e's ExMT

[ekd]

I think I can make these work.

[monkeyracer]

Originally Posted by ekd

I have some stuff here that I'd love to get CNC quotes on. The last time (back in my slotcar days) I had someone convert, it took a long time, and the CNC shop's machine couldn't read the result. Didn't pursue it further... sometimes wish I had.

I hear you on the CAD. Having some proof of quality design has to be comforting when you can't hold a part in your hand yet. Especially when you're about to lay real money down.

Not to get too off topic, but I might know a thing about CAD:

Originally Posted by ekd

Please keep me up on your jig's progress? Not much I can help with, but if a pre-order would speed things up (and I can afford it), consider me interested.

Don't want to get too into the jig idea, since there's strict rules on non-vendors and products...

Originally Posted by ekd

Is there any reason I should use BECs, instead of wiring my servos directly to batt? Got a couple of these dirt cheap:

http://www.ebay.com/itm/170694183791...84.m1439.l2649

The benefit to the BEC is regulated voltage. A battery directly to the servo works, but as the battery voltage drops the servo gets less power. The BEC gives consistent voltage the whole time.

Originally Posted by ekd

I think I can make these work.

Those look like they might work with minimal mods. I might have to go check some out.

[ekd]

Originally Posted by monkeyracer

Don't want to get too into the jig idea, since there's strict rules on non-vendors and products...

Just PM me.

The only way these shafts could be easier is if they were 5mm instead of 4.5.

edit: I was able, by peeling it forward, to tear the tube from the housing when glued with 2 part epoxy (after about 36 hrs). When I used CA, the housing began to fold beside the joint before I gave up. The $0 notch and glue mod will work.

The rover gets 1 glued, and 1 screwed.

I'm starting to wonder about Punk. Stuff I ordered later, with free shipping, from China... is piling up here. The site said it was in stock, and I paid for it 17 days ago. No answer to my message.

What are the other options? Can my FS-CT6B be set up to do what I need?

Another edit: M, if you set the jig up to place tiny pilot holes, you will be able to include more incremental options. Can't wait to see what you plan for the C-hubs...

[ekd]

Since it's the max clock (for screwed, 19*), I'll add washers between the upper link, and the mount to find the right caster, and take whatever GC improvement I get.

[ekd]

The Grizzly is in, cleaned, and checked. Smooth and pretty tight. Been a long time since I have smelled the stank of new machine tools.

The 5/16 tools and inserts are not here yet, but they're not late until tomorrow. I'll content myself with listening to it purr while I figure out how to best mount the DRO (Sargon Gold Standard), and sort tooling to see what I can fit to this tiny thing.

Frankly, I'm excited. Since I got short, I have been slowly pulling my shop down to me... but, as I'm retired, there wasn't any rush. As I have stated elsewhere, RC came along for me just in time to keep me from holing up, and as tucan said: "...its fun getting into something new. Almost like starting all over and learning everything again!". Amen. I've got work to do.

Based on M's info, I'm gonna pass on BECs. A123s hold a constant voltage right up until the end, so I'm betting it'll be fine.

In case anyone is wondering what to get me for Christmas, I have figured out what I want: A Mad Mantis. I very rarely let other guys build stuff for me, but if you check out BWD's site you'll see why I'd consider just buying it. If I had to get a Mad rig going in a hurry, his Berg Wedge would be a damn good start. Check out the kit's contents, and try to tell me anyone could be more cost effective.

Break's over...

[BentMetaL]

Have a grizzly table saw and planer. Very happy with them.

[ekd]

Originally Posted by PHAT2011

Have a grizzly table saw and planer. Very happy with them.

I can see why. Most of my tools are american and japanese, but some chinese companies have found a decent enough balance between cost and quality to be a good value. The quality of their cast iron has gone wayyy up in the last 20-30 yrs.

I'm confident this tool will allow me to keep tolerances to the levels I hold myself to. Can't blame the tools... so, no excuses.

[Abavuso]

Well, I started to design the Trans brace and so far ended up with what looks more like a Clock in tool.

This is just the first stages so You'll see more as I go.

[ekd]

Would you ever consider making some tubes to take the MS C's (13mm hex 10mm deep)? They are hefty, to say the least... and aluminum goes for the same as the axials. I just like big bearings.

What was the max clock (at the housing) you came up with? I found that at 19*, the nearby bearing pocket could be deformed by firmly tightening the screw. It wasn't enough to keep the bearing out, but over tightening would.

Do you like this plastic? I kinda do.

[Abavuso]

Originally Posted by ekd

Would you ever consider making some tubes to take the MS C's (13mm hex 10mm deep)? They are hefty, to say the least... and aluminum goes for the same as the axials. I just like big bearings.

What was the max clock (at the housing) you came up with? I found that at 19*, the nearby bearing pocket could be deformed by firmly tightening the screw. It wasn't enough to keep the bearing out, but over tightening would.

Do you like this plastic? I kinda do.

Shoot over to my thread and you'll see the tub idea I'm working on. I'm trying to save up some money to buy a minni lathe so I can start knocking out some consepts. It just costs too much for a prototype part like that to be made at a shop. I plan on making them out of delrin with just over a 1/4 in side wall.It would give you the ability to clock it as much as you would ever want to . I do like the plastic the MT has, it's very robust and I don't see it breaking without major force! I just wight the trans house would have been manufacruted about 1-2MM Thicker!

[BentMetaL]

My thought on the plastic is its pretty durable, but it doesn't hold threads very good. I had to repair a few holes.

[ekd]

Originally Posted by Abavuso

Shoot over to my thread and you'll see the tub idea I'm working on. I'm trying to save up some money to buy a minni lathe so I can start knocking out some consepts. It just costs too much for a prototype part like that to be made at a shop. I plan on making them out of delrin with just over a 1/4 in side wall.It would give you the ability to clock it as much as you would ever want to . I do like the plastic the MT has, it's very robust and I don't see it breaking without major force! I just wight the trans house would have been manufacruted about 1-2MM Thicker!

I saw the setup you are designing, it's freakin beautiful.

1 or 2MM would be perfect... and cut half the work out of your axle setup. Your braces will bring it up to "weapons grade".

Originally Posted by PHAT2011

My thought on the plastic is its pretty durable, but it doesn't hold threads very good. I had to repair a few holes.

Yeah. That's the price you pay to handle more shock loads.

Long time ago, I shared a pit garage at Willow Springs with a private but factory supported Kaw team. Rode the bike, it was a beast (secret factory head). It was the first I had heard of preventive helicoiling. Before it was ever run, every hole was tapped for inserts. They could pull it down every day without worrying about failing threads.

The smart axial guys are using brass inserts on their housings. Like an idiot, I didn't bookmark the page with the MSC part #s, but I'll look into it.

I've run quite a few brands through my abattoir, and I like the balance Exceed found when they brewed this stuff up.

edit: A, my bits aren't here, so I can't say for sure... but, if you price the included equipment and look at the background of the company (and it's size), you might consider a Grizzly. I can tell you that their service was perfect and fast, and they have a 1 yr warranty. I'm really sorry I didn't just go for it first (1st lathe guys... Empire Liquidators... are going to be filed on, Mon. They still haven't given my money back).

Grizzly includes every tool needed to get it going. I didn't go near my boxes, and had it purring in mins.

[ekd]

Guys, I had to give up on ever attempting to compete.

I have waited nearly a month (paid Sept 10) for my Punk programmable computer. I cannot even get a response to my messages... and I cannot figure out a way to integrate the system without it.

I asked for a refund tonight. I was a bit worried I would have problems making it work, due entirely to my electronics ignorance, and have become convinced I would get zero support in that.

Not sure what I'll do with all the stuff I bought, but I guess I'll just build a rover (without dig, etc.) and use it for checking around places my security system can't see.

It was a fun thought, though...

[monkeyracer]

Originally Posted by ekd

Guys, I had to give up on ever attempting to compete.

I have waited nearly a month (paid Sept 10) for my Punk programmable computer. I cannot even get a response to my messages... and I cannot figure out a way to integrate the system without it.

I asked for a refund tonight. I was a bit worried I would have problems making it work, due entirely to my electronics ignorance, and have become convinced I would get zero support in that.

Not sure what I'll do with all the stuff I bought, but I guess I'll just build a rover (without dig, etc.) and use it for checking around places my security system can't see.

It was a fun thought, though...

I have a dig switch with a mini servo mounted to a stock exmt ESC, if you want it send me a PM and we can discuss pricing.

I'd hate to see this project stop because of something like that.

[John-e Bravada]

Don't give up yet! My dual stock ESCs work ok.... 8" tires are pushing it. I don't know anything about the camrea integration but there has to be a way.

[ekd]

I appreciate the thoughts, guys. If I can figure out how to do all the tasks with 6 channels, I'll try again.

This project was good for a couple cautionary tales:

The Punk mess is my fault. I knowingly did something to myself I never did to a client in 30+ years of building custom vehicles and tools. I developed a concept that relied on critical parts available from a single source.

I made a living integrating OTS (off the shelf/multiple sources) parts into my products as much as humanly possible. My clients never had to rely on my shop to keep anything going, and the custom parts I had to build were made tough enough to outlive anything they were attached to. And, did.

The second lesson: Never buy anything off ebay that you can't afford to pay for twice... at least for a while.

Empire Liquidators agreed to my claim, and offered to give me a full refund when I send the lathe back.... in spite of the fact that they have not only had it back for a week... but have listed it again.

Still no money here... Wanna see what I got and refused?

NAMEBRAND 7X10IN PRECISION MINI LATHE MODEL 93212 | eBay

edit: what it looked like when I bought it:

http://www.ebay.com/itm/270813906108...84.m1439.l2649

Bottom line? I'm just glad that I didn't build this thing, practice, enter a meet... buy tickets and make arrangements... just to learn what I know now about Punk R/C by having the unit fail 25 days before the comp. Imagine the last couple weeks before the big day... getting the treatment I have just gotten?

This is supposed to be fun. I'm going to make sure it is. I'm not sure what I'll end up with here, but I have a lot of new parts to mess with. That has always led to something amusing.

I have thought about getting a 9ch TX, but seriously doubt I could manipulate it well/fast enough not to be an embarrassment. A 2.2 setup would have too much cam/crane weight to have a chance. So, I'm gonna build a super something. What, we will find out together.

Any ideas are welcome here. Combat Crawler? Maybe with a tiny mortar (ala Vigilante 8 )? Explosives have been known to overcome superior skills/equipment in other fields... why not competitive crawling?

[ekd]

The DRO scale is huge compared to the Grizzly. I'm debating trying a digital caliper rig instead. Anyone tried this?

Caliper2PC - Digital Caliper and PC Based Digital Readout

I have an old touchscreen, and plenty of old PCs... and a handful of calipers. There are a lot of different systems and kits sold, I don't see a lot of difference in their features though.

[ekd]

Here's a quick budget upgrade:

Side Linkage ?8*185mm 4P

$11.10... Max lower links. Same effective link length as the MT's, but the ends add 12.5mm to the wheelbase per axle. Use the MT ball mounts, mix and match the ends to chose among 6 WBs.

Drilled for the 2mm pin with 1.92mm bit, got a snug press fit.

[ekd]

I swapped ends. With the 19* axle clocked for 0* caster, the Y link extended (34mm rod), and stock Max lowers... the upper link just touches the motor at full compression, and there is a nice ramp angle to the trans.

Still haven't drilled any holes in the TVPs. So many good volunteers so far...

[ekd]

Drilled 8mm deep into heads of 3mm screws, soldered in 1.5mm spring steel (Brownell's gunsmithing). Pondered clip on heatsinks w/fan mounts... but, $20 and a week's wait seemed a bit much.

Light, stout, and (as always ) cheap.

Motor wires will be as short as possible... and completely out of the way.