diy scales

[sstecker]

with all the cool diy projects people have been doing on here, figured id post my latest one. i saw the design online, improved by going digital. wanted a project to mess around with conversational programming on a mill.

digital scales/turn plates/toe plates.

plates and blocks aluminum
top plate & block slide on the stainless bars
with weight on a central stainless piston
piston rests on a 1/2" bolt in the bottom block to raise/lower/level the corner, with a water level next to it (small slot on left side of top block);



shows piston (it now has double o-ring grooves) and bolt - have a few inches of travel to level each corner



already have an 8 bit micro controller with lcd waiting for the sensors. bolt pattern for bmw and miata.

almost complete - waiting for sight glass and 5v pressure sensors to show up and need to order 1/2" bolts, only have shcs around shop.

i was going to put the roller bearings in double shear but sight glass got in the way

[tigruppe]

If these are bolted to the hub, do you see some loss or friction in the slide design in high camber applications?

[sstecker]

when filled with hydraulic oil the only vertical slide movement, if i get all the air out, is the head of the sensor to pickup pressure. ill find out soon if it binds.

[rgconway]

Awesome project! I saw this on some formula ford site and think it's a great design. I was considering using load cells instead of hydraulics, and adapting to mount to my turntables. Do you intend to have the roller bearings roll on your garage floor? (your garage must be nicer than mine!) If you haven't, I'd consider using a steel insert in the aluminum block for the jacking bolt.

How do you expect to align the two rear hubs? With an LSD this could be difficult.

How do you plan to level the four pads? I made a water level for this as I was not satisfied with the precision of the carpenter lasers.

Did you farm-out the machine work?

I'm asking questions because I'd like to do the same. Please keep us posted

Bob

[sstecker]

Originally Posted by rgconway

Awesome project! I saw this on some formula ford site and think it's a great design. I was considering using load cells instead of hydraulics, and adapting to mount to my turntables. Do you intend to have the roller bearings roll on your garage floor? (your garage must be nicer than mine!) If you haven't, I'd consider using a steel insert in the aluminum block for the jacking bolt.

How do you expect to align the two rear hubs? With an LSD this could be difficult.

How do you plan to level the four pads? I made a water level for this as I was not satisfied with the precision of the carpenter lasers.

Did you farm-out the machine work?

I'm asking questions because I'd like to do the same. Please keep us posted

Bob

hey Thanks! should be up and running late next week.

i figure a piece of plywood will take care of rough surfaces

rear should slip

there's a water level built with push lock fittings. still waiting for the sight tubes to show up that ill epoxy into the bottom block(and goes up thru the top block). in the single picture you can see where the tube will be seen in the top block - slot on the left side. machined a 'level' mark into the top blocks.

yeah worried about the 1/2" bolt galling. i could always upsize to 3/4"

i machined everything myself. i am not a machinist, work the front office, but learning.

[endoforce5]

This looks like an old Sherline system I had in my FF days. Even though the car weighed <1000lbs. it didn't work well at all - too much binding with the rollers on the floor - even with steel plates placed on the floor to reduce friction. Seems like a great idea though. Maybe you'll have better luck if you've used higher quality components. We used both water levels and lasers to level. The laser worked better and was less hassle. We did use a higher end ART laser - not the Home depot stuff, but I bet you could make it work with a cheap laser if you took the time to make a high quality holder for the laser light source and calibrate it carefully.

[BobWright]

I would think you would want to know that your scales are right? Longacre Clearance Bin sounds like the ticket

[Cory M]

Let us know how they work, here is a similar thread with some pics of the Porsche system:

http://forums.bimmerforums.com/forum....php?t=1242293

[sstecker]

Originally Posted by endoforce5

This looks like an old Sherline system I had in my FF days. Even though the car weighed <1000lbs. it didn't work well at all - too much binding with the rollers on the floor - even with steel plates placed on the floor to reduce friction. Seems like a great idea though. Maybe you'll have better luck if you've used higher quality components. We used both water levels and lasers to level. The laser worked better and was less hassle. We did use a higher end ART laser - not the Home depot stuff, but I bet you could make it work with a cheap laser if you took the time to make a high quality holder for the laser light source and calibrate it carefully.

could be the bearings cant deal with scrub? a caster type system might work better.

Originally Posted by BobWright

I would think you would want to know that your scales are right? Longacre Clearance Bin sounds like the ticket

yeah i have a balance scale/weights to calibrate accuracy

Originally Posted by Cory M

Let us know how they work, here is a similar thread with some pics of the Porsche system:

http://forums.bimmerforums.com/forum....php?t=1242293

nice! i like how they brought the roller bearings back the the center line

[sstecker]

tested rear plates. easier to mount than wheels. i could push on the car and see the bearings roll.

front plates need a spacer to get by wilwood calipers

also need to make/mount 17" angle pieces on plate to measure toe. 8" not wide enough

[rgconway]

Very nice! I see from pic that your garage floor is way nicer than mine

BTW, regarding calibration, if you know piston/bore size precisely (I'm sure you do) and have a highly accurate pressure gauge, I would think that you could use your scales to calibrate the load cell type, instead of vice-versa.

Bob