Landy_Andy
Well-known member
From what I've read so far the maximum suggested line pressure is ~1200psi for a braking system, so with this setup it looks in the right ball park ????
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Bible iBooster Electric Brake Booster
- Thread starter snivilous
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From what I've read so far the maximum suggested line pressure is ~1200psi for a braking system, so with this setup it looks in the right ball park ????
Bebop
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I still think that's low.From what I've read so far the maximum suggested line pressure is ~1200psi for a braking system, so with this setup it looks in the right ball park ????
I've measured well over 1500psi with a hydroboost.
JohnnyJ
Low Range Drifter
When I had the pressure gauge hooked up, the best I saw from my iBooster setup was 1250psi.
Landy_Andy
Well-known member
Thanks for the info.... gonna start a new thread save polluting this one any more
white-rhino
Older than dirt
Mine is not Ibooster but I can lock up my 43” tires with 1300 coming out of the master but about 1000 at the caliper.
HYDRODYNAMIC
Rock Stacker
Somewhere, possibly my build thread I went over design PSI vs comfortable PSI vs max PSI.
The hardware must handle the force and pressure.
The body must be able to sustain the force and work to create the pressure to stop after driving for 8 hours on the trail.
When the adrenaline hits gigachad, he can rip the pedal clean off the chassis, pop the lines, and split the calipers.
Ibooster gives that high work pressure all day long and removes the pedal leverage that can over pressurize the system.
The hardware must handle the force and pressure.
The body must be able to sustain the force and work to create the pressure to stop after driving for 8 hours on the trail.
When the adrenaline hits gigachad, he can rip the pedal clean off the chassis, pop the lines, and split the calipers.
Ibooster gives that high work pressure all day long and removes the pedal leverage that can over pressurize the system.
Landy_Andy
Well-known member
Ok, after lots of reading am going to jump down the iBooster rabbit hole & grabbed the gen2 model. Not having a 3D printer & getting a quote for $100 to get it printed locally got me thinking... why plastic when you have a plasma table & some 1/8" offcuts, so....
This should be more than adequate to figure out where to mount it and be more robust too
This should be more than adequate to figure out where to mount it and be more robust too
chaplinfj60
Well-known member
i think i got mine off ebay for a little over 130 for the booster and master.Ok, after lots of reading am going to jump down the iBooster rabbit hole & grabbed the gen2 model. Not having a 3D printer & getting a quote for $100 to get it printed locally got me thinking... why plastic when you have a plasma table & some 1/8" offcuts, so....
This should be more than adequate to figure out where to mount it and be more robust too
i was able to print one also, but never really used it. i printed it in 3 sections and taped together.
Landy_Andy
Well-known member
i think i got mine off ebay for a little over 130 for the booster and master.
i was able to print one also, but never really used it. i printed it in 3 sections and taped together.
I've been looking for one locally, cheapest I've found so far was $650cad, so will have to order off Ebay too from 'down south'... at least I can move forwards with designing the pedal box assembly now & getting it mocked up into the frame.
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Im up in Canada too and ended up buying mine off ebay out of Ontario for $250ish. Included MC and the electrical plugs.
Landy_Andy
Well-known member
I didn't see any when I looked last night anywhere up here, will wait until after the holidays to get one now I have a usable mockup tool. BTW, what pedal ratio did you settle on, thanks ?
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I think I put holes for 3:1 and 4:1. Cant remember though
JohnnyJ
Low Range Drifter
I feel like early on the thread someone mentioned that standard Honda Accord had 4:1 pedal. I built mine with 4:1 and it seems fine.
Landy_Andy
Well-known member
I looked back through, another poster has 2.75:1, am thinking I'll add some adjustment into the design, maybe 2,3 & 4:1.
Got my mockup booster made from leftovers
Landy_Andy
Well-known member
Question, how much vertical deflection is there in the push rod at the clevis end to accommodate different pedal ratios ?
Gumbybronco
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If you can wait a day or so, I have one out an Accord on the shelf.
Landy_Andy
Well-known member
No problem, also... what's the width of the clevis opening for the pedal ? Thanks
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Gumbybronco
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SandhillsHB
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While the pivot point does travel in an arc motion isn't best practice to install the ibooster at a height that the pushrod is level?
Gumbybronco
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Typically yes. Level when not depressed. Then arcs during braking and returns to level.
Winchested
IH Scout SSII
Usually want the straightest possible push. At least on vac and hydro boost so you don't side load the seals.
Landy_Andy
Well-known member
Gumbybronco : Thanks for the measurements, that look like it'll support 3.5:1, 4:1 & 4.5:1 pedal ratio holes. Got the silhouette booster mocked up today & a final mount ready to cut tomorrow :-)
Gumbybronco
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Following up with clevis width.Here’s deflection in any direction. About 3cm. I’ll follow up on clevis width.
The clevis unscrews, so there’s a lot you can do with that.
Landy_Andy
Well-known member
Gumbybronco : Much appreciated... thanks, the pin hole looks to be ~1/2" diameter ?
Gumbybronco
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I’ll confirm later, but looks standard.
I didn’t use the clevis on my last install and used this instead:
SandhillsHB
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A rod end like this makes a good option use an 8mm shoulder screw with same size threads. Needs at least 12mm shoulder. You can use a longer shoulder but would need to shim each side of the ball. You want to ball and screw fixed. You do not want the ball to pivot on the screw. You want to rod end to move on the ball.
I would recommend a better rod end than something from Amazon.
https://www.amazon.com/gp/product/B0C7MYN19G/ref=sw_img_1?smid=A1THAZDOWP300U&th=1
I would recommend a better rod end than something from Amazon.
https://www.amazon.com/gp/product/B0C7MYN19G/ref=sw_img_1?smid=A1THAZDOWP300U&th=1
Gumbybronco
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Landy_Andy
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Making good progress on my iBooster pedal box 
arse_sidewards
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Finally getting around to planning out a hydraulic trailer brake actuator using one of these iBoosters.
The brakes I'm trying to drive are basically three '99-04 Superduty's worth of front calipers and they're stopping a 38" tire
Each one of these calipers has two 54mm pistons for a total piston area of 27,486 mm^2
A stock '99 Superduuty has a 1.375 (I bet it's really 35mm tho) master cylinder with a 957 mm area pushing 4580mm per front caliper and 1541.3mm per rear caliper for a total area of 12242mm yielding a ratio of 12.55.
So to get approximately that ratio with my 27,486mm^2 I'd need approximately a 52mm piston. That's probably not gonna happen but 1.75 is available (90s juice brake MDT stuff) if pricey ($120ish seems to be the lowest, $300ish typical). 1.5" stuff (e.g. 2010s Superduty) is cheap at $50ish.
Let's say I want to achieve 2000psi. With a 1.75 master I'd need 4800lb to do that, with a 1.5" master I'd need 3500psi to do that.
The Bosch literature says "up to 6.2Kn" of assistive force which is ~1400lb but we'll call it 1200 just to be safe.
Regardless, putting 2200-2600lb into the booster is just not gonna happen. It's got a 1/4" or thereabouts stamped pin clevis on the input side. It's clearly not made for that even if I do apply it. So I think maybe knock the master cylinder down yet another size to 1.375". Then I only need to apply ~3000lb of force. If you assume the booster is good for 1200 of that that leaves me with 1800 to apply. That's easy linear actuator and lever territory.
The specs at the start of this thread say it has a 1.25" stroke. Other parts of the internet say absolute max of 40mm. I have no frame of reference for how much stroke a 1.375 master cylinder pushing on a ton of caliper will actually use just to make everything bite properly. Whatever. I'll just ignore that question mark.
Here's your standard cheap china "660lb" linear actuator.
Being 4A I should be able to drive it directly off the brake controller. I hope this will give me the ability to tune it simply by adjusting the brake controller.
So slap two of those on a 2:1 "brake pedal" and I've got 2600lb. Call it close enough.
iBooster: $120
Linear actuators: $90
Brake valves $20
master cylinder $50
relays and electronic stuff to make it retract when you get off the pedal $20
$300 ain't bad.
This setup is kinda in poorly territory in several aspects so I don't expect anyone to tell me how it'll work but does anyone see anything glaringly wrong with it?
I'm particularly concerned about the linear actuator's speed not being good enough once you reduce it with a 2:1 lever and the amount of master/booster travel I need being too much with the "small" 3.75 master cylinder.
On the other hand, what I've read says too small of a master and the brakes will have a lot of travel (mushy pedal) and then grab like an on/off switch. Maybe slow is fine then?
Finally, is this even the right approach? Should I just use a junkyard ABS pump? That sure would be less fabrication if it works. Some of them look pretty easy to adapt though I suspect they draw too much for the trailer brake controller and would need to be powered some other way.
The brakes I'm trying to drive are basically three '99-04 Superduty's worth of front calipers and they're stopping a 38" tire
Each one of these calipers has two 54mm pistons for a total piston area of 27,486 mm^2
A stock '99 Superduuty has a 1.375 (I bet it's really 35mm tho) master cylinder with a 957 mm area pushing 4580mm per front caliper and 1541.3mm per rear caliper for a total area of 12242mm yielding a ratio of 12.55.
So to get approximately that ratio with my 27,486mm^2 I'd need approximately a 52mm piston. That's probably not gonna happen but 1.75 is available (90s juice brake MDT stuff) if pricey ($120ish seems to be the lowest, $300ish typical). 1.5" stuff (e.g. 2010s Superduty) is cheap at $50ish.
Let's say I want to achieve 2000psi. With a 1.75 master I'd need 4800lb to do that, with a 1.5" master I'd need 3500psi to do that.
The Bosch literature says "up to 6.2Kn" of assistive force which is ~1400lb but we'll call it 1200 just to be safe.
Regardless, putting 2200-2600lb into the booster is just not gonna happen. It's got a 1/4" or thereabouts stamped pin clevis on the input side. It's clearly not made for that even if I do apply it. So I think maybe knock the master cylinder down yet another size to 1.375". Then I only need to apply ~3000lb of force. If you assume the booster is good for 1200 of that that leaves me with 1800 to apply. That's easy linear actuator and lever territory.
The specs at the start of this thread say it has a 1.25" stroke. Other parts of the internet say absolute max of 40mm. I have no frame of reference for how much stroke a 1.375 master cylinder pushing on a ton of caliper will actually use just to make everything bite properly. Whatever. I'll just ignore that question mark.
Here's your standard cheap china "660lb" linear actuator.
Being 4A I should be able to drive it directly off the brake controller. I hope this will give me the ability to tune it simply by adjusting the brake controller.
So slap two of those on a 2:1 "brake pedal" and I've got 2600lb. Call it close enough.
iBooster: $120
Linear actuators: $90
Brake valves $20
master cylinder $50
relays and electronic stuff to make it retract when you get off the pedal $20
$300 ain't bad.
This setup is kinda in poorly territory in several aspects so I don't expect anyone to tell me how it'll work but does anyone see anything glaringly wrong with it?
I'm particularly concerned about the linear actuator's speed not being good enough once you reduce it with a 2:1 lever and the amount of master/booster travel I need being too much with the "small" 3.75 master cylinder.
On the other hand, what I've read says too small of a master and the brakes will have a lot of travel (mushy pedal) and then grab like an on/off switch. Maybe slow is fine then?
Finally, is this even the right approach? Should I just use a junkyard ABS pump? That sure would be less fabrication if it works. Some of them look pretty easy to adapt though I suspect they draw too much for the trailer brake controller and would need to be powered some other way.
Attachments
AgitatedPancake
Frobot
Interesting, I have a few questions/comments
-Why triple calipers? Won't rotor thermals become an issue before you run out of clamping force (and maybe even more so because some of the rotor vents are blocked by the additional calipers)?
-5mm per second on the actuator seems like it could become a concern unless it hardly backs off so you maintain a decent amount of residual pressure
-Why an external actuator at all? most (all?) of these iboosters come on vehicles that can already demand the ibooster to clamp the brakes even without input from the pedal. So with a little doohickey gadget, you could just command the ibooster to actuate itself when you want to use the brakes or not. IIRC they have accessible internal pressure sensors too, so you could make it reactive to how much brake pressure is in the system as well
-Why triple calipers? Won't rotor thermals become an issue before you run out of clamping force (and maybe even more so because some of the rotor vents are blocked by the additional calipers)?
-5mm per second on the actuator seems like it could become a concern unless it hardly backs off so you maintain a decent amount of residual pressure
-Why an external actuator at all? most (all?) of these iboosters come on vehicles that can already demand the ibooster to clamp the brakes even without input from the pedal. So with a little doohickey gadget, you could just command the ibooster to actuate itself when you want to use the brakes or not. IIRC they have accessible internal pressure sensors too, so you could make it reactive to how much brake pressure is in the system as well
