarcobra:

The ultimate result is hoped to be a small (25? piece) "production run" of kits and spares to actually test the ideas behind the design. It is not intended for a scratch built class...

Thanks for your comments,
Ned
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Old 07-15-2013, 06:04 PM   #79
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Regarding threading the axle for the diff nut adjust: The axle doesn't need to be solid. If it were hollow, then it's a simple matter to run a threaded rod all the way through. It might not even need any spring washers to hold tension if the rod were "stretchy" enough.

Stainless steel tube is reasonably cheap and available. One disadvantage is that the OD is not tightly controlled, so bearings may not fit. For a 0.312" tube, we could use an 8mm ID bearing to compensate. A 0.375" tube would probably need bushings, which doesn't thrill me, but hey, we're talking cheap, right? (Edit: We could also just use some sleeves, or machine some steps into the inner diff plate support and left hub, to fit inside a larger bearing.)

The inner diff plate support can be a collar with a set screw onto a flat or into a hole. I've done this before with excellent results. It's a tad heavy, but that's not a problem in this case.

The locked axle certainly has simplicity and low cost in its favor. I'm concerned that it might be too difficult to drive (especially on a slick track) for a class that is likely to attract beginners.
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Old 07-15-2013, 08:51 PM   #80
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Regarding threading the axle fohe diff nut adjust: The axle doesn't need to be solid. If it were hollow, then it's a simple matter to run a threaded rod all the way through. It might not even need any spring washers to hold tension if the rod were "stretchy" enough.

I think your idea of using tubing is interesting! Just wonder if it is strong enough not to bend? Worth a try! I have worked on converting an MRP Ball Diff to use modern wheels for a buddy and it had an o-ring in place of the tension washers. I ran MRP for years and it was a great car, and very simple.

Stainless steel tube is reasonably cheap and available. One disadvantage is that the OD is not tightly controlled, so bearings may not fit. For a 0.312" tube, we could use an 8mm ID bearing to compensate. A 0.375" tube would probably need bushings, which doesn't thrill me, but hey, we're talking cheap, right? (Edit: We could also just use some sleeves, or machine some steps into the inner diff plate support and left hub, to fit inside a larger bearing.)

Interesting you mention bushings. I have rebuilt an MRP and it uses oilite bushings and spins free. I bought some needle bearings to replace the bushings, an old team trick but they are only needed if you don't clean and oil the bushings. An interesting thing I found out about bushings and bearings, with bearings so cheap now ($1 per from Fasteddy) bushings are harder to source and more expensive!

The inner diff plate support can be a collar with a set screw onto a flat or into a hole. I've done this before with excellent results. It's a tad heavy, but that's not a problem in this case.

My concern here is the spacing. If you look at the Associated axle, the collar is very thin with no visible pin or screw. A roll pin would work but the axle has to be drillable...

The locked axle certainly has simplicity and low cost in its favor. I'm concerned that it might be too difficult to drive (especially on a slick track) for a class that is likely to attract beginners.
Exactly my concern! I hope to do back to back comparisons on prepared and unprepared tracks to see how big a deal it is. I really don't think a ball diff would be all that expensive if you know how to make it and who to source it from.


I keep hoping that since Associated is doing a re-issue of the RC10 maybe they could make up a run of 300BD's!!!!!!! Any connections?
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Old 07-15-2013, 10:14 PM   #81
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Exactly my concern! I hope to do back to back comparisons on prepared and unprepared tracks to see how big a deal it is. I really don't think a ball diff would be all that expensive if you know how to make it and who to source it from.


I keep hoping that since Associated is doing a re-issue of the RC10 maybe they could make up a run of 300BD's!!!!!!! Any connections?
.NOW you're dreaming BIG Ned...BTW...I have 2 of the re-re on order.......
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Old 07-16-2013, 03:39 AM   #82
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I think your idea of using tubing is interesting! Just wonder if it is strong enough not to bend?
Given sufficient OD and wall thickness we can get enough strength. The material on the inside of a solid rod contributes little to the strength for bending loads. I would imagine that 0.375 OD with an 0.035 wall would do. Double the wall thickness would probably be overkill.

Quote:
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My concern here is the spacing. If you look at the Associated axle, the collar is very thin with no visible pin or screw. A roll pin would work but the axle has to be drillable.
I was under the impression that we were talking about a new car, so the spacing would not be an issue (as we're not trying to fit the diff into an existing car). Drilling isn't necessary; grinding a sort-of-flat spot with a Dremel cut-off wheel will do, and could go all the way through the tube wall if necessary, so the set screw is essentially a pin. (We'll need to make sure the tubing strength remains sufficient in either case; the fact that the collar surrounds the tube at this point mitigates the problem.)
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Old 07-16-2013, 10:02 AM   #83
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Given sufficient OD and wall thickness we can get enough strength. The material on the inside of a solid rod contributes little to the strength for bending loads. I would imagine that 0.375 OD with an 0.035 wall would do. Double the wall thickness would probably be overkill.

Sounds like you have a good handle on the issues involved. I understand SOME of the principles but not that well! The SS tubing I have worked with is usually not as straight as ground drill rod type material. Would that be an issue? You're sending me down different paths than I've be thinking...just the purpose of this exercise!

I was under the impression that we were talking about a new car, so the spacing would not be an issue (as we're not trying to fit the diff into an existing car). Drilling isn't necessary; grinding a sort-of-flat spot with a Dremel cut-off wheel will do, and could go all the way through the tube wall if necessary, so the set screw is essentially a pin. (We'll need to make sure the tubing strength remains sufficient in either case; the fact that the collar surrounds the tube at this point mitigates the problem.)
You are again correct about this being for a "new car". From my experience, I believe and Associated type pod offers the best possibility of easy of build being a proven design helps too! That's where I came up with the spacing issue. I need to step back and think about the whole picture and see what makes sense f or sure...
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Old 07-16-2013, 11:21 AM   #84
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You are again correct about this being for a "new car". From my experience, I believe and Associated type pod offers the best possibility of easy of build being a proven design helps too! That's where I came up with the spacing issue. I need to step back and think about the whole picture and see what makes sense f or sure...
If there are existing parts that we can use effectively, then let's use them. Unfortunately, I don't know of any still available.

Does anybody remember when Lotus Formula one cars used bits from production British "saloon" cars? Cheap and effective!
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Old 08-23-2013, 10:07 AM   #85
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I posted a couple of comments on the Euro pan classic thread that perhaps belong here. I'm definitely hoping that your project succeeds.
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Old 08-23-2013, 02:03 PM   #86
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Thanks Ned. Yeah as I mentioned above I did take the time to go through quite a bit of this thread. It appeared that several folks were discussing the idea of making a new pan car and I'm extremely interested in that.
The link that I posted (did you look?) pointed to a one piece front.

I'm understand what tweak is btw and certainly Aluminum (and fiberglass) can tweak. I made mention of the aluminum because often that can be milled more cheaply. (I believe Fiberglass has more safety concerns). After I made that comment though I noticed that Hitcharide1 had found and was able to work with fiberglass at a really cheap price.
Lastly your pics on the other thread look to be an excellent prototype for the car. I would be a customer for that type of car for certain.

From aarcobra
Most of the pan cars being discussed are the newer Euro Type. Taylorm, hitcharide1, and Rick Davis are all working or have worked on this type, although they all are interested in the vintage pan also. Howard and I have tried to get this thread going to separate the discussions, with little luck.

Yes I looked at the link. I started this hobby in 1970 so I have owned or seen nearly all of the cars from the Dynamic Suspension Car, Heath Kit, Wen, etc. on! (Yes I'm OLD! ) The Associated 200 front end requires a lot more machining than the Delta type, but looks better!
Actually, I find fiberglass a much better material to work with and far superior in tweak resistance to aluminum, especially in the .093" to .125" thickness range used in vintage pan cars.

Ned
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Old 08-23-2013, 06:00 PM   #87
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I'm not exactly new to the sport as well. (see album for pics). Just new to this board. I stopped racing for a very long time (last race I made was the 1996 World's 1/12 and 1/10 onroad - came in last or second to last).
I think the delta style would definitely be easier to build. The R&A front (Assoc) has the advantage of a top and bottom "fork" . I like the black fiberglass in your pic's.

Oh and in honor of your forum name I thought I'd post a pic of me at Firebird Raceway here in Phx in my 289 FIA Cobra
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Old 08-23-2013, 08:51 PM   #88
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I'm not exactly new to the sport as well. (see album for pics). Just new to this board. I stopped racing for a very long time (last race I made was the 1996 World's 1/12 and 1/10 onroad - came in last or second to last).
I think the delta style would definitely be easier to build. The R&A front (Assoc) has the advantage of a top and bottom "fork" . I like the black fiberglass in your pic's.

Oh and in honor of your forum name I thought I'd post a pic of me at Firebird Raceway here in Phx in my 289 FIA Cobra
Hey making the World's is a BIG accomplishment! Congrats!!!

I agree about the "fork" but I'm looking at ease if machining first. Both types attach with two screws, so replacement would be easy. The issues I think, are the clutch and diff...

Awesome car! I have a Factory Five under construction and really need to drop the RC stuff and get to work on completing it!!! The FIA is my favorite roadster. Except for the "suit case bumps"
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Old 08-24-2013, 09:43 AM   #89
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Hey Guys,

I just ordered some stuff to prototype a ball diff. I've got two V8 pushrods coming, one 5/16" and one 3/8" O.D., from Ebay. They both have 0.080" walls, which should be strong enough, but the wall thickness only permits a 6-32 threaded rod (for adjusting the diff) to pass through the 5/16" size, which is a bit of a concern.

The 5/16" pushrod was $5, and the 3/8" pushrod was $7. Both are new. In quantities of 10, the cost drops by about half. That's thrifty, even for a tightwad like me!

I've used pushrods as axles before, and if I recall correctly, the O.D. is pretty accurate. But we'll see if that's true in this case.

I also ordered some 8x12mm and 3/8x5/8" bearings from TQ. As aarcobra mentioned, they are darn cheap! The 8x12mm should fit nicely inside the rear wheels to permit the right side to rotate freely on the 5/16" axle. I'll also use them for spacers on the left side wheel, even though that doesn't need bearings to the axle, because they are so cheap!

Next up is to get some clamping collars on order to support the inside diff ring.
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Old 08-24-2013, 10:02 AM   #90
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Howard...www.avidrc.com has bearings at super
cheap prices..many are a dollar each... Quality
Is decent also...
I'm real interested to see if Pushrod pan works...
Matt
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