Topic: Hub stands aren't cheap

[Steelmesh]

Designed this in fusion, will get a quote on getting it laser cut.

750 lb steel ball transfer each so 1,500 lb capacity per corner. I think there is diy weld together hub stand kit for $535 + shipping from turtle lab.

[Sly Bob]

Anxious to see the final product, nicely done!

[Steelmesh]

Next concept from scratch, shortened it and made it stout and tried to reduce weight, so more cut time in processing:

[Steelmesh]

Third design from scratch.  This time I set the distance between the center of the hub to ground is 13" / 330 mm radius, a 26" diameter tire diameter proxy.  The transfer bearing contact point is set to the offset of my wheels at +45mm, and there are extra holes to set it to +25mm.  This reduced height while going to an 8" / 200mm bearing width making it more stable longitudinally, while I tried to keep it simpler to reduce cost by -$150 using sendcutsend.com to get a quick estimate.  Bolt patterns, for 5-lug: 105-115mm and 4-lug: 100-110mm. Center bore is 72.7mm to go with my Solstice wheels at 72.6mm, so I can use my hub spacers.

[Steelmesh]

Edit: I'm an idiot keep reading the replies below after this post to realize my mistakes
___________________________original post start___________________________


Long story short dodged a bullet, glad I didn't jump the gun, now lets shoot the ship: I realize I'm a noob here after I made a 5-lug bolt pattern checker for the Solstice at 110mm and it didn't fit. Wrong dimension used for the hub stand pattern.  Found out that 5-lug is unique in that it's not dimensioned off a bolt circle diameter, however off a distance between two holes while taking into account hole diameter!     





Below is the actual bolt circle for a 5x110mm pattern with 12mm wheel studs.  I did try to make the tool using the diameter of the clearance holes of the wheel, that didn't work.  So I experimented with using a 12mm circle as the hole diameter and with that the tool fit good in the stock Solstice wheel.

~1 0 9 .352 is the diameter measurement
Tool width (hole center to hole center) is 1 0 4 .000
AI IQ test is trying to read those values



Before I drop a bunch of money, I'm going to cut out some 1:1 patterns from wood to see how it looks for reals.  Also have some other aluminum I want burned out and have some 20% off coupon that guy putting real Ferrari body on his custom frame has, probably can google a code I don't know it off hand.

[TomatoSoup]

Found out that 5-lug is unique in that it's not dimensioned off a bolt circle diameter, however off a distance between two holes while taking into account hole diameter!

Wow!  Did not know that, thanks for letting us know!

[Critterman]

Why should anything be standard on this vehicle, even the shared parts.

[Sol Asylum]

Well actually the lug centers are on a 110 mm circle.  Its just hard to measure that given you don't have a lug straight through the center of the circle on the opposite side to measure to.

The trick of measuring from the center of one lug to the outside edge of a lug that is two places off will get you close enough to determine the pattern.  "Close enough? being the catch words.  If you look at your drawings you will see difference between the dimensions is less than .65 mm which is about .025 inches or about as thick as 3 sheets of paper, close enough.

What dimension from centers was your measuring tool?  If it's 110 mm, keep in mind you don't have a lug straight through the center to measure to.  If measuring to the second lug keep in mind you will need to reduce the 110 by half the diameter of the lug to be close enough.

[TomatoSoup]

Well actually the lug centers are on a 110 mm circle.

Ahh, yes, makes sense.

[Steelmesh]

Well actually the lug centers are on a 110 mm circle.  Its just hard to measure that given you don't have a lug straight through the center of the circle on the opposite side to measure to.

The trick of measuring from the center of one lug to the outside edge of a lug that is two places off will get you close enough to determine the pattern.  "Close enough? being the catch words.  If you look at your drawings you will see difference between the dimensions is less than .65 mm which is about .025 inches or about as thick as 3 sheets of paper, close enough.

What dimension from centers was your measuring tool?  If it's 110 mm, keep in mind you don't have a lug straight through the center to measure to.  If measuring to the second lug keep in mind you will need to reduce the 110 by half the diameter of the lug to be close enough.

I don't know what's going on then I'm all confused and you're right obviously the tool measuring by cutting across the bolt circle wouldn't be 110mm anywhere in this universe, I am here whoops

For the bolt circle diameter, I showed the CAD work maybe I missed something. I found the 5-lug bolt circle in two ways, first just brute force guess and check until I got 110mm from the center-to-side of hole, then in the CAD you also see the other way I found the circle diameter, I got the 110mm dimension based on 12mm holes, and then applied 5/360 degrees = 72 degree lines, then the intersection would be the center of the circle.

I will cut out a wood pattern of my CAD model and see how it fits maybe it's totally off.

[TomatoSoup]

OK doing some math here!

If the arc distance between the two points is θ, and with radius r, the length of the chord between them is r*2*sin(θ/2)
(ref: https://math.stackexchange.com/questions/134606/distance-between-any-two-points-on-a-unit-circle)

θ = 360*2/5 = 144
θ/2 = 72
[sin(72) = 0.9511]
r*2*sin(θ/2) = 110/2*2*0.9511 = 104.62mm

(I think )

[Steelmesh]

Wow!  Did not know that, thanks for letting us know!

Our friends here have corrected me, I am mistaken here and apologize for leading you astray. 

Undo undo, ctrl-Z! 110mm 5-lug is 110mm bolt circle as pointed out by Sol!  The measurement of it, I don't understand the call out of measuring it from the center of 1 hole across to the back side of another hole.

This misunderstanding/mistake here is proof that most who aren't that smart can still make it building cars and engineering things (see me), I tell young people that if you're not that smart you compensate by doing things, such as triple or quadruple checking yourself, always erring on the side of caution that yourself has made a mistake. Even post it to the internet and look like an idiot in this case, in the end it helped correct my thinking, want to know more?

I remodeled it with a 110mm bolt circle actual, cut this out and tested it just now (had to fix my stupid right away as soon as I read the posts here).  With 12mm holes (close tolerance for 12mm lugs), it indeed fit on the Solstice hub perfect. Sol is our hero thanks for saying something.

Trying to understand the measurement method, center-to-[back edge] of lug hole, here is what I looked at:
This image shows the model I used to test fit to the Solstice hub that worked, notice that the measurement across 2 holes is 110.616mm and not 110mm. See following explanation and image after this. It also shows the center to center distance is 104.616mm.



In the next image, you can see in order to achieve the 110mm measurement from across the 2 lug holes, center-to-[back edge] of lug hole, you will need a 10.768mm lug hole (blue arrow), then the measured distance is 110mm (red arrow)
If you convert 10.768mm to inches you get 0.423937", fractional is closest to 27/64th which is odd for a reference lug hole size with either unit.




@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Template and tool
As for my measuring tool, it's definitely off by 0.616mm when you examine it with the wood cut out, worked good enough I guess 

[Steelmesh]

OK doing some math here!

If the arc distance between the two points is θ, and with radius r, the length of the chord between them is r*2*sin(θ/2)
(ref: https://math.stackexchange.com/questions/134606/distance-between-any-two-points-on-a-unit-circle)

θ = 360*2/5 = 144
θ/2 = 72
[sin(72) = 0.9511]
r*2*sin(θ/2) = 110/2*2*0.9511 = 104.62mm

(I think )

Winner Chicken Dinner!  CAD model says 104.62

[Steelmesh]

Updated universal hub stand pattern.  4-lug 100mm to 114.3mm, 5-lug 110mm to 114.3mm with 12mm and 14mm stud sizes depending on bolt circle diameter.

[Steelmesh]

Another point about these hub stands, been throwing around ideas for the base plate that the rollers can roll on (better than my floor), where I'd like to have some way to stop the rollers if the car were to slide off the plates as a safety feature, you can see I made slots with no bridges around the edge of the plate for the ball rollers to fall in, however not too aggressive I'd rather have the car keep rolling vs. tipping the hub stand over, as my logic.  Also, cutting out a piece of a thicker material could make a wall around the perimeter of the plate, maybe a piece of wood with some girth, another part added to the mix I'd like to minimize if possible.

I don't like this design of the plate as is, it's just my last design iteration of trying to integrate a way to stop the rollers without creating more parts.

[Sol Asylum]

Why don't you just stack two plates, bottom one is flat top has some circle cutouts?  Bolt or weld the two together and you end up with an easy curb design to limit travel.

Another idea go to the store and find a heavy duty cake pan and just use that.

[Steelmesh]

Why don't you just stack two plates, bottom one is flat top has some circle cutouts?  Bolt or weld the two together and you end up with an easy curb design to limit travel.

Another idea go to the store and find a heavy duty cake pan and just use that.

That's a good idea to try & price out shouldn't be hard to quote it. I think it will increase the cost with a big scrap drop in the middle, why I was trying to go down the path of working with 1 layer.  They do consider the laser time, so making a groove might be the same laser time to do 2 layers like your idea, could be a wash!

I'm pretty price sensitive needing 4 sets of everything, trying to keep with the theme to save money or make it better, or both.

For the cake pan, I fear my garage floor kinda of sucks, was going to look at 3/16" steel so the ball transfers don't dig in.

[Sol Asylum]

Steel plate in the cake pan and your good.

Problem with the grove is once the castor gets in there good luck getting it out.

You could draw one of your other part to be made in the drop section.  A good fab shop will do that anyway.

[Steelmesh]

Steel plate in the cake pan and your good.

I see now, that is a fantastic idea!! 

https://www.amazon.com/Bastwe-Commercial-Stainless-Professional-Dishwasher/dp/B08NCJ1THC

[Steelmesh]

I did a little redesign to add more clearance to clear the big calipers to check the caster angle, the original design may have been okay however worst case I just went full lock with the wheel, so that last design was interfering with the caliper mount.



Should have posted this on April 1st implying I was making these out of wood hehe.  These are just 1:1 parts to check fit before commit, using 0.200" wood.  I'm planning to use 0.250" steel for the structures.