Envelope-to: craig@dapaero.com
Delivery-date: Thu, 04 Aug 2022 22:58:39 -0500
Message-ID: <729c1950-8710-eb75-52de-8ae370e846af@nctv.com>
Date: Thu, 4 Aug 2022 20:58:24 -0700
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Subject: Re: arm offset
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To: DAP AERO <craig@dapaero.com>
References: <fbfd44f6-7b19-44bf-c485-b2415909db7d@nctv.com>
 <40B4C290-AF63-4447-B33C-AD5D424E67A4@dapaero.com>
From: Curtis Andrews <andrewscc@nctv.com>
In-Reply-To: <40B4C290-AF63-4447-B33C-AD5D424E67A4@dapaero.com>
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If we want a 24" sweep of the handles, then the connecting rod need to 
connect half way out form the pivot, since the crank stroke is 12" . so 
then the only variable is the length of the little arm.

since my horizontal distance is 2/3 that of the originals, that would 
mean we need a vertical offset about 3" which is not much.


on the other hand, maybe the little offset is to soften the end of the 
stroke, as it is quite jaring when it changes directions.


On 8/4/22 8:07 pm, DAP AERO wrote:
> The +/- extremes can be made even by adjusting the push rod
>
> I need dimensions of your drive gear
>
> I was hoping that by stopping the video the reason for the little arm would be more obvious
>
>> On Aug 4, 2022, at 8:00 PM, Curtis Andrews <andrewscc@nctv.com> wrote:
>>
>> ﻿it appears from the model that the rocker arm is steeper at the bottom of the stroke, which is not right, as the stroke must match above and below center line.
>>
>> If you connect the rod to the rocker arm at the arm with no offset, is the movement equal?  IF not, then that must be the reason for the offset.
>>
>>
>> if the crank was directly under the connection on the rocker arm, then it would be equal, since my crank is only half of the horizontal distance from the rocker pivot, one would think i would need less of the leg on the offset.
>>
>>
>>> On 8/3/22 8:35 pm, DAP AERO wrote:
>>> Will draw tomorrow to try and catch up
>>>
>>>>> On Aug 3, 2022, at 7:59 PM, Curtis Andrews <andrewscc@nctv.com> wrote:
>>>> ﻿Question, where is best location for connecting rod to connect to pump bar?
>>>>
>>>> attached are two original documents
>>>>
>>>> I have scaled 10" horizontal and 4" vertically
>>>>
>>>> found drawings of 9"Hor and 5 Vert  and  8" Hor and 7 vert
>>>>
>>>> but using chain and sprocket and not gears, the relationship between crank and bar  is not the same as the originals.
>>>>
>>>> people are 1.5" taller, but fatter, and we are not going miles so needs to be easier for short distances.    120 years ago, four men could produce .6 HP  today, four men can produce .4 HP  so needs to be 1/3 eaisier.
>>>>
>>>>
>>>> building generally a Sheffield #2 car but 16" wheels. 12" stroke was standard, but i can shorten if better.
>>>>
>>>> -- 
>>>> Thank You
>>>>
>>>> Curtis Andrews
>>>> 1336 E Oak St
>>>> Othello WA. 99344
>>>> andrewscc@aol.com
>>>> 509 346 8108
>> -- 
>> Thank You
>>
>> Curtis Andrews
>> 1336 E Oak St
>> Othello WA. 99344
>> andrewscc@aol.com
>> 509 346 8108
>>
-- 
Thank You

Curtis Andrews
1336 E Oak St
Othello WA. 99344
andrewscc@aol.com
509 346 8108