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Shop Holmes

Sorry for digging up the old thread, but it seems like you are the only one on here that has a vacuum chamber! I've got all of my pieces for my small one, I'm just trying to decide what to use for the hose. In the pics it looks like you used regular vinyl hose? Any issues with it sucking shut?

I'll post pics of my little 'resin mixer' once I have it up and running. "thumbsup"
 
No problems here! It is still kicking. I keep a PID controlled heater on it at all times so the resin is 85f+ and fast to heat higher during work.
 
BigSki said:
Sorry for digging up the old thread, but it seems like you are the only one on here that has a vacuum chamber! I've got all of my pieces for my small one, I'm just trying to decide what to use for the hose. In the pics it looks like you used regular vinyl hose? Any issues with it sucking shut?

I'll post pics of my little 'resin mixer' once I have it up and running. "thumbsup"
Click to expand...
I don't think there are many that do but he John isn't the only one. I have a 15 gallon vacuum chamber. I use the hose with the metal spiral wire in it to prevent it from sucking shut.
 
I use a reinforced nytril hose (sort of like fuel line) on my little 3 gallon vacuum chamber I use for stabilizing wood scales and blanks. When I am using the pump on bags I use regular Home Depot thick wall vinyl tube. No problems.

Had a great time going through this thread and seeing all the things happening on the Holmes front. Motor theory tickles my brain. Friggin magnets...how they do work.

Have you ever considered making a hub motor? I've seen them used on e-bikes and cars. Are the dimensions of a 2.2 rim just too small to make it practical? Imagine eliminating transmissions and having the option for independent 4 wheel power...Right Front Dig...lol

Ferro fluid magnetic shocks? ECU driven suspension?

If anyone could do it...it's probably you.
 
Thought plenty about it. I'm working on getting a production lathe right now that would make prototyping such things much easier. There are a lot of changes that I haven't been able to document. More workers, engineering work for other companies, machines, etc..


Direct Drive Hub motors aren't so practical on the small scale high performance end. Motors have a minimum frequency that they like to switch for good power density and efficiency (250hz is a low end number, 1500hz is high power densities). If we say a 10mph envelope of speed, that puts our pole count at 120 magnets for just 250hz. Add in a 6:1 gearbox and we could be getting somewhere, but in reality it isn't feasable to have 120 magnets in such a small diameter anyway. We would need right around 49:1 as a minimum base of reduction to even assume decent power to weight ratios. Now show me any 49:1 gearbox that would have enough torque capability while fitting inside the wheel and not weighing more than a regular drivetrain.


Practical? Sure. Super capable with a fancy enough radio? Yep. Higher performance than MOA designs? It's a big maybe. Depends on how well the 4x gearboxes and 4x motor controllers came together. I'm not working on it all personally, but I am in the process of helping another test the concept by making motors. I've been crunching the same numbers since 2006, and the only way it can work is with a sensored outrunner as the base and a certain amount of reduction. Otherwise we are stuck with a motor with much too high of terminal resistance and too slow commutation rate to make power.





I've thought more about making hub motors for ebikes. There is plenty of room to have 100 magents in them, so direct drive become feasible with decent power densities. That and the power to weight ratio and mass distribution isn't as critical.
 
Last edited:
Seems like you got that turning center figured out pretty quickly! "thumbsup"

I have a file ready to go, want to make some wheels for me??
 
We are a general machine shop at this point, so sure. I would prefer blueprints over digital drawing formats. They won't be cheap for just one set.
 
I got sick and tired of waiting for protos and taking years to bring something to market. The 6 to 12 week turnaround for protos, test, make some more, etc.. was just painful to go through again and again. On Friday I got my first taste of what we can really do now. Was making puller endbells and decided to add a little change for easier assembly. 5 minutes later we were rolling out revised parts. Bam! This is going to be really bad for my need-it-now personality.


When we aren't running parts for Holmes, the spare machine time will be used for prototype, OEM and ODM work. Right now I'm scheming on some axles for a personal vehicle, the most capable wheelchair ever. The steering knuckles and U joints were the previous sticking point. No more!!
 
I looked on your website but couldn't find a link to current job openings... seriously impressed!
 
I will be more than glad to test drive any wheelchair you care to make.
at least 8mph to get across avenues in a timely manner mine is 4-4.5 mph chair
make It sturdy, I weigh in at 600lbs
 
JohnRobHolmes said:
We are a general machine shop at this point, so sure. I would prefer blueprints over digital drawing formats. They won't be cheap for just one set.
Click to expand...

JohnRobHolmes said:
I got sick and tired of waiting for protos and taking years to bring something to market. The 6 to 12 week turnaround for protos, test, make some more, etc.. was just painful to go through again and again. On Friday I got my first taste of what we can really do now. Was making puller endbells and decided to add a little change for easier assembly. 5 minutes later we were rolling out revised parts. Bam! This is going to be really bad for my need-it-now personality.


When we aren't running parts for Holmes, the spare machine time will be used for prototype, OEM and ODM work. Right now I'm scheming on some axles for a personal vehicle, the most capable wheelchair ever. The steering knuckles and U joints were the previous sticking point. No more!!
Click to expand...

I absolutely LOVE that attitude! Keep it in house and it puts you in full control! "thumbsup"

I'll send you a jpeg of the drawing file unless you can open a .idw file. (Autodesk Inventor) Where do you want it sent?
 
jrh@ holmes hobbies please. A jpg is fine.


I would be taking more pics, but there is a lack of light in there at the moment and nothing is coming out.
 
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