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Re: $20 ebay beater
Posted: Mon Apr 14, 2008 7:03 am
by Asso_man!
Wow Ed, very nice job! We would need some close-up pics to look at those home-made parts, they look great from here. But yes indeed, each time your spur gear will have make 1 complete rotation, your front wheels will have done the same travel (assuming all the extra pulleys you used have the same diameter), which is certainly not the case for the rear wheels (less travel because of the diff and the middle gear ratio added). You would definitely need at least a one-way on the front, or maybe a diff., but it's hard to tell from the pics what is what... don't give-up, it's all good mate!
Re: $20 ebay beater
Posted: Mon Apr 14, 2008 7:20 am
by Dr. Robotnik
Asso_man! wrote:Wow Ed, very nice job! We would need some close-up pics to look at those home-made parts, they look great from here. But yes indeed, each time your spur gear will have make 1 complete rotation, your front wheels will have done the same travel (assuming all the extra pulleys you used have the same diameter), which is certainly not the case for the rear wheels (less travel because of the diff and the middle gear ratio added). You would definitely need at least a one-way on the front, or maybe a diff., but it's hard to tell from the pics what is what... don't give-up, it's all good mate!
Thanks a lot, that's exactly what I thought...I don't know if I have time to make a diff. but I can definitely slide some one ways in somewhere...I might just use YZ834B front hubs then...although I kind of wanted to do my own thing rather than a hybrid. Pah! Who am I kidding I just want to drive it now.
Re: $20 ebay beater + homemade 4wd system...
Posted: Mon Apr 14, 2008 7:28 am
by Chewbacca
Dr. Robotnik wrote:Asso_man! wrote:Looking forward to seeing those home made 4wd parts

Oh one last thing...can people comment on how the front drive ratio will turn out like this, please? I was tired and can't get my head round it. Will the front wheels be going fastest?
WOW, nice build!
Are all of your added chain gears the same size? aka 1:1 ?
If so, then yes, your front wheels will be going WAY faster than the rear.
Wait a minute though, I have to look at the pics again...
Re: $20 ebay beater + homemade 4wd system...
Posted: Mon Apr 14, 2008 7:33 am
by Dr. Robotnik
Chewbacca wrote:Dr. Robotnik wrote:Asso_man! wrote:Looking forward to seeing those home made 4wd parts

Oh one last thing...can people comment on how the front drive ratio will turn out like this, please? I was tired and can't get my head round it. Will the front wheels be going fastest?
WOW, nice build!
Are all of your addes chain gears the same size? aka 1:1
If so, then yes, your front whells will be going WAY faster than the rear.
Wait a minute though, I have to look at the pics again...
Yes sir they are! I wonder what front wheel drive will be like
But yes I noticed that this would be the case and was just double checking as I was tired when I thought about it.
So I guess my question would be where can I get chain drive gears in a larger size?
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:05 am
by Chewbacca
In my opinion you have two options:
1 -> install a second stealth tranny in the front, but then it would make sense to try to drive the chains from the idler gear, and then chop the front stealth tranny above the idler
or
2 -> try to copy the stealth ratio with your chain gears: 1st gear with the same tooth cound as the drive gear, the 2 middle chain gears like the idler gear, and the front chain gear like the diff gear.
THIS might help.
Chewie.
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:09 am
by Dr. Robotnik
Chewbacca wrote:In my opinion you have two options:
1 -> install a second stealth tranny in the front, but then it would make sense to try to drive the chains from the idler gear, and then chop the front stealth tranny above the idler
or
2 -> try to copy the stealth ratio with your chain gears: 1st gear with the same tooth cound as the drive gear, the 2 middle chain gears like the idler gear, and the front chain gear like the diff gear.
THIS might help.
Chewie.
This car isn't a Stealth, it's only drilled for 6 gear type trannies. It has an MIP gearbox at the rear and I am not going to chop one up for the front! I am running my chain from the top gear as that's where the hole in this tranny was already drilled...
What's the link for btw? It just takes me to a generic website start-up page for Conrad electronics...
Thanks for your continued interest and help.
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:16 am
by Chewbacca
O sorry the link doesn't work the way I thought it would hold on...
try this:
http://www1.conrad.de/scripts/wgate/zcop_b2c/?~template=pcat_area&zhmmh_area_kz=13&navi=breadcrumb&cachedetail=&p_load_area=1210043&p_artikelbilder_mode=Ein&p_sortopt=object_description&page=1&p_catalog_max_results=20
or from their main page follow this path:
Home -> Modellbau -> Technischer Modellbau -> Zahnräder / Ritzel -> Modellbau Ketten & Kettenräder
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:36 am
by Dr. Robotnik
Ok, great, that link works perfectly. Now I guess I need to just work out what front ratio I want...any suggestions?
The final drive of the MIP box is 2.00 so the same or what??? for the front?
Sorry for all the questions but I am new to the scratch builds.

Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:43 am
by Chewbacca
if your front wheels have the same diameter as the rear then you want the same drive ratio as the front.
If the mip reall had a total ratio of 2 it is WAY simpler to get you set.
You only have to change a SINGLE gear! the one that comes right after the one connected to the drive shaft (I'll call it the second gear).
All you have to do is find a gear with twice the amount of teeth as the first one (on tranny shaft) and use that as second gear.
I hope you got what I meant...

Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 8:48 am
by Dr. Robotnik
Chewbacca wrote:if your front wheels have the same diameter as the rear then you want the same drive ratio as the front.
If the mip reall had a total ratio of 2 it is WAY simpler to get you set.
You only have to change a SINGLE gear! the one that comes right after the one connected to the drive shaft (I'll call it the second gear).
All you have to do is find a gear with twice the amount of teeth as the first one (on tranny shaft) and use that as second gear.
I hope you got what I meant...

Ok I've got it. Thanks. I guess I have to go count the teeth on the gears now...from memory though it's a 15 toother.
A 30T from the ones you have sent me though is 60mm outside diameter!!!!
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 9:37 am
by Chewbacca
Dr. Robotnik wrote:Chewbacca wrote:if your front wheels have the same diameter as the rear then you want the same drive ratio as the front. ...
A 30T from the ones you have sent me though is 60mm outside diameter!!!!
Okay thats pretty big, then you change the 1st gear to 10 and the second to 20 leave the other 2 the way they are.
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 10:20 am
by Dr. Robotnik
Chewbacca wrote:Dr. Robotnik wrote:Chewbacca wrote:if your front wheels have the same diameter as the rear then you want the same drive ratio as the front. ...
A 30T from the ones you have sent me though is 60mm outside diameter!!!!
Okay thats pretty big, then you change the 1st gear to 10 and the second to 20 leave the other 2 the way they are.
Ok that could work. What I was thinking was that these gears weren't the right type. Even the 10 tooth one is approx. 22mm. I think mine are from rough memory just 15mm for a 15 tooth...I can't be sure as I am going from memory but they all seem pretty big to me.
BTW what are these gears for originally? Are they for RC's? My German is a bit non-existent I am afraid.
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 10:23 am
by Chewbacca
I am not sure if the pictured gears are meant for the other chain also shown there. The one that looks like s small scale bicycle chain...
I do have their catalogue, it's just down in my basement. Will try to check one of these days
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 10:24 am
by Dr. Robotnik
Oh. Well I am using the bandkette type chain at the top.
Re: $20 ebay beater + homemade 4wd kit
Posted: Mon Apr 14, 2008 10:25 am
by Dr. Robotnik
Oh btw the catalogue is online in pdf format but I am not really getting anywhere with it.