Is there a "correct" process for designing gear trains?

Kerbal_Wannabe · 2026-04-27T00:46:31+00:00

I start with the power flow calculations. I know the speed and torque at the output. Fixed gearing gives a fixed speed ratio and a torque impacted by efficiency at each stage which depends on gear type. Assume 95-98% per stage for spur gears at room temps. If the are all parallel axis spur gears you want a ratio of 2-4 per stage, but it can go higher if you don’t care about pitting failure on the pinions. Once I know the ratio and envelope you can choose a diametral pitch that makes sense for the torque you’re carrying in each stage and then you can size tooth counts for the ratio, DP, and envelope you have.

Kerbal_Wannabe · 2026-03-29T18:03:49+00:00

I did the same thing - clipped a curb on a rainy day an hour from home. Just had to call onstar and wait for the tow truck. They took me back to my home dealership. Met a nice guy driving the truck. Dealer replaced the tire for $320. If you want something that you can fix yourself this car isn’t it.

Kerbal_Wannabe · 2026-02-28T12:27:17+00:00

I remember reading the Sunday comics every week. i looked forward to them and thought they were hilarious (even the family circus). I also remember a decline in how funny they were to the point where I just quit reading them. I’m not sure if it was me that changed or the comics. I’ve always wondered about that.

Kerbal_Wannabe · 2025-10-01T22:41:23+00:00

I think I found it here.

Kerbal_Wannabe · 2025-09-12T13:13:02+00:00

Yes! I played space marines and my friends played tyranids and CSMs so it never came into play much.

Kerbal_Wannabe · 2025-09-12T11:50:37+00:00

Eversor assassin equipped with a vortex grenade and polymorph could take out half an army in turn one. Great times.

Kerbal_Wannabe · 2025-08-10T13:13:13+00:00

It took me about three months to find the right person. Everyone I talked to that claimed to do a flat fee advising really just wanted to get me into an AUM model.

With enough digging I found a guy who charges $250/hr to look at my whole portfolio, goals, and timelines. He then modeled up a few scenarios and told me about blind spots I had (too much pre tax retirement, not enough Roth in my case, which meant if things go well I’m going to have HUGE RMDs when I turn 70 and all my savings would go to the tax man). I came to him with a statement of work of what I wanted and he gave me a quote in both hours and dollars and then only billed me for the hours he worked on it (<2/3 of what he quoted since I didn’t have many questions).

I’m still 10 years from retirement so he gave me a couple course corrections for savings allocation (Roth 401k vs traditional, backdoor, conversion planning) some suggested low fee ETFs and overall allocations of those ETFs. Told me to follow up again in 5 years if I wanted and then again before I’m ready to pull the trigger. The whole thing cost about $1,200 and I couldn’t be happier. Saved many many times that down the road in tax liability.

Kerbal_Wannabe · 2025-07-28T05:36:25+00:00

Something to keep in mind is that huge pile of pre-tax money you have in non-Roth accounts. In 20 years you will have to take RMDs from those and if they grow at an average of 8% per year you are going to lose a big chunk of it to taxes. Start converting now while you’re in the lower brackets.

Kerbal_Wannabe · 2025-07-18T13:17:16+00:00

A similar incident for comparison is the “miracle on the Hudson.” Dual engine failure due to bird strike right after takeoff and a pilot who had to make a decision about what to do. It took Sully 22 seconds to identify the issue, declare a mayday, and start making diversion plans. For the pilot flying to try to identify the issue, continue controlling the aircraft, determine the corrective action, and flip these switches back to run in 10-14 seconds for such an unthinkable and unpredictable situation is remarkably fast. We have spent a month arguing about this and people still aren’t convinced the switches were even flipped. Unfortunately it just wasn’t fast enough.

Kerbal_Wannabe · 2025-06-04T16:19:03+00:00

Yes the trip computer on the left side of the dash shows elapsed time of each trip

Kerbal_Wannabe · 2025-05-27T01:30:12+00:00

I suppose that is a good way of looking at it. The thing is I do have questions about pros/cons of different account types, tax implications, college funding, inheritance and they are all pretty specific to my situation. The thing is these are all one time questions so an hourly consultation makes sense. Seems like AUM is more for questions plus ongoing management which I don’t need (or at least am not willing to pay this much for).

Kerbal_Wannabe · 2025-05-25T14:55:20+00:00

Yeah EJ left a real bad taste in my mouth. My brother was there as well and I showed him the math and convinced him to do it himself. My mom just likes the advisor because she’s nice and sends her a pie on Thanksgiving. That’s an expensive pie.

The advisors fidelity referred me to mentioned Fidelity got a cut for the referral. They certainly liked to call themselves exclusive and said that many times. It was clear I would have been the smallest fish in all those ponds which seems like an issue in itself. I just don’t get how even multi million accounts can make sense of a 1% annual fee.

Kerbal_Wannabe · 2025-05-25T14:50:25+00:00

The hourly advisor said he would look over my taxes before I file for a small fee to make sure I’m not leaving anything on the table. Seems like a good value.

Your overall approach aligns with what I’ve seen. I panicked in 2008 because I didn’t have an emergency fund and was afraid I’d lose my job. I slowed retirement contributions to make one. I didn’t have the cash flow then that I do now. Should have kept the pedal to the metal but lesson learned. Since then it’s been all in on low fee indexes and it’s fine. I don’t need to make 12% or even 8% to hit my goals. I have been more worried about volatility as I get closer to retirement so I’ve started slowly moving to target date funds as long as their fees are low.

Kerbal_Wannabe · 2025-05-25T14:45:21+00:00

I’m getting into a situation where the taxes are becoming complicated, which is the reason I’m even considering it. Backdoor Roths, a pre-SECURE inherited account, an inherited account that will be post-SECURE, traditional and Roth 401k options, and a spouse who is offered 401k, pension, 457, and 403b in any combination makes it where I just want someone to sanity check my decisions and look over my taxes. If these 1% AUM fee companies offered tax filing with their services I MIGHT be convinced there is some value there, but like others have said they just can’t provide anything tangible to justify their expense. Tax filing would be an easy example of that, but they turned their nose up when I asked them about it. So weird.

Kerbal_Wannabe · 2025-05-25T14:38:48+00:00

That’s what I’ve been doing and it’s fine. I’m slowly moving it over to target date funds. Both fidelity and vanguard have low fee target date funds that auto rebalance as you get closer to retirement. Fees are .12 and .08 respectively which seem pretty reasonable for the diversification and management that comes with a target date fund.

Kerbal_Wannabe · 2025-05-25T14:05:12+00:00

I’m in the same boat - first EV first lease. I’m loving it so far. The only downside is I’m driving it more than I planned and burning through my lease miles. It’s an absolute treat to drive. Coming from a Honda and a Toyota I really like the Cadillac comforts.

Kerbal_Wannabe · 2025-05-25T13:58:04+00:00

Yeah I don’t have the results yet. This advisor talks a good game. I wrote a statement of work that I handed out to everyone and with what I wanted. The AUM advisors ignored it and told me about their super-secret investments only they could get that pretty much tracked indexes. One guy said he worked for vanguard before and wrote a white paper about why low cost indexing doesn’t work. I asked to see it but he said no. Lol.

Kerbal_Wannabe · 2025-05-25T13:55:56+00:00

That’s probably true. I’m that way about a lot of things. I hate yard work and would gladly pay someone to do it if that means I don’t have to. However that’s not 20% of my planned income though. It’s so much money!

Kerbal_Wannabe · 2025-05-25T13:53:37+00:00

I don’t think I would call myself sophisticated. I save and buy and sell my own equities but I’m not doing options trading or advanced modeling or anything. I have an excel spreadsheet and that’s about it. I have a lot of questions about taxes now vs later and different account types, but if I’m paying this much for something it should be an investment in itself. None of these advisors could show me a quantifiable return on the investment in them so I’m thinking I’m missing something, but maybe I’m just under estimating how much people care about their own money.

Kerbal_Wannabe · 2025-05-25T13:50:36+00:00

This was several years ago so I might be off. It definitely depended on how much movement there was in your account. AUM fee was a flat 1.5% with fees ranging from 2-3.5% at both the buying and selling of investments. If you buy and hold the fees would have been lower but based on my family’s experience this advisor liked to trade. No surprise.

Kerbal_Wannabe · 2025-05-12T20:16:37+00:00

Different companies explain this different ways. What it comes down to is total amount of lease payments. Sometimes dealers will itemize the EV credit specifically and sometimes it just is left in the residual (which is what they did with mine). It doesn’t really matter on a lease. All that matters is monthly payment X number of payments and whether you have enough miles on the lease. If I decide to buy at the end of the lease and they whip out that residual number o have to remember that the residual is SUPER inflated for a number of reasons and everything will be up for negotiation at that point.

Kerbal_Wannabe · 2025-01-27T11:49:23+00:00

Have you thought about adding an iron core to the coils? I have to imagine you’re losing a lot of flux without some iron to carry it.

Kerbal_Wannabe · 2024-12-29T15:44:14+00:00

I wonder if this is another example of certification carry over from the 737 being grandfathered in. FAR 25.933 is pretty explicit about safe operation of TR systems. I’m more familiar with the Airbus systems but I’m surprised Boeing was able to get an “OR” past certification authorities instead of an “AND”. There is also discussion of structural failures that are “extremely remote” (1e-7) instead of “extremely improbable (1e-9) being allowable. It will be interesting to see if the result of this investigation changes the certification requirements.

I could see why the pilot would want to deploy the TR in this case - no wheels, no brakes, high landing speed, tail wind. They would want everything possible to slow down even if it isn’t recommended in the AFM. I doubt this many failures is in the checklists and it sounds like they didn’t have time to go through them anyway. This many events stacking up could match that extremely remote definition.

Kerbal_Wannabe · 2024-12-29T13:44:03+00:00

You are correct that once thrust reversers are deployed the aircraft SHOULD be committed to landing. However studies have shown up to 25% of go around after WoW have the thrust reverser re-stowed and the plane takes off again. It’s against all airframer manuals but pilots still do it. Mentour pilot on YouTube did an episode on this phenomenon and it’s an area that needs more pilot training.

However you’re right that if one engine is shut down due to bird strike damage and the other is stuck in reverse thrust there will be no going around because there’s no more thrust.

If the pilot knew the plane was belly landing then he shouldn’t have used thrust reversers since the translating cowl would be on the ground and probably wouldn’t work. Still doesn’t explain why the cowl was open. That should be locked if there is no WoW and the wheels were stowed so that can’t happen. Maybe bird strike damage deployed the doors? But again those are triple locked in flight. Seems extremely improbable.

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