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View Full Version : HiMaxx motors and the crappy gearbox


Combat Drone
10-18-2005, 03:47 AM
Greeting everyone;

New member and first time post. Sorry to be so blunt, but, is it just me? I have two HiMaxx 2025-4200 motors and they are such a pain in the a**.

Love the power from these little guys but keeping the prop on is impossible. Is there a solution out there besides the collet type prop adapter? The little bullet spinner is imposible to get tight and I am getting discouraged with the prop flying off all the time.

Best Regards;
Boyd

larrymcg
10-18-2005, 03:51 AM
This might not be your problem, but....

You might need to open up the back of the prop so that it fits all the way back. I have to ream mine out a bit so that they go back all the way.

Larry

qban_flyer
10-18-2005, 04:09 AM
This might not be your problem, but....

You might need to open up the back of the prop so that it fits all the way back. I have to ream mine out a bit so that they go back all the way.

Larry

Same here. Reamer in one hand, prop on the other if I am going to be using that adapter.

Also found that the H/L collet type prop adapters (for MJ brand gearboxes) work better on these motors. They are not as pretty, but the nut will tighten everything just right. No more propeller fly offs since I switched to those.

They also have a spinner like "thingy" (MJ7200) that fits over the "long" adapters. It gives them an air of "dignity". A la P-47 like.

http://www.hobby-lobby.com/gear280.htm

http://www.hobby-lobby.com/propadap.htm (look for MP Jet on this page)

flypaper 2
10-18-2005, 04:21 AM
I could never get it tight enough with that spinner thing so put a proper nut on it and tighten with a wrench. No problems since.

Combat Drone
10-18-2005, 04:24 AM
Thanks for the reply guy's.

Larry: Even when I ream them out it is sometimes impossible to get the collet to stop spinning so I can tighten it up. My bullet spinners are looking pretty knarly!:)

qban: Great links, thank you!

flypaper: Tryed that and it definately helps but sometimes I just can't keep that little sucker from spinning.

I am definately going to go with something similar to the shaft on the gws. Put a nut on it, then the prop, then tighten it like a gorilla. Now if I could just solve the gravity problem...........:p

qban_flyer
10-18-2005, 04:30 AM
Thanks for the reply guy's.

Larry: Even when I ream them out it is sometimes impossible to get the collet to stop spinning so I can tighten it up. My bullet spinners are looking pretty knarly!:)

qban: Great links, thank you!

flypaper: Tryed that and it definately helps but sometimes I just can't keep that little sucker from spinning.

I am definately going to go with something similar to the shaft on the gws. Put a nut on it, then the prop, then tighten it like a gorilla. Now if I could just solve the gravity problem...........:p

No problem. I know what it's like to lose a prop in mid air. Worse than that is not to have a replacement adapter and nut in the field box. Propellers? I always carry more than enough to supply the entire club, adapters? Fat chance, since I got me eight of these from H/L I haven't had a need to have them with me at the field anymore!

flypaper 2
10-18-2005, 04:32 AM
Another good idea is to roughen up the shaft with some emery cloth or sandpaper to give it more bite.

jobu
10-18-2005, 04:59 AM
I have a bunch of Himax motors and the GBs are a drag. I tried a Cobri Gear Box and it's awesome. Heavy nylon spur and brass or stainless pinion. No allen wrench blues either and no more stripping or damaged teeth. Honestly, these things work awesome.
www.e-flightline.com/gearboxes.htm (http://www.e-flightline.com/gearboxes.htm)

Joe

LuckyArmpit
10-18-2005, 08:37 PM
I'm not having any problems with prop coming off in my himax setups.
I'm using apc props. Using the supplied collet adapters without a hitch.
I do find the prop adapters which use set screws to be a real pain!!!
How is set my props on is the collet is over the shaft, I then use a pair of small needle nose pliers (I have shrink wrap over the two "fingers" of the pliers) to hold the shaft from moving and just tighten the nut. No biggie...
and you don't need a bazillion pounds of force.

Dave...

Matt Kirsch
10-18-2005, 09:09 PM
Isn't there a cross-drilled hole near the tip of the spinner nut? You're supposed to thread a small hex wrench through that hole and use it as leverage to tighten the nut.

qban_flyer
10-18-2005, 10:53 PM
I'm not having any problems with prop coming off in my himax setups.
I'm using apc props. Using the supplied collet adapters without a hitch.
I do find the prop adapters which use set screws to be a real pain!!!
How is set my props on is the collet is over the shaft, I then use a pair of small needle nose pliers (I have shrink wrap over the two "fingers" of the pliers) to hold the shaft from moving and just tighten the nut. No biggie...
and you don't need a bazillion pounds of force.

Dave...

Me neither, but I do prefer the nut fastener types over the smooth conical spinner ones. Colleted propeller adapters will have the propeller better centered on the shaft also.

The ones sold by H/L are really nice looking once you put the "thingy" over them. It makes them look sharp & professional.

http://www.hobby-lobby.com/gear280.htm

http://www.hobby-lobby.com/propadap.htm (look for MP Jet on this page)

Dr Kiwi
10-19-2005, 01:40 AM
Seems to me those Himaxx collets are just a fraction over-bored, and no matter how hard you tighten 'em they still don't hold well. The MPJ 8031 (long adapter for 3mm shaft), and their other collets for 4mm, 5mm etc shafts, are a lot better (especially since one can put at least 20lb.ft on the nut with a decent 1/4 drive socket wrench)! The grub screwed adapters are only good on motors or gearbox shafts which have a "flat" machined into them.

Cheers, Phil

qban_flyer
10-19-2005, 01:55 AM
Seems to me those Himaxx collets are just a fraction over-bored, and no matter how hard you tighten 'em they still don't hold well. The MPJ 8031 (long adapter for 3mm shaft), and their other collets for 4mm, 5mm etc shafts, are a lot better (especially since one can put at least 20lb.ft on the nut with a decent 1/4 drive socket wrench)! The grub screwed adapters are only good on motors or gearbox shafts which have a "flat" machined into them.

Cheers, Phil

That was my first thought, too large a collet (3.2mm?) for that shaft.

I've been getting my MP & MP Jet adapters from H/L since 2002, and use them not only on the Himax but all others with 3mm and 4mm shafts. They really grab good.

Dr Kiwi
10-19-2005, 08:51 PM
That was my first thought, too large a collet (3.2mm?) for that shaft.

I've been getting my MP & MP Jet adapters from H/L since 2002, and use them not only on the Himax but all others with 3mm and 4mm shafts. They really grab good.

Himaxx doesn't come with a 3.2mm collet - its just that the 3mm one they supply is 3.0 + something - just too much over to be impossible to tighten.

qban_flyer
10-20-2005, 01:42 AM
Himaxx doesn't come with a 3.2mm collet - its just that the 3mm one they supply is 3.0 + something - just too much over to be impossible to tighten.

Isn't it all the same? 3+mm or 3.2mm? The fact remains that the one supplied wiht the affair won't tighten around the motor/gearbox shaft properly and the ones sold by Hobby Lobby do.

Another factor to consider is the prop's hub thickness. Some APC props have deeper/thicker hubs than others. If the hub being used is not deep enough, we run out of thread before we can tighten it properly.

I have had that happen to me with some APC 11X4.7SF propellers several times. This morning when switching from one 11X4.7SF APC to another one I realized that both had different hub thicknesses and this particular topic came to mind. The thickness difference was better than 1+mm, enough to cause problems with colleted type prop adapters!

It presented no problem to me since I was using a prop saver on my U CAN DO 3D EP.

Combat Drone
10-20-2005, 02:13 AM
Thank you all for your input. I appreciate your help very much.

I agree with you qban. I took your advice and put in an order through HL.

Sure will be glad to fly the whole plane and not just the prop. Although it is pretty impressive when it flys off at WOT! :D

qban_flyer
10-20-2005, 02:29 AM
Thank you all for your input. I appreciate your help very much.

I agree with you qban. I took your advice and put in an order through HL.

Sure will be glad to fly the whole plane and not just the prop. Although it is pretty impressive when it flys off at WOT! :D

HE, HE, HE :D :D :D. Not for me, it is not impressive, especially when I have to go hunting for it. When I come back with prop in hand, I am too exhausted :p :p :p to fly for awhile.

flypaper 2
10-20-2005, 03:07 AM
The 3 mm +hubs are just poor workmanship. The 3.2 mm are actually for a 1/8 in shaft for motors that are made in the States or to US specs.

Hotshot Charlie
10-20-2005, 02:42 PM
I have never had any problems with the HiMax gearbox, but I have only used it on foamy's (Bluecor creation and a Eflite Ultimate).

Guess I'm an exception. I do agree that the Cobri looks a lot better.

I am getting ready to assemble a Mini Edge 540, I may go with the Cobri and a HiMax 2025-4200. What gearing is the best choice for this combo?

qban_flyer
10-20-2005, 05:03 PM
I have never had any problems with the HiMax gearbox, but I have only used it on foamy's (Bluecor creation and a Eflite Ultimate).

Guess I'm an exception. I do agree that the Cobri looks a lot better.

I am getting ready to assemble a Mini Edge 540, I may go with the Cobri and a HiMax 2025-4200. What gearing is the best choice for this combo?

In re-thinking this whole "collet" problem with the Himax assembly last night it occurred to me that I had not programmed the start up type on my ESC. It is defaulted to HARD START which is fine for outrunners and all direct drive motors, but it is not recommended for geared ones.

I flew this morning and even though I am still using the H/L adapters, I noticed a different sound coming from the gearbox on start up. It sounded rather nice and smooth. So, in my case it might have been a matter of mis-programming the ESC. I'll try the Himax adapter over the weekend and see if it stops slipping.