Author Topic: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine  (Read 129712 times)

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #480 on: June 14, 2020, 02:21:06 PM »
…….and BTW you have these "HOF" IMPBA members continually learning from you and yet still You are not in.  All these directors and such why have not they nominated you? I'm not currently active so Ill pay my dues and maybe Lohring will 2nd. my request. Isn't it about time James? You've learned earned the right they should pay the homage anything else and you know how ill take it. They need to give you your due so you can actually enjoy it. Please be sure ur giving it to the right people there because I'm still not convinced you are James. Those "motor building programs" there are such a farce .

:Jester:

Regards,
Hubert

Offline strictlybusiness1

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #481 on: June 15, 2020, 08:22:23 PM »
Beautiful work. How did you and Ed attach the wires to the engines? I also would like to know did you grind the spring steel turn fin. I need  to make one for scale saw How did you manufacture it and how did you color the hardware? It's beautiful.

Regards
Hubert

Hugh, we used the same single split collet system, with the collet split from "end to end", for several different size hard shaft wires (.093", .125", .1875", .250") & flexible cable drives. (.1875", .250"). The original full hard, 32 pitch, threaded on the outside, ground tapered seat, female pieces were used. All the female pieces used the same .5000" locating hole & were screwed to the flywheels with two 6-32 SHCC. Notice the large flange of the threaded female pieces which sits on the face of the flywheel that ensures accurate concentricity & total indicator runout. All the flywheels used, gas or nitro, were mounted on either a separate tapered split "end to end"collet or a taper ground on the crankshaft. The very poor design of many present day partially split type collets & their poor locating systems continues to present problems of total indicator runout & accurate concentricity!

All spring steel type skid fins were machined with carbide tooling in a similar fixture as the type used for a full tapered rudders (either AISI-01 tool steel or 7075-T651 aluminum). 01 steel rudders were hardened after machining & then tempered to a spring temper. Spring steel skid fins (.0625" thick spring steel material) & the steel rudders are indestructible!

Anything made of steel that was exposed to the water was treated with Precision Brand Tool Black protective finish for ferrous metals.

Jim Allen
« Last Edit: June 17, 2020, 04:22:32 PM by strictlybusiness1 »

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #482 on: June 16, 2020, 06:28:41 PM »
James,
How do you set the lathe and grinder correctly to get the seat and insert tapers accurate and on center?

Thanks for your time an patience.
Hubert

Offline strictlybusiness1

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #483 on: June 16, 2020, 09:05:38 PM »
James,
How do you set the lathe and grinder correctly to get the seat and insert tapers accurate and on center?

Thanks for your time an patience.
Hubert

Hugh,

The first thing I did was to regrind the hardened Morse Taper #5 adaptor's seat that my precision grade 5-C collets would be setting in. This was very easy to accomplish with the Themac tool post grinder shown because the 5-C  collet adaptor had less than .0002" total indicator runout. Notice the marks on the spindle & the 5-C collet adaptor which allow the 5-C collet adaptor to always be placed in the same spot in the lathes spindle. Both the lathes spindle & the adaptor are full hard ground steel. Cleanliness is very important when setting up these two pieces to ensure repeatability of .0000" runout. Next, I machined a 1.5" OD aluminum rod down to 1.0" on one end. The length of the taper on this rod will be 2.625" at 7 deg. This 2.625" dimension is 3.5 X the actual length of the .750" split collet piece. Trigonometry tells me the exact dimensions of the big end & little end of the taper master at its 2.625" length. The 2.625" long, 7 deg taper master, can be used to reset the compound precisely by indicating the big & the small end to zero total indicator runout. Then zero the compounds travel over the 2.625" distance of the taper master. This tool was used to easily set the compound precisely to a 7 deg angle. The same technique was used for setting the compound precisely when cutting piston top edge  tapers of .001" on the OD, over a distance of .100". Pre-machined taper masters were also used to precisely cut cylinder tapers.

Jim Allen
« Last Edit: June 17, 2020, 04:19:12 PM by strictlybusiness1 »

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #484 on: June 17, 2020, 02:13:26 PM »
That's beautiful James. I will put that all in my notes 4 sure. BTW I did get in contact with Tyler Garrard and he's also willing to share the work he's done with the wire. Here's a ball bearing strut, ferrule and prop shaft with the wire. They are not sure who produced the original design but the copied it and made a few for he and his friends. Here is one of his very nice setups. He's the one responsible for wire couplers you showed me. I see now that the clamping screws are opposing on it so balancing isn't much of an issue. As I understand the hardware is modified Gas Grim Reaper hardware.

Regards
Hubert
« Last Edit: June 17, 2020, 05:49:40 PM by DRT »

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #485 on: June 25, 2020, 01:34:06 PM »
I dug deeper into it an have an idea you may or may not like. Most of the time our electric motors have a 6 or 8 mm shaft. So why not have the motor shafts ground to a known taper like JTO and use a precision min drill chucks to couple up to 4mm wire for instance.

Regards
Hubert

Offline strictlybusiness1

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #486 on: June 26, 2020, 10:45:57 PM »
Hugh,

In my humble opinion, the couplers shown in the previous post would be the easiest to machine accurately. Center drill, then drill from one end the smaller hole first, then enlarge it. This would ensure the motor's shaft is precisely aligned with the drive shaft. If greater accuracy is needed, the standard procedure would be to center drill, drill, bore, ream to size. Machining the OD after machining the ID holes would make the OD concentric with the internal holes.This is a very easy piece to make.

Jim Allen

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #487 on: June 28, 2020, 07:52:13 PM »
I very much like it but not more than an articulated drive in boats the continually run over the 125 mark. I think the scale will be a straight shaft boat anyway but I need centerless shaft that accepts .125 or .9375.  Any ideas?

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #488 on: June 29, 2020, 04:08:42 PM »

In fact I have sourced the couplers directly to a site in Germany. At 32 dollars I dont think it would be worth my time and material  when there is no major improvement to be made to cut it myself. I follow your step by step. Im still in th eprocess of buying tools. Ive tried to reach you but the email and old number is dead. i didnt wanna just buy things without talking to you. Maybe in time as I may want several buying the stock will make sense.  What I need is the center less shaft for 2.5 mm wire. One I get the shop setup I will quickly move to the articulated ball pin universals. Pm me a contact so I buy the right Lathe. I'd also like to ask about some other really cool machines ive seen online.


Thank you
Hubert
« Last Edit: June 29, 2020, 04:13:13 PM by DRT »

Offline strictlybusiness1

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #489 on: July 10, 2020, 10:04:44 PM »
Hugh,

I have no idea where to buy 2.5 mm ground shaft. There are many lathes that would do almost anything in the model boat field. The cheapest, good quality stuff would be Chinese iron.

Jim

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #490 on: July 13, 2020, 07:45:45 PM »
Hi James
You are right and I hope the lathe I choose is the right one you showed me but it never hurts to make sure.  The other thing.... Bret Byers had put together what I think is the best solid drive system available off a shelf. He uses speed masters struts and rudders in his package. Dealing with the electric forum only puts me inline to deal with people like Chirs Hoffman with his sexually charged drivel. Im so not interested in that or Christian and Tylers recent wedding. So I went totally in the opposite direction.  Here's what Brents system looks like. I need the new email because I have some things I REALLY need you to see. Emails from the Fastest rc boat in the worlds team. This isn't for public viewing I'm sorry. James, Bret simply made a .125 pill for the zip kits supper collet. This could also be done with an Aeromarine one. The motor sitt very far foward and low so a big bulky collet wont help. I will have a look at the spit system but I'm afraid what you will see once the shop is complete is a total doing away with wires and flexes and use exclusively the "constant velocity" joint. Thats the "similar nonsense" posting u experienced from a moderator on JRCBD u get on the fast electric site. A bunch of fun runners that know zero about the science of it all. IMHO theorist that  clearly haven't been exposed to industry and cant even tell the difference beteween accurate info from a vendors plug! I plan to post the record for the big mouthed trolls then I'd want you to take your 1911 and destroy the boat on site!

After the boat has been destroyed to my satisfaction Ill go back to research with Dr Sariful Islam and the NC State department of electrical engineering and computer science . These are the kinds of places that real learning take place. Not on fun runner forums ! This will display how much I think of a competition metric when it comes to high level research and development of an electrical rotating machine. NOT A TOY BOAT! Clearly some of us dont know the difference or even understand the purpose of scientific method. It's a waste of time to talk to people that do not speak the "language' or care about the "number" . It was suggested by one there that he marks his improvement in efficiency using his "optical sensors" aka his eyes. Now such a place is not for me. Im not interested nor do I have time for buffoonery!


 
















Thanks
For you time and patience.
Hubert

« Last Edit: July 14, 2020, 01:45:04 AM by DRT »

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #491 on: July 13, 2020, 08:14:19 PM »


It was that simple JA. If "race mechanix" has to have the simple split collet you showed contracted all the way to Germany to be machined id say hes hardly as capable or connected to capable persons as I am.   :Doh: This person that has given all he has going after the German record and given up doesn't represent me! So while our body may hold him up as the best and brightest we have and I got something to say about that!  The lied about the numbers and I caught  in tthathe math of it all. Thats the extent of his help. The idea I can do math and physics quite well never occurred to them as the send out red herrings. Like the late great Bill Muncy said about a particular rich U1 owner. "You can buy fast but you cannot buy class!!!!"

Regards
Hubert
« Last Edit: July 14, 2020, 01:41:56 AM by DRT »

Offline strictlybusiness1

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #492 on: July 14, 2020, 04:50:14 PM »
Hugh,

The difference between the type of collet setups that can be used involves two main differences. The wire drive set ups for electric motors uses the motors shaft as the center. The center for the type I use is the machined hub on the face of the flywheel, gas engine or nitro engine. This is why my collet setups maintain their accuracy. Look at the locator for the collet setup you pictured. How is it located? You are aware that a difference in the design of collet itself is also a factor to be considered.

JA

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #493 on: July 14, 2020, 05:05:59 PM »
Yes sir. of course! The thing is aeromarine and zipp collets and runout is proven across the finish line so I feel fine there. The new style would require the same leap of faith by anyone that has never used it but as I say ultimately i want the articulated joint not only for how it works but also its more scale apperance. This is a scale boat so its not just about its perfomance as it is judged by its cosmetics as well. The reason I feel bret has put together a good system and shared it is its completeness. U can get the entire system and all its pieces. Its quality stuff and the price is reasonable.  Be aware the collet shown previously is not the electric one but one for a zenoah. Sorry for not making that clear. The pill works with an electric motor aeromarine style collet as well. I use a dowel to align the shaft and from experience the runout has been within acceptable limits with this style collet.

Im not at home so I have no way to tell you the model number of the chineese iron Im looking at but again what model grizzly were you speaking of again.
 
Regards
Hubert.
« Last Edit: July 14, 2020, 05:23:19 PM by DRT »

Offline DRT

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Re: .90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine
« Reply #494 on: July 15, 2020, 07:23:43 PM »
The Grim GAS strut and hardware shown to you on a fast electric rigger is much heavier than any scale or saw FE rigger needs to be. This is the ferrule strut package that will go on the boat. I prefer the Aeromarine Hydro strut. Brent has sold me the pieces so we can check the TIR when it is recieved. The big thick rudders struts etc dont do anything but increase underwater drag and add weight. Most Saw competitors use custom rudder blades, turn fins, hardware etc.  The boat makes a pass turns around slowly and goes straight in the other direction. Why would you need a big thick rudder and strut designed for a gas boat for on an FE saw rigger or scale. It seems counter intuitive to me. Just think about it for a min. The rudders, turnfins, and other underwater hardware's drag increases exponentially as a function of speed. If the design is well thought out and hardware is made from selected materials they dont have to be large and thick to be strong. One look at your turnfin and rudder blades theres no question u know what Im talking about.

Addendum
In the attachments Brent uses these struts in his solid drive package with bushings. The are much thinner than the others shown and they hold up.


Thanks
Hubert
« Last Edit: July 15, 2020, 08:07:22 PM by DRT »

 

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