40inches
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| posted on 15/5/09 at 11:55 AM |
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quote:
Originally posted by Hellfire
Sounds to me like there's a market here for a 'rent-a-reverse', in a similar way to the 'rent-a-cat' for IVA
purposes.
I'm sure whoever designs and builds a simple one that could be easily transferred from vehicle to vehicle, would soon recoup their initial
outlay and even make a few quid 
Phil
Would there be any consequences from removing reverse after IVA? Someone mentioned not being insured if you did this
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Hellfire
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| posted on 15/5/09 at 04:58 PM |
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quote:
Originally posted by 40inches
Would there be any consequences from removing reverse after IVA? Someone mentioned not being insured if you did this
I wouldn't imagine that removing reverse after IVA would be an issue. Most BEC's don't have reverse and I'm not aware that
insurance companies now state it must be a requirement.
Phil
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tommyab
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| posted on 17/5/09 at 10:21 AM |
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quote:
Originally posted by 40inches
There are a lot of variables involved in fabricating an electric reverse, not least is using a starter motor that runs in the correct direction, if
you don't want another forward gear 
Then there is finding a starter with a gear pitch that can be replicated, some manufactures use some very strange pitch and pressure angles.
You then need a starter that is small enough to fit, but powerful enough to move the car and at least the driver.
So far I have found what I believe to be a suitable starter and have ordered a spur gear that will fit on the diff flange as per MK, also have just
finished the drawings for a motor mount that can be either bolted, or welded on the chassis and is adjustable, so in theory it should fit most
7's.
All this lot should come together in about 2 weeks, so if you can wait I could put it all together with relays and wiring and try for a group buy, but
I will definitely post a shopping list, if it all works 
I'd be interested in a group buy as well. I was trying to figure out the gear myself, got the standard on gears which I can calc the teeth
profiles from, but I cant find any info. on the profiles of starter motor teeth to use as the starting point.
Do you mind me asking what motor you are using and have you got the teeth profiles of it?
cheers.
Tom
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40inches
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| posted on 17/5/09 at 03:23 PM |
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I found the Golf Mk4 to be ok for size and power. As said, starter motor gear teeth are a bit on the strange side, so I found it easier to take a VAG
ring gear to the gear manufactures and it came out as a 12DP. I was expecting a MOD pitch!
This won't be working and confirmed until I have the new spur gear back.
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nick205
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| posted on 19/5/09 at 12:07 PM |
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Could you get enough torque/grip from a starter motor to work some kind of reverse with a rubber wheel against the prop/diff. i.e. mount a rubber
tyred wheel of some sort on the starter motor shaft and then mount the motor next to/above the diff on some sort of pivot arrangement so the rubber
wheel can be lowered against the difff flange (might meed some sort of mating rubber section on the diff flange) to provide the drive. If the motor
pivoted the right way, the rotation of the wheel would pull itself against the diff flange.
Simple and cheap to make and operate (lever next to handbrake maybe) and no power loss when it's not in use.
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rb968
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| posted on 20/5/09 at 03:19 PM |
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I picked up a Ford Fiesta 1.25 Zetec starter and sent that to HPC Gears yesterday. They have confirmed it is 12 DP and have quoted me £69 +VAT for a
131mm dia spur gear (10mm width).
Might be able to push the diameter a bit if you want to "expand" the tunnel sides but thats pretty close to the max space I see as
available. Going to have a measure up tonight before I decide to order it.
Will keep you posted.
Rich
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40inches
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| posted on 20/5/09 at 03:46 PM |
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quote:
Originally posted by rb968
I picked up a Ford Fiesta 1.25 Zetec starter and sent that to HPC Gears yesterday. They have confirmed it is 12 DP and have quoted me £69 +VAT for a
131mm dia spur gear (10mm width).
Might be able to push the diameter a bit if you want to "expand" the tunnel sides but thats pretty close to the max space I see as
available. Going to have a measure up tonight before I decide to order it.
Will keep you posted.
Rich
Are you able to machine the bores yourself? the price for a 60 tooth 12DP is £43, they charge £26 to skim the gear from it's standard 19mm width
 They also charge £17 for a bore up to 99mm and a further £35 for another bore over 100mm, all plus vat!
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rb968
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| posted on 20/5/09 at 04:18 PM |
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I work for an engineering firm so opening the bore from 22mm standard and drilling the holes for the prop/diff bolt pattern is not a problem for me.
Just can't cut spur gears!
You need a friendly machine shop to finish the job!
Rich
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rb968
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| posted on 20/5/09 at 04:21 PM |
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Who is the chap on here with the water cutting machine. Can he help with the bore and holes?
Rich
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rb968
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| posted on 20/5/09 at 10:03 PM |
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After , measuring up tonight i think ineed to up the gear dia to 6" which takes it about 5mm into the cabin either side of the tunnel. Will get
anew quote. Anyone know what size gear MK supply?
Rich
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40inches
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| posted on 21/5/09 at 10:58 AM |
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quote:
Originally posted by rb968
After , measuring up tonight i think ineed to up the gear dia to 6" which takes it about 5mm into the cabin either side of the tunnel. Will get
anew quote. Anyone know what size gear MK supply?
Rich
64 teeth, if 12DP, 5.5 inches
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rb968
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| posted on 21/5/09 at 01:03 PM |
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New quote for 6.0" PCD (6.167" OD) is £78.97.
They forgot to change number of teeth but am assuming 66 based on your post.
Reason for going bigger is I have sent the starter away and am now worrying there is not enough room for it under the prop at the smaller size and
that I will blow £100 on a gear and the starter fouls the prop! I don;t want to be working to mm clearances when its spinning at that rate :-0
Will have to reinforce the tunnel side and bow out those sections to cover the gear as per the MK version. Not great but hey needs must.
Rich
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40inches
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| posted on 21/5/09 at 02:11 PM |
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quote:
Originally posted by rb968
New quote for 6.0" PCD (6.167" OD) is £78.97.
Reason for going bigger is I have sent the starter away and am now worrying there is not enough room for it under the prop at the smaller size and
that I will blow £100 on a gear and the starter fouls the prop! I don;t want to be working to mm clearances when its spinning at that rate :-0
Rich
You may have to modify top of starter as per drawing to stop prop fouling.
Check photos in this thread to see how MK have had to hack the starter for clearance.
http://locostbuilders.co.uk/viewthread.php?tid=110570
 
VAG starter
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peteday_uk@btinternet.com
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| posted on 21/5/09 at 07:11 PM |
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I noticed at Stoneleigh that MK are now mounting their starter motor from the top rails so they have no need to cut the floor.
They are using a VW starter motor.
 (was trying to insert an image, but don't know how).


Pete.
[Edited on 21/5/09 by peteday_uk@btinternet.com]
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rb968
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| posted on 22/5/09 at 08:40 AM |
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I looked at that but the handbrake mechanism seemed to be in the way.
The photos of the MK setup were useful as you say they showed you would probably need to grid away the top part of the alloy housing. The Fiesta
starter has a 4 mm approx lip which will need removing.
Rich
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rb968
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| posted on 22/5/09 at 11:03 AM |
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Have ordered the bugger now so fingers crossed ! 72 teeth 6" PCD 12 DP.
Rich
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40inches
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| posted on 22/5/09 at 12:20 PM |
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Have you paid yet? went down to HPC yesterday to see if mine was ready, not started it yet apparently was on pro former invoice, however they forgot
to send it to me, or even tell me  No apology, just that they will do their best to get it out next week???? NOT impressed!
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rb968
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| posted on 22/5/09 at 03:19 PM |
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Yep paid and the nice lady said up to 14 days.
Will wait and see ! Hope you get yours sorted.
Rich
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Ninehigh
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| posted on 22/5/09 at 08:18 PM |
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quote:
Originally posted by nick205
How about keeping a wooden pole behind your seat?
When you need to reverse you simply use the pole to "punt" yourself backwards. No need to even undo your harness. Should be easy what
with you BEC boys being so low weight of course
Why not cut a door into the floor and have a flintstones style reverse? Seeing as they're so light, and surely a hinge and a bolt is less weight
than even a carbon fibre pole
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tommyab
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| posted on 27/5/09 at 07:14 PM |
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This might be a silly question but why does the gear need to be bored out to such an extent? Would a circular plate with teeth cut and holes drilled
not do the job?
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40inches
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| posted on 28/5/09 at 12:37 PM |
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quote:
Originally posted by tommyab
This might be a silly question but why does the gear need to be bored out to such an extent? Would a circular plate with teeth cut and holes drilled
not do the job?
The prop needs to be located firmly on the diff by a spigot, the large bore fits over the diff flange and the prop spigots into the small diameter
bore.
Relying on the 4 bolts holding the prop to the diff flange don't think so! plus the gear needs to run true.
Picked mine up this morning, just finished drilling holes and chemically blacking it
.JPG)
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tommyab
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| posted on 28/5/09 at 06:25 PM |
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Hehe. Fair enough. I guess those bolts are quite small. Im not used to engineering stuff on such a small scale (offshore construction/installation
is my day job).
Thats looking good. I am following you guys progress with much interest!
Cheers,
Tom
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40inches
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| posted on 11/6/09 at 09:40 AM |
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First test
Brackets in place and adjusted.
Have put a video on YouTube http://www.youtube.com/watch?v=a0V0clui0BQ
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peteday_uk@btinternet.com
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| posted on 11/6/09 at 11:47 AM |
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I have just looked at the video. Looks good. I have to be honest and say in my own mind the reverse would be alot slower than that. Or is it simply
a case of it not being connected to anything?
[Edited on 11/6/09 by peteday_uk@btinternet.com]
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40inches
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| posted on 11/6/09 at 12:23 PM |
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It's a lot slower at the wheels, perhaps walking pace, you have to factor in the diff ratio
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