Motor Mounting Intrigue
#1
Member
Thread Starter
Join Date: Jan 2016
Location: N. Texas
Posts: 32

Hi Again,
Bought a Seawind futuristic foamie , 40'sh inch wingspan. Calls for a Rimfire brand Outrunner 28-30-950k. From the instruction manual, pictures and instructions, the motor mounts with 3 screws from the front and that's the way the bracket is designed and the cowl fits...motor is behind the mounting bracket. In one of the pictures you can see the Rimfire model number so it is the motor that is described.
Looking at the Tower Hobbies catalog and www, the picture of that motor shows the tri mounting screws on the back of the motor such that it would mount in front of the mounting bracket.....totally contradicts the picture and text in the instructions.
Problem I'm having is that I don't have that motor, but even if I did, seems something is dreadfully wrong. I have an ESC 400 from Hobby Express and it mounts on the face of a bulkhead on the rear of the motor with 4 screws.
I would like to understand the difference in the mounting pictured vs the motor advertised for sale of the 28-30-950 and then entertain your thoughts on my modifying the mounting bracket (which is really built into the plane and hope I don't have to) to fit the 400 since I have it and would have to blow another 50 bucks for what I already have.
Thanks,
Mark
Bought a Seawind futuristic foamie , 40'sh inch wingspan. Calls for a Rimfire brand Outrunner 28-30-950k. From the instruction manual, pictures and instructions, the motor mounts with 3 screws from the front and that's the way the bracket is designed and the cowl fits...motor is behind the mounting bracket. In one of the pictures you can see the Rimfire model number so it is the motor that is described.
Looking at the Tower Hobbies catalog and www, the picture of that motor shows the tri mounting screws on the back of the motor such that it would mount in front of the mounting bracket.....totally contradicts the picture and text in the instructions.
Problem I'm having is that I don't have that motor, but even if I did, seems something is dreadfully wrong. I have an ESC 400 from Hobby Express and it mounts on the face of a bulkhead on the rear of the motor with 4 screws.
I would like to understand the difference in the mounting pictured vs the motor advertised for sale of the 28-30-950 and then entertain your thoughts on my modifying the mounting bracket (which is really built into the plane and hope I don't have to) to fit the 400 since I have it and would have to blow another 50 bucks for what I already have.
Thanks,
Mark
#2

The brushless motors can be mounted either way. The shaft is reversible. There may also be different prop adapters involved.
Some brands, the shaft is installed with locktite or similar and reversing can be very difficult. Rimfire generally isn't hard.
*********************
And... Seawind is scale model
http://www.seawind.net/
Some brands, the shaft is installed with locktite or similar and reversing can be very difficult. Rimfire generally isn't hard.
*********************
And... Seawind is scale model
http://www.seawind.net/
Last edited by fhhuber; 02-21-2016 at 07:37 AM.
#3
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,856

Here's an example of reversing a shaft ...
Its pretty universal for most motors ... only differences could be some motors have a C clip up against the rear bearing and others a wheel style collet.
Some motors do not allow fitting of a collet when reversed .. that's not a problem as long as the shaft is PULLING out that way in use. The thrust will hold motor as well as the strong magnetic influence in alignment. Many EDF motors do not have clips or fixings and can be pulled apart.
Nigel
Its pretty universal for most motors ... only differences could be some motors have a C clip up against the rear bearing and others a wheel style collet.
Some motors do not allow fitting of a collet when reversed .. that's not a problem as long as the shaft is PULLING out that way in use. The thrust will hold motor as well as the strong magnetic influence in alignment. Many EDF motors do not have clips or fixings and can be pulled apart.
Nigel
#4
Member
Thread Starter
Join Date: Jan 2016
Location: N. Texas
Posts: 32

Well you two guys, I "Got-r-done". Went better than my wildest guestimation. Your encouragement certainly made it happen.
The motor is an ERC 400 Outrunner from Hobby Express at $25 rather than the $50 for the 28-30-950k motor listed in the kit.
The clip on the shaft came off easily, and I pulled the "inverted" rotor.... tugging against the magnets but with no problem.
Set screws had locktite on them but it must have been blue as a 1.5 mm hex allen walked them right out.
I soaked the frame with a heat gun knowing that the aluminum would expand more and faster than the SS shaft and I tried the pressure removal but to no avail, so I got the 2 oz ball peen and a scrap piece of ⅛ plywood and tapped her out.
Reversal was uneventful.
The mounting was easier than I thought as I Dremmeled out the triangular mounting configuration and made a concave back to the original bracket and the motor fit right in. Then took the alum. X mounting bracket that comes with the motor and mounted it on the front putting the hollowed out original plywood mounting frame between motor and bracket and pulled her up good-n snug. Will put a couple of screws though the outer holes in the added bracket to lock it to the plywood.
Put the prop on with the furnished compression adapter and locked it in place with the hub, both furnished with the kit.
The cowl fit over it perfectly and it looks real professional. I am some kind of happy camper and I do thank you guys again. Certainly made my day.
Mark
The motor is an ERC 400 Outrunner from Hobby Express at $25 rather than the $50 for the 28-30-950k motor listed in the kit.
The clip on the shaft came off easily, and I pulled the "inverted" rotor.... tugging against the magnets but with no problem.
Set screws had locktite on them but it must have been blue as a 1.5 mm hex allen walked them right out.
I soaked the frame with a heat gun knowing that the aluminum would expand more and faster than the SS shaft and I tried the pressure removal but to no avail, so I got the 2 oz ball peen and a scrap piece of ⅛ plywood and tapped her out.
Reversal was uneventful.
The mounting was easier than I thought as I Dremmeled out the triangular mounting configuration and made a concave back to the original bracket and the motor fit right in. Then took the alum. X mounting bracket that comes with the motor and mounted it on the front putting the hollowed out original plywood mounting frame between motor and bracket and pulled her up good-n snug. Will put a couple of screws though the outer holes in the added bracket to lock it to the plywood.
Put the prop on with the furnished compression adapter and locked it in place with the hub, both furnished with the kit.
The cowl fit over it perfectly and it looks real professional. I am some kind of happy camper and I do thank you guys again. Certainly made my day.
Mark
#5

Good news. A little creativity goes a long way in this hobby. I like to use a small drill press, bench vise or on occasion a c-clamp for pressing. Good call on the alum vs. stainless shrink/expansion.
#6
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,856

One word of caution when driving out shafts .....
Never have the motor bell inverted so front where grub screws are is unsupported. If you have a hard in shaft - trying to force it out that way can distort the front face of the motor bell. Always put the motor bell face down onto the slightly open vice jaws with shaft through the gap. Drive the shaft through so that face is supported by vice top.
I was careless one day and did it the wrong way - that bell is now a screw / metal object picker-upper in the den now ! Cannot be used as shaft is way out of alignment now.
Nigel
Never have the motor bell inverted so front where grub screws are is unsupported. If you have a hard in shaft - trying to force it out that way can distort the front face of the motor bell. Always put the motor bell face down onto the slightly open vice jaws with shaft through the gap. Drive the shaft through so that face is supported by vice top.
I was careless one day and did it the wrong way - that bell is now a screw / metal object picker-upper in the den now ! Cannot be used as shaft is way out of alignment now.
Nigel
#7

One other solution is to use deepwell sockets or anything with a nice amount of rigidity to support the frame close to the shaft diameter. Stacked nuts or washers, cut a piece of rigid tubing etc.
#8
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,856