Author Topic: Multiple gears  (Read 4520 times)

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #30 on: August 31, 2020, 02:23:10 PM »
Hi Mike

Yes its a similar engine the difference is the Routemaster is AH horizontal.

Jason

the pictures are the best that i have to work with sorry as i dont see how much help they would be :-)

In my drawing the Crank Cam and Dissy are sort of fixed, i have moved them a bit to enlarge the gears to get 2:1, if the have to be tweaked then so be it :-)

All dims are mm

Bernie


Offline pgp001

  • Full Member
  • ****
  • Posts: 812
  • West Yorkshire - UK
Re: Multiple gears
« Reply #31 on: August 31, 2020, 04:20:15 PM »
Bernie

Are you sure the gear on the RHS is to drive a distributor ?
It looks more like an air compressor to me. Probably to feed the air brake system.
If that is the case it will not matter too much about the gear ratio to drive it.

I guess the AEC engine prototype would be a diesel so would not have a distributor as such, but a fuel pump for the injectors.

Phil
« Last Edit: August 31, 2020, 04:27:57 PM by pgp001 »

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9466
  • Surrey, UK
Re: Multiple gears
« Reply #32 on: August 31, 2020, 04:22:41 PM »
Thanks the pictures do help.

As I said earlier the distributor looks to be the easiest to move so that is what I have gone with.

Firstly I used your second sketch and the 38.537mm dimension to determine the positions of the gears relative to the crankshaft, particularly the vertical height of the distributor. Image 3

I then altered the idler gear to a usable size with the closest whole number being 30mm and even if taken to the nearest 0.5mm then 30mm would still be the nearest(see later). It looks like it will be easiest to move the distributor sideways so I kept the vertical height the same (well actually put 24.75 as I suspect the software is rounding it from 24.749) which gives the new horizontal position of the distributor as well as the two positions for the idler. Image 4

Now looking at the photos and your 3D model I would imagine there is not a lot of room withing the gear cover and also the gears look to have quite fine teeth. For these reasons I would now suggest using MOD0.5 gears as these will have a smaller OD for the same given PCD as well as looking more in keeping.

So Crankshaft gear will be MOD 0.5 24T
Cam and distributor will be MOD 0.5 48T
Idler will be Mod 0.5 60T

This is based on using straight cut spur gears, if you intend to use helical gears as per the scans we need to look at it all again.

You should be able to draw the gears using teh FMGears tab in Fusion 360 to see how they fit within the casing.

Well that's my thoughts anyway, others may have different suggestions.
« Last Edit: August 31, 2020, 04:31:02 PM by Jasonb »

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #33 on: August 31, 2020, 04:52:03 PM »
Bernie

Are you sure the gear on the RHS is to drive a distributor ?
It looks more like an air compressor to me. Probably to feed the air brake system.
If that is the case it will not matter too much about the gear ratio to drive it.

I guess the AEC engine prototype would be a diesel so would not have a distributor as such, but a fuel pump for the injectors.

Phil
Hi Phil
You are right, my plan is to put plugs in the head where the injectors go and bury the dissy in a FIP either DPA or Inline so hence the drive through the compressor to be same as Camshaft gear, latter pref, then it look authentic if not a diesel  ;D

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #34 on: August 31, 2020, 04:55:15 PM »
Thanks the pictures do help.


Well that's my thoughts anyway, others may have different suggestions.
These look fantastic and i can redraw the casing to suit, as mentioned before there may have to be some poetic license with this.
I want to go through your maths a bit at a time and when i understand it fully only then will i will fit them into fusion.
Thank you so much
Bernie

Offline pgp001

  • Full Member
  • ****
  • Posts: 812
  • West Yorkshire - UK
Re: Multiple gears
« Reply #35 on: August 31, 2020, 05:03:05 PM »
Ah so it is one of these.

<a href="https://www.youtube.com/watch?v=KGqBASZKZMs" target="_blank">http://www.youtube.com/watch?v=KGqBASZKZMs</a>

I can see now that the injector pump is driven out of the rear end of the compressor, so it could easily become a dummy distributor instead.
Should make an interesting model.

Phil

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #36 on: August 31, 2020, 05:06:02 PM »
Yes thats the baby, i know the DPA pump was used in the horizontal eng so hiding the dissy would be easier than the inline but thats so far down the road yet i have a lot of learning ahead of me :-)

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #37 on: September 01, 2020, 02:28:42 PM »
Well i have finally started to get somewhere with this  :D, in fact i found it quite adddictive  :embarassed:
I have purchased the gears and gear cutting book and also a gear addin for fusion to make sure i really get it right


thanks to all especially jasonb for the new layout

Bernie

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: Multiple gears
« Reply #38 on: September 01, 2020, 05:21:47 PM »
Bernie if you want the calculation spreadsheet on making gears, gear cutters and gear hobb. pm me with your email address and I will gladly send them to you. This spreadsheet cover many different gears. I have recently made a spreadsheet on spiral gears that I will post as soon as I am back in town if anyone is interested.


Regards Don

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #39 on: September 01, 2020, 05:39:46 PM »
PM sent, thank you very much  :ThumbsUp:

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 3752
  • Søften - Denmark
Re: Multiple gears
« Reply #40 on: September 01, 2020, 08:22:07 PM »
Don - I'm sure that many here will appreciate yet another fine spreadsheet from you  :ThumbsUp:
It should make a nice addition to the collection on site here  :cheers:

Best wishes

Per

ps  interesting project Bernie  :)

Offline Mcgyver

  • Full Member
  • ****
  • Posts: 394
  • Toronto
Re: Multiple gears
« Reply #41 on: September 02, 2020, 12:29:53 PM »
I would guess since the PDs work out to nice even metric numbers you are working in mod gears vs DP?  Then it might not help so much, but I really like this gear design/animation page. 

https://geargenerator.com

You can set up any train you like, control what is driven by what etc.  The only thing it doesn't give is centre distances, but that can be calculated from the PC and angle you input...or down load a dxf


Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #42 on: September 02, 2020, 03:20:17 PM »
I would guess since the PDs work out to nice even metric numbers you are working in mod gears vs DP?  Then it might not help so much, but I really like this gear design/animation page. 

https://geargenerator.com

You can set up any train you like, control what is driven by what etc.  The only thing it doesn't give is centre distances, but that can be calculated from the PC and angle you input...or down load a dxf

Thank you

Offline bernienufc

  • Full Member
  • ****
  • Posts: 31
Re: Multiple gears
« Reply #43 on: September 03, 2020, 06:48:34 PM »

You should be able to draw the gears using teh FMGears tab in Fusion 360 to see how they fit within the casing.

Well that's my thoughts anyway, others may have different suggestions.

This is great, thank you for the pointer  :ThumbsUp:

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal