Author Topic: Geared Primary Drive  (Read 6234 times)

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Offline Tintop

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Re: Geared Primary Drive
« Reply #125 on: March 14, 2019, 02:30:00 pm »
my mechanical engineering gut feeling (only 5 years in the air force R&D unit before i became a designer :) ) tells me that the area in red would be highly stressed, so maybe some sort of webs in green could help?
dont know the exact reaction vectors and might not be doable because of interference with other parts, so just my 2 cents

Those were my thought as well TG.  Webs could be doable with a relief for the oil gallery, some thing like a 'flying buttress', with cross webs were the 4 6mm bolts are, but otherwise open to allow for oil return.  Assembly should not be an issue as you would mount the idler parts to the case 1st.

Would the force not be more stout on the opposite side from where TG showed his red mark?

Agreed Brent (97% upward according to Miko), which is likely why Captain's carrier is shaped as is.  However I think the issue here is Miko is trying to avoid case machining, which is required for Captain's DOHC application.
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Offline MessnerMoto

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Re: Geared Primary Drive
« Reply #126 on: March 14, 2019, 02:54:56 pm »
there is no need for that and there is no space for that... oil pump occupies green lines on yoss picture

I will recalculate stresses and deflection FEA... I will just increase thickness of adapter or remove less material from plate if needed. But 20mm thick aluminum plate with 13 M6 bolts... Probably over engineered already... will see after FEA analysis
« Last Edit: March 14, 2019, 03:22:18 pm by MessnerMoto »

Offline cr750

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Re: Geared Primary Drive
« Reply #127 on: March 14, 2019, 03:42:25 pm »
Sidenote without taking an opinion on the webbing; I would always radius the redline area of TG, and other high loaded areas with sharp corners like that for that matter. Sharp edges are prone to stress fractures. But maybe you were just modeling it quickly.
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Offline MessnerMoto

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Re: Geared Primary Drive
« Reply #128 on: March 14, 2019, 04:04:31 pm »
red line is connection between two parts... adapter plate and idler holder.... adapter plate is made from Al, idler holder is made from 4732 steel... steel because of small available space

they are connected with 4 M10 bolts and there are two locating pins around two of those m10 bolts

Offline bwaller

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Re: Geared Primary Drive
« Reply #129 on: March 14, 2019, 07:12:27 pm »
That makes sense, didn't realize the holder was steel.

I wish we were neighbors Mirko, I'd introduce you to my 550 race engine that desperately needs primary chain elimination!  ;D
« Last Edit: March 14, 2019, 07:14:41 pm by bwaller »

Offline cr750

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Re: Geared Primary Drive
« Reply #130 on: March 15, 2019, 01:08:55 am »
Missed that on first glance, need to study the whole thread better.. Makes sense then. What thickness are the flanges that hold the idler gear ?

Pmd you btw.
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Offline Tintop

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Re: Geared Primary Drive
« Reply #131 on: March 15, 2019, 06:06:55 pm »
Are there plans (after prototype) to anodize the adapter plate to prevent issues at the mating surface between the steel & Al?  Just asking, but would there ever be a need to shim the idler to change gear contact?  And Mirko I checked out your case scans again, and the oil flow graph, and now see what you are saying about no space because of the oil pump.
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Offline Don R

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Re: Geared Primary Drive
« Reply #132 on: March 15, 2019, 11:17:07 pm »
 I'm trying to think of existing contact between steel and aluminum, what comes to mind are the ball bearings, dowel pins, studs, bolts and trans parts.  I'm not seeing any corrosion there so that may not be an issue. The precision it takes to get the clearances right must be difficult, I'm glad intelligent people are working on it and excited to see the results of their efforts.
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Offline turboguzzi

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Re: Geared Primary Drive
« Reply #133 on: March 16, 2019, 06:21:05 am »
TT, there are corrossion issues with stainless steel and aluminum, normal steel doesnt have any issues with Al.

Mirko, wasnt aware either that the holder was a separate part, use different colors in your renderings please :)

nevertheless, just to give more section against the bending forces, maybe you can do something underneath the plate, works the same...

the idler holder is attached with four bolts (two inside the circle) right?

Offline MessnerMoto

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Re: Geared Primary Drive
« Reply #134 on: March 16, 2019, 09:42:57 am »
This 4 bolt holes in red.

but yoss the  resulting force on idler gear is trying to pull idler/holder up. There is basically no side loads. When force is 6000N up, side force is 100N

the "circle" is lower half of oil pump... pickup and relief

Offline Tintop

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Re: Geared Primary Drive
« Reply #135 on: March 17, 2019, 05:06:55 am »
Sorry TG but mild steel and Al do react.  It's why I had to replace the Al bodywork on my 7, rotted out around rivet holes.
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline Captain

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Re: Geared Primary Drive
« Reply #136 on: March 17, 2019, 01:05:48 pm »
 I don't wish to offend, but seriously questioning the Al -Steel compatibility is stretching it.

  What do you think the entire engine internals are made from............. ?

 Captain

Offline kmb69

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Re: Geared Primary Drive
« Reply #137 on: March 17, 2019, 01:19:13 pm »
I don't wish to offend, but seriously questioning the Al -Steel compatibility is stretching it.

  What do you think the entire engine internals are made from............. ?

 Captain

I was thinking the same thing. Especially submerged in oil.
« Last Edit: March 17, 2019, 01:22:03 pm by kmb69 »

Offline kpier883

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Re: Geared Primary Drive
« Reply #138 on: March 17, 2019, 01:55:59 pm »
Agree that with all that oil, what could happen?  Besides, aren't there steel bolts in aluminum castings all over old Honda engines?
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Offline dragracer

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Re: Geared Primary Drive
« Reply #139 on: March 17, 2019, 02:22:06 pm »
I'm just anxiously awaiting the CB900 crank/SOHC version to be produced and to know the final costs. This seems to be a much more straightforward manner in which to do the conversion for someone with minimal access to a capable machinist. I can envision new records being set in multiple venues across the two wheeled spectrum.

Increasing horsepower is expensive for every plateau you reach along the path. The effort put into this conversion will eventually speak for itself.

Offline Tracksnblades1

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Re: Geared Primary Drive
« Reply #140 on: March 17, 2019, 07:45:26 pm »
I don't wish to offend, but seriously questioning the Al -Steel compatibility is stretching it.

  What do you think the entire engine internals are made from............. ?

 Captain

👍
And it's environment will be ideal...Hot High Detergent sling oil from idler feed, main bearings, clutch shaft, and more.
All the manufacturers have used the two together successfully for years. Some applications do have gaskets, some orings, some sealer. Caterpillar and Cummins engines come to mind. Some Caterpillar commercial truck engines have aluminum oil pans. Cummins and Caterpillar both have aluminum rocker boxes bolted to cast iron heads. Some early  C10 Caterpillar engines had aluminum cylinder blocks fitted with steel sleeves with a cast iron head pinching everything together with through bolt all the way to the cast iron crankcase. With cylinder studs it sounds a little more familiar.
I'm hoping the extension will hold an extra quart of oil, safely protected from the crank and below the oil pump pickup.
😎
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Offline Tracksnblades1

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Re: Geared Primary Drive
« Reply #141 on: March 17, 2019, 07:49:49 pm »
I'm just anxiously awaiting the CB900 crank/SOHC version to be produced and to know the final costs. This seems to be a much more straightforward manner in which to do the conversion for someone with minimal access to a capable machinist. I can envision new records being set in multiple venues across the two wheeled spectrum.

Increasing horsepower is expensive for every plateau you reach along the path. The effort put into this conversion will eventually speak for itself.

+1 😎  +1 😇  +1 😉
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Offline Don R

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Re: Geared Primary Drive
« Reply #142 on: March 17, 2019, 09:32:39 pm »
 I'm watching with enthusiasm.
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Offline gschuld

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Re: Geared Primary Drive
« Reply #143 on: March 18, 2019, 05:58:10 am »
I wish I were knowledgeable enough to offer an opinion other than your work looks amazing from a casual observer.😉.

I sure hope this project has a positive outcome😎

George

Offline Terry in Australia

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Re: Geared Primary Drive
« Reply #144 on: March 19, 2019, 04:01:16 pm »
Yep, I hope it actually gets past the design phase.;D
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Offline kmb69

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Re: Geared Primary Drive
« Reply #145 on: March 19, 2019, 06:23:04 pm »
Mirko, this is an awesome and relatively inexpensive idea if it works for the 5 speed. Not possible on the Automatic or DOHC. Not sure if the "precision" existing dowel pins holes are absolutely accurate case set to case set. Would have to measure several case sets to be sure. The gear engagement accuracy for the oil pump drive is not nearly as tight as is required for the gear drive primary. Have you had the opportunity to check more than one set of cases?

Offline MessnerMoto

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Re: Geared Primary Drive
« Reply #146 on: March 20, 2019, 03:45:41 pm »
Mirko, this is an awesome and relatively inexpensive idea if it works for the 5 speed. Not possible on the Automatic or DOHC. Not sure if the "precision" existing dowel pins holes are absolutely accurate case set to case set. Would have to measure several case sets to be sure. The gear engagement accuracy for the oil pump drive is not nearly as tight as is required for the gear drive primary. Have you had the opportunity to check more than one set of cases?

When I measured this one case. And did 3d scan.... All measurements are nice round numbers with machining errors of +/-0.02 top usually -/+0.01 ...fun fact thickness of lower case is 119.99-120.00. Really precise machining of oil pan surface.


 I am planing to add shim plate below idler for just in case. There will be a possibility to adjust from -0.1mm Y position with shims... I just need to source shim plates.... It would be nice also to be able to adjust X position of idler but I don't have idea how.
« Last Edit: March 20, 2019, 03:56:28 pm by MessnerMoto »

Offline dragracer

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Re: Geared Primary Drive
« Reply #147 on: March 20, 2019, 04:28:18 pm »
Awesome design work.

So when can we expect to see a working prototype and any idea of estimated cost??

Offline turboguzzi

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Re: Geared Primary Drive
« Reply #148 on: March 20, 2019, 04:37:29 pm »
guys, tnxs for confirming my thoughts on AL=steel..... exposed to elements is another story of course, TT.

Mirko, if you are in need of shimming material, just come and grab some next time you are in milan.

if not search for Hasberg shims

would design say for nominal 0.5 shim so you can go both up and down in .1mm steps

for X, cant see the problem making the holes a bit oval, with 4 M8 bolts (?) exerting a few tons of grip it's not going to go anywhere....

you are in good company, even works GP hondas had to shim their cam gear drives :)
« Last Edit: March 20, 2019, 04:40:03 pm by turboguzzi »

Offline MessnerMoto

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Re: Geared Primary Drive
« Reply #149 on: March 21, 2019, 01:16:22 am »
guys, tnxs for confirming my thoughts on AL=steel..... exposed to elements is another story of course, TT.

Mirko, if you are in need of shimming material, just come and grab some next time you are in milan.

if not search for Hasberg shims

would design say for nominal 0.5 shim so you can go both up and down in .1mm steps

for X, cant see the problem making the holes a bit oval, with 4 M8 bolts (?) exerting a few tons of grip it's not going to go anywhere....

you are in good company, even works GP hondas had to shim their cam gear drives :)

I want to be able to shim in finer steps of 0.01mm. Will look if that company has finer shims. I will machine everything in -0.1mm(maybe -0.2mm) position. And then you can add shims to infinity position ;)

It is not a problem to add oval shaped holes... But how to position it , let say, 0.03mm from original X position?

There are 4 M10 bolts holding the idler and two bolts have locating dowels around them in current design,

 

;
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